Canal conversion between anterior and posterior semicircular canal in benign paroxysmal positional vertigo.
OBJECTIVE
To investigate the characteristics of canal conversion between the anterior and posterior semicircular canals in benign paroxysmal positional vertigo (BPPV).


METHODS
Retrospective chart review.


METHODS
Secondary referral center.


METHODS
A total of 709 patients who were treated with the Epley maneuver for BPPV of the anterior or posterior semicircular canal.


METHODS
Vestibular examinations with videonystagmography and the canalith repositioning procedure (CRP) to treat BPPV.


RESULTS
Canal conversion between the anterior and posterior semicircular canals was observed in 18 (2.9%) patients who underwent CRP. In 13 (2.3%) of 564 patients initially diagnosed with posterior canal BPPV (PC-BPPV), switch to anterior canal BPPV (AC-BPPV) was observed at a follow-up visit. In 5 (12.1%) of 41 patients who presented with AC-BPPV, canal switch to PC-BPPV occurred more frequently (p = 0.005). The average number of CRPs before nystagmus resolution was 3.6 in conversion cases versus 1.6 in the nonconversion group (p < 0.001).


CONCLUSIONS
Canal conversion between the anterior and posterior semicircular canals can occur during treatment. The possibility of canal conversions should be considered for appropriate management of BPPV of the vertical semicircular canals.
*Department of Otorhinolaryngology, Yonsei University College of Medicine; and †Department of Otology, Hana ENT Hospital, Seoul, Republic of Korea.
Sera
S
Park
Bo Gyung
BG
Kim
Sung Huhn
SH
Kim
Hosuk
H
Chu
Min Young
MY
Song
Minbum
M
Kim
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065635:Benign Paroxysmal Positional Vertigo; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning / Q000379:methods*; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000503:physiopathology*; D016896:Treatment Outcome; D014717:Vertigo / Q000503:physiopathology / Q000628:therapy*