Dementia with Lewy Bodies

Dementia with cortical Lewy bodies (LBD) was first described by Okazaki et al in 1961 and is now recognised as a relatively common cause of the dementia syndrome. The true prevalence of LBD is unknown. In post-mortem studies of patients diagnosed as having dementia in life, the mean frequency of Lewy body dementia is 12.5% (Byrne, 1997). Clinically diagnosed LBD (using operational clinical criteria) is found in 10–23% of patients presenting to, or in the care of, psychogeriatric services (Collerton et al, 1996). What is not yet certain is its nosological status; opinion is divided between regarding it as a variety of Alzheimer's disease (the Lewy body variant), a distinct disease (senile dementia of the Lewy body type) or a spectrum disorder related to both Parkinson's disease and to Alzheimer's disease (Byrne, 1992).