“…In the spinal canal, the increased collection of CSF may be in the extramedullary space (external syrinx), inside the spinal cord (syringomyelia) or both inside and outside the spinal cord. [15] An excessive amount of CSF is also present in the posterior cranial fossa, inside the brainstem (syringobulbia), anterior and around the brainstem (external syringobulbia) and around the cerebellum. [15] The cerebellum, more in its superior vermis and superior cerebellum, becomes atrophic allowing an increased collection of CSF.…”