Institution: | 1Department of Neurosurgery, Jeju National University Hospital, Jeju National University College of Medicine, Jeju, Korea.;2Department of Neurosurgery, Soonchunhyang University Hospital Seoul, Soonchunhyang University College of Medicine, Seoul, Korea.;3Department of Neurosurgery and Neurology, University of Texas Medical School at Houston, Houston, TX, USA.;4Department of Neurosurgery, University of Texas Medical School at Houston, Houston, TX, USA. |