[1] Univ Texas Hlth Sci Ctr Houston, Neurol, Houston, TX USA
[2] Univ Texas Hlth Sci Ctr Houston, Richmond, TX USA
[3] Columbia Univ, Neurol, New York, NY USA
[4] Univ Texas Hlth Sci Ctr Houston, Inst Stroke & Cerebrovasc Dis, Neurol, Houston, TX USA