Implanted Brain Stimulator for Alzheimer's Tested
They hope the device will restore some thinking ability and improve focus, attention
WebMD News Archive
By Barbara Bronson Gray
THURSDAY, March 28 (HealthDay News) -- Researchers are testing whether applying electrical stimulation directly to the brains of people with Alzheimer's disease might improve thinking, focus and alertness.
The process, called direct brain stimulation, or deep brain stimulation (DBS), has been used to treat Parkinson's disease and is being tested as a treatment for other conditions, including traumatic brain injuries and obesity, according to the researchers.
Two women have had the electronic brain stimulators implanted, and eight more patients will participate in this initial research.
"There are a lot of studies out there that say physical or mental stimulation may reduce the risk or impact of Alzheimer's disease, so we wondered if increasing stimulation to certain parts of the brain may be protective," explained study co-author Dr. Douglas Scharre, director of the division of cognitive neurology at Ohio State University.
Scharre said that while Alzheimer's tends to affect the temporal, parietal and frontal lobes of the brain, he wanted to focus particularly on the frontal lobe for two reasons: it's typically the last brain area to degenerate, and its functions -- decision-making, problem-solving, focus and alertness -- are necessary for a person to be independent.
Placing the DBS system involves two steps. First, in a surgical procedure that requires about a three-day hospital stay, the patient has tiny holes made in each side of the skull, and hair-thin wires are placed in precise spots of the brain using computer-guided technology. The wires are fed through the neck -- in the subcutaneous tissue just under the skin -- and left there for about a week while the burr holes heal, explained Scharre.
Then, in an outpatient surgery, the patient has two battery packs that look like heart pacemakers placed on each side of the chest. The wires placed the week before are then connected to the batteries.
Six weeks after the second surgery, the stimulator is turned on. "My job [as the neurologist] is to find the right settings to get the maximum benefit," said Scharre. Each wire has four contacts, providing a wide range of different voltage combinations, and the challenge is to determine the right amount to produce the best benefit, he explained.
The research could potentially be of value to millions of Americans: a recent report from the Alzheimer's Association found that one in every three seniors now dies while suffering from Alzheimer's or another form of dementia. Alzheimer's disease becomes progressively disabling with loss of memory, thinking skills, the ability to socialize and independence.
To assess the effects of DBS, the researchers give short tests to the patients, starting about two months after the surgeries, to evaluate their level of attention and alertness, and to see how fast they can complete a particular task. For example, one test shows a variety of different geometric shapes all over the page, and [the patient] is asked to pick out all the stars in a 30-second timeframe.