March 27, 2002 -- A new device promises to unclog the brains of people with Alzheimer's disease. It worked in a small study. Now it's jumped to a large-scale test.
Here's the theory. As people age, the spinal fluid that washes the brain flows less freely. If a person has Alzheimer's disease, the flow is twice as slow. The fluid gets stagnant and fills with toxic materials -- including the tangled fibers that clump into the plaque that clogs the brain of Alzheimer's patients. Increasing the flow is supposed to wash this goop away.
One way to do this is to install a drain in the brain. A Stanford University research team has invented a new shunting device that does just that.
It works great in mice. To see if it might work in people, the researchers enlisted 29 patients with mild to moderate Alzheimer's disease. By random selection, 15 of the patients got shunt implants and 14 did not. All continued on their regular Alzheimer's drugs. After a year, there was a big difference between the two groups.
"The kind of difference we saw was two to three times greater than has been shown in any of the trials for drug therapies the FDA later approved," Dawn McGuire, MD, tells WebMD. McGuire, a Stanford neurologist, is president and CEO of Eunoe Inc., the company formed to market the shunt.
The trial results -- reported last year at a neurosurgery conference -- showed that the shunt was pretty safe. Nobody had the life-threatening over-drainage of fluid seen in older shunts used to treat water on the brain. Only one patient had an infection because of the shunt, and that was successfully treated.
Best of all, the device seemed to be effective. More than a third of the patients who got the shunt had improved mental function. There was no improvement in any patient who didn't get a shunt. Not everyone with a shunt implant got better, but far fewer deteriorated. Deteriorating mental function was seen 60% of the control group but only in 27% of the shunt patients.
Neurologist Allan Levey, MD, PhD, is director of the Emory/Morehouse Alzheimer's Disease Center.
"One hopes that reducing [plaque] would improve function," Levey tells WebMD. "Ultimately that is the goal, but the first step is to arrest the relentless progression of Alzheimer's disease."
Exciting as they are, the early findings don't prove anything. That's why Eunoe is sponsoring a larger trial that will enroll 250 patients at some 25 U.S. medical centers. Emory is one of those centers.
"We are looking for people with typical Alzheimer's disease who are stabilized on their medications," Levey tells WebMD. "People have to understand this is a procedure that -- while safe -- has possible complications such as infection. Or the shunt might stop working. There are no promises: this is research. We don't know whether it will work or not."
The surgery to place the device -- called the CogniShunt -- is fairly quick. Patients usually leave the hospital the day after the shunt is installed.
"It is a small tube, like a thin straw placed into the brain," Levey says. "There is a small opening in the skull, and then the tube is placed under the skin of scalp and gets tunneled under the skin to the abdomen, where the fluid drains into the gut. It's a very routine surgery for neurosurgeons."
People interested in the study can call Eunoe Inc. at (888) 4-MYMIND.