Last March, I wrote about a Canadian study demonstrating that deep brain stimulation delivered by a device similar to a pacemaker can reawaken the circuits in the brain that lay down memory. This mechanical intervention seems to improve memory in those with early stage Alzheimer’s. People in the clinical trial had two electrodes implanted in the brain, which are connected to a battery implanted in the chest area. The brain is stimulated by these electrical impulses, sparking the memory center into activity. The study found that patients with mild forms of Alzheimer’s showed sustained increases in glucose metabolism, an indicator of neuronal activity, over a 13-month period. Most Alzheimer’s disease patients show decreases in glucose metabolism over the same period.
At the time, the FDA had given approval for Johns Hopkins Hospital to conduct a study larger than the one done in Canada. This November, the first U.S. patient in the new trial underwent surgery at Johns Hopkins, and a second patient is scheduled for the same procedure this month. The surgeries at Johns Hopkins are being performed by neurosurgeon William S. Anderson, M.D.
In this first surgery, Anderson implanted the pacemaker-like device into the area of the brain affected by Alzheimer’s disease, providing deep brain stimulation. The stimulator has already been used in thousands of people with Parkinson’s disease with good effect, though for Parkinson’s disease it is implanted into the specific area of the brain affected by that disease. What’s new is the realization that any number of diseases originating from the brain can be helped with deep brain stimulation by placing the stimulator in a specific area. Other researchers are testing deep brain stimulation to control seizures, depression and obsessive-compulsive disorder resistant to other therapies.
Paul B. Rosenberg, M.D., an associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and site director of the trial’s Johns Hopkins location was quoted as saying, "Recent failures in Alzheimer’s disease trials using drugs such as those designed to reduce the buildup of beta amyloid plaques in the brain have sharpened the need for alternative strategies. This is a very different approach, whereby we are trying to enhance the function of the brain mechanically. It’s a whole new avenue for potential treatment for a disease becoming all the more common with the aging of the population."
The study is supported by the National Institutes of Health’s National Institute on Aging. Other sites performing the FDA approved operations are the University of Toronto, the University of Pennsylvania, the University of Florida, and Banner Health System in Phoenix, Ariz. The medical device company, Functional Neuromodulation Ltd., is also supporting the trial. For this trial, all of the patients will receive the implants. Half of the patients will have their stimulators turned on two weeks after surgery, while the other half will have their stimulators turned on after one year. Neither the patients nor the doctors who treat them will know which group starts off with an active device.