Cognitive profile in prodromal disease (dementia) with Lewy bodies

This paper reviews findings on cognition in prodromal dementia with Lewy bodies (DLB). The issue of differential diagnosis between DLB and Alzheimer's disease (AD) on the one hand, and Parkinson's disease (PD) on the other hand, at prodromal stages of the diseases is discussed. The cognitive profile of prodromal DLB is also evaluated in terms of cognitive deficits and « cognitive weaknesses » (low performances although in normal range). Findings suggest that visuo-constructive tests and verbal fluency are particularly relevant to dfferentiate DLB from AD. A similar finding is evident when comparing prodromal DLB and PD. Attentional, executive and visuo-constructive tests appear to be the best predictor of DLB. Moreover, investigation of the cognitive profile in prodromal DLB highlights that cognitive difficulties are diffuse. Yet it appears that difficulties in cortical visual abilities and executive functions are prominent and likely to account, at least partially, for cognitive disturbances observed in neuropsychological tests assessing other cognitive functions.