title: Optimizing the sensitivity of the head thrust test for identifying vestibular hypofunction.
abstract: OBJECTIVE
  The head thrust test (HTT) is used to assess the vestibulo-ocular reflex. Sensitivity and specificity for diagnosing unilateral vestibular hypofunction (UVH) in patients following vestibular ablation is excellent (100%), although sensitivity is lower (35%-39%) for patients with nonsurgically induced UVH. The variability of the test results may be from moving the subject's head outside the plane of the lateral semicircular canals as well as using a head thrust of predictable timing and direction. The purpose of this study was to examine sensitivity and specificity of the horizontal HTT in identifying patients with UVH and bilateral vestibular hypofunction (BVH) when the head was flexed 30 degrees in attempt to induce acceleration primarily in the lateral semicircular canal and the head was moved unpredictably.
  
  
  METHODS
  The medical records of 176 people with and without vestibular dysfunction (n=79 with UVH, n=32 with BVH, and n=65 with nonvestibular dizziness) were studied.
  
  
  METHODS
  Data were retrospectively tabulated from a de-identified database (ie, with health information stripped of all identifiers).
  
  
  RESULTS
  Sensitivity of the HTT for identifying vestibular hypofunction was 71% for UVH and 84% for BVH. Specificity was 82%.
  
  
  CONCLUSIONS
  Ensuring the head is pitched 30 degrees down and thrust with an unpredictable timing and direction appears to improve sensitivity of the HTT.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, MD 21205, USA. mschube1@jhmi.edu
authors.forename: Michael C
authors.initials: MC
authors.lastname: Schubert
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Tusa
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Grine
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Herdman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004185:Disability Evaluation; D004244:Dizziness / Q000209:etiology / Q000503:physiopathology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology*; D049671:History, 18th Century; D006801:Humans; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D004856:Postural Balance / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014724:Vestibular Function Tests / Q000379:methods*