title: Lateral canal BPPV with Pseudo-Spontaneous Nystagmus masquerading as vestibular neuritis in acute vertigo: a series of 273 cases.
abstract: OBJECTIVE
  To investigate the incidence of Lateral Semicircular Canal BPPV (LSC BPPV) with Pseudo-Spontaneous Nystagmus in patients preliminarily diagnosed for vestibular neuritis in the Emergency Department (ED).
  
  
  METHODS
  Retrospective study of 273 patients with acute vertigo and persistent horizontal nystagmus in upright position (male 110, female 163, 14-93 years old) observed over four years. All the patients were checked for any nystagmus modification by performing the Head Pitch Test (HPT) in the upright position.
  
  
  RESULTS
  The HPT modified the beating direction of the persistent horizontal nystagmus in 56 of the 273 examined patients. The positioning tests subsequently confirmed the diagnosis of LSC BPPV in all those 56 patients. There were 37 geotropic variants and 19 apogeotropic variants and all of them were successfully treated by performing liberatory manoeuvres in the course of the same session.
  
  
  CONCLUSIONS
  Performing the HPT in the upright position helps to differentiate a direction fixed nystagmus from a direction changing one, and in so doing, to make the differential diagnosis between vestibular neuritis and LSC BPPV, achieving the goal of successfully treating LSC BPPV in the first session.
authors.affiliation: ENT Department, Unit of Audiology, Vestibology and Phoniatry, Madonna delle Grazie Hospital, 75100 Matera, Italy. Tel.: +39 0835 253 388; Fax: +39 0835 253 384; E-mail: asprella@tin.it.
authors.forename: Giacinto
authors.initials: G
authors.lastname: Asprella-Libonati
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065635:Benign Paroxysmal Positional Vertigo / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D056888:Patient Positioning; D012189:Retrospective Studies; D014717:Vertigo / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D020338:Vestibular Neuronitis / Q000150:complications* / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult
keywords: BPPV; Vestibular neuritis; positional nystagmus; pseudo-spontaneous nystagmus; spontaneous nystagmus