Cell Transplants Help Parkinson's
WebMD News Archive
April 17, 2002 -- Two different types of cell transplants and implants may help Parkinson's patients combat the symptoms of the disease. New research presented today at the annual meeting of the American Academy of Neurology shows the experimental treatments could provide lasting benefits to people who suffer from the debilitating condition.
One study found that embryonic cells transplanted into people with advanced Parkinson's can survive and continue to relieve symptoms for as long as eight years after the transplant. And the degree of relief provided by the transplant matches that found with levodopa, the most effective Parkinson's disease medication.
"The results were directly proportionate to the results people had with levodopa before the transplant," says study author Curt Freed, MD, of the University of Colorado School of Medicine in Denver, in a news release. "At best, the transplants could improve symptoms equal to the best response to levodopa previously."
But Freed says that also means patients who experienced involuntary, jerky movements as a side effect of the drug continued to have the same problems after the transplant.
The 32 patients in the study received transplants of embryo dopamine cells into the brain. Dopamine acts as a messenger between brain cells, and the brains of people with Parkinson's produce less and less of this chemical as the disease progresses.
Researchers say tests show that the transplants effectively increased dopamine activity in the part of the brain that received the transplants.
Earlier results from this study had shown improvements in younger patients alone. But now researchers say the improvements are not related to the individual's age, but to how well the individual had responded to levodopa before the transplant.
In fact, one of the patients worked in the World Trade Center in New York on Sept. 11, 2001. He walked down 33 flights, ran 5 blocks, and walked three miles to a train station.
Another study presented at the meeting shows early success with a new procedure in which cells taken from the back of the eye (retina) were implanted in the brains of six patients with advanced Parkinson's disease.
One year after the implant, researchers report that patients' muscle function has improved by nearly 50%.
This is the first human brain retinal cell implantation study in the world and "we are encouraged by the results," says study author Ray Watts, MD, of the Emory University School of Medicine, in news release.
Once implanted in the brain, researchers say the retinal cells serve as a new source of dopamine production in Parkinson's patients.
In the procedure, researchers used retinal cells from a human donor and replicated them in the lab. Those replicated cells were then attached to tiny gelatin beads that serve as microcarriers for the cells, allowing them to live in the brain and provide a continuous source of dopamine for the patient.
The cells were implanted into the side of the brain that was most affected by the disease using a guided needle, so researchers say there is little risk of infection or bleeding.
The implantation procedure is still experimental and has not been approved for general use by the FDA. Researchers are continuing their studies of the procedure.