Giant arachnoid cyst in adult presented with secondary epileptiform activity.

Background: Current studies contain controversies regarding indications and preferable surgical techniques for arachnoid cysts.

Case Description: In this paper we present case report of giant arachnoid cyst of right frontal lobe in young left-handed adult with headache, MRI sings of brain compression and epileptiform activity on EEG, treated by microsurgical cystostomy.

Conclusion: We add a case of young adult with tension headaches and possible sub-clinical seizures due to arachnoid cyst, whose symptoms disappeared after surgical management of the cyst, including normalization of EEG.