title: Anterior semicircular canal benign paroxysmal positional vertigo and positional downbeating nystagmus.
abstract: OBJECTIVE
  The aim of this study was to describe the clinical features and video-oculographic findings in patients with anterior semicircular canal benign paroxysmal positional vertigo (BPPV).
  
  
  METHODS
  
  
  
  METHODS
  This is a prospective case series.
  
  
  METHODS
  The study was set at an outpatient clinic in a general hospital.
  
  
  METHODS
  Fourteen individuals with symptoms of BPPV and positional downbeating nystagmus (pDBN) were included in the study. The diagnosis was based on a history of brief episodes of vertigo and the presence of pDBN confirmed in the video-oculographic examination during Dix-Hallpike test (DH) or head-hanging maneuver.
  
  
  METHODS
  Patients were treated by particle repositioning maneuver and the effectiveness was evaluated at 7, 30, and 180 days posttreatment. The treatment was repeated up to 4 times if pDBN was persistent.
  
  
  METHODS
  The main outcome measure is the number of patients without pDBN at 30 and 180 days.
  
  
  RESULTS
  Video-oculography showed a predominant pDBN in response to DH. Of the 14 patients, 7 had arterial hypertension, and 5 of 14 cases presented abnormalities on the caloric test. Horizontal spontaneous nystagmus was found in 3 of 14 individuals. Positional nystagmus at different positional test was observed in 5 of 14 individuals, suggesting the involvement of several canals. Of the 14 patients, 10 (71%) did not present vertigo, and the positional tests were negative at 30 days. However, 3 cases presented a positive DH with persistence of BPPV episodes and pDBN at 30 days, and another developed a contralateral posterior canal affectation. One of the patients maintained a persistent pDBN at 180 days despite the repeated maneuvers.
  
  
  CONCLUSIONS
  Video-oculography demonstrates that anterior canal BPPV is characterized by a predominant downbeating nystagmus in response to DH. These individuals may show alterations in the vestibular caloric, and they can have multicanal affectation.
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 J
authors.initials: MJ
authors.lastname: Gamiz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic / Q000502:physiology*; D011446:Prospective Studies; D012665:Semicircular Canals / Q000503:physiopathology*; D014717:Vertigo / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D014741:Video Recording