[1] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Dept Neurol, Houston, TX 77030 USA
[2] Univ Calif Los Angeles, Dept Neurol, Los Angeles, CA 90024 USA
[3] Univ Calif Los Angeles, Comprehens Stroke Ctr, Los Angeles, CA USA
[4] Mem Hermann Hosp, Clin Innovat & Res Inst, Houston, TX USA
[5] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Dept Emergency Med, Houston, TX 77030 USA