title: How to uncover the covert saccade during the head impulse test.
abstract: OBJECTIVE
  The appearance of "covert" saccades in the head impulse test in patients with vestibular loss may lead to diagnostic misinterpretations. Here, we demonstrate a procedure that can convert covert eye saccades to overt when performing the head impulse test.
  
  
  METHODS
  Patients with known vestibular deficits that have covert saccades during head impulse test.
  
  
  METHODS
  Diagnostic: random and sudden changes of the amplitude (degree of head turn) when performing the head impulse test.
  
  
  METHODS
  Evaluation of bedside test with video recording and registration from video head impulse test (v-HIT).
  
  
  RESULTS
  A video recording and registration from v-HIT that demonstrate the covert saccades of a subject and how the overt saccade is uncovered by changing the amplitude of the head impulse. Five cases are briefly presented.
  
  
  CONCLUSIONS
  By performing the head impulse test with random amplitudes, overt saccades may become detectable and advance accuracy in bedside diagnosis of vestibular deficits.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Clinical Sciences Skåne University Hospital, Lund, Sweden. Fredrik.Tjernstrom@med.lu.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Tjernström
authors.forename: Anastasia
authors.initials: A
authors.lastname: Nyström
authors.forename: Måns
authors.initials: M
authors.lastname: Magnusson
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006319:Hearing Loss, Sensorineural / Q000150:complications; D006801:Humans; D008297:Male; D019095:Point-of-Care Systems; D012438:Saccades / Q000502:physiology*; D015837:Vestibular Diseases / Q000175:diagnosis / Q000503:physiopathology; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology; D014724:Vestibular Function Tests / Q000379:methods*; D014741:Video Recording; D055815:Young Adult