title: Efficacy and safety of bilateral posterior canal occlusion in patients with refractory benign paroxysmal positional vertigo:  case report series.
abstract: OBJECTIVE
  To highlight the effectiveness, safety, and adverse effects of treating intractable posterior canal benign paroxysmal positional vertigo (BPPV) with bilateral posterior canal occlusions.
  
  
  METHODS
  Included in this study are 6 patients diagnosed with bilateral BPPV refractory to medical treatment and particle repositioning maneuvers (PRMs) who underwent bilateral posterior semicircular canal occlusions. Patients were selected from tertiary hospital referral centers in London, Ontario, Canada, and St. Louis, Missouri, USA.
  
  
  METHODS
  This study used the following interventions: preoperative and postoperative audiogram testing to monitor long-term changes in hearing, computed tomography of the head to rule out central lesions and confirm normal inner ear anatomy before surgery, magnetic resonance imaging of the head as needed to rule out posterior fossa lesions causing persistent vertigo, Dix-Hallpike maneuver to diagnose BPPV, PRM and physiotherapy vestibular rehabilitation to attempt treating BPPV before surgical intervention, and sequential transmastoid posterior semicircular canal occlusion for treatment of intractable BPPV.
  
  
  METHODS
  Postoperative resolution of vertigo induced by head movement and hearing preservation by audiometric testing and postural stability.
  
  
  RESULTS
  All patients with severe debilitating bilateral BPPV refractory to medical treatment and PRM had complete resolution of their positional vertigo after bilateral sequential posterior semicircular canal occlusion. Hearing was preserved at the preoperative level in all but 1 patient who developed bilateral postoperative, mild, high-tone sensorineural loss. Residual postoperative adverse effects included transient imbalance in all patients and episodic, nonpositional vertigo in 1 patient. When stressed by extreme head motion, some patients had mild residual instability. There were no other significant long-term complications.
  
  
  CONCLUSIONS
  Bilateral sequential posterior semicircular canal occlusion is a definitive, effective, and safe treatment modality for intractable bilateral BPPV, providing patients with resolution of their vertiginous symptoms. All 6 patients stated that the alleviation of their BPPV symptoms far out-weighed the residual motion sensitivity resulting from the occluded canals.
authors.affiliation: Division of Otolaryngology - Head & Neck Surgery, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jayant
authors.initials: J
authors.lastname: Ramakrishna
authors.forename: Joel A
authors.initials: JA
authors.lastname: Goebel
authors.forename: Lorne S
authors.initials: LS
authors.lastname: Parnes
mesh_terms: D000368:Aged; D065635:Benign Paroxysmal Positional Vertigo; D005260:Female; D019416:Head Movements / Q000502:physiology; D006309:Hearing / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012665:Semicircular Canals / Q000473:pathology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014717:Vertigo / Q000150:complications* / Q000601:surgery*