Intractable Benign Paroxysmal Positioning Vertigo: Long-Term Follow-Up and Inner Ear Abnormality Detected by Three-Dimensional Magnetic Resonance Imaging

    loading  Checking for direct PDF access through Ovid

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.

Related Topics

    loading  Loading Related Articles