Non-communicating supratentorial subarachnoid cysts.

The clinical and radiological features and operative treatment of six patients with supratentorial subarachnoid cysts are reviewed. Five were adults aged 37 to 57 years and the other a male infant, aged 8 months. Three patients presented with epilepsy and hemiparesis, one with epilepsy without signs, another as Parkinsonian syndrome, and the infant with hydrocephalus. Diagnosis was revealed at operation in four cases, in one case by ventriculography, and in one case the lesion was strongly suspected on angiographic appearances. Surgical treatment is highly effective, since the cystic lesion is benign in nature, but recurrence of symptoms is not unusual and repeated evacuation of the cyst may be required. It is, therefore, considered essential to conduct a prolonged and careful follow-up.