Nonepileptic seizures after resective epilepsy surgery

PURPOSE: To identify factors that are associated with the emergence of nonepileptic seizures (NES) after resective epilepsy surgery. METHODS: Twenty-two patients with medically refractory epilepsy in whom NESs were documented by EEG after resective surgery were compared with a larger series of epilepsy surgery patients on demographic, neurologic, and psychiatric variables. RESULTS: NES tended to become apparent in the first few months after surgery. Patients who developed NESs did not differ from other epilepsy surgery patients in terms of age, IQ, or preoperative psychiatric diagnoses. However, surgical NES patients' neurologic problems and seizures began later in life, the NES group included a larger proportion of female subjects and patients with right hemisphere surgery, and NES patients were more likely to develop non-NES psychiatric problems after surgery. CONCLUSIONS: The heterogeneous collection of behaviors subsumed under the label NESs are determined by multiple factors. Several variables were found to be specifically associated with the development of NES after resective epilepsy surgery: A disproportionate number of postsurgical NES patients are female, they have primary neurologic dysfunction in the right hemisphere, and their epileptic seizures often began after adolescence. We propose that at least one group of patients with somatoform tendencies develop NESs as part of the psychiatric instability that occurs often in the few months after resective surgery.