Impaired performances on the category cued memory test in mild Alzheimer's disease and dementia with Lewy bodies: A comparative validity study

Developing a Danish version of the LASSI-L test - reliability and predictive value in patients with mild cognitive impairment, mild dementia due to AD and subjective cognitive decline

Tests measuring proactive semantic interference as The Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L), has shown promising diagnostic properties for the diagnosis of Mild Cognitive Impairment (MCI) and dementia. LASSI-L may also be efficient in predicting cognitive decline in at-risk individuals. There is an unmet need to examine the diagnostic properties of the LASSI-L in a Danish context where traditional neuropsychological tests are typically applied when diagnosing possible dementia disorders. To investigate the reliability, convergent validity, and predictive value of the new Danish LASSI-L version in aMCI and mild dementia due to Alzheimer's disease (AD). From a memory clinic we included 17 aMCI patients, 15 patients with mild dementia (AD), 17 patients with Subjective Cognitive Decline (SCD), and 30 healthy controls. Neuropsychological assessment was applied in all patients, and biomarker analyses were performed for patients with aMCI and mild AD. Cronbach's alpha was 0.94. Patients with aMCI and mild dementia differed significantly from healthy controls on all LASSI-L measures. ROC analyses showed a very high AUC value for both patients with aMCI [0.85-0.97] and mild dementia [0.93-0.99]. SCD patients generally did not differ from controls, except for significantly lower scores on one item (Cued Recall A1) LASSI-L had high reliability and promising predictive value in the diagnosis of aMCI and mild AD due to AD. SCD patients diagnosed in a memory clinic did not differ significantly from healthy on the LASSI-L.

Different language profiles on neuropsychological tests in dementia with Lewy bodies and Alzheimer's disease

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) may lead to different cognitive profiles. The performance on single language tests have been investigated in these patient-groups, but few studies have compared DLB and AD patients' language performances on different types of tests. The aim was to compare performances for patients with DLB, AD and healthy controls on different aspects of language function. Boston Naming Test, Naming of famous faces and verbal fluency (both semantic and lexical) were investigated in 90 DLB patients, 77 matched AD patients (MMSE score ≥ 21), and in a control group (N = 61). The patients had significantly lower scores on all tests compared to controls. The AD patients scored significantly lower than DLB patients on naming measures whereas the lexical fluency score was significantly lower in DLB. No significant differences were found for the semantic fluency. The frequency of impairment on the Boston Naming Test was higher in AD as compared to DLB, whereas the frequency of impairment on the lexical fluency test was significantly higher in DLB. In conclusion, DLB may lead to a different language profile than AD, and performance on language-based tests may help to differentiate patients with AD and DLB.

Memory Outcome in Prodromal and Mild Dementia with Lewy Bodies and Alzheimer's Disease: A Longitudinal Study

BACKGROUND

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are likely to induce memory impairments from the prodromal stage but, to our knowledge, no longitudinal study of these patients' memory profile has been conducted to date.

OBJECTIVE

The aim of our study was to describe the characteristics and the evolution of the long-term memory profile of patients with prodromal and mild DLB and AD.

METHODS

We collected verbal (RL/RI-16) and visual (DMS48) memory scores from 91 DLB patients, 28 AD patients, 15 patients with both conditions (DLB/AD), and 18 healthy control subjects at their inclusion visit and at 12, 24, and 48 months.

RESULTS

On the RL/RI-16, DLB patients performed better than AD patients in terms of total recall (p < 0.001), delayed total recall (p < 0.001), recognition (p = 0.031), and loss of information over time (p = 0.023). On the DMS48, differences between these two groups were not significant (p > 0.05). Longitudinally, the memory performance of DLB patients was stable over 48 months, unlike that of AD patients.

CONCLUSION

Four indicators were relevant to distinguish between DLB and AD patients in terms of memory performance: DLB patients benefitted greatly from semantic cueing, their recognition and consolidation abilities were well-preserved, and both their verbal and visual memory performance remained remarkably stable over four years. However, no performance differences between DLB and AD patients were found regarding visual memory, either qualitatively (memory profile) or quantitatively (severity of impairment), indicating the lesser relevance of this test in distinguishing between these two diseases.