Menierè's disease: is it a bilateral disease?

Bilateral Meniere's disease (MD) is still controversial due to different criteria used to assess the involvement of the primarily affected ear and the contralateral one. We evaluated the percentage of bilateral forms in 49 patients with MD.49 patients with (MD) were studied. All were selected according to the following requirements: history, tonal audiometry, glycerol test, Auditory Brainstem Response (ABR), vestibular examination. Magnetic Resonance (MR) was performed in 14 patients.A raised hearing threshold in the contralateral ear was found in 23 patients, but only 7 (14.3%) fulfilled the requirements to be considered affected by bilateral MD. The delay of occurrence in the contralateral ear was 7 years (from 5 to 12 years). Submillimeter Magnetic Resonance is determinant for differential diagnosis with Meniere-like syndromes.A conservative approach in surgical treatment of unilateral Meniere's disease is recommended because of the possibility of evolution in a bilateral form, that can occur even after 10 years from the onset of the disease.