Vertigo and imbalance

The mechanism for maintaining balance in man is complex. Vision, proprioception, and vestibular inputs are integrated in the central nervous system, and modulated by activity from the cerebellum, the extrapyramidal system, the reticular formation, and the cortex. This integrated, modulated information provides one mechanism for control of oculomotor activity, controls posture, gait, and motor skills and allows perception of the head and body in space. Recent evidence also supports an effect upon autonomic function, cognition, and emotion. The complexity of the system is such that pathology in a variety of different bodily systems, including the endocrine system, the cardiovascular system, and the haemopoietic system, can impact upon vestibular activity, in addition to primary otological and neurological pathology.Patients with dysfunction in the vestibular end-organs or vestibular pathways commonly complain of symptoms of dizziness, vertigo, unsteadiness, light-headedness, imbalance, and a plethora of synonyms associated with a sense of instability. Not infrequently, in an attempt to define their ‘unphysiological’ experience, patients use rather vague and imprecise semantics. The clinical distinction between dizziness, a symptom of non-specific pathological significance, and vertigo, a hallucination or illusion of movement, is rarely made, although the latter is a cardinal manifestation of a disorder of the vestibular system (Dix 1973). Ten to 20 per cent of all ‘dizzy’ patients are reportedly seen in neurology clinics (Dieterish 2004), therefore it behoves the neurologist to have a clear diagnostic strategy, including knowledge of detailed neuro-otological examination, to enable appropriate diagnosis and management of the patient with vestibular symptoms.