1. Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
2. Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; and Department of Neurology, Universitat Autonoma de Barcelona, Barcelona, Spain
3. Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
4. Department of Neurosurgery, Mount Sinai School of Medicine, New York, New York
5. Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; and Department of Neurosurgery, Holy Family Hospital, Catholic University of Korea Seoul, Korea