Clinical symptoms in psychogenic seizures.

PURPOSE: To develop a classification system of psychogenic seizures based on characteristic clinical symptom clusters and sequences in order to facilitate the correct differential diagnosis of epileptic seizures. METHODS: We analysed the symptoms: clonic movements, hypermotor movements, trembling and tonic posturing of the upper/lower extremities, pelvic thrusting, stiffening of the body, version, side-to-side-head movements, non-versive head-turning and falling to the floor. We did this in a series of 16 patients with psychogenic seizures documented with prolonged video EEG monitoring. Nine patients (7 with frontal lobe epilepsy and 2 with primary generalised epilepsy with tonic, clonic seizures) served as a control group. RESULTS: We classified psychogenic seizures into 3 groups, namely (1) atonic psychogenic seizures, (2) psychogenic motor seizures and (3) psychogenic hypermotor seizures characterised by (1) falling to the ground, (2) trembling in the upper/lower extremities and (3) pelvic thrusting in combination with beating and kicking. While version exclusively occurred in epileptic seizures (incidence = 20%) and side-to-side head movements were only observed during psychogenic seizures (incidence = 8%), all other analysed symptoms were observed in both psychogenic and epileptic seizures. CONCLUSION: Our classification scheme should be useful in terms of permitting a more comprehensive clinical assessment of psychogenic seizures and their underlying psychiatric disorders. Furthermore, the differential diagnosis of psychogenic seizures should be considerably improved.