Psychometric Validation of The Cognitive Abilities Screening Instrument Using Rasch Analysis In People With Dementia

Background: The Cognitive Abilities Screening Instrument (CASI) is one of the most commonly used cognitive screening tools to assess overall cognitive function in people with dementia. However, the unidimensionliaty of the CASI using Rasch analysis has not been evaluated in people with dementia, limiting its utility in clinical and research settings. Unidimensionality verifies whether all items of a measure reflect a single theoretical construct, which is necessary to determine whether clinicians and researchers can appropriately use the sum scores of the CASI to describe overall cognitive function. This study aimed to examine unidimensionality of the CASI using Rasch analysis and estimate Rasch person reliability in people with dementia. Methods: CASI data of people with dementia was collected from medical records of one general hospital in northern Taiwan. A total of 506 people with dementia were recruited from the Department of Neurology. Unidimensionality was confirmed through two assumptions: (1) the infit and outfit mean square (MnSq) were 0.6-1.4, and (2) residual variance of the first principal component in principal component analysis was ≤ 20%. Rasch person reliability was estimated after undimensionality was supported. Results: One item from the list-generating fluency dimension was misfitted (outfit MnSq=1.42) and was deleted. The unidimensionality of the remaining 45 items (referred to as the CASI-45) was supported with an infit and outfit MnSq (0.85-1.24 and 0.84-1.28, respectively) and low residual variance of the first principal component (12.8%). The Rasch person reliability of the CASI-45 was 0.62. Conclusion: The CASI-45 showed a unidimensional construct and had acceptable Rasch person reliability in people with dementia.

Random Forest Model in the Diagnosis of Dementia Patients with Normal Mini-Mental State Examination Scores

Background: Mini-Mental State Examination (MMSE) is the most widely used tool in cognitive screening. Some individuals with normal MMSE scores have extensive cognitive impairment. Systematic neuropsychological assessment should be performed in these patients. This study aimed to optimize the systematic neuropsychological test battery (NTB) by machine learning and develop new classification models for distinguishing mild cognitive impairment (MCI) and dementia among individuals with MMSE ≥ 26. Methods: 375 participants with MMSE ≥ 26 were assigned a diagnosis of cognitively unimpaired (CU) (n = 67), MCI (n = 174), or dementia (n = 134). We compared the performance of five machine learning algorithms, including logistic regression, decision tree, SVM, XGBoost, and random forest (RF), in identifying MCI and dementia. Results: RF performed best in identifying MCI and dementia. Six neuropsychological subtests with high-importance features were selected to form a simplified NTB, and the test time was cut in half. The AUC of the RF model was 0.89 for distinguishing MCI from CU, and 0.84 for distinguishing dementia from nondementia. Conclusions: This simplified cognitive assessment model can be useful for the diagnosis of MCI and dementia in patients with normal MMSE. It not only optimizes the content of cognitive evaluation, but also improves diagnosis and reduces missed diagnosis.

Is Old Age Just a Number in Language Skills? Language Performance and Its Relation to Age, Education, Gender, Cognitive Screening, and Dentition in Very Old Finnish Speakers

Purpose: This study reports on how very old (VO) Finnish people without dementia perform in the Western Aphasia Battery (WAB) and two verbal fluency tasks and which demographic factors predict the performance. Method: The study included fifty 80- to 100-year-old community-dwelling Finnish speakers with no dementing illnesses or speech-language disabilities, who completed the WAB and two verbal fluency tasks. Multifactorial statistical analyses with recursive partitioning were carried out to determine the significant predictors out of five predictor variables (age, gender, education, dentition, and Mini-Mental State Examination [MMSE]) for four response variables (WAB Aphasia Quotient [AQ], Language Quotient [LQ], semantic, and phonemic word fluencies). Results: Overall, individual variation was notable in VO speakers. All predictor variables were statistically significantly associated with one or more of the language skills. Age was the most significant predictor; the critical age of 85–86 years was associated with a decline in WAB-AQ and semantic fluency. Poor dentition and the MMSE score both predicted a decline in WAB-LQ and phonemic fluency. A high level of education was positively associated with the skills of the best-performing individuals in WAB-AQ, WAB-LQ, and semantic fluency. Conclusions: VO age is a significant factor contributing to language performance. However, a younger age, a good cognitive performance, intact teeth, and a higher educational level also seem to have a preservative power as regards language skills. Gender differences should be interpreted with caution. The results of this study provide culture- and language-specific normative data, which aids in differentiating typical aging from the signs of acute or degenerative neuropathology to ensure appropriate medical and therapeutic interventions.

Verbal Learning as a predictor of risks of accidents in elderly drivers

ABSTRACT Background: Age-related cognitive decline impacts cognitive abilities essential for driving. Objective: We aimed to measure main cognitive functions associated with a high number of traffic violations in different driving settings. Methods: Thirty-four elderly individuals, aged between 65 and 90 years, were evaluated with a driving simulator in four different settings (Intersection, Overtaking, Rain, and Malfunction tasks) and underwent a battery of cognitive tests, including memory, attention, visuospatial, and cognitive screening tests. Individuals were divided into two groups: High-risk driving (HR, top 20% of penalty points) and normal-risk driving (NR). Non-parametric group comparison and regression analysis were performed. Results: The HR group showed higher total driving penalty score compared to the NR group (median=29, range= 9-44 vs. median=61, range= 47-97, p<0.001). The HR group showed higher penalty scores in the Intersection task (p<0.001) and the Overtaking and Rain tasks (p<0.05 both). The verbal learning score was significantly lower in the HR group (median=33, range=12-57) compared with the NR group (median=38, range=23-57, p<0.05), and it was observed that this score had the best predictive value for worse driving performance in the regression model. General cognitive screening tests (Mini-Mental State Examination and Addenbrooke's Cognitive Evaluation) were similar between the groups (p>0.05), with a small effect size (Cohen’s d=0.3 both). Conclusion: The verbal learning score may be a better predictor of driving risk than cognitive screening tests. High-risk drivers also showed significantly higher traffic driving penalty scores in the Intersection, Overtaking, and Rain tests.

Comparison of the Mini-Mental State Examination and Computerized Brief Cognitive Screening Test as Cognitive Screening Tools in Patients with Mild Cognitive Impairment

Background: The aim of this study was to establish the validity and reliability of the Computerized Brief Cognitive Screening Test (CBCog) for early detection of cognitive impairment. Method: One hundred and sixty participants, including community-dwelling and out-patient volunteers (both men and women) aged ≥ 65 years, were enrolled in the study. All participants were screened using the CBCog and Mini-Mental State Examination (MMSE). The internal consistency of the CBCog was analyzed using Cronbach’s α test. Areas under the curves (AUCs) of receiver operating characteristic analyses were used to test the predictive accuracy of the CBCog in detecting mild cognitive impairment (MCI) in order to set an appropriate cutoff point. Results: The CBCog scores were positively correlated with the MMSE scores of patients with MCI-related dementia (r = 0.678, P < .001). The internal consistency of the CBCog (Cronbach’s α) was 0.706. It was found that the CBCog with a cutoff point of 19/20 had a sensitivity of 97.5% and a specificity of 53.7% for the diagnosis of MCI with education level ≥ 6 years. The AUC of the CBCog for discriminating the normal control elderly from patients with MCI (AUC = 0.827, P < 0.001) was larger than that of the MMSE for discriminating the normal control elderly from patients with MCI (AUC= 0.819, P < .001). Conclusion: The CBCog demonstrated to have sufficient validity and reliability to evaluate mild cognitive impairment, especially in highly educated elderly people.

Working Memory Impairment in Transient Ischaemic Attack: N-back as a Sensitive Measure for Detection

Background: Transient ischaemic attack (TIA) can lead to lasting changes in brain structure and function resulting in cognitive impairment. Cognitive screening tools may lack sensitivity for detecting cognitive impairments, particularly executive function, which tends to be the earliest affected domain in vascular cognitive impairment. Aim: In this preliminary study, we examine a working memory (WMem) task as a sensitive measure of cognitive impairment in TIA. Method: Patients referred to a TIA clinic for transient neurological symptoms completed a general cognitive screening tool (Montreal Cognitive Assessment; MoCA), and a WMem task (2-N-back) in a cross-sectional design. Results: TIA patients (n = 12) showed significantly reduced WMem performance on the N-back compared to patients diagnosed with mimic clinical conditions with overlapping symptoms (n = 16). No group differences were observed on the MoCA. Conclusions: Assessing WMem may provide a sensitive measure of cognitive impairment after TIA, with implications for cognitive screening in TIA services to triage patients for further neuropsychological support, or for interventions to prevent vascular dementia.

Cognitive Impairment in Acute Heart Failure: Narrative Review

Cognitive impairment (CI) represents a common but often veiled comorbidity in patients with acute heart failure (AHF) that deserves more clinical attention. In the AHF setting, it manifests as varying degrees of deficits in one or more cognitive domains across a wide spectrum ranging from mild CI to severe global neurocognitive disorder. On the basis of the significant negative implications of CI on quality of life and its overwhelming association with poor outcomes, there is a compelling need for establishment of detailed consensus guidelines on cognitive screening methods to be systematically implemented in the population of patients with heart failure (HF). Since limited attention has been drawn exclusively on the field of CI in AHF thus far, the present narrative review aims to shed further light on the topic. The underlying pathophysiological mechanisms of CI in AHF remain poorly understood and seem to be multifactorial. Different pathophysiological pathways may come into play, depending on the clinical phenotype of AHF. There is some evidence that cognitive decline closely follows the perturbations incurred across the long-term disease trajectory of HF, both along the time course of stable chronic HF as well as during episodes of HF exacerbation. CI in AHF remains a rather under recognized scientific field that poses many challenges, since there are still many unresolved issues regarding cognitive changes in patients hospitalized with AHF that need to be thoroughly addressed.

Assessment of Cognitive Symptoms in Brain Bank-Registered Control Subjects: Feasibility and Utility of a Telephone-Based Screening

Background: For neuroscience research, the study of brain tissue of neurologically unimpaired subjects is crucial to interpret findings in neurodegenerative diseases. Sub-optimal neurological follow-up and the presence of neuropathological lesions in supposedly asymptomatic subjects casts doubt as to whether these subjects present an undetected underlying neurodegenerative disease or are resilient to neurodegeneration. Objective: We aimed to assess whether the control donors registered in the Neurological Tissue Bank-Hospital Clínic-IDIBAPS (NTB-HCI) are still free of cognitive symptoms at follow-up and to evaluate the feasibility and utility of a telephone-based screening. Methods: All control subjects older than 65 years registered at the NTB-HCI database were selected for the study. After a structured telephone interview, those subjects already diagnosed with a neurological disease were excluded. Then, a cognitive screening was performed, including the telephone version of the Mini-Mental State Examination (t-MMSE) and the eight-item interview (AD-8) to the subject and to one informant. Results: In total, 73.8% of the registered donors collaborated in the study. Only 21.4% had at least one of the three cognitive screening tools impaired, and 2.7% had a profile highly suggestive of cognitive impairment. AD-8i correlated moderately with t-MMSE. Conclusion: Telephone-based neurologic screening in control donors is feasible and was within the normal range in most of the subjects in our cohort. Albeit, the involvement of neurologists and periodic neurological screenings are desirable in a control subjects brain donor program, AD8-i could be used to screen the control’s neurological status in the absence of accurate clinical data at the time of the death.