Abstract
BACKGROUND: Current implementations of direct brain stimulation for epilepsy in patients involve high-frequency (HFS) electrical current and targeting of grey matter. Studies have shown that low-frequency (LFS) fiber-tract stimulation may also prove effective. To compare the efficacy of high-frequency grey matter stimulation to the low-frequency fiber tract stimulation technique a well-controlled set of experiments using a single animal model of epilepsy is needed. OBJECTIVE: The goal of this study was to determine the relative efficacy of different direct brain stimulation techniques for suppressing seizures using an acute rat model of focal cortical seizures. METHODS: 4-AP was injected into the S1 region of cortex in rodents over 3 h. LFPs were recorded from the seizure focus and mirror focus to monitor seizure frequency during the experiments. CC-LFS, HFS-ANT, Focal-HFS, or a transection of the CC was applied. RESULTS: Stimulation of the CC yielded a 65% ±14% (p = 0.0014) reduction of seizures in the focus and a 97% ±15% (p = 0.0026) reduction in the mirror focus (n = 7). By comparison transection of the CC produced a 65% ±18% reduction in the focus and a non-statistically significant reduction of 57% ±18% (p = 0.1381) in the mirror focus (n = 5). All other methods of stimulation failed to have a statistically significant effect on seizure suppression. CONCLUSIONS: LFS of the CC is the only method of stimulation to significantly reduce seizure frequency in this model of focal cortical seizures. These results support the hypothesis that LFSof fiber tracts has significant potential for seizure control.