Anticonvulsant Effects of Deep Brain Stimulation in Kindled Temporal Lobe Seizures
Abstract number :
4.109
Submission category :
Translational Research-Animal Models
Year :
2006
Submission ID :
6476
Source :
www.aesnet.org
Presentation date :
12/1/2006 12:00:00 AM
Published date :
Nov 30, 2006, 06:00 AM
Authors :
1,2,3Pamela A. Valentine, 1Elizabeth J. Jensen, and 2Lana J. Ozen
Deep brain stimulation (DBS) has a long history of therapeutic use in the treatment of a number of neurological disorders, perhaps most effectively for movement disorders such as Parkinson[apos]s disease. Neural stimulation may also provide a promising innovative technique for the treatment of pharmacoresistant seizure disorders. While there is experimental and clinical evidence that direct electrical stimulation of deep brain structures can prevent or decrease seizure activity, fundamental questions remain to be resolved including the identification of the most effective brain sites and stimulation parameters, long-term consequences and potential side effects. The mechanism underlying deep brain stimulation is as yet unknown, although it is thought that the application of high-frequency stimulation results in a net inhibitory effect that serves to desynchronize activity, effectively abolishing pathologically synchronized epileptiform activity. This may explain why stimulation of a number of structures have been shown to have anticonvulsant properties., In this study we examined the effect of high frequency stimulation (applied to a number of subcortical sites) on seizure thresholds of electrically kindled temporal lobe seizures. The DBS consisted of unipolar, biphasic square wave pulses, with pulse durations of 300 [micro]s, delivered at a frequency of 100 Hz and an intensity of 200 [micro]A. The DBS was applied 1 second prior to the application of the kindling stimulation to ensure effective activation prior to the seizure inducing stimulus. The seizure activity was scored with respect to the afterdischarge (AD) duration and seizure severity., Preliminary data revealed DBS applied to the entopeduncular nucleus resulted in a strong anticonvulsant effect on the seizure threshold and AD characteristics. We observed the increase in seizure threshold to occur over time which was observed to commence at about the 12th kindling session. The nominal progression in AD characteristics typically observed during kindling were largely absent, with the AD duration becoming shorter, the spike frequency lower and the spike complexity more simplistic., We conclude there may be strong anticonvulsant effects of DBS on temporal cortex seizures that are dependent on the site of stimulation., (Supported by Natural Sciences and Engineering Council of Canada (NSERC), Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary.)
Translational Research