“Thirty percent of patients with epilepsy continue to have seizures despite taking medications and other therapies. We are hoping, based on the results of this pilot study, that the Intercept Epilepsy Control System may eventually be shown to be of potential help to some of these patients,” said Nina Graves, Sr. Therapy Development Manager, today at the 58th annual American Epilepsy Society (AES) conference.

In 1998 a group of investigators began a collaboration on the design of studies to explore the effect of stimulation of the anterior nucleus of the thalamus (AN) in patients with uncontrolled seizures. Research subjects were implanted with programmable neurostimulators over the anterior chest wall, with bilateral implantation of the multi-contact electrodes into the AN. “The programmable neurostimulators are programmed through the skin similar to vagus nerve stimulation and the electrodes themselves are implanted in the thalamus. The neurostimulator is powered via a battery,” said Graves.

14 patients with intractable epilepsy ranging in age from 19-47 underwent implantation of the brain stimulator device. The patients were instructed to keep a seizure diary to monitor their seizure counts. Changes in seizure frequency were assessed relative to pre-implantation (baseline) seizure frequency. Their progress was followed for at least 12 months.

During the first 3 months of AN stimulation, the median seizure frequency reduction compared to baseline was 64% in the 14 patients. Eight of these patients had a 50% or greater decrease in seizure frequency (responders). Over the 12-month period, the median reduction in total seizure frequency was 56% with a responder rate of 57%.

“On the basis of these results as well as pre-clinical evidence of the possible efficacy of AN stimulation, we are proceeding on with a prospective, double-blind, placebo-controlled, parallel design safety and efficacy clinical trial,” said Graves. Graves points out that in the new study, each patient gets implanted with a device and one month later one group receives stimulation, while the other group does not. Both groups are then followed for three months at which point, everyone’s device gets “turned on” and each patient is followed in an “unblinded” fashion.

The abstract of the pilot study is published in Epilepsia 2004,Vol. 45, Supplement 7, p 148.