Epilepsy in patients with psychogenic non-epileptic seizures.

The aim of this study was to evaluate the frequency of epilepsy in patients who presented psychogenic non-epileptic seizures (PNES). The evaluation was carried out during intensive VEEG monitoring in a diagnostic center for epilepsy in a university hospital. The difficulties involved in reaching this diagnosis are discussed. Ninety-eight patients underwent intensive and prolonged video-electroencephalographic (VEEG) monitoring; out of these, a total of 28 patients presented PNES during monitoring. Epilepsy was defined as present when the patient presented epileptic seizures during VEEG monitoring or when, although not presenting epileptic seizures during monitoring, the patient presented unequivocal interictal epileptiform discharges. The frequency of epilepsy in patients with PNES was 50% (14 patients). Our findings suggest that the frequency of epilepsy in patients with PNES is much higher than that of previous studies, and point out the need, at least in some cases, for prolonging the evaluation of patients with PNES who have clinical histories indicating epilepsy.