William Walker, MD, is the Ernst & Helga Prosser Endowed Professor in PM&R/CERSE, and Associate Chair of Clinical Care, and Medical Director of Outpatient TBI Programs in the Department of PM&R, VCU School of Medicine. He is National Chair and Site PI for the LIMBIC-CENC National Multicenter Prospective Longitudinal study. Dr. Walker is site PI for the Virginia TBI Model System Form I and II study, and TBI Model System Collaborative study, Characterization and Treatment of Chronic Pain after Moderate to Severe TBI. Dr. Walker is Medical Director of VCU Health Concussion Care Clinic and Brain Injury Rehabilitation Services.