Characterizing the Effects of Repetive Transcranial Magnetic Stimulation Frequency and Intensity on Cortical Excitability and Physical Fatigue in Patients with Parkinson’s Disease


Jau-Shin Lou, M.D., Ph.D.
Oregon Health Sciences Unversity, Oregon


Neurophysiologic changes in the excitability of a specific brain area, the cortex, may cause the physical fatigue more common to PD patients than to age-matched control subjects. Very simply, the brain's motor circuit (that is still being understood) may be described by diagramming how each area either stimulates or inhibits the neighboring area. Too much of either behavior usually causes too much of the opposite behavior in area-to-area relationships. Dr. Jau-Shin Lou (Oregon Health Sciences Unversity, Portland) will test 33 patients and 33 control subjects to learn how cortical excitability changes brought about the diseased basal gangliae influence both physical and mental fatigue. The basal ganglia are the group of brain areas (including caudate nucleus, putamen, globus pallidus and substantia nigra) that primarily control movements such as walking and are defective in the brains of parkinsonian patients.

Progress Report (as of 3/2003)

Dr. Jau-Shin Lou is now at Oregon Health Sciences University (Portland), having been previously funded when training with Dr. Joseph Jankovic in Houston. He has used his latest funds to study silent periods (as opposed to periods of cortical excitement) in nine PD patients, in an attempt to modify this excitability using transcranial magnetic stimulation (rTMS). Stimulation in this instance means a smoothing-out of the activity of the cells leading to extensions of the patients’ silent periods. His data were sufficient to enable him to apply for funding from NIH that, having been granted, gave him the opportunity to explore the development of rTMS as a noninvasive therapy for the symptoms of PD, comparing its motor effects between patients and non-affected control subjects.