[1] Univ Cincinnati, Dept Neurol & Rehabil Med, Neurosci Inst, Acad Hlth Ctr, Cincinnati, OH 45267 USA
[2] Univ Cincinnati, Dept Radiol, Neurosci Inst, Acad Hlth Ctr, Cincinnati, OH 45267 USA
[3] Med Univ S Carolina, Dept Publ Hlth Sci, Charleston, SC USA
[4] NINDS, NIH, Bldg 36,Rm 4D04, Bethesda, MD 20892 USA