This project will use neuroimaging (7T MRI: structural, diffusion and rest-state functional MRI), from Dr. Noam Harel's protocol IRB# STUDY00008096, and non-invasive brain stimulation (TMS: PAS. SAI) techniques to quantify structural and functional changes in brain function. The TMS experiment will use a Magstim Bistimn 2002 transcranial magnetic stimulation (TMS) unit and standard figure-of-eight coil (70 mm diameter) to deliver stimulation on the surface of the scalp. Stimulation will be delivered using either a single pulse or with a paired-pulse protocol (two stimuli, through the same TMS coil at inter-stimulus intervals of 50 or 80 ms). All surface EMG signals will be pre-amplified within the sensor and sent wirelessly via blue-tooth connection to a Delsys data collection system. Quantitative assessments of motor function (gait, gait initiation, reactive balance, bradykinesia, repetitive alternating movements, rigidity, stop-signal reaction time), and neuropsychological function will used to assess behavioral status at baseline and 30-36 months later.
The purpose of this project is to increase our understanding of the early state and temporal evolution of neuroplastic changes in the cortex and subthalamic nucleus (STN) of people with PD, and the relationship of these changes to the emergence and expression of PD motor and non-motor signs. Neurophysiological biomarkers derived from this work may be important for the early detection and prediction of progression of disease. They can also provide the means to assess the efficacy of interventions designed to prevent or slow disease progression.