Arachnoid cysts: computed tomography findings.

Described are 26 cases of arachnoid cysts. Of these cysts, 54% were in the sylvian cistern, three (1.2%) were in the suprasellar cistern, and the rest were over the cerebral sulci. There were symptoms of seizures at presentation in 30.8%, and in 23% there were symptoms of hydrocephalus and compression of the brain. A total of 61.5% presented with mental retardation and/or cerebral palsy. Trauma and infection accounted for 35% of these cysts. Associated porencephaly were present in five cases. There was a male preponderance. Left-sided lesions accounted for 61.5% of the lesions. The radiologic appearances, especially of suprasellar cysts, and the differential diagnoses of these lesions are discussed. Their recognition and the role of surgery are stressed.