Evaluation of investigations to diagnose the cause of dizziness in elderly people: a community based controlled study.

OBJECTIVE: To compare the findings in dizzy elderly people with those in controls of a similar age to identify which investigations differentiate dizzy from non-dizzy patients and to design an investigational algorithm. DESIGN: Community based study of clinical and laboratory findings in dizzy and control elderly people. SETTING: Research outpatient clinic at a teaching hospital. SUBJECTS: 149 dizzy and 97 control subjects aged over 65 years recruited from a community survey and articles in the local press. MAIN OUTCOME MEASURES: Findings on physical examination, blood testing, electrocardiography (at rest and over 24 hours), electronystagmography, posturography, and magnetic resonance imaging of head and neck (125 (84%) dizzy subjects and 86 (89%) controls); hospital anxiety and depression score; responses to hyperventilation, carotid sinus massage, and the Hallpike manoeuvre. RESULTS: Blood profile, electrocardiography, electronystagmography, and magnetic resonance imaging failed to distinguish dizzy from control subjects because of the frequency of asymptomatic abnormalities in controls. Posturography and clinical assessment (physical examination, dizziness provocation, and psychological assessment) showed significant differences between the groups. A cause of the dizziness was identified from clinical diagnostic criteria based on accepted definitions in 143 subjects, with 126 having more than one cause. The most common diagnoses were central vascular disease (105) and cervical spondylosis (98), often accompanied by poor vision and anxiety. CONCLUSION: Expensive investigations are rarely helpful in dizzy elderly people. The cause of the dizziness can be diagnosed in most cases on the basis of a thorough clinical examination without recourse to hospital referral.