Surgeons Implant Brain 'Pacemaker' for Alzheimer's Disease

Researchers at Johns Hopkins Medicine surgically implanted a pacemaker-like device into the brain of a patient in the early stages of Alzheimer's disease, the first such operation in the United States. 

The device, which provides deep brain stimulation and has been used in thousands of people with Parkinson's disease, is seen as a possible means of boosting memory and reversing cognitive decline.

As part of a preliminary safety study in 2010, the devices were 

implanted in six Alzheimer's disease patients in Canada. 

Researchers found that patients with mild forms of the disorder 

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.

The surgery is part of a federally funded, multicenter clinical trial 

marking a new direction in clinical research designed to slow or halt 

the ravages of the disease, which slowly robs its mostly elderly 

victims of a lifetime of memories and the ability to perform the 

simplest of daily tasks, researchers at Johns Hopkins say. Instead of 

focusing on drug treatments, many of which have failed in recent 

clinical trials, the research focuses on the use of the low-voltage 

electrical charges delivered directly to the brain. There is no cure 

for Alzheimer's disease.

The first U.S. patient in the new trial underwent surgery at The 

Johns Hopkins Hospital, and a second patient is scheduled for the 

same procedure in December. The surgeries at Johns Hopkins are 

being performed by neurosurgeon William S. Anderson, M.D.

Other sites performing the operation, supported by the National 

Institutes of Health's National Institute on Aging (R01AG042165), 

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.

"We are very excited about the possibilities of this potentially new 

way to treat Alzheimer's," says Lyketsos, director of the Johns 

Hopkins Memory and Alzheimer's Treatment Center in Baltimore.

While experimental for Alzheimer's patients, more than 80,000 

people with the neurodegenerative disorder Parkinson's disease 

have undergone the procedure over the past 15 years, with many 

reporting fewer tremors and requiring lower doses of medication 

afterward, Lyketsos says. Other researchers are testing deep brain 

stimulation to control depression and obsessive-compulsive disorder 

resistant to other therapies.

The surgery involves drilling holes into the skull to implant wires 

into the fornix on either side of the brain. The fornix is a brain 

pathway instrumental in bringing information to the hippocampus, 

the portion of the brain where learning begins and memories are 

made, and where the earliest symptoms of Alzheimer's appear to 

arise. The wires are attached to a pacemaker-like device, the 

"stimulator," which generates tiny electrical impulses into the brain 

130 times a second. The patients don't feel the current, Rosenberg 

says.

For the trial, all of the patients will be implanted with the devices. 

Half 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 treating them will know 

which group gets an early or later start.

"Deep brain stimulation might prove to be a useful mechanism for 

treating 

Alzheimer's disease, or it might help us develop less invasive 

treatments 

based on the same mechanism," Rosenberg says.

By 2050, the number of people age 65 and older with Alzheimer's 

disease may triple, experts say, from 5.2 million to a projected 11 

million to 16 million, unless effective treatments are found.