title: Multiple positional nystagmus suggests multiple canal involvement in benign paroxysmal vertigo.
abstract: CONCLUSIONS
  Video-oculography demonstrates a higher occurrence of atypical positional nystagmus in patients with benign paroxysmal positional vertigo (BPPV). This includes anterior and horizontal canal variants and multiple positional nystagmus, suggesting combined lesions affecting several canals.
  
  
  OBJECTIVE
  To analyse the video-oculographic findings of positional tests in patients with BPPV.
  
  
  METHODS
  Seventy individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of positional nystagmus as confirmed by video-oculographic examination during the Dix-Hallpike test, the McClure test or the head-hanging manoeuvre. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal (Epley's manoeuvre for the posterior or anterior canals and Lempert's manoeuvre for the lateral canal) and the effectiveness was evaluated at 7 and 30 days.
  
  
  RESULTS
  Twenty-nine individuals (41.43%) presented an affected unilateral posterior canal. Fifteen patients (21.43%) presented a pure horizontal direction-changing positional nystagmus consistent with a diagnosis of horizontal canal BPPV. Twelve individuals (17.14%) presented a unilateral down-beating nystagmus, suggesting possible anterior canal BPPV. In addition, 14 patients (20%) showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV, 5 had bilateral posterior canal BPPV and 2 presented a positional down-beating nystagmus in both left and right Dix-Hallpike manoeuvres and the head-hanging manoeuvre, which is highly suggestive of anterior canal BPPV. However, seven individuals showed positional horizontal and vertical side-changing nystagmus that could not be explained by single-canal BPPV. These patients with multiple positional nystagmus showed changing patterns of positional nystagmus at follow-up.
authors.affiliation: Otology and Neurotology Group, CTS495, Department of Surgery, Hospital de Poniente de Almería, El Ejido, Almería, Spain. jalopeze@cajamar.es
authors.forename: Jose A
authors.initials: JA
authors.lastname: Lopez-Escamez
authors.forename: Maria I
authors.initials: MI
authors.lastname: Molina
authors.forename: Maria
authors.initials: M
authors.lastname: Gamiz
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Fernandez-Perez
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomez
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Palma
authors.forename: Cristobal
authors.initials: C
authors.lastname: Zapata
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002150:Caloric Tests; D005260:Female; D019416:Head Movements; D006801:Humans; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic / Q000502:physiology*; D012665:Semicircular Canals / Q000503:physiopathology*; D014717:Vertigo / Q000503:physiopathology*; D014724:Vestibular Function Tests; D014741:Video Recording