title: Utricular dysfunction in patients with benign paroxysmal positional vertigo.
abstract: OBJECTIVE
  The objective of this study was to test the hypothesis that utricular function is impaired in patients with idiopathic benign paroxysmal positional vertigo.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Tertiary dizziness clinic and vestibular research laboratory.
  
  
  METHODS
  Twelve patients with unilateral idiopathic benign paroxysmal positional vertigo were examined 1 week and 1 month after successful treatment with positioning maneuvers and compared with 24 healthy subjects.
  
  
  METHODS
  None.
  
  
  METHODS
  Otolith function was assessed with estimation of the subjective visual vertical and analysis of the torsional otolith-ocular reflex. Unilateral stimulation of the utricle was performed on a rotator that allowed eccentric lateral displacement of the patient during earth-vertical rotation with constant velocity. The otolith-ocular reflex was recorded with three-dimensional video-oculography.
  
  
  RESULTS
  There was no difference in the estimation of the subjective visual vertical between patients and controls. The peak-to-peak amplitude of the otolith-ocular reflex torsional eye position was smaller in patients than in the control group. The gain of the unilateral otolith-ocular reflex was reduced in patients on both sides on first testing. After several weeks, only the affected labyrinth showed a reduced otolith-ocular reflex gain.
  
  
  CONCLUSIONS
  Our findings document otolith dysfunction in patients with idiopathic benign paroxysmal positional vertigo possibly secondary to degeneration of the utricular macula. This finding may account for the transient mild imbalance and dizziness that some patients with benign paroxysmal positional vertigo experience even after resolution of positional vertigo.
authors.affiliation: Department of Neurology, Charité, Campus Virchow-Klinkum, Schlosspark-Klinik, Berlin, Germany. michael.von_brevern@charite.de
authors.forename: Michael
authors.initials: M
authors.lastname: von Brevern
authors.forename: Tanja
authors.initials: T
authors.lastname: Schmidt
authors.forename: Uwe
authors.initials: U
authors.lastname: Schönfeld
authors.forename: Thomas
authors.initials: T
authors.lastname: Lempert
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Clarke
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D011446:Prospective Studies; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012444:Saccule and Utricle / Q000503:physiopathology*; D014717:Vertigo / Q000503:physiopathology*; D014724:Vestibular Function Tests