title: The number of procedures required to eliminate positioning nystagmus in benign paroxysmal positional vertigo.
abstract: OBJECTIVE
  To evaluate the number of weekly canalith repositioning procedures needed to eliminate positioning nystagmus in patients with benign paroxysmal positional vertigo and to verify influences of canalithiasis or cupulolithiasis and/or semicircular canal involvement.
  
  
  METHODS
  clinical prospective with transversal cohort.
  
  
  METHODS
  Sixty patients with benign paroxysmal positional vertigo were consecutively selected according to each combination of canalithiasis or cupulolithiasis with semicircular canal involvement. Patients were treated by means of canalith repositioning procedures repeated weekly until the elimination of the positioning nystagmus. Analysis of Variance was used to verify differences between the variables.
  
  
  RESULTS
  An average of 2.13 procedures (from 1 to 8) was needed to eliminate the positioning nystagmus. Canalithiasis required an average of 1.53 procedures, while cupulolithiasis needed 2.92 procedures (p=0.0002). An average of two procedures was needed to eliminate the positioning nystagmus in cases with posterior canal involvement, 2.39 procedures in cases with anterior canal involvement and 2.07 procedures in cases with lateral canal involvement (p=0.5213).
  
  
  CONCLUSIONS
  From one to eight weekly canalith repositioning procedures were needed, with an average of two, to eliminate positioning nystagmus in benign paroxysmal positional vertigo. Cupulolithiasis requires a greater number of procedures than canalithiasis to eliminate positioning nystagmus. Semicircular canal involvement didn't influence the number of therapeutic maneuvers.
authors.affiliation: Program of Post-graduation in Otorhinolaryngology and Head and Neck Surgery, Federal University of São Paulo-Escola Paulista de Medicina, Otorhinolaryngology. rdorigueto@yahoo.com.br
authors.forename: Ricardo Schaffeln
authors.initials: RS
authors.lastname: Dorigueto
authors.forename: Maurício Malavasi
authors.initials: MM
authors.lastname: Ganança
authors.forename: Fernando Freitas
authors.initials: FF
authors.lastname: Ganança
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D010037:Otolithic Membrane / Q000503:physiopathology*; D026741:Physical Therapy Modalities; D011446:Prospective Studies; D012665:Semicircular Canals / Q000503:physiopathology*; D014717:Vertigo / Q000150:complications / Q000503:physiopathology / Q000628:therapy*