1. Department of Neurosurgery, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
2. Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
3. Department of Biological Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
4. Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
5. Department of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA