In March, 2010, the scientific Journal, Epilepsia, published results of the trial entitled Stimulation of the Anterior Nucleus of Thalamus for Epilepsy (SANTE), authored by Fisher and colleagues, with trial sponsorship from Medtronic®, Inc. The trial studied 110 people with partial seizures with or without secondary generalization, not responsive to at least three seizure medicines. At baseline, the average seizure frequency was 57 seizures per month, with a median seizure frequency about 20 per month. Under anesthesia, wires were implanted in a "pacemaker" structure deep in brain called thalamus. The wires were connected under the skin to a battery-powered programmable stimulator on the chest. For the first three months (after a three-month baseline), half of the patients were given 5 Volts stimulation and half 0 Volts (placebo). One subject initially had seizures triggered by each stimulation cycle, but this improved immediately when the voltage was reduced. Not counting that individual’s seizures, the median reduction of seizures compared to baseline was 40% in the stimulated group and 15% in the control group. Injuries from seizures and the seizure type designated by the patient as most severe were significantly improved by stimulation. Subjects who previously had not benefited from vagus nerve stimulation or epilepsy surgery still could show benefit from deep brain stimulation. After the three-month blinded phase, all stimulators were turned to 5 V, and both groups continued to improve over time. By two years of stimulation, seizures were reduced a median 56%, and for those reaching three years, a median of 68% (to 1/3rd baseline levels). Stimulation was generally well tolerated. There were no deaths attributable to stimulation, no symptomatic brain hemorrhages and no brain infections during the trial. There was a suggestion of increased depression or memory problems in some subjects, and a few subjects had seizures triggered at the immediate onset of stimulation, which improved with lowering voltage. The conclusion is that deep brain stimulation is a useful new therapy for some people whose seizures cannot be controlled by other means.

Robert S. Fisher, M.D., Ph.D.
Editor-in-Chief, epilepsy.com