High frequency deep brain stimulation in the hippocampus modifies seizure characteristics in kindled rats.
OBJECTIVE
This experimental animal study evaluates the effect of high frequency deep brain stimulation (HFS DBS) on seizures in the Alternate Day Rapid Kindling model for temporal lobe epilepsy (TLE). The target for HFS is the hippocampus, as this structure is often presumed to be the seizure focus in human TLE.


METHODS
Rats (n = 12) were fully kindled in the hippocampus according to the Alternate Day Rapid Kindling protocol. Characteristics of the evoked afterdischarges (AD) were determined in the baseline period using AD threshold, AD latency, and AD duration as parameters. Rats were divided into a treated group (n = 7) that received 130 Hz HFS for 1 week, and a control group (n = 5) that did not receive HFS. Rats were retested in the following week. After 1 additional week of rest, the HFS group was continuously stimulated again for 1 week, during which AD evoked by kindling stimuli were characterized again.


RESULTS
HFS had a direct effect on evoked AD: during HFS, it increased AD threshold to 203 +/- 13% of controls (p < 0.01) and increased AD latency to 191 +/- 19% (p < 0.05). It decreased AD duration to 71 +/- 9% (p < 0.05) of controls. The effect outlasted the HFS stimulation as in the week following HFS similar differences, but smaller in size, could still be established.


CONCLUSIONS
Continuous HFS (130 Hz) in the hippocampus of epileptic rats modulates the characteristics of evoked AD in a way that reflects a reduction in excitability of the target region.
Wyckhuys
Tine
T
Laboratory for Clinical and Experimental Neurophysiology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. Tine.Wyckhuys@UGent.be
De Smedt
Tim
T
Claeys
Pieter
P
Raedt
Robrecht
R
Waterschoot
Liesbeth
L
Vonck
Kristl
K
Van den Broecke
Caroline
C
Mabilde
Cyriel
C
Leybaert
Luc
L
Wadman
Wytse
W
Boon
Paul
P
D000818:Animals; D046690:Deep Brain Stimulation / Q000379:methods*; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000706:statistics & numerical data; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology / Q000517:prevention & control*; D005071:Evoked Potentials / Q000502:physiology; D006624:Hippocampus / Q000503:physiopathology*; D007696:Kindling, Neurologic / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000503:physiopathology* / Q000517:prevention & control