title: The vestibulo-ocular reflex and subjective balance after vestibular schwannoma surgery.
abstract: OBJECTIVE
  To evaluate the vestibulo-ocular reflex and its relationship with subjective balance in a long-term follow-up after vestibular schwannoma surgery.
  
  
  METHODS
  Retrospective cohorts study in a tertiary referral hospital. Forty-nine consecutive patients on which vestibular schwannoma surgery was performed at least 1 year before.
  
  
  METHODS
  Patients are classified in accordance with the morphology of the vestibulo-ocular reflex (VOR) into two groups: Group A, in which covert and overt saccades always occur in an organized fashion; and group B, in which covert and overt saccades randomly occur during head impulse and once finished. We evaluate the presence of covert and overt saccades and the morphology of the VOR measured by the video head impulse test (vHIT) and its relationship with subjective balance measured by Dizziness Handicap Inventory (DHI).
  
  
  RESULTS
  The group B patients returned a higher score in total DHI and all three subscales without any predominant subscale (P = 0,0002; t test). Group B patients were older than those in group A (P = 0,024; t test). No differences were found in sex distribution, tumor size, or side or time interval after surgery. Regarding the unaffected side, overt saccades were found to be more frequent in group B patients (P = 0.05; X(2)).
  
  
  CONCLUSIONS
  Long-term follow-up after vestibular schwannoma surgery has shown that 22% of the patients display a particular abnormality in the VOR because refixation saccades occur in a random fashion after elicitation of the reflex in the HIT test. These patients report the higher level of vestibular disability and handicap.
  
  
  METHODS
  2b.
authors.affiliation: Department of Otorhinolaryngology, Otoneurology Unit, University Hospital of Salamanca, University of Salamanca, Salamanca, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Batuecas-Caletrio
authors.forename: Santiago
authors.initials: S
authors.lastname: Santacruz-Ruiz
authors.forename: Angel
authors.initials: A
authors.lastname: Muñoz-Herrera
authors.forename: Nicolas
authors.initials: N
authors.lastname: Perez-Fernandez
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D009464:Neuroma, Acoustic / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D013506:Otologic Surgical Procedures / Q000009:adverse effects / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D004856:Postural Balance / Q000502:physiology*; D011788:Quality of Life; D012016:Reference Values; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D062606:Tertiary Care Centers; D016896:Treatment Outcome; D014717:Vertigo / Q000209:etiology / Q000503:physiopathology; D014724:Vestibular Function Tests
keywords: Vestibulo-ocular reflex; balance; dizziness; handicap inventory; vestibular schwannoma