NEUROPSYCHOLOGICAL PERFORMANCE IN LEWY BODY DEMENTIA AND ALZHEIMERS-DISEASE

Background Lewy body dementia(LBD) is emerging as a common cause of de generative dementia. However, LED cannot yet be diagnosed with certain ty in life. There is some preliminary evidence that the pattern of cog nitive impairment in LED is different from that in Alzheimer's disease (AD). We set out to compare the performance on different subtests of the Cambridge Cognitive Examination (CAMCOG) of LBD patients and AD pa tients who were similar in overall degree of cognitive impairment. Met hods All patients were recruited from a memory clinic. LED (n=17)was d iagnosed according to the MeKeith clinical criteria. AD (n=17)was diag nosed according to NINCDS-ADRDA criteria. The performances of LED and AD patients on the neuropsychological subscales of the CAMCOG were com pared by applying Hotelling's multivariate test of significance and su bsequent univariate F tests. Results There were no statistically signi ficant differences between the two groups on Mini-Mental State Examina tion and global CAMCOG rating. Hotelling's test with LED and AD as the between-group factor and the neuropsychological subtests from CAMCOG as dependent variables revealed a statistically significant group effe ct (P < 0.05). Univariate F tests showed that recall (P < 0.02) and pr axis (P < 0.003) significantly contributed to this effect. Conclusions These results suggest that there may be different neuropsychological profiles in the two conditions, with IBD subjects being better on reca ll but worse on praxis than those with AD.