Stem Cells Show Promise in Treating Parkinson’s Disease

Two new studies suggest that stem cell therapy could offer a new way to treat Parkinson’s disease by replacing damaged brain cells. Scientists have worked for decades toward this goal, and the latest results are a hopeful step forward. Encouraging Early Results In one study, Dr. Lorenz Studer and his team at Memorial Sloan Kettering treated 12 patients with either a low or high dose of stem cells. Over 18 months, patients who received the higher dose improved by about 20 points on a standard Parkinson’s symptom scale — a major improvement, since the disease usually worsens over time. The low-dose group also improved, but less dramatically. Parallel Study in Japan A separate research team in Kyoto, Japan, gave stem cell transplants to seven patients, and they too saw their symptoms improve. In both studies, the transplanted cells started producing dopamine — the chemical that is lost in Parkinson’s disease and responsible for key symptoms like tremors, stiffness, and slow movement. Decades of Scientific Progress Dr. Studer explained that this breakthrough is the result of nearly 30 years of research. It took his team about 10 years to discover how to turn stem cells into dopamine-producing neurons, and another decade to refine the process and ensure the cells were safe for patient use. How the Treatment Works The therapy uses progenitor neurons — cells designed to mature into fully functional dopamine-producing brain cells. These cells are injected into a brain region responsible for movement control. The transplanted cells do not produce immediate results, as they need time to mature and connect with other brain cells. Brain scans later confirmed the cells were active and doing their job. A Potential New Approach to Treat Parkinson’s Dr. Viviane Tabar, another researcher on the team, believes this method could become a new way to treat Parkinson’s — not just by easing symptoms but by replacing lost neurons and helping repair brain circuits. Risks and Caution Despite the promising results, there are still concerns. Past attempts to replace brain cells have sometimes led to side effects like movement disorders or, in rare cases, cancer. Dr. Mya Schiess emphasized the need for long-term monitoring to watch for potential risks. Looking Ahead Stem cell therapy may offer real hope — especially for patients whose symptoms no longer respond to medication. A larger clinical trial, led by BlueRock Therapeutics, is planned to start later this year, moving the research closer to potential approval.