The process of deep brain stimulation involves using a pacemaker-like implanted device to apply controlled mild electrical pulses to specific areas of the brain. In recent studies, it has been used – with some success – to treat conditions such as Parkinson's disease, major depression and Tourette syndrome. Now, in the ADvance Study, researchers at several research centers are exploring its use in restoring memory function to people with Alzheimer’s disease.
ADvance so far involves 20 test subjects in Canada and the U.S., all of whom are between 55 and 80 years of age, and have mild Alzheimer's. Five of those people have already received the implants at Toronto Western Hospital, with a sixth subject becoming the first American recipient last Thursday, at The Johns Hopkins Hospital in Baltimore.
The main part of each device is a neurostimulator, that is implanted under the skin in the chest. Two wires run from that unit and up the neck, under the scalp and through two holes in the skull, to a region of the brain known as the fornix. The fornix is involved in bringing information to the hippocampus, which is where memories are created, and where some of the earliest symptoms of Alzheimer’s are detected. Using this DBS-f (deep brain stimulation of the fornix) setup, tiny electrical impulses will applied to the fornix at a rate of 130 per second – the recipients will apparently not be able to feel them.
All of the test subjects will receive regular physiological, psychological and cognitive assessments, along with having brain imagery gathered, for a period of 12 months after receiving their implants. However, only half of those peoples’ devices will be turned on for that period. Neither the test subjects nor the researchers conducting the evaluations will know which people are in the “on” or “off” groups. After the one-year period, however, people in the “off” group will have the option of getting their device turned on for the remainder of the study.
The ADvance Study was initiated by Toronto-based medical tech company Functional Neuromodulation, Ltd., with the DBS-f implants supplied by project partner Medtronic. Along with Toronto Western and Johns Hopkins hospitals, other participating institutions include Banner Alzheimer's Institute in Phoenix, the University of Florida Center for Movement Disorders and Neurorestoration, and the University of Pennsylvania.
Additional test subjects are still needed – anyone who’s interested can learn more at the ADvance website.