Pathogenetic role of myelitis for syringomyelia.

CSF-flow obstruction is regarded as a mandatory factor for the development of syringomyelia. However, there are conditions in which syringomyelia is not associated with evident persistent CSF-flow obstruction, as in the case of inflammatory spinal cord lesions. In these instances we hypothesize that the accumulation of vasogenic edema may play a role in the development of the syrinx. Recently proposed theories underline, even in the event of CSF-flow obstructions, a major role for the accumulation and final coalescence of interstitial spinal fluid, rather than CSF penetration through the spinal cord.