Many are arguing about what a Chiari is and isn’t. Some say that a Chiari Malformation is nothing but a posterior fossa hypoplasia (small area in the back of the skull), and the tonsillar ectopia (herniated cerebellar tonsils) are just a symptom. Since a skull cannot be shrunken, it would make “Acquired Chiari” an impossibility.

Is this argument relevant? Perhaps, and perhaps it is just sidetracking us from the painful truth that there are many with other pathologies causing their herniation, and those pathologies are not being explored.

The fact remains that the diagnostic criteria for a Chiari Malformation ONLY consist of ONE measurement – how far the cerebellar tonsils herniate below the foramen magnum (the hole at the base of the skull). Most of us have NEVER had measurements of the posterior fossa taken when radiologists made the initial diagnoses. When we discuss the issue with our surgeons, they usually still never measure. Yet, without measurement, they tell us that our “Chiari” is congenital (which is old textbook information). We’re told that we can either try to continue to treat the symptoms, OR we can try the only means of fixing (or bypassing) the problem and halting the progression of symptoms by agreeing to a Posterior Fossa Decompression. We are taught to trust our professionals, and we’re usually so desperate for relief that we trust them and agree to surgery. They never look for (and often do not know about) etiological/pathological cofactors that could have been causing the tonsillar prolapse in the first place.

THAT is what we need to change!

For more information on Acquired Chiari Malformations, please see the following articles (available in over 90 languages):

https://chiaribridges.org/whats-in-a-name-chiari-malformation/

https://chiaribridges.org/overview-chiari-comorbidities-etiological-pathological-cofactors/