Attention and Fluctuating Attention in Patients With Dementia With Lewy Bodies and Alzheimer Disease

Abstract

LEWY BODIES are intraneuronal eosinophilic inclusion bodies that are seen in the brainstem and cortex of patients with Parkinson disease and some patients with dementia. Studies^1-6 have suggested that dementia with Lewy bodies (DLB) accounts for 10% to 25% of dementia cases in clinical populations. An international meeting in 1996 developed operationalized clinical diagnostic criteria⁷; key features included fluctuating cognition associated with disturbances of consciousness, persistent or recurrent visual hallucinations, and parkinsonism. Early and pronounced impairments were described as characteristic and thought to underpin fluctuating cognition, although there have been few empirical studies in this area. The complex array of neuropsychiatric, motor, and cognitive deficits and the extreme sensitivity reactions to neuroleptic drugs experienced by DLB patients raise a number of vital treatment issues that can only be managed optimally with accurate diagnostic assignment.⁷ In most studies examining the clinical criteria for the operationalized diagnosis of DLB, the specificity of diagnosis has been high, but sensitivity has been poor.⁸ There have been a paucity of studies examining the neuropsychological profile of DLB and the contribution of neuropsychological evaluation to the diagnostic workup. Expert opinion has highlighted attentional deficits as a key area in DLB,⁷ although the empirical evidence base is small.