Neuropsychological differentiation between Alzheimer's disease and dementia with Lewy bodies in a memory clinic

Abstract

Objective: The aim of this study was to identify a useful neuropsychological instrument for making a differential clinical diagnosis between Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Methods: We examined 402 AD and 38 DLB patients with neuropsychological tests that covered general cognition, frontal lobe cognitive function, non-verbal abstract reasoning, working memory and attention, and verbal memory. Discriminant analysis using a stepwise method was performed to identify the measures best able to discriminate between AD and DLB. Results: The AD patients performed significantly worse than the DLB patients on orientation to time, delayed recall subtests on the Mini-Mental State Examination, and logical memory subtests 1 and 2 of the Revised Wechsler Memory Scale. The DLB patients performed significantly worse than the AD patients on the attention, repetition, and pentagon copying subtests of the Mini-Mental State Examination, the constructional praxis subtests of the Alzheimer's Disease Assessment Scale-cognitive component-Japanese version, the Frontal Assessment Battery total score, Raven's Coloured Progressive Matrices (RCPM) sets A, AB, and B, and backward digit span. Discriminant analyses between AD and DLB established the key variables as Logical Memory 1, Logical Memory 2, backward digit span, RCPM, and delayed recall on the Mini-Mental State Examination. We inferred the AD-DLB discriminant index from the following discriminant analyses: AD-DLB discriminant index = (Backward digit span score + RCPM set B score) − (Logical Memory 1 score + Logical Memory 2 score), which offered a highly favourable value for diagnostic utility. Conclusions: The AD-DLB discriminant index, consisting of backward digit span, RCPM set B, and logical memory 1 and 2, is useful to differentiate between AD and DLB.

Comparing the neuropsychological profiles of mild dementia with Lewy bodies and mild Alzheimer’s disease

“…In addition, the AVLT 20‐min delayed recall was also a discriminator, but it had less area under the curve than the MES 5‐min delayed recall. Our findings confirmed previous reports of the discriminant value of delayed recall—including the delayed recall subscore of the MMSE, AVLT percentage retention, and Logical Memory subtests 1 and 2 of the Wechsler Memory Scale‐Revised—between these two types of dementias …”

“…Comparisons of language between these two types of dementias are still controversial. Several studies reported the differentiating values of neuropsychological measures between DLB and AD, but the neuropsychological tests, dementia severity of patients, and discriminant accuracy varied . Most of them used only Mini‐Mental State Examination (MMSE) subscores, rather than comprehensive neuropsychological assessment, to distinguish DLB from AD.…”

Neural basis of visual perception and reasoning ability in Alzheimer's disease: correlation between Raven's Colored Progressive Matrices test and 123I‐IMP SPECT imaging results

“…However, the correlations found in the analysis may be affected by this variability. It has been reported that the patients with DLB have performed significantly worse than the patients with AD on RCPM (Kawai et al, 2013). RCPM has been useful to differentiate between AD and DLB.…”

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

“…Decreased occipital α activity showed correlation with worse brain functions related to attention/concentration (WMS-R-attention/concentration, Verbal Fluency Test for words), visuospatial discrimination (VPTA-shape discrimination scales), and global cognition (ADAS-J cog, CDR sum of boxes). Neuropsychological studies revealed that DLB patients have prominent functional deficits in attention, visual perception, working memory, and frontal executive function compared to AD [65-67]. The occipital dominant impairment observed in DLB patients could explain the deficits in visual attention and visual perception because visual information flows from the occipital cortex to higher cognitive areas such as the VAN and DAN [68].…”