Transplantation: Treatment of Parkinson’s Disease Essay -- Health Medi

Transplantation: Treatment of Parkinson’s Disease Parkinson’s disease (PD) is a slowly-progressive disease which ultimately robs its victims of voluntary motor control. The disease manifests itself as a series of symptoms which include "bradykinesia, rigidity, tremor, and impairment of postural reflexes (Fitzgerald, 1992:215)". It is a result of a loss of neurons in the substantia nigra pars compacta (SNpc). Chemotherapy, in the form of drugs such as levodopa and carbidopa, has been effective in alleviating many of the symptoms in the early stages of PD; however, with increasing losses in the number of cells in SNpc, such therapy becomes more and more ineffective. New therapies, using selegiline (deprenyl) and antioxidants (tocopherol or Vitamin E) focus on halting the progression of the disease by potentially salvaging surviving SNpc cells (Ahlskog, 1990). A more aggressive approach in the treatment of PD has surfaced in recent years. Researchers are experimenting with the prospects of transplanting tissue directly into the afflicted areas of the central nervous system (CNS) of PD patients. In both animal models of PD and humans, marginally successful transplants have been performed using adrenal chromaffin cells and fetal neurons. Genetically-altered, dopamine-producing tissues are currently being proposed as an alternative in transplant therapy of PD. As techniques become more refined, such "brain-grafting" may be the panacea for not only PD, but also for other debilitating diseases such as Huntington’s disease and Alzheimer’s disease. According to Fitzgerald (1992:215), the "cardinal pathological feature [of PD] is loss of neurons from the substantia nigra". Most of this loss occurs in the SNpc, of which approxima... ...zgerald, M. J. T. Neuroanatomy: Basic and Clinical. London: Bailliere Tindall, 1992. Freed, C. R. et.al. 1992. Improved drug responsiveness following fetal tissue implant for Parkinson’s disease. Neurochemistry International, 20: 321S-327S. Freed, C. R. et.al. 1990. Transplantation of human fetal dopamine cells for Parkinson’s disease. Fetal Human Transplant, 47:505-12. Freed, W. J. et.al. 1991. Brain grafts and Parkinson’s disease. Journal of Cellular Biochemistry, 45:261-7. Hurtig, H. et.al. 1989. Postmortem analysis of adrenal-medulla-to caudate autograft in a patient with Parkinson’s disease. Annals of Neurology, 25(6):607-13. Kordower, J. H. et.al. 1991. Putative chromaffin cell survival and enhanced host-derived TH-fiber innervation following a functional adrenal medulla autograft for Parkinson’s disease. Annals of Neurology, 29(4):405-12.