Dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia in older people, accounting for 10-15% of all cases. It occupies part of a spectrum that includes Parkinson's disease and primary autonomic failure, all of which share a neuritic pathology based upon abnormal aggregation of the synaptic protein alpha-synuclein. It is important to identify DLB patients accurately because they have specific symptoms, impairments and functional disabilities that differ from those of other common dementia syndromes, including Alzheimer's disease, vascular cognitive impairment and frontotemporal dementia. Clinical diagnostic criteria for DLB have been validated against autopsy but fail to detect a substantial minority of cases with atypical presentations that are often due to the presence of mixed pathology. Newly developed rating scales for the core features of DLB (fluctuation, visual hallucinations and parkinsonism) should improve clinical diagnostic accuracy, as should the use of structural and functional neuroimaging. DLB patients frequently have severe neuroleptic sensitivity reactions, which are associated with significantly increased morbidity and mortality. Cholinesterase inhibitor treatment is usually well tolerated and substantially improves cognitive and neuropsychiatric symptoms. Virtually unrecognized 20 years ago, DLB could within this decade be one of the most treatable neurodegenerative disorders of late life.