Endolymphatic hydrops in patients with unilateral and bilateral Meniere's disease

All definite Meniere's disease (MD) had endolymphatic hydrops (EH) at least in the cochlea or the vestibule. Symptoms of MD may appear after formation of EH. It is assumed that the probability of immediate progression to bilateral MD from unilateral MD is very low in patients without EH on the non-affected side.To evaluate the EH on both sides in patients with unilateral and bilateral MD, and to investigate factors with progression to bilateral MD including the degree of EH, hearing level, and the duration of MD.The study included 29 patients with unilateral definite MD and 12 patients with bilateral definite MD. The endolymphatic space size was visualized by using 3-Tesla magnetic resonance imaging.All patients with unilateral and bilateral MD had significant or mild EH at least in the cochlea or the vestibule on the affected side. On the non-affected side, EH was not observed at all in eight patients, but asymptomatic EH was observed in the cochlea in 14 patients and in the vestibule in 16 patients. There was no relationship between the EH on the non-affected side and the duration of MD.