Cerebellar Stimulation for Seizure Control: 17-Year Study

Abstract

Since 1974, 32 seizure patients have undergone chronic cerebellar stimulation (CCS); 27 have been contacted with 9 (7 spastic, 2 epileptic) continuing to use CCS for an average of 14.3 years (10–17 years). 6 (67%) are seizure-free and 3 (33%) have a reduction of seizure frequency. In the last 2 years, 2 other patients with spastic seizures, who were using CCS for 13 years, died of respiratory illness; 1 had been seizure-free and the other had a reduction. Of the remaining 16 patients (12 spastic, 4 epileptic) who did use CCS for an average of 8.3 years (2–14 years) and now have nonfunctioning stimulators, 5 (31%) continue to be seizure-free, 7 (44%) have a reduction and 4 (25%) have no change or a slight increase. Overall, 23 (85%) patients have benefitted from CCS. Stimulation charge densities were 0.9–2.5 µC/cm²/phase delivered at 10–180 pulses/sec to bilateral electrode pads on the superomedial cerebellar cortex. CCS is relatively safe and nonablative, and could be offered for patients with intractable seizures originating from bilateral or extratemporal foci.

Significance of Cerebellar Atrophy in Intractable Temporal Lobe Epilepsy: A Quantitative MRI Study

“…The reason for this difference may be the rigorous methods by which we measured cerebellar volumes and defied CA. After normalization for total brain volume, the prevalence of CA in our patients decreased to 16.2%. This finding suggests that in as many as a third of patients, with apparent CA, a proportionate degree of generalized cerebral atrophy is also present.…”

“…the cerebellar volumes, CA was present in 25.9% of the epilepsy patients; with normalization, it was present in only 16.2%. The atrophy was symmetric between the cerebellar hemispheres, and there was no significant difference in volume between the hemisphere ipsilateral and the hemisphere contralateral to the side of the temporal lobectomy.…”

Deep Brain Stimulation for Epilepsy

“…demonstrated that 23 of 32 patients (85%) benefited overall from long-term CS. 66 Controlled, double-blind trials, however, demonstrated improvement in only 2 of 14 patients (14%). 67,68 A recent double-blind trial of 5 patients demonstrated a significant reduction in generalized tonic-clonic seizures and tonic seizures at 2 years follow-up.…”

Deep brain stimulation for medically refractory epilepsy

“…One patient, whose epilepsy failed to respond to stimulation, died as a result of a seizure 17 months after electrode implantation. Davis and Emmonds 16 subsequently discovered that 23 of 27 evaluable patients who underwent long-term CS (average follow-up 14.3 years) had an overall reduction in seizure frequency. Interestingly, 12 of the patients had a nonfunctioning stimulator at the time of the report, yet 5 were found to be seizure-free, and 7 had experienced a reduction in seizure frequency.…”