title: Predicting a successful treatment in posterior canal benign paroxysmal positional vertigo.
abstract: OBJECTIVE
  To elucidate the characteristics and prognostic value of positioning nystagmus during the second position of the Epley maneuver (90 degrees contralateral head turn from the initial Hallpike maneuver).
  
  
  METHODS
  The Epley maneuver was performed in 126 patients with confirmed posterior canal benign paroxysmal positional vertigo (PC-BPPV). The characteristics of positioning nystagmus were investigated using video Frenzel goggles.
  
  
  RESULTS
  During the second position, 99 patients developed torsional upbeating nystagmus, which was in the same direction (orthotropic nystagmus) as during the first position (Hallpike maneuver), whereas 15 patients showed a reversed pattern. In 12 patents, nystagmus was not induced during the second position. All 99 patients with orthotropic nystagmus had resolution of BPPV after the first or second trial of the Epley maneuver. In contrast, 12 of the 15 patients with reversed nystagmus and 8 of the 12 patients without nystagmus failed to resolve.
  
  
  CONCLUSIONS
  During the second position of the Epley maneuver, an orthotropic pattern of nystagmus predicts a successful repositioning, whereas reversed nystagmus or no nystagmus is suggestive of poor response to repositioning.
authors.affiliation: MTV (Migraine, Tinnitus, and Vertigo) Clinic, Oh Neurology Center, 200-13, Icheon-dong, Nam-gu, Daegu 705 - 836, South Korea. byung_in@hotmail.com.
authors.forename: Hui Jong
authors.initials: HJ
authors.lastname: Oh
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Byung In
authors.initials: BI
authors.lastname: Han
authors.forename: Jeong Geun
authors.initials: JG
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D017063:Outcome Assessment, Health Care / Q000379:methods*; D026741:Physical Therapy Modalities; D011187:Posture; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014717:Vertigo / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D014724:Vestibular Function Tests / Q000379:methods*