Psychiatric classification of nonconversion nonepileptic seizures

To determine the frequency and type of non-conversion nonepileptic seizures (NES).

Although conversion disorder is the most common psychiatric disorder among patients with NES, many patients with nonepileptic paroxysmal behavioral events have other psychiatric disorders, with natural histories and treatments different from those of conversion disorder.

Retrospective review of a series of consecutive admissions for video-electroencephalography monitoring. All patients identified with NES were interviewed by a psychiatrist. Patients with conversion and other psychiatric disorders were divided into separate groups.

A comprehensive epilepsy center.

Twenty-one patients evaluated for possible epileptic seizures had a psychiatric disorder other than conversion that accounted for their events. Among these patients, Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) anxiety disorders (n = 9) were the most common diagnosed category, followed by all forms of psychotic disorders (n = 7) and impulse control problems in the setting of attention deficit disorder residual type (n = 2). In contrast to 71 patients with conversion NES seen over the same period of time, the non-conversion group showed no female predominance and the nonconversion patients were significantly less likely than the conversion patients to have been physically or sexually abused in childhood or adolescence.

These results support the validity of the nosologic distinction of nonconversion from conversion NES and suggest that DSM-III-R anxiety disorders are an important diagnostic confound in clinical epilepsy.