Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA. Electronic address: jacuoco@carilionclinic.org.Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA.Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA.Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA.Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA.Carilion Clinic, Section of Neurosurgery, Roanoke, Virginia, USA; Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Virginia Tech School of Neuroscience, Blacksburg, Virginia, USA; Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA.