1. School of Medicine, New York Medical College, Valhalla (A.J.D.).
2. Department of Neurosurgery (C.D.G., J.P., C.R.M., J.B.C., M.T., A.M., J.S., S.H., F.A.-M.), Westchester Medical Center, Valhalla, NY.
3. Department of Neurology (R.N., P.O., S.A.M., F.A.-M.), Westchester Medical Center, Valhalla, NY.
4. Department of Neurosurgery, University of New Mexico, Albuquerque (C.B.).
5. Department of Neurology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence (S.Y.).