Visual recognition memory differentiates dementia with Lewy bodies and Parkinson's disease dementia.

OBJECTIVE

To compare cognitive impairments in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), to discriminate between the two entities.

METHODS

10 DLB and 12 PDD consecutive patients performed a neuropsychological battery designed to assess several cognitive domains: verbal and visual memory (Delayed Matching to Sample (DMS)-48), language, gnosia, praxia and executive functions.

RESULTS

DLB patients had poorer performances in orientation (p<0.05), Trail Making Test A (p<0.05) and reading of names of colours in the Stroop Test (p<0.05). Their scores were also lower in the visual object recognition memory test (DMS-48), in both immediate (p<0.05) and delayed recognition (p<0.05). No differences were observed in the other tests.

CONCLUSION

Despite global similarities in cognitive performances between DLB and PDD patients, we observed important differences: in particular, DMS-48, a test of visual object recognition memory and visual storage capacity, was poorer in DLB patients.