Double‐blind, Randomized Controlled Pilot Study of Bilateral Cerebellar Stimulation for Treatment of Intractable Motor Seizures

• Published in: Epilepsia (Copenhagen) 2005-07, Vol.46 (7), p.1071-1081
• Main Authors: Velasco, Francisco, Carrillo‐Ruiz, José D., Brito, Francisco, Velasco, Marcos, Velasco, Ana Luisa, Marquez, Irma, Davis, Ross
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Animals; Anticonvulsants. Antiepileptics. Antiparkinson agents; Biological and medical sciences; Cerebellar stimulation; Cerebellum - physiology; Deep Brain Stimulation - instrumentation; Deep Brain Stimulation - methods; Double-Blind Method; Electrode complications; Electrodes, Implanted - adverse effects; Electroencephalography - statistics & numerical data; Epilepsy; Epilepsy, Partial, Motor - diagnosis; Epilepsy, Partial, Motor - therapy; Epilepsy, Tonic-Clonic - diagnosis; Epilepsy, Tonic-Clonic - therapy; Equipment Failure; Female; Follow-Up Studies; Functional Laterality - physiology; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Intractable motor seizures; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Neuropharmacology; Neurosurgery; Neurosurgical treatment; Pharmacology. Drug treatments; Pilot Projects; Skull, brain, vascular surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Treatment Outcome
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2005.70504.x

Purpose: The efficacy and safety of cerebellar stimulation (CS) was reevaluated in a double‐blind, randomized controlled pilot study on five patients with medically refractory motor seizures, and especially generalized tonic–clonic seizures. Methods: Bilateral modified four‐contact plate electrodes were placed on the cerebellar superomedial surface through two suboccipital burr holes. The implanted programmable, battery‐operated stimulator was adjusted to 2.0 μC/cm2/phase with the stimulator case as the anode; at this level, no patient experienced the stimulation. Patients served as their own controls, comparing their seizure frequency in preimplant basal phase (BL) of 3 months with the postimplant phases from 10 months to 4 years (average, eight epochs of 3 months each). During the month after implantation, the stimulators were not activated. The patient and the evaluator were blinded as to the next 3‐month epoch, as to whether stimulation was used. The patients were randomized into two groups: three with the stimulator ON and two with the stimulator OFF. After a 4‐month postimplantation period, all patients had their stimulator ON until the end of the study and beyond. Medication was maintained unchanged throughout the study. EEG paroxysmal discharges also were measured. Results: Generalized tonic–clonic seizures: in the initial 3‐month double‐blind phase, two patients were monitored with the stimulation OFF; no change was found in the mean seizure rate (patient 1, 100%, and patient 5, 85%; mean, 93%), whereas the three patients with the stimulation initially ON had a reduction of seizures to 33% (patient 2, 21%; patient 3, 46%; patient 4, 32%) with a statistically significant difference between OFF and ON phase of p = 0.023. All five patients then were stimulated and monitored. At the end of the next 6 months of stimulation, the five patients had a mean seizure rate of 41% (14–75%) of the BL. The second patient developed an infection in the implanted system, which had to be removed after 11 months of stimulation; the seizures were being reduced with stimulation to a mean of one per month from a mean of 4.7 per month (BL level) before stimulation. At the end of 24 months, three patients were monitored with stimulation, resulting in a further reduction of seizures to 24% (11–38%). Tonic seizures: four patients had these seizures, which at 24 months were reduced to 43% (10–76%). Follow‐up surgery was necessary in four patients because of infection in one p