CHIARI MALFORMATION-SYRINGOMYELIA AND TREATMENT

摘要

Chiari malformation refers to a decreased caudal fossa volume and caudal displacement of the cerebellar vermis into or through the foramen magnum (Fig.l). Debate as to the accuracy of the use of this human term in the canine has resulted in alternative terms in the veterinary literature, namely caudal occipital malformation syndrome (COMS), and occipital hypoplasia. Affected dogs have a small caudal fossa with a normal sized cerebellum and medulla, resulting in overcrowding of the caudal fossa. Indentation and protrusion/hemiation of the cerebellum, a kinked appearance to the medulla, and development of fibrous tissue through the craniocervical region, contributes to attenuation of the dorsal subarachnoid space and alteration of cerebrospinal (CSF)flow.