Imaging of the endolymphatic space in patients with Ménière's disease

Objective: To examine endolymphatic hydrops (EH) using magnetic resonance imaging (MRI) in patients with definite Ménière's disease (MD) and those with nonotological diseases.

Methods: We studied 32 patients with unilateral MD, 10 patients with bilateral MD and 21 patients with control ears who had other benign diseases not associated with hearing or vestibular dysfunction. The mean age of the subjects was 54.0 years (range 27-74) in the MD group and 56.1 years (range 24-79) in the control group. Using MRI, the degree of EH was classified as none, mild and significant in the cochlea and vestibule separately. The ratio of the area of endolymphatic space to the vestibular fluid space was calculated for the vestibule. The duration of MD was defined as the months between the first attack of MD and the MRI study.

Results: EH was present in the cochlea of 45/52 affected ears of patients with MD (87%) and in 16/42 control ears (38%). Significant cochlear hydrops was present in 37/52 affected ears (71%) and in 4/42 control ears (10%). EH in the vestibule was present in 49/52 affected ears (94%) and in 3/42 control ears (7%). Significant vestibular hydrops was present in 40/52 affected ears (77%) and in none of the 42 control ears. There was no relationship between the degree of EH and its duration. Using a cut off value for the relative size of EH in the vestibule of 41.9%, the test had a sensitivity of 88.5% and a specificity of 100% to diagnose definite MD.

Conclusion: Cochlear EH was occasionally observed in control ears on MRI, as in normal temporal bone specimens. The presence or absence and degree of vestibular EH were significantly different between ears with MD and control ears. EH in the vestibule might be a specific predictor of definite MD.