Repetitive Transcranial Magnetic Stimulation (TMS) for Progressive Supranuclear Palsy and Corticobasal Degeneration

Drug therapy of atypical parkinsonism is generally considered either ineffective or minimal 1. Therefore, there is an urgent need to find alternative therapies to treat atypical parkinsonian disorders. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive tool that modulates cortical excitability with minimal discomfort and holds therapeutic promise in treating neurological and psychiatric disorders. The basal ganglia-thalamocortical circuits that are affected in Progressive Supranuclear Palsy (PSP) and Corticocbasal Ganglionic Degeneration (CBGD) are likely structurally and functionally segregated. The \'motor\' circuit is implicated in parkinsonian akinesia and hypokinesia; a \'prefrontal\' circuit is implicated in working memory and mood regulation, and linked with non-motor symptoms such as depression and apathy. In this proposal, we characterize motor and prefrontal network dysfunction in PSP and CBGD patients, and propose that high-frequency and low-frequency rTMS directed over separate motor and prefrontal cortical targets of each network may show specific and selective beneficial effects on motor vs. cognitive function in PSP and CBGD patients, respectively. Quantitative motor outcome measures include timed finger tapping tasks. Quantitative cognitive outcome measures comprise a visual analogue scale (VAS). If successful, this pilot study will provide proof of principle data to suggest potential benefits for rTMS in PSP/CBGD patients, and provide sufficient data and experience to support future PSP/CBGD studies that include the use of rTMS to investigate the pathophysiology of motor and non-motor features of PSP and CBGD patients.