Anosognosia for memory in dementia with Lewy bodies compared with Alzheimer's disease

Abstract

Objectives Anosognosia is the inability to recognize one's own symptoms. Although dementia with Lewy bodies (DLB) is the second most common degenerative dementia, there is little evidence of memory deficit awareness in this condition. The objectives of this research were to compare anosognosia between individuals with DLB and dementia due to Alzheimer's disease (AD) and to evaluate whether medial temporal atrophy, a marker of AD pathology, could help to explain different rates of anosognosia in DLB and dementia due to AD. Methods/Design This is a cross‐sectional study that took place at the Memory Clinic of D’Or Institute for Research and Education (IDOR). Twenty individuals with DLB and 20 with dementia due to AD were included in this study. We assessed anosognosia for memory using an index derived from subjective memory complaints (using the Memory Complaint Questionnaire) and from the performance in memory neuropsychological testing (Rey Auditory Verbal Learning Test). Thirty‐one participants also underwent brain Magnetic Resonance Imaging to evaluate hippocampal atrophy with a visual scale (MTA‐score [medial temporal atrophy score]). Results There was no significant difference between groups regarding age, years of education, sex or time of disease. Individuals with DLB had a higher index of anosognosia than dementia due to AD (2.92 and 1.87; p = 0.024), meaning worse awareness of memory deficits. MTA‐score was slightly higher in dementia due to AD than in DLB, albeit without statistical significance. Conclusion Our study was the first to demonstrate that anosognosia for memory is worse in DLB than in dementia due to AD. This finding supports the hypothesis that anosognosia in DLB is a heterogeneous phenomenon.

Dispersion-based cognitive intra-individual variability in dementia with Lewy bodies.

“…The incremental utility of IIV-d for predicting DLB over-and-above clinician ratings may reflect the difficulty inherent in identifying cognitive fluctuations via clinical interview (Litvan et al, 1998; Mega et al, 1996), and suggests that IIV-d may serve as a useful standardized performance-based measure of cognitive fluctuations in DLB that can supplement the current standard of practice (i.e., identification via thorough clinical history/interview). Clinically, IIV-d may be particularly helpful as an objective indicator of cognitive fluctuations when informant report is unavailable and patients with suspected DLB present with anosognosia (Calil et al, 2021), especially considering that at least one measure of cognitive fluctuations should be documented when applying DLB diagnostic criteria (McKeith et al, 2017). When multiple sources of data on cognitive fluctuations are available (e.g., standardized informant report, clinical interview), clinicians may consider also examining IIV-d to assess convergence of data and enhance the reliability of identifying cognitive fluctuations, yet this multivariate approach would best be supplemented by future research which develops norms that facilitate interpretation of IIV-d.…”

“…Although the MFCS and clinician ratings may be useful indicators of DLB, they are critically limited by their reliance on subjective (and perhaps unavailable) reports from a nonclinician observer (e.g., caregiver, family member) and substandard reliability, respectively. Clearly then, identifying an objective metric for cognitive fluctuations is critical for the diagnosis and management of DLB, particularly for patients with DLB and anosagnosia but without collateral informants (Calil et al, 2021).…”

Ecological validity of cognitive fluctuations in dementia with Lewy bodies

“…In turn, intraindividual variability-dispersion may be a useful standardized behavioral measure of cognitive fluctuations for several reasons. First, individuals with DLB often exhibit anosognosia (Calil et al, 2021) and may not present with the collateral necessary to complete informant-report measures of daily cognitive fluctuations. Second, intraindividual variability-dispersion can be calculated from an individual's performance across the neurocognitive test batteries recommended for (McKeith Boeve, 2017) and commonly used by professionals for diagnosing DLB (Rabin et al, 2014;Sullivan & Bowden, 1997).…”

Prediction of Alzheimer’s Disease Progression Based on Magnetic Resonance Imaging

“…Since the atrophy of medial temporal structures or ventricular enlargement shown on sMRI is not unique to AD, , it is necessary to explore more targeted and specific biomarkers of AD progression from other MRmodes.…”

“…According to the hippocampal markers and conversion times, Cox proportional hazards models proved that LSR is better to predict AD conversion than NHV. Since the atrophy of medial temporal structures or ventricular enlargement shown on sMRI is not unique to AD, 98,99 it is necessary to explore more targeted and specific biomarkers of AD progression from other MRmodes.…”