1. From the Department of Neurosurgery, Regional Cardiocerebrovascular Center, Seoul National University Bundang Hospital, Seongnam, Korea (S.P.B., T.K., S.U.L., J.S.B., J.H.H., C.Y.K., O.K.K., C.W.O.); and Department of Neurosurgery, Hangang Sacred Heart Hospital, Hallym University, 12 Beodeunaru-ro 7-gil, Yeongdeungpo, Seoul 07247, Korea (G.H., H.S.B.).