vertigo
vertigo, sensation of spinning or tilting or that one’s surroundings are rotating. Usually the state produces dizziness, mental bewilderment, and confusion. If the sensation is intense enough, the person may become nauseated and vomit. The cause of vertigo is often unknown. However, several diseases and disorders of the inner ear—including benign paroxysmal positional vertigo (BPPV; a mechanical inner-ear disorder), Ménière disease (a progressive ear disease), and vestibular neuritis (inflammation of the vestibulocochlear nerve)—can cause the condition. Minor or severe head injury, migraine, and prolonged bed rest are other causes.
Aircraft pilots and underwater divers are subject to vertigo because the environments in which they work frequently have no reference points by which to orient their direction of movement. The illusions caused by disorientation are perhaps the most-dangerous aspect of vertigo; a pilot, for example, may sense that he is gaining altitude when in reality he is losing it, or he may feel that he is steering to the right when he is on a straight course. See also spatial disorientation.
Vertigo often resolves on its own, without treatment. In some cases, however, patients may benefit from a type of physical therapy known as vestibular rehabilitation. Canalith-repositioning maneuvers, a form of vestibular rehabilitation for individuals with BPPV, involves a series of head-position changes, which help to move displaced canaliths (or otoliths; calcium carbonate crystals) back into the utrical of the inner ear (the detachment of canaliths from the otolithic membrane of the inner ear results in incorrect signaling to the brain, resulting in vertigo). Medications may be given to relieve nausea. In rare cases, vertigo is treated with surgery.
