Abstract: The purpose of this study was to determine the effect of surgical intervention of arachnoid cysts (ACs) on seizure outcome.The patients who has ACs with epilepsy treated in our hospital from Jan 1999 to Dec 2001 were reviewed .39 patients were reviewed.29 of the 39 patients were treated with operation (cyst removed or cyst-peritoneal shunt).In operating group 18 patients (72%) dealing with cysts removed were seizure free, 7 patients(28%) experienced seizure improvement.5 of 10 patients treated with anticonvulsant drugs (50%) remained unchanged, 5 of 10 patients improved.The successful outcome of the above cases suggests that removing cyst, fenestration, bipolar coagulation are likely to prove an effective method.

Key words: intracreanial arachnoid cyst, epilepsy, treatment