[1] Yale Univ, Sch Med, Dept Internal Med, New Haven, CT 06510 USA
[2] Yale Univ, Sch Med, Dept Neurol, New Haven, CT 06510 USA
[3] Yale Univ, Sch Med, Robert Wood Johnson Clin Scholars Program, New Haven, CT 06510 USA
[4] VA Connecticut Healthcare Syst, Clin Epidemiol Res Ctr, West Haven, CT USA
[5] VA Connecticut Healthcare Syst, Med Serv, West Haven, CT USA
[6] VA Connecticut Healthcare Syst, Neurol Serv, West Haven, CT USA