title: Spontaneous nystagmus in horizontal canal benign paroxysmal positional vertigo.
abstract: OBJECTIVE
  Benign paroxysmal positional vertigo of horizontal semicircular canal (HSC-BPPV) is characterized by either geotropic or apogeotropic nystagmus induced by head roll test. Some patients also present with spontaneous nystagmus. The aim of this study is to examine the clinical manifestation of spontaneous nystagmus in HSC-BPPV and evaluate the effect on the treatment outcome.
  
  
  METHODS
  Electronystagmography and video eye movement recordings of 125 patients diagnosed as HSC-BPPV were reviewed retrospectively. Presence of spontaneous nystagmus was analyzed and treatment outcome after repositioning therapy was compared.
  
  
  RESULTS
  Overall, spontaneous nystagmus was observed in 19 patients (15.2%) with HSC-BPPV at initial presentation. In canalolithiasis group (n=64), the treatment outcome did not differ between patients with or without spontaneous nystagmus. However, in cupulolithiasis group (n=61), patients presenting with spontaneous nystagmus (n=10) required more repositioning therapy sessions.
  
  
  CONCLUSIONS
  The presence of spontaneous nystagmus at initial presentation may implicate poorer treatment outcome in cupulolithiasis HSC-BPPV patients.
authors: Department of Otolaryngology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors: Eun Jin
authors: EJ
authors: Son
authors: Hye Jin
authors: HJ
authors: Lim
authors: Yun-Hoon
authors: YH
authors: Choung
authors: Keehyun
authors: K
authors: Park
authors: Hun Yi
authors: HY
authors: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002150:Caloric Tests; D004584:Electronystagmography; D005260:Female; D006801:Humans; D020347:Lithiasis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000503:physiopathology* / Q000628:therapy*; D012189:Retrospective Studies; D012399:Rotation; D012665:Semicircular Canals / Q000503:physiopathology*; D014717:Vertigo / Q000503:physiopathology* / Q000628:therapy; D014741:Video Recording; D055815:Young Adult