[Surgical treatment for symptomatic arachnoid cysts]

During the period from 1983 to 1999, 12 patients with symptomatic arachnoid cyst were treated. The mean patient age was 20.6 years. The most common location was the middle fossa (10 cases). Initial CT scan revealed associated subdural hygroma in 7 patients and hydrocephalus in one. Clinical symptoms were related to increased intracranial pressure, cranio-megaly and seizure. One infant with a huge arachnoid cyst was treated, using a cystoperitoneal (CP) shunt. Four patients underwent membraectomy. Combination CP shunt and membraectomy was performed in 5 patients. The remaining 2 arachnoid cysts were complicated with subdural hygroma and, initially, they were observed conservatively, but hygroma gradually changed to hematoma. One was treated by irrigation and the other hematoma was spontaneously absorbed. Significant complications included extensive subdural effusion in one patient, contralateral chronic subdural hematoma in two, intracranial hypotension in two, and shunt dependency in one. There were no recurrences during the follow-up period (mean 3.6 years).