1. From the Department of Neurology (J.J.D., R.L.R.), Case Western Reserve University, School of Medicine, Cleveland, Ohio; Research Service and FES Center of Excellence (J.J.D., K.R., J.M.R., K.B., J.G., J.M., E.F., E.B.M., R.L.R.), Cleveland Veterans Affairs Medical Center, Ohio; and Department of Mathematics and Statistics (J.H.), Cleveland State University, Ohio.