Application of the DSM-5 Criteria for Major Neurocognitive Disorder to Vascular MCI Patients

Hippocampal atrophy and white matter lesions characteristics can predict evolution to dementia in patients with vascular mild cognitive impairment

BACKGROUND

Vascular mild cognitive impairment (VMCI) is a transitional condition that may evolve into Vascular Dementia(VaD). Hippocampal volume (HV) is suggested as an early marker for VaD, the role of white matter lesions (WMLs) in neurodegeneration remains debated.

OBJECTIVES

Evaluate HV and WMLs as predictive markers of VaD in VMCI patients by assessing: (i)baseline differences in HV and WMLs between converters to VaD and non-converters, (ii) predictive power of HV and WMLs for VaD, (iii) associations between HV, WMLs, and cognitive decline, (iv)the role of WMLs on HV.

METHODS

This longitudinal multicenter study included 110 VMCI subjects (mean age:74.33 ± 6.63 years, 60males/50females) from the VMCI-Tuscany Study database. Subjects underwent brain MRI and cognitive testing, with 2-year follow-up data on VaD progression. HV and WMLs were semi-automatically segmented and measured. ANCOVA assessed group differences, while linear and logistic regression models evaluated predictive power.

RESULTS

After 2 years, 32/110 VMCI patients progressed to VaD. Converting patients had lower HV(p = 0.015) and higher lesion volumes in the posterior thalamic radiation (p = 0.046), splenium of the corpus callosum (p = 0.016), cingulate gyrus (p = 0.041), and cingulum hippocampus(p = 0.038). HV alone did not fully explain progression (p = 0.059), but combined with WMLs volume, the model was significant (p = 0.035). The best prediction model (p = 0.001) included total HV (p = 0.004) and total WMLs volume of the posterior thalamic radiation (p = 0.005) and cingulate gyrus (p = 0.005), achieving 80% precision, 81% specificity, and 74% sensitivity. Lower HV were linked to poorer performance on the Rey Auditory-Verbal Learning Test delayed recall (RAVLT) and Mini Mental State Examination (MMSE).

CONCLUSIONS

HV and WMLs are significant predictors of progression from VMCI to VaD. Lower HV correlate with worse cognitive performance on RAVLT and MMSE tests.

The Inflammasome Adaptor Protein ASC in Plasma as a Biomarker of Early Cognitive Changes

Dementia is a group of symptoms including memory loss, language difficulties, and other types of cognitive and functional impairments that affects 57 million people worldwide, with the incidence expected to double by 2040. Therefore, there is an unmet need to develop reliable biomarkers to diagnose early brain impairments so that emerging interventions can be applied before brain degeneration. Here, we performed biomarker analyses for apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and amyloid-β 42/40 (Aβ42/40) ratio in the plasma of older adults. Participants had blood drawn at baseline and underwent two annual clinical and cognitive evaluations. The groups tested either cognitively normal on both evaluations (NN), cognitively normal year 1 but cognitively impaired year 2 (NI), or cognitively impaired on both evaluations (II). ASC was elevated in the plasma of the NI group compared to the NN and II groups. Additionally, Aβ42 was increased in the plasma in the NI and II groups compared to the NN group. Importantly, the area under the curve (AUC) for ASC in participants older than 70 years old in NN vs. NI groups was 0.81, indicating that ASC is a promising plasma biomarker for early detection of cognitive decline.

Fractal dimension of the cortical gray matter outweighs other brain MRI features as a predictor of transition to dementia in patients with mild cognitive impairment and leukoaraiosis

Background

The relative contribution of changes in the cerebral white matter (WM) and cortical gray matter (GM) to the transition to dementia in patients with mild cognitive impairment (MCI) is not yet established. In this longitudinal study, we aimed to analyze MRI features that may predict the transition to dementia in patients with MCI and T2 hyperintensities in the cerebral WM, also known as leukoaraiosis.

Methods

Sixty-four participants with MCI and moderate to severe leukoaraiosis underwent baseline MRI examinations and annual neuropsychological testing over a 2 year period. The diagnosis of dementia was based on established criteria. We evaluated demographic, neuropsychological, and several MRI features at baseline as predictors of the clinical transition. The MRI features included visually assessed MRI features, such as the number of lacunes, microbleeds, and dilated perivascular spaces, and quantitative MRI features, such as volumes of the cortical GM, hippocampus, T2 hyperintensities, and diffusion indices of the cerebral WM. Additionally, we examined advanced quantitative features such as the fractal dimension (FD) of cortical GM and WM, which represents an index of tissue structural complexity derived from 3D-T1 weighted images. To assess the prediction of transition to dementia, we employed an XGBoost-based machine learning system using SHapley Additive exPlanations (SHAP) values to provide explainability to the machine learning model.

Results

After 2 years, 18 (28.1%) participants had transitioned from MCI to dementia. The area under the receiving operator characteristic curve was 0.69 (0.53, 0.85) [mean (90% confidence interval)]. The cortical GM-FD emerged as the top-ranking predictive feature of transition. Furthermore, aggregated quantitative neuroimaging features outperformed visually assessed MRI features in predicting conversion to dementia.

Discussion

Our findings confirm the complementary roles of cortical GM and WM changes as underlying factors in the development of dementia in subjects with MCI and leukoaraiosis. FD appears to be a biomarker potentially more sensitive than other brain features.

Tools for the Assessment of Risk-Taking Behavior in Older Adults with Mild Dementia: A Cross-Sectional Clinical Study

Diseases such as Alzheimer's cause an alteration of cognitive functions, which can lead to increased daily risk-taking in older adults living at home. The assessment of decision-making abilities is primarily based on clinicians' global analysis. Usual neuropsychological tests such as the MoCA (Montreal Cognitive Assessment) cover most of the cognitive domains and include mental flexibility tasks. Specific behavioral tasks for risk-taking, such as the Balloon Analogue Risk Task (BART) or the Iowa Gambling Task (IGT), have been developed to assess risk-taking behavior, particularly in the field of addictology. Our cross-sectional study aims to determine whether the MoCA global cognitive assessment could be used as a substitute for behavioral tasks in the assessment of risky behavior. In the current study, 24 patients (age: 82.1 ± 5.9) diagnosed with mild dementia completed the cognitive assessment (MoCA and executive function assessment) and two behavioral risk-taking tasks (BART, simplified version of the IGT). Results revealed no relationship between scores obtained in the MoCA and behavioral decision-making tasks. However, the two tasks assessing risk-taking behavior resulted in concordant risk profiles. In addition, patients with a high risk-taking behavior profile on the BART had better Trail Making Test (TMT) scores and thus retained mental flexibility. These findings suggest that MoCA scores are not representative of risk-taking behavioral inclinations. Thus, additional clinical tests should be used to assess risk-taking behavior in geriatric settings. Executive function measures, such as the TMT, and behavioral laboratory measures, such as the BART, are recommended for this purpose.

Decreased Cerebrovascular Reactivity in Mild Cognitive Impairment Phenotypes

BACKGROUND

Cerebrovascular health plays an important role in cognitive health in older adults. Cerebrovascular reactivity (CVR), a measure of cerebrovascular health, changes in both normal and pathological aging, and is increasingly being conceptualized as contributory to cognitive decline. Interrogation of this process will yield new insights into cerebrovascular correlates of cognition and neurodegeneration.

OBJECTIVE

The current study examines CVR using advanced MRI in prodromal dementia states (amnestic and non-amnestic mild cognitive impairment phenotypes; aMCI and naMCI, respectively) and older adult controls.

METHODS

CVR was assessed in 41 subjects (20 controls, 11 aMCI, 10 naMCI) using multiband multi-echo breath-holding task functional magnetic resonance imaging. Imaging data were preprocessed and analyzed using AFNI. All participants also completed a battery of neuropsychological tests. T-tests and ANOVA/ANCOVA analyses were conducted to compare controls to MCI groups on CVR and cognitive metrics. Partial correlation analyses between CVR derived from regions-of-interest (ROIs) and different cognitive functions were conducted.

RESULTS

CVR was found to be significantly lower in aMCI and naMCI patients compared to controls. naMCI showed intermediate patterns between aMCI and controls (though aMCI and naMCI groups did not significantly differ). CVR of ROIs were positively correlated with neuropsychological measures of processing speed, executive functioning, and memory.

CONCLUSION

The findings highlight regional CVR differences in MCI phenotypes compared to controls, where aMCI may have lower CVR than naMCI. Our results suggest possible cerebrovascular abnormalities associated with MCI phenotypes.

Performance of the Rowland Universal Dementia Assessment Scale in Screening Mild Cognitive Impairment at an Outpatient Setting

Introduction

Mild cognitive impairment (MCI) is defined as the symptomatic pre-dementia phase on the continuum of cognitive decline. Early recognition and application of potential interventions could prevent or delay the progression to dementia. The Rowland Universal Dementia Assessment Scale (RUDAS) shows good performance in the screening of dementia but has limited data regarding its diagnostic properties in the screening of MCI. The objectives of this study were to assess the psychometric properties of the Thai version of the RUDAS (RUDAS-Thai) in the screening of MCI, identify associated factors for the RUDAS performance, and determine the optimal cutoff point in detecting MCI.

Methods

This was a cross-sectional study conducted from January 2020 to March 2021. Older patients at the outpatient clinic of an internal medicine department at a tertiary care hospital in Thailand were examined. Baseline data were collected, and the RUDAS-Thai was administered to each patient. Afterward, a geriatrician assessed each patient for MCI.

Results

A total of 150 patients were included, of whom 42 cases (28%) had MCI. The overall performance of the test using an area under the receiver operating characteristic curve (AUC) was 0.82 (95% confidence interval 0.75–0.89). At the optimal cutoff point of 25/30, the AUC was 0.76 with sensitivity and specificity of 76.2 and 75%, respectively. The educational level affected the test performance according to regression analysis. For patients with years of education ≤6 and >6, the optimal cutoff points were 25/30 and 26/30, respectively.

Conclusion

The RUDAS-Thai performed well in differentiating patients with MCI from normal cognition; however, it was affected by educational level. A score of 25/30 or lower for persons with ≤6 years of education or 26/30 or lower for persons with higher than 6 years of education is the optimal cutoff point for indication of developing MCI.

Longitudinal changes in MoCA performances in patients with mild cognitive impairment and small vessel disease. Results from the VMCI-Tuscany Study

OBJECTIVES

The Montreal Cognitive Assessment (MoCA) is a cognitive screening test largely employed in vascular cognitive impairment, but there are no data about MoCA longitudinal changes in patients with cerebral small vessel disease (SVD). We aimed to describe changes in MoCA performance in patients with mild cognitive impairment (MCI) and SVD during a 2-year follow-up, and to evaluate their association with transition to major neurocognitive disorder (NCD).

MATERIALS AND METHODS

Within the prospective observational VMCI-Tuscany Study, patients with MCI and SVD underwent a comprehensive clinical, neuropsychological, and functional evaluation at baseline, and after 1 and 2 years.

RESULTS

Among the 138 patients (mean age 74.4 ± 6.9 years; males: 57%) who completed the study follow-up, 44 (32%) received a major NCD diagnosis. Baseline MoCA scores (mean±SD) were lower in major NCD patients (20.5 ± 5) than in reverter/stable MCI (22.2 ± 4.3), and the difference approached the statistical threshold of significance (p=.051). The total cohort presented a decrease in MoCA score (mean±SD) of -1.3 ± 4.2 points (-2.6 ± 4.7 in major NCD patients, -0.7 ± 3.9 in reverter/stable MCI). A multivariate logistic model on the predictors of transition from MCI to major NCD, showed MoCA approaching the statistical significance (OR=1.09, 95% CI=1.00-1.19, p=.049).

DISCUSSION

In our sample of MCI patients with SVD, longitudinal changes in MoCA performances were consistent with an expected more pronounced deterioration in patients who received a diagnosis of major NCD. MoCA sensitivity to change and predictive utility need to be further explored in VCI studies based on larger samples and longer follow-up periods.

Predementia constructs: Mild cognitive impairment or mild neurocognitive disorder? A narrative review

BACKGROUND

Predementia is a heuristic umbrella concept to classify older adults with cognitive impairment who do not suffer dementia. Many diagnostic entities have been proposed to address this concept, but most of them have not had widespread acceptance.

AIMS

To review clinical definitions, epidemiologic data (prevalence, incidence) and rate of conversion to dementia of the main predementia constructs, with special interest in the two most frequently used: mild cognitive impairment (MCI) and minor neurocognitive disorder (miNCD).

METHODS

We have selected in three databases (MEDLINE, Web of Science and Google scholar) the references from inception to 31 December 2019 of relevant reviews, population and community-based surveys, and clinical series with >500 participants and >3 years follow-up as the best source of evidence.

MAIN RESULTS

The history of predementia constructs shows that MCI is the most referred entity. It is widely recognized as a clinical syndrome harbinger of dementia of several etiologies, mainly MCI due to Alzheimer's disease. The operational definition of MCI has shortcomings: vagueness of its requirement of "preserved independence in functional abilities" and others. The recent miNCD construct presents analogous difficulties. Current data indicate that it is a stricter predementia condition, with lower prevalence than MCI, less sensitivity to cognitive decline and, possibly, higher conversion rate to dementia.

CONCLUSIONS

MCI is a widely employed research and clinical entity. Preliminary data indicate that the clinical use of miNCD instead of MCI requires more scientific evidence. Both approaches have common limitations that need to be addressed.

Association of nimodipine and choline alphoscerate in the treatment of cognitive impairment in patients with cerebral small vessel disease: study protocol for a randomized placebo-controlled trial-the CONIVaD trial

BACKGROUND

Vascular cognitive impairment (VCI) is an extremely disabling condition that includes post-stroke dementia and VCI caused by cerebral small vessel disease (SVD). Currently, there is no approved treatment for this condition. Drugs active on the cholinergic pathway have been tested in VCI patients showing positive but limited efficacy. The calcium-antagonist nimodipine also showed some moderate positive effects in VCI patients.

AIMS

CONIVaD (choline alphoscerate and nimodipine in vascular dementia) is a pilot, single-center, double-blinded, randomized trial aimed to assess whether the association of choline alphoscerate and nimodipine is more effective than nimodipine alone in reducing cognitive decline in patients with SVD and mild-to-moderate cognitive impairment.

METHODS

All patients are evaluated at baseline and after 12 months with: (1) clinical, daily functions, quality of life, and mood assessment and (2) extensive neuropsychological evaluation. After the baseline evaluation, patients are randomly assigned to one of the two arms of treatment: (1) nimodipine 90 mg/die t.i.d plus placebo b.i.d and (2) nimodipine 90 mg t.i.d plus choline alphoscerate 1200 mg/die b.i.d. for a total of 12 months. The primary endpoint is cognitive decline, expressed as the loss of at least two points on the Montreal Cognitive Assessment at 12 months. Secondary endpoints include safety and tolerability, functional, quality of life, and neuropsychological measures.

DISCUSSION

CONIVaD study is the first randomized controlled trial to examine the cognitive efficacy of combined choline alphoscerate-nimodipine treatment in VCI patients. Results of this pilot study will serve as a methodological basis for other clinical controlled, multicentric, double-blinded, and randomized trials.

TRIAL REGISTRATION

Clinical Trial NCT03228498. Registered 25 July 2017.

The role of the neuropsychologist in memory clinics

International recommendations and guidelines on the diagnosis and management of cognitive impairment highlight the relevance of a multidimensional approach with increasing attention to well-established cognitive evaluations and interventions. Memory clinics represent a model that offers the expertise of several health specialties. This commentary aims at detailing the contribution of the neuropsychologist in this setting, and highlighting the need of implementing its presence in all the dedicated services. The neuropsychologist can offer an expertise that can be employed both in clinical routes and research, being able to synergistically interact with all the other health specialists involved in memory clinics. The role of the neuropsychologist in cognitive impairment diagnosis includes the development and the administration of comprehensive test batteries and the determination of both the degree of impairment and the cognitive profile, thus contributing to differential diagnoses. In the management of cognitive impairment, the neuropsychologist expertise can contribute in care planning and monitoring, in administering cognition-focused interventions, and in measuring treatment response. In cognitive impairment research, beyond the development and administration of test batteries, the neuropsychologist can contribute actively to the choice of cognitive study outcomes, data analysis, and results interpretation within an interdisciplinary framework. An overview of the actual weight of neuropsychologists in Italian memory clinics shows that, despite the presence of a psychologist in the team could be felt as an added value, several difficulties are still encountered in the integration of this figure as a permanent member. Efforts need to be made in this direction.

Cognitive impairment in late life bipolar disorder: Risk factors and clinical outcomes

BACKGROUND

Late Life Bipolar Disorder (LLBD) is associated with a high prevalence of cognitive impairments, but few studies have examined their risk factors and clinical correlates METHODS: Participants with bipolar disorder older than 60 (n = 86) were recruited from psychiatric outpatient and inpatients units. Patients were assessed with various instruments, including the Clinical Dementia Rating scale, the Montreal Cognitive Assessment and the Cumulative Illness Rating Scale. The distribution of disorder-specific and general risk factors was compared between patients with LLBD plus cognitive impairments (mild cognitive impairment or dementia) and those with LLBD but no cognitive impairment. Analyses were first conducted at the bivariate level, then using multiple regression. The association with disability, aggressive behavior and suicidal ideation was also explored.

RESULTS

Cognitive impairments in LLBD were associated with a diagnosis of type 1 bipolar disorder (OR = 6.40, 95%CI: 1.84 - 22.31, p = 0.004), fewer years of education (OR = 0.79, 95%CI: 0.69 - 0.91, p = 0.001) and higher severity of physical diseases (OR 26.54, 95%CI: 2.07 - 340.37, p = 0.01). Moreover, cognitive impairments were associated with an increased likelihood of disability and recent aggressive behavior, but not suicidal ideation.

LIMITATIONS

retrospective design, conflation of MCI and dementia, not all subjects were in euthymia CONCLUSIONS: In LLBD, the presence of cognitive impairments was associated with a diagnosis of type I bipolar disorder, lower education and more severe physical comorbidities. In turn, MCI or dementia were associated with increased disability and aggressive behavior. These findings may aid the identification of patients at risk for cognitive deterioration in everyday clinical practice.