Sunday, May 5, 2013

Chiari Malformation

Today for Ehlers-Danlos awareness month I want to share about a condition many people with Ehlers-Danlos have. It is called Chiari malformation. I am still in the process of getting a final diagnosis for this but it's hard to nail down because the MRI doesn't always show Chiari. There is a category of Chiari malformation that is called Chiari zero. This diagnosis goes mainly by symptoms rather than MRI image. On an MRI it's hard to see Chiari because of the position you have to be in for the MRI. It's best if you can get a standing MRI. I definitely have the symptoms of Chiari and some days are a lot worse than others so I would fall in the category of Chiari zero. Chiari gives you a really bad headache and I have had a headache again some days worse than others but I've had a headache every single day for the past three years. This is just one of the many things that you have to deal with when you have Ehlers-Danlos syndrome. And you might be interested because not only people with Ehlers-Danlos suffer with this but anyone can have this.

Chiari Malformation
In the back of your brain, there are tonsils, called cerebellar tonsils, that can descend through the base of the skull (foramen magnum). If there is only a slight tonsillar protrusion thru the foramen magnum and the patient does not exhibit typical symptoms of Chiari, the patient may be diagnosed as having cerebellar tonsil ectopia – sometimes considered a milder form of Chiari malformation. A final clinical diagnosis is made only after a neurologic exam and detailed history is taken.

Chiari malformation is a congenital anomaly of the cerebellum and brainstem. Although four types have been described, types I and II are more common. Type I is identified by protrusion of cerebellar tonsils through the foramen magnum, down to the C1 or C2 level of the cervical spine. It may or may not be associated with syringomyelia/hydromyelia. Type II is the most common type of Chiari malformation, always associated with myelomeningocele. The remainder of this summary describes Chiari type I malformation.
Presentation usually begins in adulthood, from ages 20 to 50 years. The most common symptoms are a headache or neck pain, aggravated by coughing, sneezing or extension of the head and neck. Other symptoms may include imbalance or distorted vision. Less common are altered sensation or weakness of the arms and/or legs, which are typically associated with hydromyelia.
MRI scan of the brain and/or cervical spine is the diagnostic test of choice to confirm Chiari malformation. Hydromyelia/syringomyelia can also be identified by MRI scan. Various degrees of Chiari malformation or tonsillar ectopia can be identified on the MRI scan.
The only effective treatment for Chiari malformation is surgery. The most common surgical procedure is suboccipital craniectomy to decompress the cerebellar tonsils (surgical opening of the bony compartment of the back of the head) with laminectomy of C1 and/or C2 to decompress the cervical spinal cord. The opening of the dura (lining of the brain and spinal cord) with dural grafting to expand the cranial and upper cervical spine space completes the procedure. Sometimes the surgeon will elect to not open the dura. The procedure is performed under general anesthesia and usually lasts two to three hours.

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