Do skull base lesions and their surgical treatment cause epileptic seizures?

Objectives Few reports exist on the risk of seizures with skull base lesions and their surgical treatment. Patients and methods All patients referred for surgery of a skull base lesion at George Washington University Hospital from January 1998 to August 1999 were reviewed. After excluding patients with other risk factors 136 patients were included. Results No seizures were reported before or after surgery, but 59 patients (43%) were taking anticonvulsants. Only 17 (12.5%) had EEG. Four of these showed no abnormalities, 2 were abnormal without sharp waves and 11 had sharp waves (an increase compared to the general population). Most sharp waves affected the temporal lobe on the side of surgery. All EEGs were performed less than 4 months after surgery. Conclusion This study does not indicate that seizures are common in this patient group, but there was an increased amount of epileptiform activity on EEG and many patients were taking AED. A prospective study with systematic patient interviews, pre- and post-surgical EEG and a longer follow up is needed.