Exquisite Goods

Category: Heritable Disorders of Connective Tissue

A collection of over 200 disorders involving genetic mutations of the proteins that make up the bodies connective tissues. They are all known to be carried down from one generation to the next; some are known to be autosomal dominant (only one parent has to carry the gene) and others are autosomal recessive (both parents have to carry the gene).

  • The Important Questions to Ask Your Neurosurgeon [Revised]

    The Important Questions to Ask Your Neurosurgeon [Revised]

    Most Chiarians go to see a surgeon with an expectation of them being knowledgeable in their field. However, while they might be a neurosurgeon, their knowledge of Chiari and its comorbid/pathological conditions might not rank high in their practice. Make the most of your initial appointment by interviewing them and what they really know about Chiari Malformations. Be cautious of inflated success rates. Chiari decompression in general offers a just over a 50% success rate (which means it has a nearly 50% failure rate). Surgeons that claim a 100% (or near 100% success rate) are usually not basing their success on how their patients feel afterward, it is based on if they were successful with the aspects of the surgery:
             Removal of the occipital bone ✓
              Opening the dura and adding the patch/graft ✓
              Laminectomy ✓
              Cauterization/resection of cerebellar tonsils ✓

    WE DESERVE BETTER THAN THAT!

    HERE IS A LIST OF CHIARI QUESTIONS WE RECOMMEND ASKING AT YOUR FIRST NEUROSURGERY APPOINTMENT:

    General Questions:

    • How do you define a Chiari Malformation?
    • What do you believe causes a Chiari malformation?
      • Are all Chiari malformations from a small posterior fossa?
      • Do I have a small posterior fossa? If yes, how big is it? If size is unknown, was my posterior fossa measured? If not, why not? How did you come to the conclusion that I have a small posterior fossa?
      • How common do you believe Acquired Chiari malformations to be?
    • Do you always recommend decompression surgery for all of your patients with herniated cerebellar tonsils? Why/why not?
    • In an average month, how many Chiari decompressions do you perform? How many tethered cord releases? How many craniocervical fusions? What percentage of your practice is spent treating patients with these connective tissue related conditions?
    • Looking at my brain scan, is any part of my “brainstem” herniated (below the posterior fossa)? If so, does that make me a Chiari 1.5?

    Intracranial Hypotension (low pressure) Questions:
    *Article to help you understand CSF Leaks & Intracranial Hypotension prior to your appointment.
    If you have SYMPTOMS OF LOW INTRACRANIAL PRESSURE and/or suspect a cerebrospinal fluid leak, we recommend asking the following questions:

    • S.E.E.P.S.
      • Looking at my brain scan, do you see any Subdural fluid collections?
      • Looking at my brain scan, do you see an Enhancement of pachymeninges?
      • Looking at my brain scan, do you see an Engorgement of my venous structures? Should we do an MRV to make sure?
      • Looking at my brain scan, does my Pituitary appear to be enlarged?
      • Looking at my brain scan, does my brain appear to be Sagging?
    • Looking at my corpus callosum:
      • Does there appear to be a depression?
      • Is there an inferior pointing of the splenium?

    If he/she answers affirmatively to any of the above S.E.E.P.S. questions, ask: 

    • What should be done to find/repair a potential leak?
    • Are you aware that it is common for CSF Leaks to not show up on MRI?
    • Are you willing to do a CT Myelogram and/or a digital subtraction myelogram, if I develop symptoms of a leak and none can be found on MRI?
    • Are you aware that it can often take multiple epidural blood patches to try and seal a leak, and sometimes when a blood patch fails to work, a surgical dural repair might be necessary?

    Intracranial Hypertension (high pressure) Questions:
    *Article to help you understand Intracranial Hypertension prior to your appointment.
    If you have SYMPTOMS OF HIGH INTRACRANIAL PRESSURE, we recommend asking the following questions:

    • Looking at my brain scan, do I have cerebrospinal fluid in my sella turcica (Empty Sella Syndrome)?
    • Looking at my brain scan, do you see any evidence of my optic nerves are swollen (papilledema)?
      • If so, should I be referred to a neuro-ophthalmologist?
    • Looking at my brain scan, do my lateral ventricles appear small or flattened?
      • If so, do I need to have my pressures checked?
        • If yes, are you aware of the risks of developing a CSF Leak from a lumbar puncture?
      • What are the symptoms of a CSF Leak, should one develop?
        • What is your plan of action if I should develop these leak symptoms?
        • Are you aware that it is common for CSF Leaks to not show up on MRI?
        • Are you willing to do a CT Myelogram if I develop symptoms of a leak, and none can be found on MRI?
      • Should a leak be found, are you aware that it can often take multiple epidural blood patches to try and seal a leak?

    Tethered Cord Questions: 
    *Article to help you understand Tethered Cord: Sorry, Coming Soon.
    If you have SYMPTOMS OF TETHERED CORD, we recommend asking the following questions:

    • Looking at my brain/cervical scan, does my brainstem appear to be elongated?
    • Looking at my cervical scan, does my spinal cord appear to be stretched?
    • Looking at my lumbar scan, does my conus reach my mid/low L2?
    • Looking at my thoracic and lumbar scan, does my spinal cord appear to be pulling to the back, or one particular side?
      • If so, should we do a prone MRI to see if it has actually adhered to that side?
    • Looking at my lumbar scan, do I appear to have fatty tissue inside the epidermis?
      • If the answer to any of these questions is affirmative, do you suspect that I have a tethered spinal cord?
      • If so, should we plan for a Tethered Cord Release before or soon after decompression surgery, so the likelihood of a failed decompression is reduced?
      • If I have urological issues, can I get a referral for urodynamic testing to rule out any other potential causes of my urological issues?

    Craniocervical Instability (CCI) & Atlantoaxial Instability (AAI):
    *Article to help you understand CCI & AAI prior to your appointment.
    If you have SYMPTOMS OF CRANIOCERVICAL INSTABILITY or SYMPTOMS OF ATLANTOAXIAL INSTABILITY, we recommend asking the following questions:

    • Looking at my brain/cervical scans, what are the measurements of my clivoaxial angle and Grabb-Oakes?
    • Do these measurements meet the diagnostic criteria for Craniocervical Instability?
    • Looking at my flexion and extension imaging, how many millimeters of translation are there between flexion and extension?
    • Does Chamberlain’s Line cross my odontoid? If so, does it cross at a level that would indicate Basilar Invagination?
    • Looking at my rotational imaging, what is the percentage of uncovering of the right and left articular facets on rotation?
    • Do the percentages from my rotational imaging meet the diagnosis criteria for Atlantoaxial Instability?

    IF A DIAGNOSIS CRITERIA IS MET IN ANY OF THE ABOVE, WE STRONGLY RECOMMEND THAT YOU WAIT ON DECOMPRESSION AND PURSUE THE TREATMENT OF SAID CONDITION(S) AND THAT OF EHLERS-DANLOS SYNDROME, AS EACH OF THESE CONDITIONS CAN BE PATHOLOGICAL TO AN ACQUIRED CHIARI AND EACH IS A STRONG INDICATOR THAT A CONNECTIVE TISSUE PROBLEM EXISTS. 

    *The questions in this article will periodically change as we are able to expand our recommended questions.

    *Original version released September 2018, revised 2023.

  • Spine Pulled Tight – A Guide to Understanding Tethered Cord Syndrome

    Spine Pulled Tight – A Guide to Understanding Tethered Cord Syndrome

    TETHERED CORD SYNDROME (TCS) INVOLVES A STRETCHING OF THE SPINAL CORD, AND OFTEN YOUR MEDULLA OBLONGATA
    AS WELL, WHICH LEADS TO A HOST OF NEUROLOGICAL PROBLEMS.

     

    Before we talk about Tethered Cord Syndrome, let’s first talk about the anatomy associated with the spinal column (in layman’s terms).

    •  The role of the vertebral column is to hold the spine strong (so it can be upright) and protect the spinal cord from injury. In a normal vertebral column, there are thirty-three vertebrae on each side (seven cervical vertebrae, twelve thoracics, five lumbar, five fused vertebrae in the sacrum and another four fused vertebrae in the coccyx).

    •  Each vertebra in the upper twenty-four vertebrae is separated by intravertebral discs largely composed of the fibrous protein, collagen. The main role of these discs is to allow the vertebral column to move and flex.

    •  The role of the spinal canal is to hold cerebrospinal fluid around the spinal cord, which not only cushions the cord against injury, but it also lubricates the cord, cleanses the cord, and brings essential nutrients that the spinal cord needs. The spinal canal is made up of several layers that form the meninges. These layers are also composed of high concentrations of collagen. The outermost layer of the meninges is the dura mater. The dura mater should be dense and strong, so cerebrospinal fluid cannot leak from it.

    •  The spinal cord relays messages from the brain to the nerves that allow the body to function. When part of the spinal cord is compromised, it can inhibit signals from getting to the nerves from that point downward. The brainstem (midbrain, pons, and medulla oblongata) is attached to the spinal cord at the top (the medulla and spinal cord meet at what is called the cervicomedullary junction) and the spinal cord continues down to the mid/lower back. From there it becomes a delicate elastic band of fibrous collagen-based tissue called the filum terminale that extends from the conus medullaris (the lowest point of the spinal cord before it becomes the filum terminale) to the dural sac at the S2 level.1

    Chiari Malformation has many conditions that can be associated with it (comorbid conditions) and sometimes those comorbid conditions can be at the root cause (etiological cofactor) or one of the causes along the way (pathological cofactor) to the tonsils being as low as they are (making the Chiari “secondary” to one or more “other” conditions). Tethered Cord Syndrome (TCS) is one of those pathological conditions.2 Like Chiari, it is a neurological disorder; however, it is one of the spinal cord.3

    Tethered Cord happens when the sticky fibrous tissue of the filum adheres to fatty/scar tissue or the dura lining of the spinal canal.1 While this tethering can happen anywhere in the spinal canal, it is most common at the lumbosacral level.4 When the tethered filum pulls the spinal cord tightly enough that it causes neurological problems, it becomes known as Tethered Cord Syndrome (TCS). Tethered Cord is most common in patients with Spina Bifida (myelomeningocele, meningocele), Spina Bifida Occulta (lipomeningomyelocele, lipomyelocele) and patients with Ehlers-Danlos Syndromes (EDS), a Hereditary Disorder of Connective Tissue (HDCT) where one or more of the types of collagen (the most abundant protein in the human body) is mutated at a cellular level. Tethered cord can be congenital or acquired. It can be obvious in childhood or symptoms may not present themselves until adulthood. Some children may develop minor signs that are overlooked by untrained medical professionals and can progress slowly or rapidly over time.

    More Symptoms of Tethered Cord Syndrome

    A Tethered Cord Syndrome diagnosis can be somewhat of a challenge. The signs and symptoms of the condition are not always present and when they are, they are often not recognized, so it is important to know all indicators. People with Tethered Cord (TC) can have sacral dimples, discoloration, and hairy patches on their lower back that can lead a doctor to investigate further, however, some have no external signs at all. Some have kyphosis (rounded back) and scoliosis (curved spine). Sometimes radiological criteria are not met or are ambiguous, yet an Occult Tethered Cord (characterized by the presence of symptoms with normal conus position and inconclusive findings of the filum) can still exist.5 Symptoms can be elusive as well and can happen all at once or gradually over the course of many years. Many symptoms worsen due to activity; climbing stairs has been reported as causing pain that varies from uncomfortable to excruciating.

    One of the reasons that Tethered Cord is often overlooked is that many neurosurgeons are not aware of the connection it can have with a Chiari Malformation and the medical tests used for determining if a tethered cord problem exists are not always accurate or accurately read.

     

    Magnetic Resonance Imaging (MRI)

    • A lumbar MRI is usually the first step. This gives a visualization of the spinal cord in relation to the surrounding vertebrae. The actual tethering is not always obvious on MRI, sometimes the only proof of the tethering is the pulling it creates on the spinal cord. Doctors will look for the position of the conus medullaris when looking for signs that the spinal cord is being pulled. The consensus amongst most surgeons is that a normal conus should be located from the T12 to the lower L2. There is much debate on the importance of establishing evidence of a low-lying conus.5 When conus reaches the lower L2 or below, doctors should be investigating why it’s low and consider if the cord might be tethered. When looking for the location of the conus, your position can make all the difference. MRIs are generally performed supine (lying down) and the cord is not pulled as tightly as it is when upright. For this reason, upright MRIs are becoming the method of imaging preferred by most neurosurgeons looking to confirm or deny if tethering exists in a patient showing symptoms. Other signs of tethering that might be visible in a lumbar MRI include an enlarged foramen magnum, thick or fatty filum, presence of fatty tissue inside the canal, or the filum might be pulling to one side of the canal.5

    • A prone MRI of the lumbar region can be an invaluable tool for those where other MRIs indicate that the filum might be pulling to one side (usually the back side) of the canal. With prone MRIs, imaging is done while the patient is lying face down (as opposed to facing up, like most supine MRIs). If the anteroposterior conus movement of >10% of the canal width was evident from the supine to the prone, then the likelihood of it pulling to one side do to tethering is less likely and more conservative management might be better appropriate than a surgical release.6

    • A cervical MRI can also show signs that a tethered cord might exist. The cervical spinal cord can sometimes appear narrow from it being pulled tight. The medulla oblongata can become elongated. This happens because the brainstem is attached to the top of the spinal cord and that cord is being pulled tight, essentially pulling everything down and tight. This elongation of the medulla from the tethering can cause secondary symptoms by itself, known as Dysautonomia.

    · Low/herniated cerebellar tonsils consistent with what is seen in a Chiari Malformation. When the brainstem is herniated (where part/most of the medulla is below the foramen magnum) along with the cerebellar tonsils, it is considered a Chiari 1.5 (which should be a good indicator that you might be dealing with an Acquired Chiari Malformation, where the herniated tonsils are secondary to another condition). One study quoted that out of 2,987 patients with a tonsillar herniation of 5mm or greater, 14% met the diagnostic criteria (based on “generally accepted clinical and radiographic criteria”) and 63% of the 289 patients with tonsillar herniations of < 5mm.5

    · A syrinx is common with Tethered Cord, as it causes a blockage of fluid at the foramen magnum. A syrinx can develop anywhere in the spine, usually in the lower cord, but with Tethered Cord Syndrome it can develop in the lower medulla (Syringobulbia) as well because of the low brainstem is at the point of the blockage of fluid from the Chiari Malformation.

    Even with an upright MRI and every symptom listed, patients are often told they do not have Tethered Cord. This is simply due to a lack of education on the subject and medical bias between doctors. It is important to make sure that you have the images viewed by a neurosurgeon that is familiar not only with Tethered Cord but Chiari and Comorbids as well. (Nearly half of the large study quoted above were referred following a failed Chiari Decompression.5) The combination of the images and the patient’s symptoms should tell the neurosurgeon if surgical intervention is required. Patients often require several consultations before they can find a knowledgeable enough physician.

     

    What We Recommend BEFORE DECOMPRESSION is considered:
    If you have symptoms of TCS, especially if accompanied by any of the MRI indicators mentioned above, it is both reasonable and prudent to ask your neurosurgeon to investigate further before decompression is considered. A Tethered Cord Release Surgery prior to decompression may relieve the tension that is pulling the brainstem and cerebral tonsils downwards reducing the risk of a failed decompression. There is a chance with small tonsillar herniations that the Tethered Cord Release might allow the cerebellar tonsils to rise enough to the point that cerebrospinal fluid flow is reestablished to where decompression is no longer needed. However, failure to release a tethered cord prior to decompression surgery increases the likelihood of a failed decompression. (In fact, in the study quoted above, out of the 3,276 patients with herniated tonsils, 46% of them were referred for evaluation after a failed decompression surgery.5) An MRI of all three levels of the spine should be done to rule out other possible causes for leg/back symptoms along with urodynamic testing, an Electromyogram (EMG) Test and Nerve Conduction Study (NCS) of the lower limbs is also suggested.

     

    TREATMENT OPTIONS:
    For some, physical therapy can help with symptoms for a while. However, ultimately it will likely need to be surgically treated with a Tethered Cord Release.

    Tethered Cord Release (TCR) Surgery involves the untethering of the spinal cord. An incision is made in the lumbar area, the filum terminale is separated and the factors that are tethering the spinal cord to the vertebrae are severed. Surgical treatment is not without risk and does not guarantee relief of symptoms. However, in a large study, up to 83% of adult patients report relief, 16% unchanged, and 1% report feeling worse.5 In children, the numbers are even better with 93% obtaining improved symptoms and 7% unchanged.5 Most patients describe the surgery as extremely painful for the first two weeks and “better than they ever remember feeling” (often because they have been tethered for much of their lives) after two weeks. The most common complication involves retethering (often from the scar tissue from the release) and multiple surgeries may be required over a lifetime. Finding a neurosurgeon experienced with TCRs and the surgical treatment of Ehlers-Danlos patients can sometimes help reduce the risks associated with scar tissue formation, but scar tissue can happen with even the best of neurosurgeons.

    For the TCS patient, herniated tonsils really should be assumed an Acquired Chiari Malformation (even if a small posterior fossa is evident), and by correcting the tethered cord before decompression the decompression will be less likely to fail.

     

    Special Note: There are other conditions that can present with similar symptoms. Diastasis Recti is a type of abdominal hernia common to pregnant women, those with obesity, and EDS patients. This separation in the abdominal muscles is known to sometimes cause lower back pain and many of the same pelvic floor problems seen with Tethered Cord Syndrome (TCS). Unlike TCS however, it does not usually require surgical treatment. If you suspect Diastasis Recti, we recommend that you talk to your Primary Care Physician about referring you to physical therapy to bring your abdominal muscles back together before considering Tethered Cord Release (TCR).7

     

     

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    References: 

    1 Henderson, Fraser C., et al. “Neurological and Spinal Manifestations of the Ehlers–Danlos Syndromes.” American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 21 Feb. 2017, <www.onlinelibrary.wiley.com/doi/10.1002/ajmg.c.31549/full>.

    2 “Section of the Filum Terminale Surgery for Tethered Spinal Cord Syndrome in Patients with Chiari Malformation and Syringomyelia.” North Shore-Long Island Jewish Health System The Chiari Institute, Chiari Connection International, 02 Oct. 2006, <http://www.chiariconnectioninternational.com/docs/TCS_SFT_Explained.pdf>.

    3 Quake. “Overview: Chiari Comorbidities & Etiological/Pathological Cofactors [Revised].” Chiari Bridges, 16 Nov. 2019, <http://chiaribridges.org/overview-chiari-comorbidities-etiological-pathological-cofactors/>.

    4 Arslanoglu, A., et al. “Multidisciplinary Combined Approach for Tethered Spinal Cord Syndrome: Radiology, Surgery and Physical Therapy.” Balkan Military Medical Review, 2006, <https://pdfs.semanticscholar.org/8c30/18bf5bfbd6f3e7e5e9c3559bbbfdcac82e04.pdf>.

    5 Milhorat, Thomas H., et al. “Association of Chiari malformation type I and tethered cord syndrome: preliminary results of sectioning filum terminale.” Surgical Neurology, Elsevier, July 2009. <https://www.sciencedirect.com/science/article/abs/pii/S0090301909002572>.

    6 Aoun, Salah G., et al. “The Use of Prone Magnetic Resonance Imaging to Rule Out Tethered Cord in Patients With Structural Spine Anomalies: A Diagnostic Technical Note for Surgical Decision-making.” Cureus vol. 11,3 e4221. 11 Mar. 2019, doi:10.7759/cureus.4221. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6510567/>.

    7 “A Complete Guide to Diastasis Recti: Truths on Abdominal Muscle Separation.” Braceability, 05 June, 2018. <https://www.braceability.com/blogs/info/diastasis-recti>.

  • Overview: Chiari Comorbidities & Etiological/Pathological Cofactors [Revised]

    Overview: Chiari Comorbidities & Etiological/Pathological Cofactors [Revised]

    When you start to educate yourself on a condition like Chiari, your vocabulary will be challenged. Most of us study with a medical journal article opened in one tab and medical dictionary in the next. Amongst all the medical terminology you will tackle, there are probably a few terms as important to your understanding of Chiari than comorbidities and pathological/etiological cofactors. When two or more conditions tend to co-occur, they are said to be comorbid with one another. It makes no inferences of a causal relationship between the conditions, only that they co-occur. This co-occurrence deduces that a correlation exists, but when the nature of that correlation is not known, they are just said to be comorbidities. When a “causal relationship” is known or suspected, the conditions start being discussed in terms of pathology or etiology, which are similar, but not exactly the same thing.

    An etiological cofactor exists when the “root cause” of a condition is known or believed to be known. That “root cause” is the etiological cofactor. When an etiological cofactor can cause a series of events or conditions that can become “direct causes” for other conditions, that series of events creates a pathology. Conditions along the path are called pathological cofactors. Understanding these cofactors is imperative in understanding Chiari and all of the comorbid conditions that accompany it.

    ETIOLOGICAL COFACTOR:

    Chiari Malformation often seems like a beast that wreaks havoc on our bodies on every level. Indeed it is, but as you can see from the diagram above, it really is not the “root” of everything that is going wrong. There is a bigger beast at work in so many of us, and its name is Ehlers-Danlos. It is not by chance that so many of us with Chiari have so many other conditions in common (especially conditions like Degenerative Disc Disease, arthritis and other connective tissue problems). It is not by chance that so many of us have a history of miscarriage and similar familial histories. It is not by chance that Chiari is more prevalent in females than males. And it is definitely not by chance that Chiari is running in families and they cannot find a definitive genetic link. They cannot find it because they are not looking at the beast hiding in the background.

    Ehlers-Danlos Syndromes are a group of inherited disorders involving a genetic mutation in one or more of our bodies’ collagen. Collagen is the most abundant protein, making up 1/3 of the proteins in the human body, affecting our bones, skin, muscles, and connective tissue[1]. Collagen is often described as a “cellular glue” that helps hold the body together. When that glue fails to hold, everything seems to go awry; before and after birth: skulls can under-develop in utero, organs tend to prolapse, and bones begin to shift as joint laxity increases (including the bones/vertebrae at the craniocervical junction). Ehlers-Danlos is a primary “root cause” of Chiari Malformations and a majority of the other problems we have. The list in blue is far from being a complete list of conditions caused by EDS. They are commonly accompanied with Chiari because they can cause or attribute to a Chiari malformation (pathological cofactors).[2]

    PATHOLOGICAL COFACTORS:

    Cranial Settling occurs when the skull has dropped and the odontoid (C2/axis) enters into the foramen magnum (Basilar Invagination). This drop can further compromise the craniocervical junction and as it pushes everything down, it increases the likelihood of an Acquired Chiari Malformation.

    Craniocervical Instability (CCI) & Atlantoaxial Instability (AAI) usually occurs with cranial settling and Basilar Invagination (BI). The settling and/or softening of tissue can cause a shifting of the C2 (resulting in CCI or AAI) and the cerebellar tonsils (which are already inclined to prolapse) simply drop down with each shift affecting ones ability to tilt/rotate their head.[3]

    Intracranial Hypertension (IH – High Intracranial Pressure) occurs when your intracranial pressure (ICP) becomes elevated. This elevation can happen for a variety of reasons.

    1. Space Occupying Masses (cysts, tumors or hydrocephalus) take up space inside the skull causing a “mass effect.”
    2. When no mass effect exists, many doctors look no further and give the diagnosis of Idiopathic Intracranial Hypertension.

    Because the area of the skull is fixed in an adult cranium and partially fixed in that of a child, the elements inside the fixed space (CSF, blood volume and brain matter) tend to get pushed out wherever they can (the only place that they can escape without breaking through the dura is through the foramen magnum and the brain matter that’s closest to the foramen magnum is the cerebellar tonsils).[4]

    Tethered Cord Syndrome occurs when the tissue inside the epidermis adheres to the spinal cord or filum terminale. While this tethering can happen anywhere along the spinal canal, it is most common in the lower lumbar and/or sacral spine. When this adhesion happens it creates a pulling down of the spinal cord and consequently, the brainstem located at the top of the spinal cord and the cerebellar tonsils just get pulled down with it.[5]

    Intracranial Hypotension (Low Intracranial Pressure, often involving a CSF Leak) usually involves a cerebrospinal fluid leak or an over-draining shunt, we will highlight the former. Ehlers-Danlos patients tend to have weak dura matter. Tears/holes in the dura can happen anywhere in the dura surrounding the brain or spinal canal and they can happen completely spontaneously (without a known cause). When the leak occurs in the spinal canal, they can create a suctioning effect where cerebrospinal fluid (CSF) is being pulled down and out, causing the intracranial pressure (ICP) to drop. The cerebellar tonsils that are already prone to prolapse (due to EDS) end up getting suctioned downward with the CSF.[6] Cranial leaks often happen when high pressure is left untreated until the high pressure causes a leak in the dura mater. In cranial leaks, fluid usually leaks through the nose or ears (less common), and you can often taste the metallic taste of the cerebrospinal fluid in the back of your throat. While both spinal leaks and cranial leaks can cause low pressure and low-pressure symptoms, and while both can start, stop, and start again spontaneously, there is an increased risk whenever there is an opening where cerebrospinal fluid leaks outside of the human body (if cerebrospinal fluid can make it out of the body, microscopic bacteria can make it inside the same opening where it can enter in the meninges).[7]

    Posterior Cranial Fossa Hypoplasia (PCFH) is the only etiological cofactor listed above that is definitely congenital. The role of collagen in bone development has been long-standing, especially its known contribution to certain conditions like Osteogenesis Imperfecta. However, more recent studies are discovering the role collagen plays in congenital posterior fossa anomalies. Posterior Cranial Fossa Hypoplasia is the most commonly “acclaimed” cause of Chiari malformations, but studies show, that even when all of the other causes above are factored out, only approximately 52% of those left (that fail to meet “the diagnosis criteria” for any of the above), have a small posterior fossa.[8]

    COMORBIDITIES: 

    While all of the conditions listed in the diagram are comorbidities, some are etiological/pathological of an Acquired Chiari (even though nearly 100% of us are told that our Chiari Malformation is congenital) and others have Chiari Malformation as their etiological/pathological cofactor:

    Syringomyelia occurs when cerebrospinal fluid (CSF) is obstructed and a CSF filled cyst/cavity forms inside the spinal cord. This cyst is directly related to the obstruction of cerebrospinal fluid that can be caused by Chiari Malformation, Spinal Stenosis (a narrowing of the spinal canal, spinal cyst/tumor, a herniated disc), or irregular curvature of the spine (scoliosis). When that cyst/cavity extends into the medulla oblongata (the lowest part of the brainstem), it is called Syringobulbia, and it comes with a new set of symptoms consistent with the damage being done to the brainstem. So when Chiari Malformation exists with a syrinx, and there is no stenosis or disc problem in close proximity below it, the Chiari Malformation should be listed as the etiological condition of the syrinx. If more than just the Chiari Malformation is believed to be causing the syrinx, each would be more accurately described as pathological.

    Dysautonomia occurs when damage has been done to the brainstem or Vagus nerve. Whenever either of these is damaged, often from compression at/near the craniocervical junction, the autonomic nervous system can begin to dysfunction.

    Confused? If you understand the causal relationships but find yourself wondering if a comorbid condition is an etiological or a pathological, think of it in terms of a domino effect. Only the first domino is etiological. All of the dominoes in between (on the path) are pathological. The important thing to remember in this array of medical terminology is that while everything is definitely not Chiari, it almost always shares a connection to it, and that is why so many of us have so many conditions and symptoms that doctors call unrelated! It is imperative in our fight that we know “what” we have and “why” it is happening. With such a broad spectrum of symptoms (like we all have), we must educate ourselves and not just believe the limited knowledge of our doctors.

    *Revised November 2019

    References: 

    1  McIntosh, James. “Collagen: What Is It and What Are Its Uses?” Medical News Today, MediLexicon International, 16 June 2017, <www.medicalnewstoday.com/articles/262881.php>.

    2 Quake. “The Chiari Malformation Ehlers-Danlos Connection (Short Version).” Chiari Bridges, 7 Dec. 2017, <www.chiaribridges.org/chiari-malformation-ehlers-danlos-connection-short-version>.

    3 Hawkeye. “Overview: Craniocervical Instability and Related Disorders.” Chiari Bridges, 6 Dec. 2017, <www.chiaribridges.org/craniocervical-instability-related-disorders>.

    4 Quake. “Brain Under Pressure – Understanding Intracranial Hypertension.” Chiari Bridges, 10 Dec. 2017, <www.chiaribridges.org/brain-pressure-understanding-intracranial-hypertension>.

    5 Storm. “The Tethered Cord – Chiari Malformation Connection!” Chiari Bridges, 15 Dec. 2017, <www.chiaribridges.org/tethered-cord-chiari-malformation-connection>.

    6 Argent. “Overview: Cerebrospinal Fluid Leaks.” Chiari Bridges, 10 Dec. 2017, <www.chiaribridges.org/cerebrospinal-fluid-leaks>.

    7 Pérez, Mario A et al. “Primary Spontaneous Cerebrospinal Fluid Leaks and Idiopathic Intracranial Hypertension” Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society vol. 33,4 (2013): 330-7. doi:10.1097/WNO.0b013e318299c292, <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4040082/>

    8 Quake. “Overview: Chiari Malformation.” Chiari Bridges, 6 Dec. 2017, <www.chiaribridges.org/chiari-malformation>.

  • A Mother’s Story

    A Mother’s Story

    Today is 11th April, 2019. Spring is in the air, yet I struggle to appreciate its presence. My daughters are at school, my son is at home in bed yet again. Like so many other days he is unable to get up. My son is 19 years old and looks just like any other 19 year old. You would never guess that this 19 year old is fighting a tremendously unfair battle every single day and has done so for several years.

    Let me rewind.

    My son was around 9 years old when he first complained of a lack of feeling on his right side and regular headaches. Doctors in Ireland, where we were living at the time, told him to drink more fluids after his daily soccer practice and put the numbness down to a trapped nerve. When he was 14 years old and living in Canada, he was told exactly the same by doctors there. However, when I finally insisted on him being referred to a neurologist, this very neurologist laughed at my son for wasting his time. He was told that it was all in his head. I vividly remember telling him off myself in the carpark on our way home.

    I also remember being disappointed about his worsening school reports, blaming the onset of teenage years for his inability to concentrate and retain information. Blurred vision was also dismissed when his eye test came back just fine. Doctors didn’t grow concerned until he was 16 years old and living in France when a routine soccer medical check-up showed a sudden scoliosis deterioration from 8 degrees to 40 degrees. Subsequent MRIs showed Chiari Malformation (CM) with extensive Syringomyelia.

    Neurosurgeons were quick to reassure him that all should be fine after a decompression surgery. Nevertheless, I spent hours researching these unknown rare conditions and found two experienced neurosurgeons, one in England and one in Belgium, for second opinions. Whereas surgeons in France took a more traditional approach and talked about inserting a shunt, both these surgeons warned strongly against this and so we made the decision to go to Belgium for the surgery. We felt well informed and were full of hope when my son embarked on his healing process 3 years ago.

    Let me tell you where we are now.

    Doctors in Europe tell us that my son is one of the unlucky few as his health has drastically deteriorated. Scar tissue has attached itself to his brain tonsils but that only explains part of his deteriorated health. So I embarked on a mission to get to the bottom of these problems. Surely there was hope to be found in the health system in France, one of the best in the world! After countless appointments with multiple health professionals, we were dumbfounded by the complete lack of understanding, knowledge and pure arrogance in relation to CM and its associated conditions, which resulted in my son’s mental health being questioned yet again.

    I started carrying out my own research, which clarified the distinct link between brain disorders and compromised immune/digestive systems. Whereas his doctors are reluctant to make that link, the evidence is clear. 18 months after surgery, my son got struck down by glandular fever. Again, we were hopeful that this would only be a temporary setback. Today however, my son suffers from chronic fatigue syndrome as well as dysautonomia.

    At our wits end last summer, we turned to a hospital in the United States that specialized in Chiari Malformation. Our first consultation with its Managing Director turned out to be an eye opener. This neurosurgeon could literally finish our sentences. My son was finally understood. It turns out that doctors in Europe had failed to diagnose another condition, Ehlers-Danlos Syndrome (EDS), which caused craniocervical instability. This in itself can be a debilitating condition but the combination of craniocervical instability with brain decompression surgery can be a death sentence. He further explained that such patients are deemed to benefit from Occipitocervical Fixation (OC) Fusion surgery. However, this surgery has not yet received the green light for these conditions from Health Services in Europe.

    Armed with a diagnosis of Complex Chiari, we faithfully returned to my son’s French doctors, only to be met, yet again, by a lack of understanding. My request for an upright flexion/extension MRI was seen as outlandish and peculiar. Turns out, an upright MRI is not yet available in France. Instead they still rely on flexion/extension X-ray images which fail to adequately detect craniocervical instability.

    In recent discussions, our son’s Belgian neurosurgeon cautiously recognizes the link between CM and EDS. However, as these studies are in their infancy in Europe, doctors still carry out decompression surgeries without checking for EDS. He also questions the durability of an OC Fusion but agrees that much more extensive research needs to be carried out in Europe and that my son is extremely unfortunate this hasn’t happened yet.

    So where does this leave my son? In the land of limbo. Knowing that Europe is trailing some 10 years behind the States in this field. France, with its inherent reluctance to change, probably closer to 15 years. School is no longer an option for my son as his brain fog and memory loss have become more and more of a problem, his fatigue too debilitating and his headaches too frequent.

    We are tired of fighting the system, tired from having to spell out the name of his conditions to health professionals, tired of being misunderstood. There are days I avoid going out as I don’t want to answer people’s well-meant questions. There are days I am ashamed of the anger that wells up inside me when friends air their worries about their children’s school results. There are days I feel like I am being punched in the stomach when I see his friends play a soccer match. People tell me I am strong. I don’t agree. I wish I had been strong all those years ago and believed my son over his doctors.

    My son is my hero. My son is a fighter. My son has generally done what health professionals told him to do, taken every medication health professionals told him to take, followed the advice health professionals told him to take, yet the system continues to let him down. When I look into my son’s eyes, I still see this steadfast determination but I now also see pain and disillusionment. My son believed me when I told him we would overcome this together. My son believed me when I told him the worst would be over soon. My son doesn’t believe me anymore. I feel that I have failed him.

    Complex Chiari diagnosed so late is a life sentence. It has brought pain, sadness and isolation, not only to my son but to my entire family. My husband and I are learning to compartmentalize, enjoy moments. We live in hope that our son’s better periods will begin to lengthen and pick ourselves up every time these come to an abrupt end. We have to. We owe it, not only to our son but to our daughters too.

    We continue our journey through the unknown, thankful for the sources of information coming from the United States, usually met with skepticism and resistance by French health professionals. However, one thing I have learned from our journey so far is that we cannot fight these conditions and health services alone. Surely there must be more people out there in Europe. Surely, as a group we can start making a difference. Let’s unite! Let’s educate! Let’s raise awareness! Our children deserve so much better! Our children deserve to be heard, supported, and at the very least, understood!

  • Brain Under Pressure – Understanding Intracranial Hypertension [Archived]

    Brain Under Pressure – Understanding Intracranial Hypertension [Archived]

    INTRACRANIAL HYPERTENSION (IH) AND IDIOPATHIC INTRACRANIAL HYPERTENSION (IIH) ARE CONNECTED, BUT ARE NOT THE SAME THING AND THEREFORE SHOULD NOT BE USED INTERCHANGEABLY.

    Intracranial Hypertension (IH) means high pressure inside the skull. Intracranial Pressure (ICP) is measured in millimeters of mercury (mmHg). Most scholars agree that on average, “normal pressure” should be between 5-15 mmHg and that 20-25 mmHg is when the ICP crosses the line into being IH. Pressure can be brought on by several different means: space-occupying masses such as hydrocephalus and cranial cysts/tumors; cranial edema (Encephalitis); trauma; stroke; aneurysm; certain infections/diseases (Meningitis), liver failure[1], kidney failure[2]; or as a side-effect of certain medications (such as: Tetracycline[3][5], Sulfasalazine[4], Lithium[5], excess amounts of Vitamin A, steroid use[6], growth hormone treatments[6], and the hormonal Intrauterine Device (IUD), “Mirena”[7]); however, sometimes the cause of the pressure is completely unknown. When an etiological cofactor exists, it is considered Secondary Intracranial Hypertension (SIH); when no other cause is identified, it is known as Idiopathic Intracranial Hypertension (IIH) or Primary Intracranial Hypertension (PIH).

    “Idiopathic Intracranial Hypertension (IIH) was first noticed in 1893, by the German physician Heinrich Quincke, who named it Serous Meningitis. As its absence of space occupying masses/lesions began to draw more thought, it was renamed Pseudotumor Cerebri (PTC) by Max Nonne in 1904. Sometime later, the term “Benign Intracranial Hypertension” began being used interchangeably with Pseudotumor Cerebri, to describe the fact that while it is sharing some of the same characteristics that a cranial tumor would cause, it is benign (not harmful), but arguments were made against it in that blindness is not indicative of being benign.”[6] The name finally settled as “Idiopathic Intracranial Hypertension,” which means IH of an unknown cause. No matter what you choose to call it, the pain and damage remains the same for those who have it.

     

    UNDERSTANDING IDIOPATHIC INTRACRANIAL HYPERTENSION
    IIH is a neurological disorder where the cerebrospinal fluid within the skull is elevated, without the presence of a space-occupying mass, edema (brought on by things such as trauma, infection, or disease), or any adverse reactions to certain medications. Studies show that IIH is more common amongst women between the ages of 20 and 50,[8] and there is a slight increase amongst those that are overweight. Some studies also suggest a connection between obstructive sleep apnea and transverse cerebral venous sinus stenosis.[9] Amongst the general population, IIH is believed to exist in 1/100,000 (0.00001). Amongst those that are 10% above their ideal body weight, the numbers increase to 13/100,000 (0.00013), and rising to 19/100,000 (0.00019) in those 20% above their ideal body weight.[10] Although doctors often tend to pass this off as merely a side effect of weight gain, the increase is slim and seems to decrease as the percentage of weight gain above ideal weight continues to rise above the 10% margin. Additionally, the weight factor excludes men and children under the age of 10, which may simply be because women are more likely than men to have comorbid conditions that would lead to Intracranial Hypertension. Studies show that the women to men ratio for Chiari Malformation is believed to be 3:1 and those with both Chiari Malformation and Ehlers-Danlos Syndromes 9:1[11]). However weight is not irrelevant with IIH, the overweight/obese patient population report finding improvement of some symptoms when weight loss of 5-10% of one’s overall body weight, when accompanied by a low-salt diet[12]. 

     

    UNDERSTANDING THE IH/IIH CONNECTION: THE MONRO-KELLIE DOCTRINE
    The association between IH/IIH and Chiari Malformation, appears to be a malicious intricate pathological circle. The cranium (skull) consists of brain matter, cerebrospinal fluid, and both venous and arterial blood. A hypothesis, referred to as the Monro-Kellie Hypothesis (or Monro-Kellie Doctrine), states, “The sum of volumes of brain, CSF, and intracranial blood is constant. An increase in one should cause a decrease in one or both of the remaining two.”[13] Therefore, if there is an abundance of cerebrospinal fluid (IIH or hydrocephalus), both cranial blood volume and brain matter should be forced to deplete. This depletion is usually directed in the path of least resistance – through the foramen magnum and into the spinal canal. When the cranial brain matter closest to the bottom of the skull (cerebellar tonsils) goes through the foramen magnum and into the spinal canal (an Acquired Chiari Malformation), it blocks the flow of cerebrospinal fluid, which in turn, continues to raise intracranial pressure.

     

    SYMPTOMS OF INTRACRANIAL HYPERTENSION
    Intracranial Hypertension (IH) can be either acute or chronic and comes with a variety of symptoms, many of which can help distinguish IH pain from typical pain associated with Chiari Malformation. A typical Chiari headache originates at the back of the skull (at the occiput), but IH headaches are usually described as pressure at the top of the head, that radiates downward. Headaches tend to be worse when laying down (which is opposite of low pressure headaches that are often relieved by laying down). Those that suffer from IH, often report waking up from sleep with a bad headache, and often a slight incline can help alleviate the headache pain. Pulsatile Tinnitus occurs when you hear a ringing in your ears that coincides with your heart beat. The tale-tell symptom of IH involves the damage done to the optical nerves.  Papilledema is when the optic discs swell in response to the increased cranial pressure.[14] Symptoms of Papilledema include: headaches behind the eyes, blurred vision, fleeting vision, dimmed vision, double vision, visual obscurations, decreased peripheral vision, and photopsia. Another source of IH damage is seen in the pituitary gland and is known as Empty Sella Syndrome (ESS). As the high intracranial pressure (ICP) tries to take over, cerebrospinal fluid finds its way to the sella turcica and starts filling it with spinal fluid (partially or completely)[15]. The intruding CSF attempts to envelope this depression in the sphenoid bone, and squeezes the pituitary gland, flattening it until it appears “empty.” While some initially suffer no symptoms of the damage done to the pituitary gland, most eventually develop a variety of hormonal issues, known as hypopituitarism.

     

    DIAGNOSIS CRITERIA
    Diagnosis of Intracranial Hypertension usually begins with investigating either the headaches or the vision problems. The least invasive test is having a neuro-ophthalmologist check behind your eyes for Papilledema. It is not considered conclusive in testing for IH, but it is essential in determining the extent of the damage to the optical nerves. Magnetic Resonance Imaging (MRI) of the brain can be useful in showing signs of Intracranial Hypertension. In cases where one or more space-occupying masses exists, further imaging and often biopsy may be required. The type of mass, its exact location, and the amount of damage that it is believed to be doing, will be used to determine the best treatment. If imaging gives an indication that the intracranial pressure is high, but no space-occupying mass exists, additional testing is usually necessary to confirm, some of which can be potentially be dangerous for those with Heritable Disorders of Connective Tissue (HDCT), such as Ehlers-Danlos Syndromes (EDS). Lumbar punctures (LP), also known as a spinal tap, are often used to test the opening CSF pressure, but by puncturing the dura (which is thinner than normal with Connective Tissue Disorders), the risk of a CSF leak is high. When an LP causes a CSF leak, the first indication is usually a post-dural-puncture headache (PLPH) and eventually, the intracranial hypertension will decrease, as the leak causes intracranial hypotension.[16] CSF leaks can escalate very quickly and can be difficult to identify and treat; therefore, we recommend that LPs be done only when absolutely necessary, and that they be done only under fluoroscopy, by qualified surgeons that fully understand the likelihood of Connective Tissue Disorders, the symptoms of leaks, and have a plan of action should those symptoms occur. Sometimes, ICP can fluctuate and have high spikes that cause problems, rendering LPs useless unless they are done at the precise time. When these spikes are suspected ICP monitoring bolts might be the better option, but still poses a risk of leaks.[17] 

     

    TRANSVERSE SINUS STENOSIS (TSS)

    Transverse sinus stenosis (TSS) occurs when there is a narrowing of the transverse sinus (dural venous sinus), which in turn can compromise cerebral venous outflow. TSS is common in idiopathic intracranial hypertension (IIH). Depending on the study that you are reading, it is proving to be present in 65-100% of those diagnosed specifically with IIH. Its direct connection seems relatively obscure, and there is no indication of its prevalence in intracranial hypertension (IH), but it is worth looking for and treating if found. While scholars remain undecided as to whether TSS is a cause or consequence of IH, if it does prove to be a cause of high pressure, IIH will likely no longer have an idiopathic element to it and it will become another etiology of Intracranial Hypertension. TSS can often be undetectable with standard Magnetic Resonance Imaging (MRI). The correct procedure would be Magnetic Resonance Venography (MRV, with the ATECO technique [18]), specifically looking for signs of stenosis, to include looking for fistula(s) and aneurysm(s). The lack of a fistula or aneurysms however, does not exclude the possibility of a TSS existing (remember it’s being found in 65-100% of those with IIH). Even with MRV, TSS can often be misinterpreted as “flow-related artifacts.” [18] Because the prevalence of TSS in IIH patients is high (some studies call it “universal”) [19], we recommend that all IIH patients have a MRV with the ATECO technique done before surgical treatment and that venous stenting be considered as a viable surgical treatment.

     

    TREATMENT OPTIONS
    Treatments for Idiopathic Intracranial Hypertension usually starts with weight loss and/or medicinal options; Diamox (Acetazolamide) and Topamax (Topiramate) are most frequently prescribed. Those with IH/IIH should avoid consuming caffeine, as it can increase pressure and therefore is counter-productive to treatment measures. Diamox is a carbonic anhydrase inhibitor and Topamax can also inhibit carbonic anhydrase, but is an anticonvulsant, often prescribed for the treatment of neuropathy and seizure disorders. Both are believed to successfully lower the production of cerebrospinal fluid. Topamax can also help suppress the appetite, which can help with weight loss, but it also comes with many side-effects like all nerve meds do. When medication fails to decrease ICP, a Ventriculoperitoneal Shunt (VP Shunt) or Ventriculoatrial Shunt (VA Shunt) are surgically placed to drain cerebrospinal fluid straight from the ventricle. Shunts are known for failing and often need a multitude of revisions. Venous stenting is not a new procedure, yet it is not readily offered. While there are studies indicating that the successful reduction of intracranial pressure can help with TSS. Stenting is not only a surgical treatment for the stenosis (which could significantly reduce the possibility of a life-threatening aneurysm in patients with a connective tissue disorder), but it is also a surgical treatment for intracranial hypertension as it “improves CSF resorption in the venous system.” [18] Therefore, it seems illogical to shunt (just dealing with the pressure) and leave such a potentially life-threatening condition untreated. [20] Studies are indicating as high as a 94% of patients being cured of all IIH symptoms as a direct result of venous stenting. [18] While all surgeries pose a risk of complications, and the statistics for stenting are likely inflated and skewed (like that of decompression surgeries), these statistics on stenting are definitely encouraging!

    Intracranial Hypertension is a complex issue that should be explored whenever a Chiari Malformation exists, before a decompression surgery is performed. When both Intracranial Hypertension and Chiari Malformation are found to co-exist, the treatment should be in consideration of the correlation of the two, as they both are pathological co-factors of one another. Failure to recognize and treat Intracranial Hypertension before or soon after decompression surgery, will increase the likelihood of a failed decompression. While a decompression surgery can lower Intracranial Hypertension, as cerebrospinal fluid is once again allowed to flow, if space-occupying masses or a case of Idiopathic Intracranial Hypertension (where too much cerebrospinal fluid is being created) are left untreated, those problems will still exist after decompression surgery and the high pressure is likely to cause the cerebellar tonsils to fall once again.

    *Revised October 2018

     

    [wpedon id=”4396″ align=”center”]

     

    References:

    1 Jalan, R. “Intracranial Hypertension in Acute Liver Failure: Pathophysiological Basis of Rational Management.” Seminars in Liver Disease., U.S. National Library of Medicine, Aug. 2003, <www.ncbi.nlm.nih.gov/pubmed/14523680>.

    2 Chang, D, et al. “Benign Intracranial Hypertension and Chronic Renal Failure.” Cleveland Clinic Journal of Medicine., U.S. National Library of Medicine, <www.ncbi.nlm.nih.gov/pubmed/1525975>.

    3 Holst, Anders Vedel, et al. “A Severe Case of Tetracycline-Induced Intracranial Hypertension.”Dermatology Reports, PAGEPress Publications, 31 Jan. 2011, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4211491/>.

    4 Sevgi, E, et al. “Drug Induced Intracranial Hypertension Associated with Sulphasalazine Treatment.” Headache., U.S. National Library of Medicine, Feb. 2008, <www.ncbi.nlm.nih.gov/pubmed/18070060>.

    5 Kelly, S J, et al. “Pseudotumor Cerebri Associated with Lithium Use in an 11-Year-Old Boy.”Journal of AAPOS : the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus., U.S. National Library of Medicine, Apr. 2009, <www.ncbi.nlm.nih.gov/pubmed/19393521>.

    6 Aylward, Shawn C. “Intracranial Hypertension: Is It Primary, Secondary, or Idiopathic?”Journal of Neurosciences in Rural Practice, Medknow Publications & Media Pvt Ltd, 2014, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4173226/>.

    7 Etminan, Mahyar, et al. “Risk of Intracranial Hypertension with Intrauterine Levonorgestrel.”Therapeutic Advances in Drug Safety, SAGE Publications, June 2015, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4519742/>.

    8  “Pseudotumor Cerebri Information Page.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, <www.ninds.nih.gov/Disorders/All-Disorders/Pseudotumor-Cerebri-Information-Page>.

    9 Thurtell, Matthew J., et al. “An Update on Idiopathic Intracranial Hypertension.” Reviews in Neurological Diseases, U.S. National Library of Medicine, 2010, <www.ncbi.nlm.nih.gov/pmc/articles/PMC3674489/>.

    10 Wani, Irfan Yousuf, et al. “Complete Ophthalmoplegia: A Rare Presentation of Idiopathic Intracranial Hypertension.” Annals of Indian Academy of Neurology, Medknow Publications & Media Pvt Ltd, 2015, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4683894/>.

    11 Henderson, Fraser C., et al. “Neurological and Spinal Manifestations of the Ehlers–Danlos Syndromes.” American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 21 Feb. 2017, <www.onlinelibrary.wiley.com/doi/10.1002/ajmg.c.31549/full>.

    12 Thurtell, Matthew J., and Michael Wall. “Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management.” Current Treatment Options in Neurology, U.S. National Library of Medicine, Feb. 2013,<www.ncbi.nlm.nih.gov/pmc/articles/PMC3554852/>.

    13 Mokri, B. “The Monro-Kellie Hypothesis: Applications in CSF Volume Depletion.” Neurology., U.S. National Library of Medicine, 26 June 2001, <www.ncbi.nlm.nih.gov/pubmed/11425944>.

    14 Schirmer, Clemens M, and Thomas R Hedges. “Mechanisms of Visual Loss in Papilledema.”Journal of Neurosurgery, <www.thejns.org/doi/full/10.3171/FOC-07/11/E5>.

    15 “Empty Sella Syndrome Information Page.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, <www.ninds.nih.gov/Disorders/All-Disorders/Empty-Sella-Syndrome-Information-Page>.

    16 Panikkath, Ragesh, et al. “Intracranial Hypertension and Intracranial Hypotension Causing Headache in the Same Patient.” Proceedings (Baylor University. Medical Center), Baylor Health Care System, July 2014, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4059569/>.

    17 Abraham, Mary, and Vasudha Singhal. “Intracranial Pressure Monitoring.” Journal of Neuroanaesthesiology,  <www.jnaccjournal.org/article.asp?issn=2348-0548;year=2015;volume=2;issue=3;spage=193;epage=203;aulast=Abraham>.

    18 Ahmed, Wilkinson, et al. “Transverse Sinus Stenting for Idiopathic Intracranial Hypertension: A Review of 52 Patients and of Model Prediction.” American Society of Neuroradiology, July 2011. <www.ajnr.org/content/32/8/1408.long>.

    19 Riggeal, Bruce, et al. “Clinical course of idiopathic intracranial hypertension with transverse sinus stenosis.” American Academy of Neurology, 2012. <www.ncbi.nlm.nih.gov/pmc/articles/PMC3589184/>.

    20 Patel, et al. “Evaluating and treating venous outflow stenoses is necessary for the successful open surgical treatment of arteriovenous fistula aneurysms.” Society for Clinical Vascular Surgery, Volume 61, Issue 2. February 2015. <www.sciencedirect.com/science/article/pii/S0741521414014116>.

     

     

  • What’s In A Name? An Expansive Review of the Name and Definition of Chiari Malformation

    What’s In A Name? An Expansive Review of the Name and Definition of Chiari Malformation

    THE DEFINITION OF A CHIARI MALFORMATION HAS BEEN LONG DEBATED. IT REALLY IS NO WONDER THAT PATIENTS AND MEDICAL PROFESSIONALS ALIKE ARE CONFUSED. THEN, WITH US FULLY UNDERSTANDING ALL SIDES OF THE DEBATE, WE DEFINED A CHIARI MALFORMATION AS STRUCTURAL DEFECTS IN WHICH THE CEREBELLUM, THE HIND PART OF THE BRAIN, DESCENDS BELOW THE FORAMEN MAGNUM INTO THE SPINAL CANAL. THIS DEBATE IS BEING ANALYZED THIS YEAR, AS CERTAIN ORGANIZATIONS ARE BRAVING TO ATTEMPT TO BRING DOCTORS ALL UNDER ONE UNIFORM DEFINITION AND DIAGNOSTIC CRITERIA. THEREFORE, AMIDST ALL THE CONFUSION AND DEBATE, WE WANTED TO EXPLAIN THE FACTORS INVOLVED, AND WHY WE WENT WITH THE DEFINITION THAT WE DID, AND WHY ONE STANDARD IS SO IMPORTANT!

    To better facilitate our explanation, we will call all associated terms by their specific medical names:

    Tonsillar Ectopia (TE) = tonsillar herniation of any size
    Posterior Fossa Hypoplasia (PFH) = an underdeveloped posterior fossa

    Chiari Malformation Vs. Arnold Chiari Malformation

    The most common type of Chiari is Type 1 (which includes a Chiari 1.5, where the brainstem is also below the foramen magnum). Many people use the term “Chiari Malformation” when diagnosed with Type 1, while others cling to the name “Arnold Chiari Malformation” with the same diagnosis. Is there a difference? The name “Chiari Malformation” came from Hans Chiari, an Austrian pathologist, who first discovered the malformation in the late 19th century.[1, 2] Julius Arnold, a German pathologist, later expanded on Chiari Type 2, and Type 2 took on his name “Arnold Chiari Malformation.” Therefore, technically speaking, a Chiari Malformation and an Arnold Chiari Malformation are not the same; Arnold Chiari Malformation is specific to Chiari Type 2 (which usually includes a myelomeningocele, the most serious form of Spina Bifida). However, they are used interchangeably by many, even by medical professionals and the misnomer is of little consequence one way or the other.[3]

    Chiari Malformation = Posterior Fossa Hypoplasia Theory

    Many ascribe to the theory that a Chiari Malformation ONLY consists of a posterior fossa hypoplasia (which means that the back of the skull is malformed, and therefore the cranial area (space) at the rear is too small). They believe that a tonsillar ectopia is only a symptom, and a Chiari Malformation can exist with or without an accompanying ectopia. This argument is not without merit, because much of what was initially being looked at by Hans Chiari were deformities in the posterior skull upon postmortem examination (so there wasn’t soft tissue to analyze). He originally attributed much to hydrocephalus, but expanded his research into the pons, medulla oblongata, and cerebellum (which can all be attributed to intracranial pressure as a pathology of a “tonsillar ectopia”). To ascribe to this belief would also mean that “Acquired Chiari Malformations” cannot exist, as one doesn’t “acquire” a small posterior fossa. And that would also mean that Chiari Type 2, Type 3 and Type 4 technically would not be a Chiari Malformation at all either, since their definitions do not require a posterior fossa hypoplasia. Perhaps type 3, which has an opening at the back of the skull, but no “small posterior fossa” is even implied in the definitions.

    But to look at the full history of what became known as a Chiari Malformation, we can begin by looking at the research of a German pathologist, named Theodor Langhans. In his research in 1881 (a decade before Hans Chiari conducted his research on what became known as a Chiari Malformation), while looking at syringomyelia (“a cavity created in the spinal cord”), he noted a “change in the cerebellar cavity.” Upon dissection of the cerebellum, he described the cerebellar tonsils as “two symmetrical pyramidal tumors,” pushing the brainstem forward.[4] In fact, the other noted researchers: Nicholas Tulp (1593–1674), John Cleland (1835–1925), and Julius Arnold (1835–1915), all centered on the hindbrain hernia [herniation] without speculation as to its etiology/pathology. It is said that “many of the English translations of Chiari’s work contain inaccuracies.” But note that Chiari’s first paper was on “ectopia of cerebellar tissue,” and that he went on to define Type 1 as showing, “elongation of the tonsils and medial parts of the inferior lobes of the cerebellum into cone shaped projections, which accompany the medulla oblongata into the spinal canal.”[5] Which sounds like what is now known to be a Chiari 1.5. Much later, in 1938, at a time when the posterior fossa decompression became the popular surgical treatment for a Chiari Malformation, a Chiari 2 patient “underwent posterior fossa exploration with the authors not considering hindbrain herniation in their differential. Penfield and Coburn later stated that: ‘In retrospect it seems that we should have suspected the Arnold-Chiari malformation. Instead, a suboccipital craniotomy was carried out…” So even the early neurosurgeons seeking to perfect their surgical treatment felt that it was a mistake to concentrate on the posterior fossa and not take into account etiologies of the hindbrain herniation. That mistake is still going on 80 years later.[6]

    The biggest problem that they are going to have with strictly defining a Chiari Malformation as a small posterior fossa resides in the fact that the diagnosis criteria for a Chiari Malformation only consists of ONE MEASUREMENT, the length of the tonsillar ectopia (how far the tonsils herniate below the foramen magnum). Generally, there are no measurements of the posterior fossa taken when radiologists make the initial diagnoses. Furthermore, most neurosurgeons see the radiology reports, and depending on symptomology, they make the decision to decompress or not to decompress without ever measuring the size of the posterior fossa. Most never look for (and often do not know about) etiological/pathological cofactors that could have been causing the tonsillar prolapse in the first place.

    Where does this assumption leave us?
    Unfortunately it leaves most of us with failed decompressions, fighting with our neurosurgeons that “something is still wrong.” These neurosurgeons look at their post-operative checklist and see that they successfully did everything surgically required in their out-of-date textbooks:
    1. Suboccipital bone was appropriately decompressed. ✔️
    2. Dura was opened and dura patch was successfully inserted. ✔️
    3. Lamina was successfully removed from the C1 (and sometimes the C2 as well). ✔️
    They did all that was required of them based on the diagnoses presented! They don’t have time (or don’t care) to look beyond that, so once again, the idea of our continued symptoms are thought of as being psychosomatic.
     
    While we applaud the efforts of those seeking to get a measure of consistency in how Chiari is defined, the truth remains that until the diagnosis criteria is changed as well, we are being diagnosed with Chiari Malformation based on our tonsillar herniation; it is presumed to be congenital; we are being surgically treated as though it is congenital, and we are ending up with failed decompressions. This confusion is beyond unacceptable, it’s reprehensible!
    When it is all redefined, hopefully we will have a well defined diagnosis criteria, or it is all irrelevant. And the many that really did acquire what was assumed to be “congenital” who are now being told that they do not have Chiari Malformation at all, will be able to get lawyers for “an improper diagnosis” that lead to the incorrect brain surgery being done. There are surgeons coming around and finally seeing that there is merit to these studies that have been done since the late 1990s, that have shown a pushing/pulling effect that can cause the tonsillar ectopia that gets us diagnosed with a Chiari Malformation, and we applaud them for having the integrity to stand up and get it right. That’s exactly what we need and deserve!
    If you were diagnosed with a Chiari Malformation and want to know how all of this might be affecting you, we encourage you first to find your initial radiology reports, and see if there were measurements taken of the posterior fossa. And then wait with that information… wait and see what changes are actually made to the definition. While you are waiting learn. Learn everything you can about every etiological/pathological cofactor, and every comorbidity. If it is “officially” redefined as a small posterior fossa, we will have to work together as a community (like we always do) to help lawyers see how we have been getting lost in the shuffle, year after year. If it’s not officially changed and Chiari continues to be defined as a structural defect involving the cerebellar tonsils, we will have to continue in our fight to make these cofactors of Acquired Chiari Malformation known!

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    References:

    1 Tubbs, et al. “Hans Chiari (1851–1916).” Journal of Neurology, Pioneers in Neurology, Springer Berlin Heidelberg, 26 Mar. 2010, <https://link.springer.com/article/10.1007/s00415-010-5529-0>.

    2 “Hans Chiari.” Whonamedit – Dictionary of Medical Eponyms, <www.whonamedit.com/doctor.cfm/1123.html>.

    3 Tubbs, R. Shane, and W. Jerry Oakes. The Chiari Malformations: A Historical Context . 2013, <https://pdfs.semanticscholar.org/79dd/127d31820d612600c0b032225437295d86c3.pdf>.

    4 Mortazavi, M M, et al. “The First Description of Chiari I Malformation with Intuitive Correlation between Tonsillar Ectopia and Syringomyelia.” Advances in Pediatrics., U.S. National Library of Medicine, Mar. 2011, <https://www.ncbi.nlm.nih.gov/pubmed/21361763>.

    5 Pearce, J M S. “Arnold Chiari, or ‘Cruveilhier Cleland Chiari’ Malformation.” Journal of Neurology, Neurosurgery & Psychiatry, BMJ Publishing Group Ltd, 1 Jan. 2000, <https://jnnp.bmj.com/content/68/1/13>.

    6 Mortazavi, Martin M., et al. “The First Posterior Fossa Decompression for Chiari Malformation: the Contributions of Cornelis Joachimus Van Houweninge Graftdijk and a Review of the Infancy of ‘Chiari Decompression.’” SpringerLink, Springer, Dordrecht, 6 Apr. 2011, <https://link.springer.com/article/10.1007%2Fs00381-011-1421-1>.

  • The Chiari Malformation Ehlers-Danlos Connection

    The Chiari Malformation Ehlers-Danlos Connection

    CHIARI (KEE-AR-EE) MALFORMATIONS ARE FAR FROM RARE, THEY ARE JUST RARELY UNDERSTOOD, EVEN BY MOST MEDICAL PROFESSIONALS. A CHIARI MALFORMATION EXISTS WHEN THE LOWEST PART OF THE HIND BRAIN (THE CEREBELLAR TONSILS) PROLAPSES INTO THE HOLE AT THE BOTTOM OF THE SKULL (FORAMEN MAGNUM), ENTERS THE SPINAL CANAL AND OBSTRUCTS THE FLOW OF CEREBROSPINAL FLUID (CSF), PUTS PRESSURE ON THE BRAIN STEM AND SPINE, AND MAY RESULT IN VARYING DEGREES OF NERVE COMPRESSION.

    PREVALENCE OF CHIARI: Once thought to occur in 1 in 1000 people, it is now believed to be much more frequent of an occurrence. A 2016 pediatric study found it to occur in 1 in 100 children[1]. Since Chiari Malformation Type 1, the most common type, tends to become symptomatic during late teens and early adulthood, it is likely to be much more common when adults are factored in.

    THE CONNECTION: Chiari malformations were originally believed to be caused by a posterior fossa hypoplasia (small area inside the back of the skull) and doctors speculated that lack of maternal prenatal care or drug abuse caused the deformity. However, as studies continue, they are finding that many with this hind brain herniation have connective tissue disorders, such as Ehlers-Danlos Syndromes. Ehlers-Danlos Syndromes involve a mutation in one of the collagen genes. Collagen is a protein that is often described as a “cellular glue” that helps hold the body together. When that glue fails to hold, everything seems to go awry; specifically, as related to Acquired Chiari Malformations: organs tend to prolapse, and bones begin to shift as joint laxity increases (including the bones/vertebrae at the craniocervical junction). They are finding that these acquired Chiari malformations are far more common than originally thought. There are many pathological co-factors that can cause or attribute to the formation of a Chiari Malformation, and most can be linked to these Heritable Disorders of Connective Tissues (HDCTs), including a posterior fossa hypoplasia. In one large study, they found those with a Chiari malformation and no associated co-factors, with only slightly over 52% having a small Posterior Cranial Fossa (PCF). When other co-factors were present, the number of Chiarians found with a small PCF plummeted and therefore it is should be considered acquired until proven otherwise.[2]

    DIAGNOSES: A decade ago, it took 10-20 years from the onset of symptoms to be diagnosed and now it takes an average of 1-2 years, because medical professionals are slowly beginning to look for it. Magnetic Resonance Imaging (MRI) remains the best tool for diagnosis. Some medical professionals believe that a tonsillar herniation of less than 5mm is simply a tonsillar ectopia and only diagnose a Chiari malformation when the descent is > 5mm. However, the 5mm requirement is controversial and many doctors now base their diagnoses not solely on measurements, but rather on symptomology and a combination of other factors (including Cine MRI, a patient’s symptoms, and other relevant factors). Due to the prevalence of connective tissue issues, gravity often proves to be a significant factor and should be taken into account by use of an upright MRI whenever possible.[3] EDS should be diagnosed by a geneticist before surgery is considered.

    TREATMENT OPTIONS: There is no cure for a Chiari malformation, but there are treatment options. When symptoms are minimal and not life-altering, pain management is usually offered. However, it is important to know that while medications may ease some symptoms, Chiari symptoms tend to be progressive. Decompression surgery is the only treatment available to attempt to halt the progression of the damage being done to your Central Nervous System (CNS). The most common reason that decompression surgeries fail, is undiagnosed co-morbid conditions, especially those that can be etiological/pathological co-factors. More than one surgery might be necessary to successfully treat a Chiari malformation and any/all co-morbid conditions and there is a correlation between early surgical intervention and positive surgical outcomes[4].

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    References:

    1 Eltorai, Ibrahim M. “Rare Diseases and Syndromes of the Spinal Cord” Cham: Springer International Publishing: Imprint: Springer, 2016. Page 43, 15.2, <www.springer.com/us/book/9783319451466>.

    2 Milhorat, Thomas H., et al. “Mechanisms of Cerebellar Tonsil Herniation in Patients with Chiari Malformations as Guide to Clinical Management.” Acta Neurochirurgica, Springer Vienna, July 2010, <www.ncbi.nlm.nih.gov/pmc/articles/PMC2887504>.

    3 Henderson, Fraser C., et al. “Neurological and Spinal Manifestations of the Ehlers–Danlos Syndromes.” American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 21 Feb. 2017, <www.onlinelibrary.wiley.com/doi/10.1002/ajmg.c.31549/full>.

    4 Siasios, John, et al. “Surgical Management of Patients with Chiari I Malformation” International Journal of Pediatrics, Article ID 640127, Hindawi, 2012, <https://www.hindawi.com/journals/ijpedi/2012/640127>.

  • Overview: Cerebrospinal Fluid Leaks

    Overview: Cerebrospinal Fluid Leaks

    Cerebrospinal fluid (CSF) is the clear, colorless liquid that surrounds the brain and spinal cord and is contained within a lining called the dura. The cerebrospinal fluid protects and cushions the brain and central nervous system. Among other functions, this fluid provides buoyancy to the brain, allowing it to float and weigh less, thus reducing the pressure at the base of the brain. A cerebrospinal fluid (CSF) leak occurs when there is a tear or hole in the dura that then allows this fluid to escape[1]. When leaks occur, the overall volume and pressure within the skull drops, and the cushioning and buoyancy effect is reduced, causing the brain to slump. In many cases, this leads to a condition known as intracranial hypotension and a vast range of symptoms.

    The main symptom of a CSF leak is a headache that is worse when upright and improves when lying down horizontally. This is sometimes called a “positional” or “orthostatic” headache. However, not all positional headaches can be attributed to a CSF leak, and not all CSF leak headaches are positional. This is particularly the case in the chronic (vs acute) phase of CSF leaks, where the “positional” or “orthostatic” characteristic of symptoms may become more constant, lessen, or disappear entirely, including headache. Symptoms often worsen as the day goes on. Other leak symptoms can include, but are not limited to: nausea, vomiting, neck pain or stiffness, heaviness of head, pain between the shoulder blades, feeling of pressure within the head, changes in hearing (muffled or underwater sensation), tinnitus (ringing, buzzing, or pulsatile), feeling of liquid in the ears, sense of imbalance, sensitivity to light, sensitivity to sound, pain or numbness in the arms, changes in cognition (“brain fog,” memory loss, or loss of concentration), dizziness or vertigo, scalp sensitivity or tingling sensation within the scalp, visual changes (blurring, double vision, visual field defects), pain behind the eyes or when moving eyes, facial numbness or pain, sinus pressure, temporomandibular joint pain and stiffness, and subdural hematoma[2]. Cranial leak specific symptoms can vary even more and can include: fluid discharge from ears, nose (usually only one side) and to back of throat often reported as salty or metallic tasting, recurring or chronic meningitis, loss of sense of smell, change in hearing or ringing in the ears, and less frequently cognitive changes. Rare signs or complications of CSF leaks can include: quadriplegia, dementia (often mimicking Frontotemporal Lobe Dementia), Parkinsonism, other movement disorders, ataxia (unsteady gait), hypersomnolence, stupor, coma, stroke (hemorrhagic or ischemic), and even death.

    CSF leaks are often very hard to locate, if ever. Approximately 50% of leaks cannot be found on imaging. Imaging and other tests used to attempt to find leaks are often read as “normal” even when there is a leak present. Other times, especially (but not always) in the case of chronic leaks, the positional symptoms either lessen or go away altogether, including the headache. Many who are leaking are not even aware that they are leaking. Leaks are often misdiagnosed as well[3]. Some of those common misdiagnoses are Postural Orthostatic Tachycardia Syndrome (POTS), migraines, sinus headaches, Meniere’s Disease, Chronic Fatigue Syndrome, Parkinson’s Disease (sometimes other neurodegenerative diseases), Fibromyalgia, Ehlers-Danlos Syndrome, Tarlov Cyst, Chiari Malformation, Cervical Spine Disease, cervicogenic headache, tension headache, and Sinusitis. To make diagnosis even more complex and elusive, CSF leaks can and do often occur along with any of these disorders and perhaps several simultaneously. A leak can cause an acquired Chiari malformation or coexist and complicate an existing congenital Chiari malformation[4]. Some patients have had unnecessary decompression surgeries when the underlying, sole cause was a leak all along.

    Leaks can be caused by:

    1. Medical procedures (also called iatrogenic leaks) for various diagnostic or therapeutic reasons such as lumbar punctures to collect fluid for analysis if meningitis is suspected, lumbar puncture for injection of contrast (myelography), spinal anesthesia, epidural injections, epidural steroid injections, prior skull base or spinal surgery, CSF shunt over-drainage, prior sinonasal surgery, and chiropractic or other spinal manipulations.
    2. Traumatic injuries such as brachial plexus injuries falls, sports injuries, motor vehicle accidents, roller coaster rides, and other whiplash injuries.
    3. Spontaneous leaks that occur with minimal or no clear cause. Sometimes spontaneous leaks may be associated with some sort of spinal pathologies such as calcified disk material or bone spurs. These leaks are usually ventral (or in front of the spinal cord).

    There is growing evidence suggesting that a significant number of spontaneous CSF leaks occur as the result of a preexisting weakness in the dura[5]. Heritable Disorders of Connective Tissues (HDCT’s) such as Marfan Syndrome, Ehlers-Danlos Syndrome (both classical and hypermobility type), autosomal dominant Polycystic Kidney Disease, and other HDCT’s predispose patients to CSF leaks. One leak expert estimates that “slightly less than 100% of patients with spontaneous CSF leaks have an underlying connective tissue disorder.”[6] The dura is made out of connective tissue and patients with HDCT’s have thinner dura mater, that is more susceptible to tears and leaks. HDTC patients are more prone to spinal conditions such as perineural cysts, meningeal diverticula, and other HDCT defects such as aneurysms and dilatations. Oftentimes, a CSF leak is the first sign of an underlying HDCT.

    Lumbar punctures (LP’s or spinal taps) should be avoided in patients with Chiari Malformation and/or in patients with HDCT’s[7]. There is a risk of causing a herniation of the cerebellar tonsils or making an existing herniation worse from the pull-down mechanism involved in lumbar punctures. Unfortunately, lumbar punctures are not always avoidable and sometimes very necessary, especially in cases to rule out life-threatening viral or bacterial conditions such as meningitis, subarachnoid hemorrhage, encephalitis, or syphilis. In these cases, measures can be taken to minimize LP risks such as using a certain needle type and size, limit the number of cc’s collected (by spontaneous drip ONLY), and, of course, always done under fluoroscopy by a competent physician[8]. Additionally, it is important to be aware that patients with HDCT’s are at greater risk for the dura to fail to heal following an LP. Patient’s should be aware of post-dural puncture headache (PDPH) symptoms and speak with their physicians if they suspect a leak following an LP.

    The procedures and tests used to diagnose leaks will vary between patients and certain criteria are used to diagnose leaks[9]. Some of these tests and procedures might be: endoscopic exam and fluid collection and Beta-2-Trasnferrin testing (cranial leaks), Cisternography (including radioisotope cisternogram), Magnetic Resonance Imaging (MRI) including Magnetic Resonance (MR) myelography, Dynamic CT myelography, Digital Subtraction myelography, and Intrathecal saline infusion-enhanced myelography, a lumbar puncture to collect and test fluid and measure opening pressure. This imaging often includes both brain and spinal imaging. The normal opening pressure is not uncommon and does not rule out a leak. High pressure can also occur while leaking. Pre-existing intracranial hypertension can be related to the development of spontaneous spinal CSF leaks. Some reports suggest that spontaneous cerebrospinal fluid (CSF) leaks are strongly associated with idiopathic intracranial hypertension (IIH). There are 5 main findings on imaging that doctors look for, however, the absence of these findings does not rule out a CSF leak. The mnemonic SEEPS is used for most of these findings: subdural fluid collection, enhancement of pachymeninges, engorgement of venous structures, pituitary hyperemia, and sagging of the brain[10]. Other imaging findings that might be seen are small ventricles, cisterns might have less fluid, optic chasm might flatten over pituitary, pituitary might enlarge, empty sella, fluid in front of the pons, or pons might become flatter than normal. Repeat imaging is often necessary.

    Treatment of leaks can either be medical or surgical. Conservative treatment is often recommended, if possible. This can include bed rest and avoidance of coughing, sneezing, straining, bending, twisting, and lifting, increased fluid intake and caffeine, the use of an abdominal binder, and sometimes steroids are recommended. Others may have a lumbar drain placed in the low back to decrease the pressure of the CSF around the area of the leak in an attempt to allow this area to heal. Some patients may need an epidural blood patch. Where a blood patch is not successful, a fibrin glue patch may be tried. About 30-40% of leaks occur at multiple sites, especially in those with an HDCT. Multisite patches may be required. Higher volumes of blood may be needed in order to reach where it needs to go, and/or the position of the needle may need to vary from the standard placement (transparietal or lateral placement)[11]. It is not uncommon for several patches to be tried. Many doctors make the mistake that if an EBP fails, there was no leak as well. Sometimes when more conservative and less invasive treatments have failed, neurosurgery may be necessary. Surgical repairs vary and are tailored according to the type and location of the leak. Sometimes in a select set of patients, other procedures have been used including epidural saline infusions through an implanted epidural catheter or lumbar dural reduction surgery. A condition known as rebound intracranial hypertension (RHP) may occur following any of these treatments[12]. Usually, but not always, there is a different pattern to the headache where one feels worse when horizontal and better when upright. Sometimes, acetazolamide (Diamox) or a similar medication is prescribed to help treat RHP.

    Leaks are poorly recognized, poorly understood, under-researched, understudied, often misdiagnosed, can complicate existing conditions, are difficult to find, mimic many other disorders (including Chiari Malformation), and can be comprised of a vast array of symptoms. Most doctors are familiar with the symptoms of a leak in the acute phase. Very few doctors are familiar with how long-term, chronic CSF leaks “present” in regard to headaches and other leak symptoms and often miss the more subtle symptoms of chronic leaks. Like Chiari and other related disorders, no two patients with CSF leaks have the same symptoms and often experience misdiagnosis, delayed diagnosis, are disbelieved concerning their symptoms of the severity thereof, and all too often dismissed to suffer excruciating pain, decline, and debility. Educating yourself as much as possible about CSF leaks will help guide and empower you and those around you who may have existing, suspected or potential future complications that may arise due to CSF leaks.

    CSF Leak Symptoms List: https://chiaribridges.org/glossary/symptoms-of-intracranial-hypotension/

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    References:

    1 “CSF Leak: A Curable Cause of Headache.” A Non-Profit Hospital in Los Angeles, <www.cedars-sinai.edu/Patients/Programs-and-Services/Neurosurgery/Centers-and-Programs/Cerebrospinal-Fluid-Leak/CSF-Leak-A-Curable-Cause-of-Headache.aspx>.

    2 “Cerebrospinal Fluid (CSF) Leak.” A Non-Profit Hospital in Los Angeles, <www.cedars-sinai.edu/Patients/Health-Conditions/Cerebrospinal-Fluid-CSF-Leak.aspx>.

    3 Schievink, Wouter l. “Misdiagnosis of Spontaneous Intracranial Hypotension.” Archives of Neurology, American Medical Association, 1 Dec. 2003, <www.jamanetwork.com/journals/jamaneurology/fullarticle/785098>.

    4 Haider, Ali S., et al. “Spontaneous Intracranial Hypotension Presenting as a ‘Pseudo-Chiari 1.”Cureus, Cureus, 16 Feb. 2017, <www.ncbi.nlm.nih.gov/pmc/articles/PMC5354398/>.

    5 Reinstein, Eyal, et al. “Connective Tissue Spectrum Abnormalities Associated with Spontaneous Cerebrospinal Fluid Leaks: a Prospective Study.” European Journal of Human Genetics, Nature Publishing Group, Apr. 2013, <www.ncbi.nlm.nih.gov/pmc/articles/PMC3598315/>.

    6 Schievink, Wouter l. “Q & A With Dr. Schievink.” Spinal CSF Leak Foundation, 14 July 2014, <www.spinalcsfleak.org/q-a-with-dr-schievink/>.

    7 Erbay, Sami H., et al. “Is Lumbar Puncture Contraindicated in Patients with Chiari I Malformation?” American Journal of Neuroradiology, American Journal of Neuroradiology, 1 Apr. 2005, <www.ajnr.org/content/26/4/985>.

    8 Matas, Sandro Luiz de Andrade. “Why Should We Use Atraumatic Needles in Lumbar Puncture?” Arquivos De Neuro-Psiquiatria, <www.scielo.br/pdf/anp/v71n9B/0004-282X-anp-71-09b-681.pdf>.

    9 Schievink, W. l., et al. “Diagnostic Criteria for Spontaneous Spinal CSF Leaks and Intracranial Hypotension.” American Journal of Neuroradiology, American Journal of Neuroradiology, 1 May 2008, <www.ajnr.org/content/29/5/853>.

    10 Schievink, Wouter l. “Spontaneous Spinal Cerebrospinal Fluid Leaks and Intracranial Hypotension.” JAMA, American Medical Association, 17 May 2006, <www.jamanetwork.com/journals/jama/fullarticle/202849>.

    11 Griauzde, J., et al. “Large-Volume Blood Patch to Multiple Sites in the Epidural Space through a Single-Catheter Access Site for Treatment of Spontaneous Intracranial Hypotension.”American Journal of Neuroradiology, American Journal of Neuroradiology, 30 Apr. 2014, <www.ajnr.org/content/early/2014/04/30/ajnr.A3945>.

    12 Kranz, P. G., et al. “Rebound Intracranial Hypertension: A Complication of Epidural Blood Patching for Intracranial Hypotension.” American Journal of Neuroradiology, American Journal of Neuroradiology, 1 June 2014, <www.ajnr.org/content/35/6/1237>.

  • Overview: Complications Associated With A Chiari Decompression

    Overview: Complications Associated With A Chiari Decompression

    From Intracranial Hypertension (formerly known as Pseudotumor Cerebri), Hydrocephalus, Tethered Cord Syndrome, to conditions related to the presence of a connective tissue disorder, such as Ehler’s-Danlos Syndrome, the primary reason for post-decompression complications seen in the Chiari Patient Community continues to be largely related to undiagnosed and untreated comorbid conditions. Time and time again, we see decompression failure, or a recurrence of symptoms after decompression, because there are other underlying conditions that need to be addressed. For this reason, we strongly recommend that patients get evaluated for the possibility of these known comorbid conditions before undergoing decompression surgery, unless circumstances require emergency surgery. (More information about the testing we recommend can be found in “The Treatments” article). Potential complications of decompression surgery may vary, depending upon the specific technique used, such as whether a duraplasty is performed, and how much bone is removed during a suboccipital craniectomy. The most common complications are infection, CSF leak, and Pseudomeningocele in adult patients.


    INFECTIONS

    Surgical site infections:
    A surgical site infection is a risk of any surgery. While hospitals and surgical staff strive to maintain a sterile environment, hospitals are known for harboring pathogens, including many that are antibiotic resistant. Patient factors, including diabetes, age, being overweight, and being a smoker can also increase a patient’s risk of developing a post-operative infection.[1] Antibiotics are typically given post-surgically (and sometimes before surgery) in order to reduce the risk of infection. Some infections require wound revision surgery, to remove pus and infected tissue in order to improve healing.


    MENINGITIS

    Meningitis is an additional surgical risk when the dura is opened during a decompression. It is characterized by inflammation of the meninges, the linings of the brain. There are three main types of meningitis: aseptic, bacterial and chemical.

    CSF Meningitis/Blood (left); CSF Meningitis (middle); CSF (right)

    ♦ Aseptic Meningitis is by far the most common type, and is generally less severe than the bacterial type. Most cases of aseptic meningitis are caused by viruses, but may rarely be fungal, autoimmune, parasitic or drug-induced.[2] The treatment for aseptic meningitis is usually supportive care.[3] Chemical meningitis is also a risk any time surgery or other procedures or treatments are performed on the brain or spine.[4]

    ♦ Bacterial Meningitis is much more serious and can be life threatening. Three types of bacteria cause most cases: streptococcus pneumoniae, Group B streptococcus, and Neisseria meningitidis. Typical treatment includes antibiotics and supportive care.


    CSF LEAKS

    Duraplasty leak:
    Post-decompression CSF leaks are a risk of decompression surgery whenever the dura is opened. The risk of a CSF leak dramatically increases with the presence of untreated hydrocephalus[5], intracranial hypertension (IH)[6], and connective tissue disorders, such as Ehlers-Danlos Syndrome. Nationwide statistics indicate that the risk of a CSF leak post-duraplasty is 10-15%. However, some surgeons report a significantly lower incidence of CSF leaks in their patients.[7] The use of biologic glue to seal the dural suture line has greatly reduced the incidence of post-duraplasty CSF leaks. A common sign of a leak is clear fluid leaking from the incision site.

    Pseudomeningocele:
    A pseudomeningocele is a type of CSF leak, where the leak creates a pocket in the muscles in the back of the neck. It is one of the most common complications of duraplasty. While some surgeons have managed to keep the incidence of pseudomeningocele low in their patients, some report an incidence as high as 18%.[8] A study at Vanderbilt University at 2013 showed that the development of a pseudomeningocele after decompression significantly reduced the benefit of decompression at one-year post-op on pain, disability and quality of life.[9] A smaller pseudomeningocele may re-absorb on its own. However, with large and persistent PM’s, the duraplasty may adhere to the cerebellar tonsils, blocking flow and making a revision surgery more difficult. There is much debate among neurosurgeons as to whether doing routine duraplasty as part of decompression outweighs the risks. Some argue that duraplasty increases the risk of complications, while others say that failure to perform duraplasty often results in inadequate decompression, reduced benefit, and the need for additional surgeries. Some experts argue that duraplasty using the patient’s own pericranial tissue and using water-tight sutures and biologic glue minimizes the risk of a leak and makes routine duraplasty the best option for most patients. A squishy pocket of fluid is often seen near the base of the skull and a PM can be confirmed and monitored with an MRI. In some cases, a surgeon may try draining the pocket of fluid with a needle and syringe.


    BLEEDING AND ANESTHESIA-RELATED COMPLICATIONS

    Excessive Blood Loss:
    Excessive blood loss is a risk of any major surgery, but can be minimized by a careful surgical technique. Patients with connective tissue disorders may have an increased risk of bleeding complications, due to fragile blood vessels, particularly with vascular EDS or vascular crossover symptoms. Cessation of blood-thinning medications, such as warfarin, aspirin and NSAIDS also reduces the risk of bleeding.

    Anesthesia Risks:
    While risks of general anesthesia are quite low, the risk may be higher if you or someone related to you has had previous adverse interaction to general anesthesia. Some EDS patients are also prone to anesthesia issues, such as requiring more anesthesia or ineffectiveness of local anesthetics. Therefore, it is important to inform your anesthesiologist of your pertinent medical history.[10]


    BONY REGROWTH

    Regrowth of the bone removed during decompression is a risk associated with the pediatric patient population, particularly patients under the age of 2. Surgeons have reported as much as a 50% incidence of bony regrowth in patients under the age of 5, and as much as 80% in patients under age 2. Regrowth of bone may result in the need for future surgery.[5]


    CRANIOCERVICAL INSTABILITY

    While Craniocervical Instability is not uncommon among those with connective tissue disorders, it is pretty rare in the general population. However, aggressive bone removal during decompression surgery can create an unstable craniocervical junction. It is important to discuss with your surgeon how much bone they plan to remove, and the risks and benefits of laminectomy, particularly if you also have a connective tissue disorder, which increases your risk for developing instability.


    CEREBELLAR SLUMPING (PTOSIS)

    Cerebellar slumping (aka cerebellar ptosis) occurs as a result of too much bone being removed around the foramen magnum that there is no longer enough bone to support the weight of the cerebellum. The brain slumps downward toward the spine, re-herniating the cerebellar tonsils, and often compressing the cerebellum itself against the back of the skull and brain stem. This can often result in worse symptoms than the patient had before decompression. Surgical techniques have been developed to revise the decompression and provide more support to the cerebellum.[11]


    OCCIPITAL NEURALGIA

    Occipital neuralgia is nerve pain, often accompanied by numbness and/or tingling, of the occipital nerve in the back of the head. It can be caused by compression of or damage to the occipital nerve. While the presence of a Chiari malformation itself can cause compression of the cranial nerves, including the occipital nerve, decompression surgery can also cause occipital neuralgia. This can be due to compression of the nerve from the use of retractors to hold apart musculature during surgery, or the build-up of scar tissue around the nerve. More conservative treatment of occipital neuralgia may include medications, such as lidocaine patches and medication that target nerve pain, physical therapy, cutaneous nerve stimulators, and nerve root blocks. Severe and persisting occipital neuralgia may require surgical decompression of the nerve or occipital neurectomy, surgical removal of the occipital nerve.[12]


    SCAR TISSUE AND ADHESIONS

    Like with occipital neuralgia and pseudomeningocele, the development of scar tissue and adhesions can cause symptoms to return or failure to relieve symptoms after a decompression surgery. Adhesions and scar tissue can develop wherever tissue is cut, including the dural graft, cauterized tonsils and the skin incision. Scar tissue and adhesion can inhibit or block CSF flow and often require revision surgery to remove the scar tissue. A careful selection of the graft material used for a duraplasty may reduce the risk of developing adhesions and scar tissue.[13] 


    DECOMPRESSION FAILURE

    While perhaps technically not a complication, the failure rate of decompression surgery to alleviate symptoms deserves a mention here. While proper complications can often result in the failure of a decompression to relieve symptoms, or in fact, may make them worse than before decompression, even complication-free decompressions surgeries have a high rate of failure, as much as 40%, depending upon the study. Some reasons for decompression failure in the absence of the above-listed complications include failure to diagnose and treat comorbid conditions that may be causing symptoms, an inadequate decompression (failure to create enough space by removing bone and performing a duraplasty), and some or all of the symptoms being due to another cause, such as migraines. In cases of an inadequate decompression, a more aggressive decompression revision surgery may provide relief. In cases where a comorbid condition exists, that condition must be diagnosed and treated. However, there are still a small percentage of patients who do not get relief, even with further decompression and other treatments. The reason for this is not clearly understood.[5]

     

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    References:

    1 Torpy, Janet M. “Postoperative Infections.” JAMA, American Medical Association, 23 June 2010, <www.jamanetwork.com/journals/jama/fullarticle/186132>.

    2 Ramachandran, Tarakad S. “Aseptic Meningitis Treatment & Management.” Aseptic Meningitis Treatment & Management: Approach Considerations, Medical Care, Prevention, 22 Aug. 2017, <www.emedicine.medscape.com/article/1169489-treatment>.

    3 “Meningitis.” Meningitis | Brain & Spine Foundation, <www.brainandspine.org.uk/meningitis>.

    4 McDaniels, Edison. “Chiari Decompression Surgery.” Neurosurgery101-TheBlog, 3 Apr. 2013, <www.surgeonwriter.com/chiari-4/>.

    5 Trumble, Eric. “Chiari Overview & Surgical Issues.” Chiari and Syringomyelia Foundation, Chiari and Syringomyelia Foundation, 13 Oct. 2015, <www.csfinfo.org/videos/physician-lecture-videos/csf-lectures-archive/chiari-overview-surgical-issues/>.

    6 “Chiari Surgery.” Chiari Surgery | Mayfield Chiari Center, 10 Dec. 2017, <www.mayfieldchiaricenter.com/chiari_surgery.php>.

    8 “Pseudomeningocele Following Chiari Surgery Decreases Quality of Life.” CHIARI MEDICINE, 17 May 2015, <www.chiarimedicine.com/blog/2015/5/17/pseudomenigocele-following-chiari-surgery-decreases-quality-of-life>.

    9 Parker, S. L., et al. “Effect of Symptomatic Pseudomeningocele on Improvement in Pain, Disability, and Quality of Life Following Suboccipital Decompression for Adult Chiari Malformation Type I.” Journal of Neurosurgery., U.S. National Library of Medicine, Nov. 2013, <www.ncbi.nlm.nih.gov/pubmed/24010974>.

    10 “The Risks of Anesthesia and How to Prevent Them.” WebMD, WebMD, 2016, <www.webmd.com/a-to-z-guides/anesthesia-risks-what-patients-should-know>.

    11 “Surgical Technique Alleviates Cerebellar Slumping.” Cerebellar Slumping, 31 May 2007, <www.conquerchiari.org/articles/surgery/techniques/cerebellar-slumping.html>.

    12 Mueller, Diane. “Occipital Neuralgia and Chiari Malformation.” CHIARI MEDICINE, 4 Apr. 2013, <www.chiarimedicine.com/blog/2013/4/4/occipital-neuralgia-and-chiari-malformation>.

    13 Attenello, Frank J., et al. Suboccipital Decompression for Chiari I Malformation: Outcome Comparison of Duraplasty with Expanded Polytetrafluoroethylene Dural Substitute versus Pericranial Autograft. 4 Sept. 2008, <www.link.springer.com/article/10.1007/s00381-008-0700-y>.

  • Overview: Craniocervical Instability and Related Disorders

    Overview: Craniocervical Instability and Related Disorders

    Craniocervical Instability and related pathologies of the craniocervical junction are an important topic for anyone diagnosed with Chiari 1 malformation. “Complex Chiari,” or the presence of craniovertebral abnormalities or instability in addition to the presence of cerebellar tonsillar herniation, is present in approximately one fourth of all cases of Chiari 1 malformation[1]. These cases usually involve the presence of a genetic connective tissue disorder and are thought by experts to be the cause of most Chiari decompression failures[2]. When the doctor and patient alike are not knowledgeable about these conditions and the additional symptoms that often accompany them, these more complex cases are often treated with a standard decompression, which can actually weaken the stability of the craniocervical junction more, and result in an increase of symptoms rather than a clinical improvement. Understanding what signs and symptoms to look for that may indicate that your Chiari is more complex, is vital in receiving the appropriate treatment the first time. This is especially important considering that, according to Chiari expert Paolo Bolognese, M.D., “[with revision surgeries], the results are not as good as if you had done the posterior decompression well the first time.”[3]

    Punjabi and White define instability as the “loss of the ability of the spine under physiological loads to maintain relationships between vertebrae in such a way that there is no damage or subsequent irritation of the spinal cord, (brain stem) or nerve roots, and in addition that there is development of deformity or incapacitating pain due to structural changes.”[4] This means that the ligaments and muscles that normally hold the spine together, are too weak or damaged to handle the normal range of motion and weight of anatomic structures. For example, in Craniocervical Instability, the neck is not strong enough to support the normal weight of the head, without elements of the spine moving in such a way that it causes pain or damage to the nervous system (spinal cord, brain stem, and even cranial nerves). The result is that the bones that make up the lower skull and upper spine get pushed out of their normal anatomic location and begin to impinge on or cause stretching of these parts of the nervous system.

    Craniocervical Instability can result from or be exacerbated by a trauma, such as a severe whiplash injury. However, many cases of CCI are associated with some sort of connective tissue disorder, such as a heritable disorder of connective tissue (HDCT, like Ehlers-Danlos Syndrome or Marfan’s), or an autoimmune condition that affects the connective tissue (such as Rheumatoid Arthritis), or a few other rarer conditions that affect the integrity of bony structures in the skull and spine. Instability can result either from lax ligaments and other connective tissues, soft bones (also seen in HDCTs) or from something like pannus formation, where repeated rubbing together of the joints causes a build-up of granulated tissue around bony structures and changes the way certain bones lie in relationship to one another[5]. Craniocervical Instability can also result as a complication of Chiari decompression surgery, when too much bone is removed from the skull, resulting in the instability of the skull on the top of the spine[6].

    In the patient community, the term “CCI” is often used in reference to both Craniocervical Instability and Atlantoaxial Instability (AAI). CCI is often used to refer to the commonly seen combination of issues with the craniocervical junction, that include the instability of the joints where the skull meets the C1 vertebrae (which is true CCI), the instability of the joints between C1 and C2 (true AAI), a retroflexed odontoid, pannus formation, and a kyphotic clivo-axial angle (which are all forms of basilar impression/invagination). But CCI really should refer to the movement of the skull with respect to the spine. This sliding is referred to as “translation” and is measured on dynamic imaging in millimeters. The pathological threshold for the degree of translation of the basion with respect to the odontoid process between flexion and extension is 2mm, and any amount of translation greater than 1mm is capable of producing symptoms7. Likewise, at the C1-C2 joint, instability in the form of AAI can cause an excessive uncovering of the joint facets. Facets are the surfaces of the vertebrae that articulate with next vertebra. An uncovering of the facets that exceeds 20% is considered pathological.

    The occipito-atlantic joint allows for about half of the cervical spine’s ability to flex and extend (tilt forward and backward). Likewise, the atlantoaxial joint [the articulation between C1 (atlas) and C2 (axis)] accounts for about half of the cervical spine’s ability to rotate the head. Because of this, these vertebrae lack the same amount of stability as the remainder of the spine, and ligaments are largely responsible for their stability[8]. Therefore, ligamentous laxity, as seen in connective tissue disorders, make these areas of the spine particularly prone to pathologic instability. Symptoms of AAI may include visual changes, syncope (fainting) or near-syncopal episodes, dizziness, nausea, facial pain, difficulty swallowing, choking, respiratory issues, and upper cervical tenderness. These symptoms will usually improve with the use of a neck brace[9]. For patients with connective tissue disorders, as are seen in 12-20% of patients diagnosed with Chiari, dynamic imaging is very important in identifying potential instability. The ideal tests to diagnose CCI and AAI are an upright MRI with flexion and extension and a 3D CT with rotational views, respectively[10]. It is important to note that ventral brain stem compression may not be seen on traditional supine MR imaging, while it may be very evident on dynamic imaging.

    Basilar Invagination and Basilar Impression are also often seen with instability. They are almost identical to one another, and refer to upward displacement of the bones of the spine. However, technically, Basilar Invagination is caused by this deformation with normal bone, while Basilar Impression results from softening of bone[11]. For our purposes, this distinction is less important, but we will discuss any displacement in terms of “Basilar Invagination,” or “BI” for short. Forms of Basilar Invagination now include the prolapse of the odontoid process through the foramen magnum (the original condition described by the term), cranial settling, a kyphotic clivo-axial angle, and a retroflexed odontoid[12]. The kyphotic clivo-axial angle is an important and relatively easy measurement to indicate potential deformative stress on the brain stem. The clivus is a wedge-shaped bone that normally lies above and ventral to the top of spine. When it lies more horizontally, it creates a sharp angle that results in a bending of the brainstem. The odontoid peg (also called the odontoid process or the dens) is the part of the C2 vertebrae, or Axis, that the skull pivots upon, so named because of its tooth-like shape. A retroflexed odontoid occurs when the odontoid is bent backwards, often compressing the front of the brain stem. Other important measurements involving ventral brain stem compression for a kyphotic clivo-axial angle and/or retroflexed odontoid include the Grabb-Oakes and Harris measurements.

    • The clivoaxial angle is measured by drawing a line along the posterior (back, or when lying more horizontal, the top) side of the lower clivus and intersecting that line with a line drawn on the posterior side of the axis.  If the angle created is less than 135°, it is considered pathological.  Like instability, a kyphotic clivoaxial angle is often seen in patients with connective tissue disorders and degenerative rheumatoid disease[13].  See figure 1 below.
    Left – Clivoaxial Angle (CXA). Right – Grabb-Oakes measurement.

    For the Grabb-Oakes measurement, a line is drawn from the basion (the midpoint of the anterior margin of the foramen magnum) to the inferior posterior C2. A perpendicular line is then drawn from the center of this line to the dura of the brain stem. A Grabb-Oakes measurement greater than 9 mm denotes a form of basilar invagination. This is a very helpful measurement for determining how much a retroflexed odontoid is compressing the brain stem. See Figure 2 above.

    The Harris measurement is the distance between the basion and the Posterior Axial Line. This distance should not be more than 12 mm. A measurement of more than 12 mm also denotes instability. This measurement can also be used to measure the translation between flexion and extension in dynamic imaging[14]. See Figure 3.

    Harris measurement

    Symptoms of ventral brain stem compression can occur with various types of BI and instability. They may be referred to together as a “cervicomedullary syndrome” and may include[15]:

    • A heavy headache (often referred to as feeling like a “bobblehead” or feeling like the head is a “bowling ball”)
    • A Chiari-type pressure headache aggravated by Valsalva maneuvers (because these conditions, like Chiari, can also cause flow issues)
    • Dysautonomia (including tachycardia, heat intolerance, orthostatic intolerance, syncope (fainting), polydipsia (extreme thirst), delayed gastric emptying, chronic fatigue)
    • Neck pain (often severe)
    • Central or mixed sleep apnea
    • Facial pain or numbness – Occasionally, including Trigeminal Neuralgia
    • Balance and coordination impairment
    • Muscle weakness
    • Dizziness and vertigo
    • Vision problems, including double vision and downward nystagmus
    • Reduced gag reflex and dysphagia (difficulty swallowing)
    • Tinnitus (ringing in the ears) and hearing loss
    • Nausea and vomiting
    • Paralysis
    • In more severe cases, non-epiform seizures have also been documented

    In addition to producing significant pain and neurological symptoms, the compression and kinking of the brain stem can cause significant injury to the brain stem neurons by stretching the axons of the nerves to the point that they break and recoil, producing what are called “axon retraction bulbs” that can be seen on microscopic examination of the cells. The stress placed on the brain stem by both compressing and stretching simultaneously is much greater than the mere sum of these two mechanisms. Interestingly, during the flexion of the normal spine, it stretches 17% of its length. Research has shown that the axon of a giant squid fails when stretched to 20% if its length. Therefore, the normal motion of the human neck brings us very close to injuring our brain stem. Consequently, it only takes a slight alteration of our normal anatomy to cause injury to these delicate nervous tissues[16].

    Treatment of Craniocervical Instability typically begins with more conservative medical management, such as neck bracing, activity limitation, physical therapy (including isometrics, sagittal balance, core strengthening and cardio), and pain management. Other causes of symptoms such as co-morbid conditions, multiple sclerosis, dystrophy, mitochondrial disorders, vitamin deficiencies and Lyme disease should be ruled out or treated. However, surgical intervention via a craniocervical fusion is indicated when the following criteria are met:

    Severe headache or neck pain >7/10
    AND cervicomedullary syndrome
    AND neurological deficits referable to the craniocervical junction
    AND radiological findings indicative of instability

    Surgeons and patients alike should consider surgery after medical management has been maximized and the patient has shown a positive response to neck bracing[10].

    Various specific surgical techniques are applied in craniocervical fusions. A more common technique is the open reduction and fusion stabilization procedure. This procedure involves stabilizing the head with screws, making an incision that exposes the occiput through C2, and fixing plates to the occiput which attach to the C1 and C2 (and sometimes C3) vertebrae with rods. A newer technique adapted by Dr. Paolo Bolognese is using a less invasive Chiari decompression surgery known as MIST (minimally invasive subpial tonsillectomy) along with a fusion using screws placed in the occipital condyles. Although the dura is opened to partially resect the tonsils, a duraplasty is not done. Advantages of this procedure include a smaller incision, smaller hardware, less bone removal, and a thicker bone for which to insert screws in the occiput. Risks of both methods include vertebral artery injury, and a slightly increased risk for segmental instability below the fusion, along with the standard risks of any surgical procedure, such as bleeding, infection, and complications from anesthesia. Both procedures demand the hands of a very skilled and experienced surgeon because vital structures lie in and around the area. Using condylar screws may increase the risk of injury to major vessels, particularly in the hands of a less experienced surgeon. An important cranial nerve also lies just deep to the occipital condyles, making precise screw placement extremely important. This may limit the procedure in becoming more widely used, but the resulting fusion may be stronger, despite the reduced amount of hardware[17].

    In the presence of a retroflexed odontoid, an open reduction, fusion and stabilization procedure may be enough to relieve ventral brain stem compression. However, in more severe cases, a further surgery called an odontoidectomy may be needed to remove the odontoid process. This surgery may be done through the mouth or the nose[18].

    Every Chiari patient should be aware of hereditary connective tissue disorders and the signs and symptoms of Craniocervical Instability and Basilar Invagination. Many neurosurgeons do not evaluate their patients for these conditions prior to performing Chiari decompression surgery, often resulting in the need for revision surgeries and poor results. Being an educated patient can help you ask the right questions and insist on the proper evaluation and testing to avoid the pitfalls that many other patients have faced.

    References:

    1 Bolognese, Paolo A, director. Surgical Techniques for Chiari Malformations. YouTube, American Syringomyelia Chiari Alliance Project, 16 Mar. 2015, <www.youtu.be/KfYmJnB6sPQ>.

    2 Bolognese, Paolo A. “Modern Classification and Subclassification of Chiari Malformations.”YouTube, American Syringomyelia Chiari Alliance Project, 16 Mar. 2015, <www.youtu.be/ZQ9ZmquN-M0>.

    3 Bolognese, Paolo A. “2016 ASAP CM/SM Conference – ‘Complex Posterior Fossa’ – Bolognese.” YouTube, American Syringomyelia Chiari Alliance Project, 7 Dec. 2016, <www.youtu.be/3jKH_DHadO8>.

    4 Augustus A. White III, Manohar M. Panjabi, et al. “Clinical Biomechanics of the Spine.” By Augustus A. White III, <www.leomed.at/listhoscan/white_90.pdf>

    5 The Pain Relief Foundation, The Pain Relief Foundation, <www.thepainrelieffoundation.com/craniocervical-instability/>.

    6 Bolognese, Paolo. Complex Posterior Fossa revisions. YouTube. December 7, 2016. <www.youtu.be/3jKH_DHadO8>.

    7 Menezes, Arnold H. “Craniovertebral Junction Anomalies: Diagnosis and Management.”Seminars in Pediatric Neurology, vol. 4, no. 3, Sept. 1997, <www.sempedneurjnl.com/article/S1071-9091(97)80038-1/fulltext>.

    8 Yang, Sun Y., et al. “A Review of the Diagnosis and Treatment of Atlantoaxial Dislocations.”Global Spine Journal, Georg Thieme Verlag KG, Aug. 2014, <www.ncbi.nlm.nih.gov/pmc/articles/PMC4111952/>.

    9 Henderson, Fraser C., et al. “Neurological and Spinal Manifestations of the Ehlers–Danlos Syndromes.” American Journal of Medical Genetics Part C: Seminars in Medical Genetics, <www.onlinelibrary.wiley.com/doi/10.1002/ajmg.c.31549/full>.

    10 Henderson, Sr. , Fraser C. “Neurological Management of Hereditary Disoders of Hypermobility Connective Tissue Disorders.” Ehlers-Danlos Society Annual Conference 2015. Ehlers-Danlos Society Annual Conference 2015, 14 Aug. 2015, Baltimore, <www.ehlers-danlos.com/2015-annual-conference-files/Henderson_0.pdf>.

    11 Hain, Timothy C. “Basilar Invagination, Basilar Impression and Atlantoaxial Subluxation.”Basilar Invagination, Basilar Impression and Atlantoaxial Subluxation, 19 Apr. 2013, <https://dizziness-and-balance.com/disorders/central/cerebellar/basilar_invagination.htm>.

    12 Kim, Louis J., et al. “JNS JOURNAL OF Neurosurgery OFFICIAL JOURNALS OF THE AANS since 1944.” Treatment of Basilar Invagination Associated with Chiari I Malformations in the Pediatric Population: Cervical Reduction and Posterior Occipitocervical Fusion | Journal of Neurosurgery: Pediatrics, Vol 101, No 2, Nov. 2004, <www.thejns.org/doi/abs/10.3171/ped.2004.101.2.0189?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed>.

    13 Henderson, Sr. , Fraser C. “Cranio-Cervical Instability in Patients with Hypermobility Connective Disorders.” OMICS International, OMICS International, 18 Apr. 2016, <www.omicsgroup.org/journals/craniocervical-instability-in-patients-with-hypermobility-connective-disorders-2165-7939-1000299.php?aid=71754#11>.

    14 Bono, C M, et al. “Measurement Techniques for Upper Cervical Spine Injuries: Consensus Statement of the Spine Trauma Study Group.” Spine., U.S. National Library of Medicine, 1 Mar. 2007, <www.ncbi.nlm.nih.gov/pubmed/17334296>.

    15 Henderson, Sr. , Fraser C. “Diagnosis and Treatment of Craniocervical Instability in the Chiari Patient.” Chiari and Syringomyelia Foundation Educational Lecture. 20 July 2011, Greater Metropolitan Washington Area, Greater Metropolitan Washington Area, <www.youtu.be/U33T8JFXvk0>.

    16 Henderson, F C, et al. “Neuropathology of the Brainstem and Spinal Cord in End Stage Rheumatoid Arthritis: Implications for Treatment.” Annals of the Rheumatic Diseases, U.S. National Library of Medicine, Sept. 1993, <www.ncbi.nlm.nih.gov/pmc/articles/PMC1005138/>.

    17 Bolognese, Paolo A. “Surgical Techniques for Chiari Malformations.” YouTube, American Syringomyelia Chiari Alliance Project, 16 Mar. 2015, <www.youtube.com/watch?v=KfYmJnB6sPQ>.

    18 Hwang, Steven W., et al. “C1–C2 Arthrodesis after Transoral Odontoidectomy and Suboccipital Craniectomy for Ventral Brain Stem Compression in Chiari I Patients.”European Spine Journal, Springer-Verlag, Sept. 2008, <www.ncbi.nlm.nih.gov/pmc/articles/PMC2527411/>.