CSF is the fluid that fills the empty spaces around the brain and spinal cord. The body naturally produces, absorbs, drains and replenishes the fluid. But with age, the replenishing process slows. "Past research shows that toxic and inflammatory substances are found in the cerebrospinal fluid of Alzheimer's patients, which in turn, may lead to brain cell damage," says Allan Levey, M.D., Ph.D., professor of neurology, Emory University School of Medicine and principal investigator of the Emory study. "We hope the COGNIShunt will help to drain off some of those toxins and allow the CSF to better replenish itself."
Shunting has long been used as treatment for hydrocephalus, a condition in which an abnormal accumulation of CSF causes neurological problems, including dementia, problems walking and incontinence.
In the Emory study, surgeons will surgically implant the COGNIShunt into a normal cavity, or ventricle, in the brain. Then they will tunnel a tube through the neck and into the abdominal cavity for proper drainage. It is a relatively short and common procedure that usually requires a one-to two-day hospital stay.
The duration of the study, at Emory and 11 other sites, is 18 months. The first nine months of the study is double-blind placebo, meaning all participants will receive the shunt but the shunt will not be open, or working, in the placebo group. The second nine months of the trial is open-label, meaning participants in the placebo group can have their shunt revised to be opened, so it will work. Eunoe, Inc., the maker of the COGNIShunt, is funding this clinical trial to assess the effectiveness of the treatment and to test the hypothesis that the toxic and inflammatory factors in CSF contribute to the pathology of Alzheimer's disease.
An Alzheimer's researcher for 15 years, Dr. Levey points out, "Treatment methods vary greatly in other diseases, but with Alzheimer's, this is the first time more diverse, therapeutic options are being tested. We hope this surgical option will lead to dramatic benefits for these patients, and in the long run, open up even more avenues for surgical treatments. Surgical treatment options sometimes produce dramatic benefits and are rapidly gaining acceptance for related neurodegenerative disorders such as Parkinson's disease."
In a pilot study of the COGNIShunt, the device was well tolerated by individuals with mild to moderate Alzheimer's disease. As with most surgical procedures, there are some risks associated with implanting the device. The risks include infections, bleeding or a chance that the shunt or tube could stop working. But doctors hope to prove the benefits of this device will outweigh the risks.
Three other Emory doctors will serve as co-principal investigators of the study. They are Jim Lah, M.D., Ph.D., assistant professor of neurology, Nelson Oyesiku, M.D., associate professor of neurosurgery, and Larry Tune, M.D. professor of psychiatry and behavioral sciences.
Participants are being recruited for this study. Criteria include mild to moderate Alzheimer's disease with no other causes of dementia. Participants can remain on their prescribed medications throughout the trial. Participants must be between the ages of 62 and 85 and be in good, general health. To find out more about this study, call (404) 728-6453.