1. Rehabilitation Medicine Department Clinical Center National Institutes of Health Bethesda MD USA
2. Office of the Clinical Director Intramural Research ProgramNational Institute of Neurological Disorders and StrokeNational Institutes of Health Bethesda MD USA
3. Biostatistics & Clinical Epidemiology Service Intramural Research ProgramClinical Center, National Institutes of Health Bethesda MD USA
4. Stanford University School of Medicine Stanford CA USA
5. Office of the Clinical Director National Human Genome Research InstituteNational Institutes of Health Bethesda MD USA