1. Veterans' Administration Medical Center, New Orleans, Louisiana, U.S.A.
2. Clinical Director, NINDS, NIH, Building 10, Room 5N226, 10 Center Dr. MSC1428, Bethesda, MD 20892–1428, U.S.A.
3. Southern Illinois University School of Medicine, Division of Orthopedics and Rehabilitation, Springfield, Illinois, U.S.A.