title: [Benign paroxysmal positional vertigo of the horizontal semicircular canal].
abstract: OBJECTIVE
  Assesment of 8 new cases of benign paroxysmal positional vertigo of the horizontal semicircular canal (BPPV-HC), since this variant of benign positional vertigo occurs rarely. An oculographic study of features in the positional response was carried out. Electrooculograpy (EOG) allows an exhaustive study of positional nystagmus.
  
  
  METHODS
  We have studied retrospectively 8 patients with BPPV-HC and positive head rotation manoeuvre registered by EOG techniques. Possible alterations in other EOG tests in the group of patients were analyzed.
  
  
  RESULTS
  Most of the patients (7/8) expressed bilateral horizontal geotropic changing-direction nystagmus. One patient exhibited apogeotropic horizontal nystagmus. 5/8 cases showed caloric hypofunction.
  
  
  CONCLUSIONS
  We have proven that BPPV-HC is an uncommon disorder. In most of the cases, provocative manoeuver generates bilateral horizontal geotropic changing-direction nystagmus that probably is due to canalitiasis of the horizontal semicircular canal. The rest, a few cases, exhibit apogeotropic horizontal response that can be secondary to cupulolitiasis or location particles in the anterior portion of the horizontal canal. A caloric test showed abnormal in many and can help to locatize the affected ear.
authors.affiliation: Servicio de Otorrinolaringología, Hospital Arnau de Vilanova, Valencia.
authors.forename: E
authors.initials: E
authors.lastname: Doménech Campos
authors.forename: M
authors.initials: M
authors.lastname: Armengot Carceller
authors.forename: R
authors.initials: R
authors.lastname: Barona de Guzmán
mesh_terms: D000328:Adult; D000368:Aged; D004585:Electrooculography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic / Q000502:physiology; D012189:Retrospective Studies; D012399:Rotation; D012665:Semicircular Canals / Q000503:physiopathology*; D012720:Severity of Illness Index; D014717:Vertigo / Q000150:complications / Q000503:physiopathology*