The aetiology of dizziness and how to examine a dizzy patient.

Dizziness embraces various sensations of spatial disorientation. A common symptom, it has been experienced by at least one third of the population by the age of 65. Peripheral causes include disorders of the labyrinth and vestibular nerve such as Ménière's disease, benign paroxysmal positional vertigo, acute vestibulopathy (vestibular neuronitis) and acoustic neuroma. The most common lesions of the central nervous system that cause dizziness are infratentorial ischaemia, mechanical trauma, multiple sclerosis and cerebellar atrophy. Other aetiological factors include intoxications, psychogenic causes, cervical problems and cardiovascular diseases. The history and physical examination are the cornerstones of the search for the cause of dizziness. The most valuable otological methods are electronystagmography and audiometry. Of the clinical neurophysiological methods, brainstem auditory evoked potentials are more useful than electroencephalography. Computed tomography and magnetic resonance imaging should be used when a CNS disorder is suspected.