What are the problems/challenges of stem cells for Parkinson’s disease that are keeping it from becoming a major treatment?
There are significant problems with stem cells as a potential savior therapy for Parkinson’s disease. First, when you take a cell and make it divide you must be able to turn it on and off. If you cannot control growth of the cells, then they have the potential to form cancers. This limitation of stem cell therapy is an area that has drawn increasing attention from researchers and funding organizations, and pairing stem cell therapy with gene therapy for example may help to alleviate this issue. The other major issue with stem cell therapy is that it fails to address the complexity of Parkinson’s disease. Parkinson’s disease was long thought to be a simple loss of dopaminergic cells in an area of the midbrain called the substantia nigra. We are now aware that there is a much greater level of complexity to this disease and that multiple motor and non-motor circuits and regions (Alexander, DeLong et al. 1986; Alexander, Crutcher et al. 1990) throughout the brain area affected. Additionally, Parkinson’s disease may actually be multiple diseases with similar manifestations. This issue of multiple regions as well as the issue of addressing multiple motor and non-motor symptoms may prove limiting for stem cells or for any transplantation strategy. An important area of research therefore, will need to be investigation into “how to encourage stem cells” to repopulate and repair multiple brain circuits in many brain regions (Arias-Carrion, Freundlieb et al. 2007; Steindler 2007; Trzaska and Rameshwar 2007; Wang, Chen et al. 2007; Deuschl 2008; Svendsen 2008; Wijeyekoon and Barker 2008; Xi and Zhang 2008).
University of Florida Parkinson’s Treatment Tips blog written by Michael S. Okun, M.D., You can also read Dr. Okun’s book Ask the Doctor about Parkinson’s Disease (Demos Publishing).