Currently, he is a clinical researcher and movement disorders neurologist treating patients with Parkinson's disease and related disorders. His research interest focuses upon Parkinson's disease, particularly on detecting early stages of disease, examining the impact of non-motor symptoms on disease subtype and prognosis, and testing new treatments for non-motor manifestations such as sleep disorders. He co-directs the National Residents Course in movement disorders, serves on the executive of the educational committee of the Movement Disorders Society, and (with Daniela Berg) is co-chair of the MDS task force on the definition of Parkinson’s.