Summary

Dementia associated with Lewy bodies (here termed Lewy body dementia) is potentially recognizable in life. Clinical features such as fluctuations in cognitive performance, recurrent visual hallucinations and systematized delusions and spontaneous parkinsonism are all suggestive of the diagnosis and may occur before the dementia is established. Early gait disturbance, unexplained falls and sensitivity to neuroleptic treatment are also useful clinical pointers. The dementia itself is characterized by deficits in memory and language, together with a greater degree of impairment of attention, visuospatial skills and psychomotor processing than is seen in Alzheimer's disease. Two sets of clinical diagnostic criteria based upon some of these features have been proposed and validated by the Nottingham and Newcastle groups; both demonstrate good specificity but the Newcastle criteria appear to have superior sensitivity. A new set of consensus criteria, combining the most valuable features of both existing efforts, would represent an important advance in the clinical diagnosis of Lewy body dementia.

Introduction

There is an increasing consensus that the syndrome of dementia associated with Lewy bodies may be recognizable in life and distinguishable from other dementia syndromes such as Alzheimer's disease. This distinction would be valuable for research, especially for drug trials. But an accurate diagnosis of Lewy body dementia is even more important in routine clinical practice. Patients with Lewy body dementia may present with psychiatric rather than cognitive symptoms, including hallucinations, delusions or fluctuating confusional states; early recognition in these patients may allow a safer and more rational approach to investigation and treatment. In patients with established dementia, these same manifestations pose particular management pitfalls which are at least potentially avoidable.