Although the cause is unknown, Menieres disease probably results from an abnormality in the volume of fluid in the inner ear. Too much fluid may accumulate either due to excess production or inadequate absorption. In some individuals, especially those with involvement of both ears, allergies or autoimmune disorders may play a role in producing Ménières disease. In some cases, other conditions may cause symptoms similar to those of Ménières disease.
People with Ménières disease have a sick inner ear and are more sensitive to factors, such as fatigue and stress, that may influence the frequency of attacks.
Acoustic trauma and other insults to the inner ear may trigger increased levels of extra-cellular glutamate, which in turn cause excessive activation of cochlear NMDA receptors. This process results in damage or killing of sensory cells and is thought to be responsible for abnormal spontaneous "firing" of auditory nerves, which may be perceived as tinnitus. Under normal circumstances, the NMDA receptors are thought to play no role in fast excitatory neurotransmission, respectively normal hearing. Keyzilen ® is blocking cochlear NMDA receptors to suppress the aberrant excitation of the auditory nerve that is perceived as tinnitus.
The dura mater and the mastoid or craniotomy are then closed with a variety of materials, and the patient is observed in the intensive care unit. Because the balance fibers are cut suddenly, the surgery causes intense vertigo and imbalance for a few days requiring supportive medical care, medications for nausea and eventually physical therapy. A cane or walker may be needed for a while, depending on the patient’s health and activity level prior to the surgery. Once the patient is able to ambulate safely, he may be discharged home, but vestibular and balance therapy is continued on an out-patient basis to speed the patient’s recovery as much as possible. A return to full function occurs in most patients, although many do feel imbalanced when tired or stressed.