1. From the Stroke Clinic (C.C., F.B.) and the Departments of Genetics (E.A., A.J., L.M.), Neurochemistry (C.R.), and Radioimmunoassay (M.d.l.A.F., I.G.), Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez,” Mexico. C.C. is now appointed at the Stroke Clinic, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City. F.B. has moved to Hospital Angeles, Querétaro, Mexico.