David Y Hwang1,2. 1. Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale School of Medicine, PO Box 208018, New Haven, CT, 06520, USA. david.hwang@yale.edu. 2. Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, New Haven, CT, USA. david.hwang@yale.edu.