title: [Inferior vertical nystagmus: is magnetic resonance imaging mandatory?].
abstract: BACKGROUND
  The presentation of a down-beating nystagmus force to discard vascular pathology of brain and cervical joint with magnetic resonance imagine (MRI). Recent studies support the low profitability of this study and is subjected that this oculomotor sign has a peripheral origin especially when the patient has a benign paroxysmal positional vertigo (BPPV) with affection of the superior semicircular canal.
  
  
  OBJECTIVE
  To evidence the profitability of MRI in a population of patients with positional down-beating nystagmus.
  
  
  METHODS
  We present a retrospective study with 42 consecutive patients. A complete clinical history and physical examination was performed. All of them perform vestibular tests (caloric and rotatory), cranial and cervical MRI.
  
  
  RESULTS
  Fifty-two percent of patients present clinical manifestations and physical exploration compatible with BPPV. MRI was normal in 67%. We found spondylopathy in 26% and vascular cerebral pathology in 5%. Prevalence of type I Arnold-Chiari malformation was 9% in our population. None of them was founded when the main symptom was suggestive of BPPV. Results obtained of vestibular tests didn't contribute additional information to give an ethiologic diagnosis.
  
  
  CONCLUSIONS
  The profitability of vestibular tests and MRI in our population with down beating nystagmus was very low. We must evaluate the real necessity of this test with the clinical context.
authors.affiliation: Hospital Universitario de Getafe, 28905 Getafe, Espana.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Esteban-Sánchez
authors.affiliation: Hospital Universitario de Getafe, 28905 Getafe, Espana.
authors.forename: Almudena
authors.initials: A
authors.lastname: Rueda-Marcos
authors.affiliation: Hospital Universitario de Getafe, 28905 Getafe, Espana.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Sanz-Fernández
authors.affiliation: Hospital Universitario de Getafe, 28905 Getafe, Espana.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Martín-Sanz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D055815:Young Adult