title: Anterior canal lithiasis: diagnosis and treatment.
abstract: OBJECTIVE
  To describe the clinical and oculographic features in patients with anterior semicircular canal benign paroxysmal positional vertigo and to determine the efficacy of a canalith repositioning procedure for its management.
  
  
  METHODS
  Case series with chart review of patients presenting positional vertigo and positional downbeating nystagmus during a 2-year period.
  
  
  METHODS
  Outpatients' tertiary referral center for balance disorders.
  
  
  METHODS
  Eighteen patients suffering from positional vertigo and presenting positional downbeating nystagmus were treated with a maneuver based on a modification of the procedure proposed by Crevits.
  
  
  METHODS
  disappearance of positional downbeating nystagmus.
  
  
  RESULTS
  Positional downbeating nystagmus was elicited unilaterally with the Dix-Hallpike maneuver in 6 cases. In 4 patients, it was triggered by both left and right Dix-Hallpike tests. In 8 patients, the positional nystagmus was elicited by a straight head-hanging maneuver. The positional nystagmus was purely downbeating in 12 patients. In the remaining, a torsional component was detected. After the treatment, only 1 patient showed positional nystagmus at 30 days.
  
  
  CONCLUSIONS
  In anterior canal benign paroxysmal positional vertigo, the presence of a positional downbeating nystagmus in response to positional tests is key for diagnosis. In a significant number of patients, the affected side may not be detected because of the inconstant presence of a torsional component. Treatment with a simplified maneuver based on Crevits's technique can be considered an effective method for the treatment of anterior canal lithiasis, especially when the affected side cannot be detected clearly.
authors.affiliation: Department of Neuroscience, Otorhinolaryngology Unit, University of Pisa, Pisa, Italy. a.casani@med.unipi.it
authors.forename: Augusto Pietro
authors.initials: AP
authors.lastname: Casani
authors.forename: Niccolò
authors.initials: N
authors.lastname: Cerchiai
authors.forename: Iacopo
authors.initials: I
authors.lastname: Dallan
authors.forename: Stefano
authors.initials: S
authors.lastname: Sellari-Franceschini
mesh_terms: D000328:Adult; D000368:Aged; D065635:Benign Paroxysmal Positional Vertigo; D004424:Ear Canal; D004427:Ear Diseases / Q000175:diagnosis* / Q000628:therapy*; D005260:Female; D006801:Humans; D020347:Lithiasis / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000150:complications; D026741:Physical Therapy Modalities; D012665:Semicircular Canals / Q000503:physiopathology; D014717:Vertigo / Q000150:complications / Q000209:etiology