Vertigo and Imbalance

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Vertigo, by definition, is an illusion of movement, of the patient or the surroundings. The origin of the name suggests a sense of rotational movement, but should apply to any direction of movement experienced. Imbalance always accompanies vertigo, but is not always due to vertigo and is not a synonym. Imbalance occurs for many reasons without vertigo.

Normal balance needs:

• accurate sensory information from the eyes, proprioceptive receptors and the vestibular labyrinth with coordination of this information within the brain

• normal motor neural control by the central nervous system of an intact musculoskeletal system: normal muscles and joints (Figure 1).

Defects in any of these impair balance—with or without vertigo.

Vertigo arises if information from vestibular sources conflicts with data from the other sensory systems, or when a disordered central integration system in the brain does not correctly relate the body's movements to the vestibular input. Vertigo is always a symptom of vestibular defect. This may lie in the labyrinth (peripheral) or in its connections within the brain (central). When severe, it is accompanied by nausea and vomiting.

Vertigo is caused by: (a) peripheral vestibular disorders (labyrinthine); (b) middle ear infections spreading to the labyrinth; …