[1] Univ Calif San Francisco, Dept Neurol Surg, 1001 Potrero Ave,Bldg 1,Room 101, San Francisco, CA 94110 USA
[2] Zuckerberg San Francisco Gen Hosp, Brain & Spinal Injury Ctr, San Francisco, CA 94110 USA
[3] Univ Calif San Diego, Dept Psychiat, San Diego, CA 92093 USA
[4] Univ Calif San Francisco, Dept Anesthesia & Perioperat Care, San Francisco, CA 94143 USA
[5] Univ Utah, Sch Med, Dept Neurol, Salt Lake City, UT 84112 USA
[6] Loyola Univ Chicago, Stritch Sch Med, Chicago, IL 60660 USA
[7] San Francisco VA Med Ctr, San Francisco, CA 94121 USA
[8] Univ Cincinnati, Dept Neurol Surg, Cincinnati, OH 45220 USA
[9] Univ Calif San Diego, Dept Family & Prevent Med, La Jolla, CA 92093 USA