title: Recovery of the horizontal vestibulo-ocular reflex in motorized head impulse test is common after vestibular loss.
abstract: CONCLUSIONS
  Decreased horizontal vestibulo-ocular reflex (VOR) gain measured with the motorized head impulse rotator usually recovers at least partially within a few months after sudden unilateral vestibular loss. In addition to traditional evaluation of nystagmus, head impulse test responses provide valuable information on the severity and recovery of vestibular loss.
  
  
  OBJECTIVE
  To quantify recovery of vestibular function with the motorized head impulse test in patients with acute unilateral peripheral vestibular loss, and to compare these results with other signs and symptoms.
  
  
  METHODS
  We recorded prospectively the horizontal VOR with the motorized head impulse rotator in 30 patients with sudden unilateral vestibular deficit on average 3 days after the onset (early). Twenty patients were measured sequentially on average 3 months later (late). We calculated VOR gain and asymmetry (mean ± standard deviation).
  
  
  RESULTS
  The early ipsilesional gain of 0.49 ± 0.21 improved highly significantly to the late gain of 0.79 ± 0.23 (p = 0.0000). The respective asymmetry improved highly significantly from 32 ± 18% to 12 ± 14% (p = 0.0002). Gain or asymmetry recovered at least partially in 80% of the patients. The late high symptom score correlated with low gain (p = 0.043) and high asymmetry (p = 0.018).
authors.affiliation: Department of Otorhinolaryngology, Helsinki University Central Hospital, Finland. topi.jutila@hus.fi
authors.forename: Topi
authors.initials: T
authors.lastname: Jutila
authors.forename: Heikki
authors.initials: H
authors.lastname: Aalto
authors.forename: Timo P
authors.initials: TP
authors.lastname: Hirvonen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D053483:Eye Movement Measurements; D005260:Female; D005500:Follow-Up Studies; D019416:Head Movements; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D015203:Reproducibility of Results; D013997:Time Factors; D015837:Vestibular Diseases / Q000150:complications / Q000503:physiopathology*; D014724:Vestibular Function Tests; D055815:Young Adult