Examining the Validity and Utility of Montreal Cognitive Assessment Domain Scores for Early Neurocognitive Disorders.

OBJECTIVES: Montreal Cognitive Assessment (MoCA) total scores have been widely used to identify individuals with neurocognitive disorders (NCDs), but the utility of its domain-specific scores have yet to be thoroughly interrogated. This study aimed to validate MoCA's 6 domain-specific scores (ie, Memory, Language, Attention, Executive, Visuospatial, and Orientation) with conventional neuropsychological tests and explore whether MoCA domain scores could discriminate between different etiologies in early NCDs. DESIGN: Baseline data of a cohort study. SETTING AND PARTICIPANTS: Study included 14,571 participants recruited from Alzheimer's Disease Centers across United States, aged ≥50 years, with global Clinical Dementia Rating of ≤1, and mean age of 71.8 ± 8.9 years. METHODS: Participants completed MoCA, conventional neuropsychological tests, and underwent standardized assessments to diagnose various etiologies of NCDs. Partial correlation coefficient was used to examine construct validity between Z scores of neuropsychological tests and MoCA domain scores, whereas multinomial logistic regression examined utility of domain scores to differentiate between etiologies of early NCDs. RESULTS: MoCA domain scores correlated stronger with equivalent constructs (r = 0.15-0.43, P < .001), and showed divergence from dissimilar constructs on neuropsychological tests. Participants with Alzheimer's disease were associated with greater impairment in Memory, Attention, Visuospatial, and Orientation domains (RRR = 1.13-1.55, P < .001). Participants with Lewy body disease were impaired in Attention and Visuospatial domains (RRR = 1.21-1.47, P < .001); participants with frontotemporal lobar degeneration were impaired in Language, Executive, and Orientation domains (RRR = 1.25-1.75, P < .01); and participants with Vascular disease were impaired in Attention domain (RRR = 1.14, P < .001). CONCLUSIONS AND IMPLICATIONS: MoCA domain scores approximate well-established neuropsychological tests and can be valuable in discriminating different etiologies of early NCDs. Although MoCA domain scores may not fully substitute neuropsychological tests, especially in the context of diagnostic uncertainties, they can complement MoCA total scores as part of systematic evaluation of early NCDs and conserve the use of neuropsychological tests to patients who are more likely to require further assessments.

Assessment of small intestinal bacterial overgrowth in Alzheimer's disease.

There is great interest in crosstalk between the gastrointestinal and immune systems. Small intestinal bacterial overgrowth (SIBO) is a bowel disorder prevalent among patients with Parkinson's disease; SIBO treatment has been shown to modulate neurological inflammation, motor and cognitive outcomes there. However, to date, no link between Alzheimer's dementia and SIBO has been established. This pilot study sought to estimate the prevalence of SIBO in Alzheimer's dementia in the outpatient setting in Singapore General Hospital. It entailed performing a hydrogen breath test and objectively scoring gastrointestinal symptoms and their severity in 48 patients, comparing symptom scores and mean breath test values in those with mild to moderate Alzheimer's against age- and sex-matched controls that did not fulfill DSM-V criteria for probable Alzheimer's. Here, the prevalence of positive breath tests and symptoms of SIBO were no greater among Alzheimer's patients than in controls. This suggests that the gut microbiome changes and increased bowel inflammation seen in previous studies on Alzheimer's patients are likely effected through pathways other than SIBO, and are likely more complex than a mere increase in small bowel bacterial volume. Rather, future research could be directed along the lines of qualitative changes in small bowel microbiota, or pathologies in other parts of the gastrointestinal tract such as the colon or stomach, aspects which are not adequately captured by the hydrogen breath test. Keywords: Alzheimer's disease; dementia; gut-brain axis; small intestinal bacterial overgrowth; microbiome.

Hyperfamiliarity in Dementia and Mild Cognitive Impairment.

INTRODUCTION: Hyperfamiliarity, a phenomenon in which feelings of familiarity are evoked by novel stimuli, is well described in epilepsy and the lesioned brain. Abnormality of familiarity in Alzheimer's disease (AD) and mild cognitive impairment (MCI) have also been described in the literature, but more from a neuropsychological approach perspective. Currently, there is a lack of study on the real-life experience of familiarity abnormality in dementia and MCI. Our aim was to compare the occurrence of hyperfamiliarity among dementia and MCI. MATERIALS AND METHODS: We recruited 73 participants, 29 with AD, 10 with vascular dementia, 7 with MCI and 27 healthy controls, and administered a questionnaire to assess hyperfamiliarity frequency. RESULTS: Hyperfamiliarity was observed in real-life in cognitive impairment, but was unrelated to its severity or underlying aetiology. CONCLUSION: This study highlights the similar rate of occurrence of hyperfamiliarity in the daily life of individuals with cognitive impairment. Future research should examine neuropsychological correlations and mechanisms that contribute to such observations.

Education and Executive Function Mediate Engagement in Advance Care Planning in Early Cognitive Impairment.

BACKGROUND: Advance care planning (ACP) is an important component to holistic care for people with early cognitive impairment (ECI) who are generally still mentally capable of making rational decisions. This study explores the willingness of people with ECI to engage in ACP and how clinical and behavioral variables shape their decisions. METHODS: Ninety-eight persons with ECI (mild cognitive impairment or early dementia, Clinical Dementia Rating = 0.5/1.0) and assessed to have adequate insight (Clinical Insight Rating Scale) underwent an ACP information session. They were assessed on their knowledge of dementia (Knowledge of Alzheimer Disease) and willingness to engage in ACP, and were interviewed on their beliefs and attitudes toward ACP (Perceived Barriers and Benefits Scale to ACP). Univariate analysis and logistic regression identified factors that predicted persons willing or unwilling to engage in ACP based on their responses to the perceived barriers and benefits of ACP as well as sociodemographic and clinical variables. RESULTS: Fifty-two persons (54%) were keen on ACP. On univariate analysis, persons with better executive function [Frontal Assessment Battery (FAB)] (t = -3.63, P < .0001), were more educated (t = -2.11, P = .038) and had lower barriers to ACP (t = 2.47, P = .015), particularly less "passive coping" (t = 2.83, P = .006), were more keen on ACP. Logistic regression revealed that the combined predictive model comprising FAB, education, and passive coping as a whole reliably differentiated those unwilling to engage in ACP from those who were willing (χ(2) = 18.995, P = .001 with df = 4). Wald criterion showed that FAB (P = .016) and passive coping (P = .023) contributed most to prediction. CONCLUSIONS: Better education and executive function predict willingness to engage in ACP, and these factors are instrumental in a person's ability to acquire knowledge and process information. Initiating ACP discussions early, increasing efforts at education, and providing tailored information are important interventions that facilitate completion of ACP.

Chronic impairment of prospective memory after mild traumatic brain injury.

Prospective memory (PM), the ability to recall future intentions, is crucial for independent living. Impairment of PM is a common complaint following head injury and is a significant impediment to good recovery, yet no studies have explored PM in mild traumatic brain injury (mTBI). In this study, prospective memory was examined in 31 mTBI patients and matched controls within a month of injury and 3 months after. mTBI patients performed more poorly than controls on the MIST task (Raskin, 2004) within the first month following injury, indicating that PM impairment is part of the acute cognitive sequelae of mTBI. These problems persisted beyond 3 months post-injury, suggesting that PM may be a sensitive indicator of cerebral compromise in mild brain injuries.