Validity of the Mini-Mental State Examination-2 in Diagnosing Mild Cognitive Impairment and Dementia in Patients Visiting an Outpatient Clinic in the Netherlands

Bayesian estimation for the accuracy of three neuropsychological tests in detecting Alzheimer's disease and mild cognitive impairment: a retrospective analysis of the ADNI database

BACKGROUND

The neuropathological confirmation serves as the gold standard for diagnosing Alzheimer's disease (AD), but it is usually not available to the living individuals. In addition, the gold standard for diagnosing Mild Cognitive Impairment (MCI) remains unclear yet. Neuropsychological testing, such as the Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog), is commonly used tests in identifying AD and MCI, offering convenience, affordability, non-invasiveness, and accessibility in clinical settings. We aimed to accurately evaluate the discriminative ability of the three tests administrated at the same visit simultaneously in detecting AD and MCI due to AD in the absence of a gold standard.

METHODS

A total of 1289 participants aged over 65 were included from the baseline visits of Alzheimer's disease Neuroimaging Initiative. Bayesian latent class models, accounting for conditional dependence between MoCA and MMSE, were conducted to assess the diagnostic accuracy of the three tests for detecting AD and MCI.

RESULTS

In detecting AD, the ADAS-cog had the highest Youden's Index (0.829), followed by the MoCA(0.813) and MMSE(0.796). The ADAS-cog and MoCA showed similar sensitivity (0.922 vs 0.912) and specificity (0.907 vs 0.901), while the MMSE had lower sensitivity (0.874) and higher specificity (0.922). For MCI detection, the ADAS-cog had the highest Youden's Index (0.704) compared to the MoCA (0.614) and MMSE (0.478). The ADAS-cog exhibited the highest sensitivity, closely followed by the MoCA and MMSE (0.869 vs 0.845 vs 0.757), and the ADAS-cog also had good specificity (0.835 vs 0.769 vs 0.721). The estimated true prevalence of AD among individuals aged over 65 was 20.0%, and the estimated true prevalence of MCI due to AD was 24.8%.

CONCLUSIONS

The findings suggest that the ADAS-cog and MoCA are reliable tools for detecting AD and MCI, while the MMSE may be less sensitive in detecting these conditions. A large underdiagnosis of the MCI and Alzheimer's population still remains in clinical screening.

Leveraging network analysis to determine sex differences in factors associated with frailty among older adults living alone

BACKGROUND

Frailty is a complex geriatric syndrome typically characterized by multiple underlying etiological factors. We determined the contributing factors, by sex, using a network analysis.

METHODS

The study sample consisted of a cross-sectional cohort of community-dwelling older adults aged ≥ 65 years living alone in a Korean city (N = 1,037). Frailty was assessed via the Korean Frailty Index. Participants were assessed for sociodemographic, health-related, mental and cognitive, and social characteristics. Mixed graphical models including all variables were estimated using the R-package mgm discretely by sex. We also used the Walktrap cluster algorithm to identify differences in the network structure in terms of connectivity around frailty between the sex groups for further insights.

RESULTS

In both the networks for males and females, frailty correlated most strongly with nutritional status, presence of complex chronic disease, and self-efficacy, and exhibited proximity to decreased sleep quality and loneliness. However, frailty showed an association with suicidal ideation and the number of falls per year only in males, whereas it showed an association with functional disabilities only in females. The overall network connectivity around frailty was stronger with dense interactions (more edges) in the network for females than for males.

CONCLUSIONS

The results signify the need for sex-group customized multi-domain assessments and interventions for the prevention and improvement of frailty among community-dwelling older adults.

[Features of neuropsychological status and results of magnetic resonance morphometry in patients with Alzheimer's disease and glaucoma]

OBJECTIVE

To identify the relationship of neuropsychological changes in patients with Alzheimer's disease (AD) and primary open-angle glaucoma (POAG) and to evaluate the results of magnetic resonance (MR)-morphometry in patients with these diseases.

MATERIAL AND METHODS

We examined 32 patients (median age 67 [61.25; 76.75] years, 78.1% women) diagnosed with AD and POAG. The patients were divided into the AD group (n=16) and the POAG group (n=16). Complaints and anamnesis were collected for all patients, neurological status and neuropsychological status were assessed. MRI of the brain, followed by morphometry, was performed.

RESULTS

Cognitive impairments (CI) were revealed in patients of both groups. The severity of CI in patients with AD was more pronounced than in patients with POAG (p<0.001). Alzheimer's type of CI was detected in both groups. MR-morphometry revealed a decrease in the volume of the left hippocampus, the volume of the right and left amygdala as well as a decrease in the thickness of the right and left entorhinal cortex in the AD group compared with the POAG group (p<0.05). A significant decrease in the thickness of the right medial orbitofrontal cortex was found in the POAG group compared with the AD group (p<0.05).

CONCLUSION

In AD and POAG, there is a similarity of the neuropsychological profile, which reflects the neurodegeneration characteristic of these diseases. MRI morphometry requires an assessment of both volumes and thickness of brain structures. A neuroimaging pattern identified in patients with POAG can be regarded as an indicator of the glaucomatous process.

Improvement of poststroke cognitive impairment by intermittent theta bursts: A double-blind randomized controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) is known to improve cognitive impairment caused by Alzheimer's disease and Parkinson's disease, but studies are lacking with respect to the efficacy of iTBS on poststroke cognitive impairment (PSCI).

OBJECTIVE

This study was conducted to investigate the effect of left dorsolateral prefrontal cortex (DLPFC) iTBS on improving cognitive function in stroke patients.

METHODS

Fifty-eight patients with PSCI are randomly divided into iTBS (n = 28) and sham stimulation groups (n = 30). Both groups receive routine cognitive-related rehabilitation. The iTBS group is treated with iTBS intervention of the left DLPFC, and the sham stimulation group is treated with the same parameters at the same site for 2 weeks. Outcome measures are assessed at baseline (T0) and immediately after the last intervention (T1) by mini-mental state examination (MMSE), Oxford cognitive screen, and event-related potential P300.

RESULTS

There are no differences in baseline clinical characteristics between the two groups. After intervention, the MMSE scores and P300 amplitude increase significantly for both groups, and the P300 incubation period reduces significantly. The change value of the iTBS group is significantly higher than that of sham stimulation group (p < .05). Compared with the sham stimulation group, the iTBS group has more significant changes in semantic comprehension and executive function (p < .05).

CONCLUSION

iTBS can effectively and safely improve overall cognitive impairment in stroke patients, including semantic understanding and executive function, and it also has a positive impact on memory function. Future randomized controlled studies with large samples and long-term follow-up should be conducted to further validate the results of the present study.

Cognitive impairment and associated factors among mature and older adults living in the community of Gondar town, Ethiopia, 2020

Cognitive impairment and dementia are age-related major public health concerns in the elderly population. It is a major cause of disability, dependency, and poor quality of life. However, in Ethiopia, the magnitude of this cognitive impairment among the elderly community was not investigated. Hence, this study sought to determine the prevalence of cognitive impairment and associated factors among mature and older adults living in the community of Gondar town, Ethiopia, in 2020. A community-based cross-sectional study was conducted at Gondar town, from February 20 to April 30, 2020. Using a single-stage cluster sampling technique, 403 study participants were recruited. Data was collected by a pretested interviewer-administered structured questionnaire which consisting of sociodemographic variables, the Oslo Social Support Scale, and a Standardized Mini-mental State Examination (SMMSE) tool. Epi data version 3.0 was used to enter coded data and then exported into STATA 14 for analysis. Variables with a p-value < 0.25 in the bi-variable logistic regression were included in the multivariable regression. From multivariable logistic regression, variables having a p-value ≤ 0.05 were declared as statistically significant variables. In this study, a total of 403 study participants were involved, and 393 (97.5%) of them completed the survey. Among older participants screened for cognitive impairment, 43.8% was positive for cognitive impairment with a 95% CI (38.8-48.7%). The majority of the participants were (57.5%) male and (44.8%) aged over 60 years. After adjustment, the variables associated with cognitive impairment were age ≥ 75 years [odds ratio (OR) = 7.03, 95% CI 2.78-17.77] and between 61 and 74 years [OR = 3.18, 95% CI 1.81-5.59], and unable to read and write [OR = 5.05, 95% CI 2.04-12.50], low income level [OR = 2.60, 95% CI 1.26-5.20], being female [OR = 2.52, 95% CI 1.50-4.26], poor social support [OR = 2.50, 95% CI 1.30-4.81], and rural residence [OR = 2.39, 95% CI 1.26-4.51]. The prevalence of older participants who screened positively for cognitive impairment was high at Gondar town. The independent predictors of cognitive impairment among older individuals were older age, being unable to read and write, being female, low income, poor social support, and rural dwelling. Therefore, routine screening and social support, as well as free healthcare services for the mature and older community, are needed. Moreover, we strongly recommend the next researcher to use a diagnosis tool to estimate the actual prevalence of the problems among older people.

Relationship between Vitamin C Deficiency and Cognitive Impairment in Older Hospitalised Patients: A Cross-Sectional Study

Vitamin C is a powerful antioxidant and facilitates neurotransmission. This study explored association between vitamin C deficiency and cognitive impairment in older hospitalised patients. This prospective study recruited 160 patients ≥ 75 years admitted under a Geriatric Unit in Australia. Cognitive assessment was performed by use of the Mini-Mental-State-Examination (MMSE) and patients with MMSE scores <24 were classified as cognitively-impaired. Fasting plasma vitamin C levels were determined using high-performance-liquid-chromatography. Patients were classified as vitamin C deficient if their levels were below 11 micromol/L. Logistic regression analysis was used to determine whether vitamin C deficiency was associated with cognitive impairment after adjustment for various covariates. The mean (SD) age was 84.4 (6.4) years and 60% were females. A total of 91 (56.9%) were found to have cognitive impairment, while 42 (26.3%) were found to be vitamin C deficient. The mean (SD) MMSE scores were significantly lower among patients who were vitamin C deficient (24.9 (3.3) vs. 23.6 (3.4), p-value = 0.03). Logistic regression analysis suggested that vitamin C deficiency was 2.9-fold more likely to be associated with cognitive impairment after adjustment for covariates (aOR 2.93, 95% CI 1.05−8.19, p-value = 0.031). Vitamin C deficiency is common and is associated with cognitive impairment in older hospitalised patients.