1 Department of Neurosurgery, University of Wisconsin-Madison, 600 Highland Avenue, Box 8660, Madison, WI 53792, USA. Electronic address: lake@neurosurgery.wisc.edu.
2 Department of Neurological Surgery, Thomas Jefferson University Hospitals, 909 Walnut Street, Third Floor, Philadelphia, PA 19107, USA. Electronic address: ashwini.sharan@jefferson.edu.
3 Department of Neurological Surgery, Thomas Jefferson University Hospitals, 909 Walnut Street, Third Floor, Philadelphia, PA 19107, USA. Electronic address: chengyuan.wu@jefferson.edu.