Epilepsy and intracranial meningiomas.

BACKGROUND: Only a few studies have reflected the incidence and causes of preoperative and postoperative seizures in meningiomas. This study concerned the incidence and types of preoperative epilepsy, and the predisposing factors for postoperative epilepsy in meningiomas.

METHODS: Epilepsy occurred in 323 surgically treated intracranial meningiomas. The focus here is different types of seizures, tumor locations, onset of seizures and the histopathological features of the meningiomas.

RESULTS: From analysis of 323 patients with intracranial meningiomas, aged 10 to 79, 98 (30.3%) were found to have different types of preoperative epilepsy; in 32 (32.7%) of them, the seizures persisted postoperatively. Among 225 patients without preoperative seizures, 39 (17.3%) developed postoperative seizures. Thus, a history of preoperative seizures is a significant index (p < 0.005) for predicting the occurrence of postoperative seizures. In a total of 71 patients with postoperative seizures, the precipitating factors in the first week were cerebral edema and hemorrhage at the surgical sites. In late postoperative seizures (onset beyond one week post-surgery), the main cause was tumor recurrence. Patients with sagittal and convexity meningiomas had a higher incidence of seizures. There is no relationship between the histopathological features of the tumor and the occurrence of epilepsy in meningiomas.

CONCLUSIONS: There is a significant incidence of postoperative seizures in meningioma patients with a history of preoperative seizures. Surgical excision of tumor, absence of postoperative hemorrhage or edema and anticonvulsant therapy reduced the occurrence of postoperative seizures.