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FROM: Medscape: http://www.medscape.com/viewarticle/496796 Motor Cortex Surface Stimulation May Reverse Parkinsonian Symptoms By Anne Harding NEW YORK (Reuters Health) Jan 03 - The results of a new study in baboons suggest epidural stimulation of the motor cortex could offer a simpler, safer alternative to deep brain stimulation for treating Parkinson's disease symptoms. Delivering electrical stimulation to the internal globus pallidus or the subthalamic nucleus has proven therapeutic value for the disease, Dr. Stephane Palfi of the Henri Mondor Hospital in Creteil, France, and colleagues note, but the skill required to implant the electrodes deep in the brain, as well as the risks of electrode misplacement, have limited the procedure's use. Abnormal synchronized oscillation of neurons in the primary motor cortex has been tied to parkinsonian symptoms, the researchers point out. They conducted the current study to determine whether stimulating the primary motor cortex at the surface of the brain might reduce these symptoms "with fewer technical constraints." The researchers implanted a four-contact electrode along the left primary motor cortex in baboons with chemically induced parkinsonian symptoms to deliver high-frequency, low-voltage stimulation. During stimulation, the baboons with moderate to severe disability showed a significant improvement in akinesia and bradykinesia. There were no adverse effects seen in any of the animals. PET scans found increased activity in cerebral regions involved in cortical motor control during stimulation, while electrophysiological studies showed a reduction in abnormally high firing rates of output neurons in the globus pallidus and subthalamic nucleus. Postmortem tests found no evidence of cell loss or inflammation in the stimulated areas of the brain. "Motor cortex stimulation is a simple and safe procedure to modulate subthalmo-pallido-cortical loop and alleviate parkinsonian symptoms without requiring deep brain stereotactic surgery," the researchers conclude in their report in the December 2nd issue of Neuron. The next steps in the research will be phase I and phase II clinical trials, Dr. Palfi told Reuters Health. Such trials should provide much more information on the mechanisms through which brain stimulation exerts its effects, he said. Neuron 2004;44:769-778. ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn