Comparison of Endolymphatic Duct Dimensions and Jugular Bulb Abnormalities Between Meniere Disease and a Normal Population

Background: The pathogenesis of Meniere disease (MD) has not been fully understood. According to the widely accepted theory, imbalances due to overproduction and/or impaired absorption of endolymph may cause endolymphatic hydrops, which is the hallmark pathological finding in MD. Some developmental temporal bone abnormalities may impair endolymph circulation and absorption, and these abnormalities could be a part of MD pathophysiology. However, structural features of the temporal bone cannot explain MD pathophysiology definitively. The authors aimed to determine the length and width of the endolymphatic duct (ED) along with jugular bulb (JB) abnormalities in MD patients and normal controls using high-resolution computed tomography, and to discuss the results supporting and opposing endolymphatic hydrops based on the data obtained. Methods: Thirty-six ears of 18 patients with unilateral MD and 34 ears of 17 normal subjects were enrolled. Jugular bulb abnormalities and ED dimensions were evaluated in 3 groups: affected and unaffected ears of MD patients, and healthy controls. The ED dimensions and JB abnormalities were evaluated with high-resolution computed tomography. Results: The ED was found to be significantly shorter and narrower in the affected ears of the MD patients than in the healthy control group. In addition, more JB abnormalities were detected in the affected ears of the MD patients than in the healthy control group. However, there was no difference between the affected and unaffected ears of the MD patients. Conclusion: Structural ED abnormalities and JB abnormalities may be predisposing factors for the development of Meniere disease, but cannot fully explain MD pathophysiology.