Of the 32 patients with active intractable seizures, 27 had spastic cerebral palsy (CP) and 5 had epilepsy (EP), and all underwent chronic cerebellar stimulation (CCS) (amplitude 1–2 µC/cm2phase, rate 10–180 pps, duration of implantation 0.5–7 years, average 4.5 years). Grand mal seizures occurred in 23 patients (19 CP, 4 EP); with CCS 17 patients stopped, 4 had a reduction, 3 were unchanged. Petit mal occurred in 9 patients (8 CP, 1 EP); with CCS 4 patients ceased seizuring, 3 reduced and 2 were unchanged. Myoclonic seizures were present in 6 patients (5 CP, 1 EP); with CCS 1 patient stopped, 3 had a reduction while 2 patients were unaffected. Severe psychomotor seizuring affected 2 EP patients, 1 had a marked behavioral improvement and finally stopped seizuring for the past 9 months. Overall, CCS stopped 18 (57%) of the patients seizuring, reduced a further 9 (28%), with no effect in 5 patients (15%).