Psychological effects of short term cerebellar stimulation in epilepsy.

The effects of short term cerebellar stimulation on integrative functions as measured by standardized psychological tests were studied. The patient group consisted of 12 epilepsy patients undergoing chronic cerebellar stimulation as treatment for intractable seizures. Three comparison groups included nonstimulated epilepsy patients, stimulated cerebral palsy patients, and stimulated stroke patients. Cerebellar stimulation resulted in some alterations in test performance. Improvements occurred from first to second test administration for both stimulated and nonstimulated subjects, as a probable practice effect. Short term stimulation of the cerebellar cortex does not result in apparent deficits. However, significant improvement in verbal output and in visual-motor performance occurred for the stimulated epilepsy group along with a small decrement in sustained concentration in a numerical task. Preliminary hypotheses were offered to explain the results.