Pallidotomy is a surgical procedure designed to rebalance the normal interplay of brain circuits that initiate and restrain voluntary movement. The procedure is now carried out with exquisite precision guided by advanced brain imaging and microelectrode recordings from single brain cells. An astounding new technology, chronic brain stimulation, involve electrodes implanted deep in the brain. Beyond relief of symptoms, chronic brain stimulation may even slow the progression of the disease. We must pursue this possibility and determine the long term consequences of these surgical procedures.
Stem cells offer an entirely new therapeutic approach.
Cell implantation offers hope for actually replacing nerve cells lost in Parkinson's and many other diseases. Clinical trials of fetal tissue transplantation, still underway, have developed methods for implanting cells into the brain, and demonstrated the viability of the concept and promising results for at least some patients. Now, neural stem cells, cells that have the capacity to renew themselves indefinitely and to specialize to form all cell types of the brain, offer a potentially unlimited supply of dopamine cells. Stem cell therapy has already produced dramatic success in animal models of Parkinson's and other neurological diseases. Beyond the impact on Parkinson's disease itself, Parkinson's research will certainly lead to insights about many other diseases in which nerve cells die.