title: Approach to bilateral benign paroxysmal positioning vertigo.
abstract: BACKGROUND
  Bilateral benign paroxysmal positioning vertigo (bBPPV) is rather rare, accounting for up to 10% in the reported benign paroxysmal positioning vertigo (BPPV) series. Inappropriate head positioning during testing in unilateral BPPV causes the otolith debris in the uppermost ear to move toward the cupula, resulting in an inhibitory nystagmus and mimicking bBPPV.
  
  
  OBJECTIVE
  We analyzed the clinical data of patients with bilaterally positive Dix-Hallpike maneuver and compared them with the characteristics of patients with unilateral BPPV. We further tried to propose a simple schematic approach to the treatment of patients with bilaterally positive Dix-Hallpike maneuver.
  
  
  METHODS
  Medical records of 232 patients treated for BPPV at our dizziness clinic during 1999 to 2003 were reviewed. An algorithm used for the treatment of patients with bilaterally positive BPPV is discussed.
  
  
  RESULTS
  Twenty-eight patients with bilaterally positive Dix-Hallpike test were found. Sixteen were diagnosed with bBPPV, and 12 were diagnosed with unilateral mimicking bBPPV. Thirty patients with unilateral posterior canal BPPV served as control subjects. No difference in age, sex distribution, duration of symptoms, number of treatments per ear, and recurrence was found between bBPPV and unilateral BPPV. The female sex appeared to be predisposed for more treatments. The total duration of BPPV symptoms obtained by history was found to correlate with the number of recurrences after treatment.
  
  
  CONCLUSIONS
  We conclude that bBPPV can be readily distinguished from unilateral mimicking bBPPV. Patients with bBPPV do not differ from patients with unilateral BPPV in clinical characteristics. The mechanism of otolith debris dislodgment appears to be the main cause of bilaterality, trauma being a more common trigger than other known causes of BPPV.
authors.affiliation: Department of Neurology, Assaf Harofeh Medical Center, Zerifin, Israel. lpollak@asaf.health.gov.il
authors.forename: Lea
authors.initials: L
authors.lastname: Pollak
authors.forename: Rafael
authors.initials: R
authors.lastname: Stryjer
authors.forename: Mark
authors.initials: M
authors.lastname: Kushnir
authors.forename: Shlomo
authors.initials: S
authors.lastname: Flechter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D018709:Statistics, Nonparametric; D014717:Vertigo / Q000503:physiopathology* / Q000628:therapy*; D014722:Vestibule, Labyrinth / Q000503:physiopathology