An illusion that a person or his or her surroundings are spinning. Vertigo is often the result of a disturbance of semi-circular canals in the inner ear or the nerve tracts leading from them. The condition can also be caused by some brain disorders affecting the brainstem, the cerebral cortex, or the cerebellum. Sudden-onset vertigo is treated with antihistamine drugs and a lot of rest. In certain cases the antihistamine drugs are also given to stop further attacks.