Long-term hippocampal DBS effectively reduces seizures in experimental models

The results of the first reported study of deep brain stimulation (DBS) in an animal model for temporal lobe epilepsy (TLE) presented today at the American Epilepsy Society (AES) 66th Annual Meeting suggests that DBS may have potential as therapy for this common and often difficult to treat form of epilepsy. A team of investigators at Ghent University, Belgium, and the University of Amsterdam, Netherlands, found that long-term hippocampal DBS has a strong effect in reducing seizures in the experimental model.

Bregt Van Nieuwenhuyse, MSc, from the Laboratory for Clinical and Experimental Neurophysiology, Ghent University Hospital, and colleagues implanted three groups of animals with DBS electrodes in the right hippocampus and with EEG electrodes in the left hippocampus. Twenty-four hours after inducing seizures group one was given DBS therapy for one week, group two was stimulated for ten weeks, and the third or control group was not stimulated. (Platform A.04)

"We found that animals stimulated for ten weeks had significantly fewer seizures in week 14, compared to the other two groups whose seizures increased at relatively similar rates," says Van Nieuwenhuyse. " When DBS was stopped animals treated for ten weeks averaged four seizures per day and remained at that level to week 14, while seizures in the control group had increased to about 26 seizures per day during the same period."

Long-term DBS has been shown to have increasing efficacy over time in human trials involving stimulation of the anterior nucleus of thalamus, with some epilepsy patients becoming seizure free. Commenting on whether hippocampal DBS might have similar benefit for TLE patients, Van Nieuwenhuyse said, "Just as the efficacy of DBS of the anterior nucleus of thalamus improves over time, our results in animal models and long term follow-up (8.5years) of patients in a hippocampal DBS for TLE open label study also suggests that longer stimulation periods may herald higher efficacy. More and more it is shown that electrical stimulation of the brain exerts true neuromodulatory effects."

Future research will be aimed at trying to unravel how hippocampal DBS exerts its anti-convulsive and neuromodulatory effects. Neuromodulation through controlled stimulation of specific regions in the brain may provide an opportunity in the treatment of various neurological disorders.

Source: Ghent University