Balance in man is a sophisticated and complex mechanism comprised of sensory inputs from the vestibular apparatus, vision, and proprioception. These pass into the central nervous system (CNS), are integrated and modulated by activity of the cerebellum, the extrapyramidal system, the limbic system, and the cerebral cortex, and provide perception of head and body position in space, eye movement control, and appropriate static and dynamic postural function. Alterations in the sensory inputs, integrating mechanisms, or effector organs can result in the perception of dizziness or vertigo, disordered eye movements and disequilibrium, or instability. A wide variety of pathological processes may give rise to dizziness, such that patients present to many different specialists, but most commonly to the ear, nose, and throat (ENT) or neurology departments (table 1).

Dizziness is extremely common, both in primary care and at the tertiary level, and by the age of 60 years, one third of the population has suffered from a balance disorder. While in primary care many cases of dizziness resolve spontaneously, in tertiary care dizziness is commonly associated with significant morbidity and, in the older population, if compounded by falls, mortality. Thus, a clear diagnostic strategy including a detailed neuro-otological examination, as outlined in the previous article, is essential if an accurate diagnosis is to be made. Diagnosis is key to the rehabilitation and management of the dizzy patient.

Three main groups of disorders giving rise to disequilibrium can be identified—general medical, neurological, and otological—with a few other disorders such as visual vertigo, cervical vertigo, and the multisensory dizziness syndrome in the elderly, falling outside this classification. A detailed history and examination, as outlined in the preceding section, will usually point the examiner in the correct direction for appropriate investigation. Inevitably there is some overlap (fig 1), in as much …