[Syringomyelia associated with posterior fossa cyst: a case report].

We report a case of a 47-year-old woman with a posterior fossa cyst associated with syringomyelia and hydrocephalus. Her birth was traumatic and she had suffered a fractured skull. About 10 years prior to coming to our department she had occipitalgia and a pain had developed over a month from her right shoulder to hand. Shortly before presenting occasional electric-like shocks were felt in her right hand associated with coughing and hiccuping. Magnetic resonance imaging (MRI) revealed a large midline posterior fossa cyst, hydrocephalus and syrinx (C1-Th11). Cisternography could not demonstrate communication between the cyst and the subarachnoid space and the 4th ventricle was present but without communication with the cyst. The cyst was tentatively diagnosed as an arachnoid cyst. One week after placement of a cyst-peritoneal shunt, CT scans showed a decrease in cyst and ventricle size and 2 months later a follow-up MRI revealed resolution of the syringomyelia. We suspected that cyst-peritoneal shunt was effective for this patient who had syringomyelia associated with incommunicated posterior fossa cyst.