Intracranial meningiomas and epilepsy: incidence, prognosis and influencing factors.

In a retrospective study of a consecutive series of 222 surgically treated meningiomas, it was found that 26.6% of the patients presented epilepsy as their initial symptom. In this group, surgical excision of the intracranial meningiomas stopped the epilepsy in about 62.7% of the patients. But approximately one-fifth of the patients with intracranial meningiomas and no history of preoperative epilepsy developed new onset postoperative seizures. Of the patients with early onset of postoperative epilepsy, epilepsy appeared in 66.7% within first 48 h after surgery. Of the patients with postoperative epilepsy, 71.2% were seizure-free following 1 year of anticonvulsant therapy. Regarding preoperative existing factors, intracranial meningiomas located at supratentorium, convexity, and with evidence of or severe peritumoral edema significantly contributed to preoperative epilepsy. And in patients with preoperative epilepsy, those tumors with evidence of or severe perifocal edema and cerebral edema at the operative site were significantly more likely to suffer from postoperative epilepsy.