title: Intraoperative Subcortical Electrical Mapping of the Optic Tract in Awake Surgery Using a Virtual Reality Headset.
abstract: BACKGROUND
  Brain mapping during awake craniotomy is a well-known technique to preserve neurological functions, especially the language. It is still challenging to map the optic radiations due to the difficulty to test the visual field intraoperatively. To assess the visual field during awake craniotomy, we developed the Functions' Explorer based on a virtual reality headset (FEX-VRH).
  
  
  METHODS
  The impaired visual field of 10 patients was tested with automated perimetry (the gold standard examination) and the FEX-VRH. The proof-of-concept test was done during the surgery performed on a patient who was blind in his right eye and presenting with a left parietotemporal glioblastoma. The FEX-VRH was used intraoperatively, simultaneously with direct subcortical electrostimulation, allowing identification and preservation of the optic radiations.
  
  
  RESULTS
  The FEX-VRH detected 9 of the 10 visual field defects found by automated perimetry. The patient who underwent an awake craniotomy with intraoperative mapping of the optic tract using the FEX-VRH had no permanent postoperative visual field defect.
  
  
  CONCLUSIONS
  Intraoperative visual field assessment with the FEX-VRH during direct subcortical electrostimulation is a promising approach to mapping the optical radiations and preventing a permanent visual field defect during awake surgery for epilepsy or tumor.
authors.affiliation: Department of Neurosurgery, CHU Angers, Angers, France. Electronic address: emazerand@gmail.com.
authors.forename: Edouard
authors.initials: E
authors.lastname: Mazerand
authors.affiliation: Digital Interactions in Health and Disability Laboratory, ESIEA, Laval, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Le Renard
authors.affiliation: Department of Ophthalmology, CHU Angers, Angers, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hue
authors.affiliation: Department of Neurosurgery, CHU Angers, Angers, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Lemée
authors.affiliation: Digital Interactions in Health and Disability Laboratory, ESIEA, Laval, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Klinger
authors.affiliation: Department of Neurosurgery, CHU Angers, Angers, France; UMR-S1066, University of Angers, Angers, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Menei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D016292:Procedural Sedation; D003399:Craniotomy; D005260:Female; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008297:Male; D008875:Middle Aged; D065866:Optic Tract; D010775:Photic Stimulation; D014584:User-Computer Interface; D063367:Virtual Reality Exposure Therapy; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology* / Q000517:prevention & control; D055815:Young Adult
keywords: Awake craniotomy; Brain mapping; Brain tumor; Glioma; Optic radiations; Virtual reality