title: Early adaptation and compensation of clinical vestibular responses after unilateral vestibular deafferentation surgery.
abstract: OBJECTIVE
  To describe vestibulo-ocular function in the immediate postoperative period after unilateral vestibular deafferentation from vestibular schwannoma resection.
  
  
  METHODS
  Prospective longitudinal study.
  
  
  METHODS
  Tertiary medical center.
  
  
  METHODS
  Five patients who underwent vestibular schwannoma resection via retrosigmoid approach.
  
  
  METHODS
  Bedside video-oculography and video head impulse testing (HIT).
  
  
  METHODS
  Static and dynamic measures of vestibulo-ocular reflex (VOR) function including spontaneous nystagmus, skew deviation, VOR gain during HIT, and presence of saccades related to HIT.
  
  
  RESULTS
  Mean ipsilesional horizontal VOR gain decreased from 0.88 ± 0.09 preoperatively to 0.27 ± 0.20 on POD 2 (p = 0.004). Mean contralesional VOR gain declined from 0.95 ± 0.1 preoperatively to 0.79 ± 0.17 on POD 2 (p = 0.032). By POD 4, ipsilesional VOR gain remained low, whereas contralesional VOR gain returned to baseline. Initially on POD 1 to 3, compensatory saccades occurred exclusively after the head stopped moving (overt) with latency of 192.8 ± 36.1 ms; by POD 5, saccade latency decreased to 134.5 ± 23.5 ms (p = 0.026), and saccades were occurring during the head rotation. Skew deviation was present and remained abnormal through POD 5 in 3 of the 5 patients.
  
  
  CONCLUSIONS
  In the postoperative period, gaze stability seems to improve from contralesional VOR gain restoration and reduced latency of compensatory saccades.
authors: *Department of Neurology, and †Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, U.S.A.
authors: Georgios
authors: G
authors: Mantokoudis
authors: Michael C
authors: MC
authors: Schubert
authors: Ali S Saber
authors: AS
authors: Tehrani
authors: Aaron L
authors: AL
authors: Wong
authors: Yuri
authors: Y
authors: Agrawal
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D007758:Ear, Inner / Q000502:physiology; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000601:surgery*; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D013506:Otologic Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D011184:Postoperative Period; D011446:Prospective Studies; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D016896:Treatment Outcome; D014722:Vestibule, Labyrinth / Q000502:physiology*