Chiari Zero [C0m]
An often unrecognized type of Chiari Malformation in which the cerebellum is blocking the foramen magnum, but not descended through it (no herniation). Because of its position, it is blocking the flow of cerebrospinal fluid.
BACKGROUND: In 1998 a study was done on 5 patients that had Syringomyelia (a condition in which a CSF filled cyst forms inside the spinal cord, further compromising the spinal cord itself), but no hindbrain herniation. The presence of the syrinx was indicative of something obstructing the flow of CSF (and four were symptomatic), but because of the lack of tonsillar ectopia, they were not considered Chiari Malformations.
- What they discovered was that the blockage of CSF alone causes problems, even serious ones like Syringomyelia.
- This finding alone demanded a re-evaluation of all they knew about Chiari and the size-based standard adopted for a Chiari 1 malformation.
OBSTACLES IN DIAGNOSIS/TREATMENT: This study and studies since have all been very small studies that do not fit the criteria for scientific methods. However, ignoring the presence of a syrinx or pretending that there might be another potential cause for its existence other than the obstruction of cerebrospinal fluid, is negligent at best; while the cause of Syringomyelia is not always a Chiari Malformation, all studies point to it being brought on by some sort of obstruction or disruption of spinal fluid. Many sites claim Chiari Zero as controversial, but the real problem is not that it is controversial, but that medical professionals do not know (or do not known enough) about it.
Treatment Options: See treatment options for Chiari 1 and Chiari 1.5.