Stem cell transplants have raised hopes for those who have Parkinson's disease as well as their loved ones. Dopamine cells transplanted into the brains of Parkinson's patients seemed to give ease from the symptoms of the devastating degenerative disease. However, it now appears that such therapies may not bring long-term relief because of the ongoing nature of the disease, which continues to cause damage in the brains of sufferers.
Dopamine cells have been transplanted into the brains of patients with Parkinson's with the hope they might serve to replace degenerated neurons. The theory is that since Parkinson's disease is due to dopamine deficiency in certain areas of the brain, a transplant of dopamine cells would counteract the symptoms of the condition which include impaired coordination and balance, slowed movement, stiffness of the trunk and limbs, and in its most visible incarnation: tremors.
A research team comprised of scientists from Rush University Medical Center in Chicago and Mount Sinai School of Medicine in New York City analyzed the brain tissue from a patient who had received a dopamine cell transplant some 14 years earlier. The team found that the transplanted cells had come to take on changes associated with Parkinson's disease (PD) along with abnormal function. Researchers noted that after an initial improvement following the transplant, the patient's condition deteriorated. The findings of this study were published in the April 2008 issue of Nature Medicine.
The director of the Robert and John M. Bendheim Parkinson's Disease Center at Mount Sinai School of Medicine, Dr. C. Warren Olanow, believes the findings represent an obstacle that is not insurmountable but needs to be overcome. Olanow believes that stem cells can be used to create therapies for diseases like Parkinson's and that the results of this study, while disappointing, point the way to new directions in Parkinson's research. "The more knowledge we gain about the nature of the disease, the better our chances to find the cause of why cells degenerate and to develop a treatment that can protect them," says Olanow.
An important piece of information has been gleaned through the findings of this study. Before this time, it was believed that a single event, for instance, an infection, might be responsible for the early damage to cells that can trigger the degenerative disease. Due to the evidence that healthy, implanted cells in a Parkinson's patient also sustain damage, the idea that the disease manifests as an ongoing process has gained credibility.