Deep brain stimulation: a new approach to the treatment of epilepsy.

BACKGROUND: Deep brain stimulation, known to be effective in the treatment of movement disorders, is now attracting increasing interest in the treatment of other neurological and psychiatric diseases, particularly pain syndromes and epilepsy. It may be a new treatment option for intractable epilepsy.
METHODS: Selective literature review of human applications of deep brain stimulation in epilepsy presented together with the author's own experimental and clinical experience.
RESULTS: Conceptually, deep brain stimulation might be used to prevent the spread of epileptic discharges or to suppress their generation. Various target structures in the brain, including the thalamus, the subthalamic nucleus, and foci in the hippocampus and neocortex, are currently of interest and are being analyzed in multicenter clinical studies. In parallel, experimental models of epilepsy are being used to help determine the suitable stimulation parameters, e.g., frequency or type of stimulation. Recent clinical studies on stimulation of epileptic foci indicate a favorable ratio of efficacy to adverse effects in the treatment of temporal lobe epilepsy, although only a small number of patients have been so treated to date.
CONCLUSIONS: Large-scale studies involving stimulation of the thalamus and of cortical foci are now underway in the United States. On the basis of the favorable results of focus stimulation, a multicenter study in Europe is currently comparing the safety and efficacy of hippocampal stimulation to that of surgical treatments. These studies are expected to yield benchmark findings in the next few years that will determine the role deep brain stimulation will play in the treatment of epilepsy.