Vestibular neuronitis

Vestibular neuronitis is characterized by a sudden loss of the balance mechanism in one ear. The person is so violently dizzy that he or she usually cannot walk for several days or weeks, and may be unable to get up and move around at all.

Vestibular loss may be precipitated by a virus (viral neuronitis) or a tiny blood clot in the arterial system that brings blood to the balance mechanism. These blood vessels are so small that they can be blocked by a microscopic clot of no more than four or five red cells clumped together.