Endolymphatic hydrops

Alternative names

Hydrops; Meniere's disease

Definition

Meniere's disease is a disorder of the inner ear affecting balance and hearing, characterized by abnormal sensation of movement (vertigo), dizziness, loss of hearing in one or both ears, and noises or ringing in the ear (tinnitus).

Causes, incidence, and risk factors

The fluid-filled semicircular canals (labyrinths) of the inner ear, in conjuction with the cranial nerve VIII, control balance and sense of body position. Meniere's disease involves a swelling of part of the canal (endolymphatic sac). The endolymphic sac controls the filtration and excretion of the fluid in the semicircular canals.

The exact cause of Meniere's disease is unknown. In some cases, it may be related to middle ear infection (otitis media), syphilis, or head injury. Other risk factors include recent viral illness, respiratory infection, stress, fatigue, use of prescription or nonprescription drugs including aspirin, and a history of allergies, smoking, and alcohol use. There may be genetic risk factors as well.

About 100,000 people per year develop Meniere's disease.

Symptoms

• Abnormal sensation of movement of self or the environment (vertigo)
  o May be episodic
  o Lasts from minutes to more than 8 hours
  o Worse with sudden movement
  
• Dizziness
  
• Hearing loss in one ear
  o Low frequency noises lost first
  o Extent of hearing loss may change
  
• Noises or ringing in one ear (tinnitus)
  
• Nausea, vomiting
  
• Sweating (may be profuse)
  
• Uncontrollable eye movements
  

Signs and tests
A neurologic examination may show an abnormality of cranial nerve VIII that may include abnormalities of hearing, balance, or eye movement.

Tests to distinguish Meniere's disease from other causes of vertigo may include:

• Head CT scan or head MRI scan
  
• Caloric stimulation (tests reflexes of the eyes) - abnormal results indicate Meniere's disease
  
• Evoked potential studies (BAER)
  
• Electronystagmography
  
• Audiology/audiometry
  

Treatment

There is no known cure for Meniere's disease. Treatment is focused on lowering the pressure within the endolymphatic sac and on treating symptoms, which tend to occur in discrete "attacks."