Intractable benign paroxysmal positioning vertigo: long-term follow-up and inner ear abnormality detected by three-dimensional magnetic resonance imaging

Otol Neurotol. 2010 Feb;31(2):250-5. doi: 10.1097/MAO.0b013e3181cabd77.

Abstract

Objective: To investigate the occurrence rate, prognosis, and inner ear abnormality in intractable benign paroxysmal positioning vertigo (BPPV).

Study design: A prospective study.

Setting: Tertiary referral university hospital.

Patients: Intractable BPPV was defined in case of either a persistent nystagmus or a frequent relapse each lasting more than 1 year after the initial diagnosis.

Intervention: T2-weighted 3-dimensional fast imaging employing steady-state acquisition sequences of magnetic resonance imaging (MRI) were reconstructed 3-dimensionally for 13 intractable BPPV patients and 14 control volunteers.

Main outcome measure: Transition and relapse of nystagmus were monitored. Semicircular canals were evaluated for a stenosis or filling defect (obturation).

Results: Eighteen patients (4 with posterior canal type, 2 with horizontal canal type with geotropic nystagmus, and 12 with apogeotropic nystagmus) fulfilled the above criteria for intractability among 495 BPPV patients. The occurrence rate of intractable BPPV was 3.6%. Also, the rate of nystagmus transition was significantly higher in patients with geotropic nystagmus and the posterior canal type (100%) compared with those with apogeotropic nystagmus (33.3%). Of the 13 intractable BPPV patients who underwent MRI, 11 (84.6%) had a total of 23 canals with abnormal appearance (29.5%), showing a significantly higher incidence compared with controls. There was no correlation between the affected canal diagnosed by MRI and the type of nystagmus.

Conclusion: The low incidence of nystagmus transition in patients with apogeotropic nystagmus suggests a difference in pathophysiology between apogeotropic nystagmus and other types of BPPV. Stenosis and filling defect (obturation) of canals on MRI, which would indicate an innate narrowing and/or an otoconial jam of the semicircular canal, may account for the intractability of BPPV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ear, Inner / abnormalities
  • Ear, Inner / pathology*
  • Follow-Up Studies
  • Humans
  • Image Processing, Computer-Assisted
  • Long-Term Care
  • Magnetic Resonance Imaging
  • Nystagmus, Pathologic / pathology
  • Prognosis
  • Semicircular Canals / abnormalities
  • Semicircular Canals / pathology
  • Vertigo / diagnosis*
  • Vertigo / pathology