The effect of electrical stimulation of the subthalamic nucleus on seizures is frequency dependent.
OBJECTIVE
Animal studies and anecdotal human case reports have indicated that the subthalamic nucleus (STN) may be a site of anticonvulsant action.


METHODS
We tested the hypothesis that continuous electrical stimulation of the STN inhibits seizures acutely. We determined the effects of three stimulation frequencies, 130 Hz, 260 Hz, and 800 Hz, on generalized clonic and tonic-clonic flurothyl seizures. Adult male rats were implanted with concentric bipolar stimulating electrodes in the STN bilaterally. After recovery, rats underwent flurothyl seizures to compare the effects of each stimulation frequency on seizure threshold. Rats were tested 4 times, twice in the stimulated condition, and twice in the unstimulated condition. The order of trials was random, except that stimulation trials alternated with control trials. Flurothyl seizure thresholds under each stimulation condition were compared with control values from the same animal.


RESULTS
Bilateral stimulation of the STN at 130 Hz produced a significant increase in the seizure threshold for clonic flurothyl seizures, whereas stimulation at 260 Hz did not appear to have any effect on seizures. STN stimulation at 800 Hz significantly lowered seizure threshold for tonic-clonic seizures.


CONCLUSIONS
We conclude that electrical stimulation of the STN can be anticonvulsant, but the effects appear to depend on the stimulation frequency and the type of seizure.
Lado
Fred A
FA
Department of Neurology, Comprehensive Epilepsy Management Center, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York 10461, U.S.A. flado@aecom.yu.edu
Velísek
Libor
L
Moshé
Solomon L
SL
D000818:Animals; D003292:Convulsants; D004292:Dominance, Cerebral / Q000502:physiology; D004599:Electric Stimulation Therapy / Q000379:methods*; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004829:Epilepsy, Generalized / Q000139:chemically induced / Q000503:physiopathology*; D004830:Epilepsy, Tonic-Clonic / Q000139:chemically induced / Q000503:physiopathology*; D005481:Flurothyl; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000503:physiopathology*
D003292:Convulsants; D005481:Flurothyl