1. From the Department of Neurosurgery (S.-T.T., S.-Y.C.) and Department of Anesthesiology (T.-Y.C.), Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation/Tzu Chi University, Hualien, Taiwan; and the Institute of Medical Sciences (S.-T.T., S.-Y.C.), and the Department of Anatomy (G.-F.T.) and Department of Physiology and Master Program in Medical Physiology (C.-C.K.), School of Medicine, Tz