[1] W Virginia Univ, Sch Med, Dept Behav Med Psychiat, Morgantown, WV 26506 USA
[2] W Virginia Univ, Sch Med, Dept Neurol, Morgantown, WV 26506 USA
[3] W Virginia Univ, Sch Med, Dept Neurosurg, Morgantown, WV 26506 USA
[4] W Virginia Univ, Sch Med, Dept Radiol, Morgantown, WV 26506 USA
[5] Johns Hopkins Univ, Dept Radiol, Baltimore, MD 21205 USA