Grant: CIHR Fellowship

Non-invasive brain stimulation (NIBS) was developed with the intent to modulate brain activity in order to promote recovery of function. One particular technique, transcranial magnetic stimulation, has been shown to be efficacious in the treatment of major depression and is now approved by Health Canada. Even though over 1000 peer-reviewed articles exploring the effects of NIBS protocols have been published over the past decade, they have yet to be approved for treatment of other disorders of the nervous system, such as Parkinson's disease. Although a large number of studies have shown improvements of symptoms and function following NIBS suggesting great clinical potential, notable variability in the amplitude of the response to treatment between individuals is observed. Thus, there is a need to find ways to identify which individual will respond to treatment. However, the identification of any predictive measure of response is lacking. Moreover, there is inadequate information available on the stability of the response to stimulation between sessions in a single individual. A better understanding of the stability is essential since treatments are based on the assumption, although not tested yet, that a patient will show a stable response over multiple days. Using the three fundamental NIBS protocols in populations of healthy individuals and in Parkinson's patients, the objectives of this proposal are to 1) study within subject variability, and 2) explore for possible predictors of response. We also aim to identify shared predictors of response between both populations. This research is critical for the current development of clinical trials and would be key in the eventual process of seeking approval from Health Canada of these treatments for several disorders, particularly of Parkinson's disease. Results will provide practical insights into the clinical application of NIBS and would facilitate the optimization of stimulation protocols in several disorders.