1Department of Neurosurgery, Warren Alpert Medical School of Brown University and Rhode Island Hospital Providence, Rhode Island, USA
2Division of Neuropathology and Department of Pathology, Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island, USA
3Department of Neurosurgery, Roger Williams Hospital, Providence, Rhode Island, USA
4Department of Neurosurgery, Lahey Clinic, Burlington, Massachusetts, USA