1. Department of Neurology, Oregon Health and Science University, Portland, Oregon, United States
2. Department of Neurological Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, United States
3. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
4. Deparment of Neurological Surgery, New Jersey Medical School, Newark, New Jersey, United States
5. Department of Biostatistics, Kansas University Medical Center, Kansas City, Kansas, United States
6. Department of Radiology, Thomas Jefferson University Hospitals, Philadelphia, Pennsylvania, United States