Ménière's disease Ménière's disease Ménière's disease (MD) is a disorder of the inner ear that is characterized by episodes of feeling like the world is spinning (vertigo), ringing in the ears (tinnitus), hearing loss, and a fullness in the ear. Typically only one ear is affected, at least initially; however, over time both ears may become involved. Episodes generally last from 20 minutes to a few hours. The time between episodes varies. Over time the hearing loss and ringing in the ears may become constant. The cause of Ménière's disease is unclear but likely involves both genetic and environmental factors. A number
Inner ear sends information to the brain about the attitude, rotation, and linear motion of the head. The type of motion or attitude detected by a hair cell depends on its associated mechanical structures, such as the curved tube of a semicircular canal or the calcium carbonate crystals (otolith) of the saccule and utricle. The human inner ear develops during week 4 of embryonic development from the auditory placode, a thickening of the ectoderm which gives rise to the bipolar neurons of the cochlear and vestibular ganglions. As the auditory placode invaginates towards the embryonic mesoderm, it forms the auditory vesicle or