Effects of chronic cerebellar stimulation on chronic limbic seizures in monkeys.

No influences of chronic cerebellar stimulation were found in 10 different controlled experiments in 5 different monkeys with chronic alumina-induced psychomotor seizures. The stimulation parameters used were comparable to those used in human epileptics, and continuous daily EEG and behavioral monitoring allowed all seizures to be measured for daily frequency and duration over the several weeks of the experiments. Nocturnal seizures were similarly quantified in 3 monkeys to verify that cerebellar stimulation did not affect them. Motor cortex potentials evoked by cerebellar pulses confirmed that the stimulations were activating the cerebellum throughout the experiments, and measures of electrode access resistance and impedance verified that the electrodes remained in contact with the cerebellum. In one monkey given phenobarbital medication, interictal morbid behavior appeared to be improved by chronic stimulation of either cerebellum or dorsolateral frontal cortex, thus indicating an arousal influence of brain stimulation not due to cerebellum per se.