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WEDNESDAY, Aug. 27, 2003 (HealthDayNews) -- The current form of fetal cell transplantation to treat people with Parkinson's disease is not effective and causes negative side effects such as involuntary movements.
So says a U.S. study in the current issue of the Annals of Neurology.
However, the researchers add their study's findings suggest that increasing the number of transplanted fetal cells may offer successful results for people with the disease.
Parkinson's is caused when certain brain cells that produce the chemical dopamine die. Current treatment primarily relies on replacing dopamine. This treatment is effective in the early stages of the disease. But it's limited by motor complications, the development of disease-related problems that don't respond to therapy, and disease progression.
Researchers hoped they could reverse Parkinson's by transplanting fetal brain cells to replace the dead dopamine-producing cells. Once transplanted, the fetal brain cells would start producing dopamine.
This new study found that more than 50 percent of people who had fetal brain cell transplants suffered a condition called dyskinesia, which causes potentially disabling involuntary movements.
Dyskenesia is a common side effect of medicines taken to treat Parkinson's. The condition usually subsides within a few hours after a patient stops taking medication.
But this study found that in people who had fetal cell transplants, dyskenesia persisted even when the people were off medication for days or weeks.
This study's findings are similar to earlier studies that examined fetal cell transplants for people with Parkinson's. But unlike the earlier research, this new study suggests that increasing the number of transplanted fetal cells may improve the chances of success.
"In previous studies investigators believed the abnormal movements were caused by the implanted cells producing excessive levels of dopamine," study lead author Dr. C. Warren Olanow, professor and chairman of neurology at Mount Sinai School of Medicine in New York City, says in a news release.
"Because patients were not improved, and had such devastating side effects, this led many researchers to believe that fetal cell transplantation and even stem cells hold little or no potential value as a treatment," Olanow says.
But after examining the data, he and his colleagues concluded that the dyskenesia was caused by the transplanted fetal cells producing too little dopamine.
"The importance of this interpretation is that it implies the possibility that improving transplantation protocols to enhance dopamine restoration in the brain might both improve Parkinsonian features and prevent the complicating involuntary movements," Olanow says.
"While this interpretation is speculative, we believe these results have important implications for the future of fetal and stem cell transplantation."
More information
Here's where you can learn more about Parkinson's disease.
