Impaired Neurovascular Coupling and Increased Functional Connectivity in the Frontal Cortex Predict Age-Related Cognitive Dysfunction.

Impaired cerebrovascular function contributes to the genesis of age-related cognitive decline. In this study, the hypothesis is tested that impairments in neurovascular coupling (NVC) responses and brain network function predict cognitive dysfunction in older adults. Cerebromicrovascular and working memory function of healthy young (n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed. To determine NVC responses and functional connectivity (FC) during a working memory (n-back) paradigm, oxy- and deoxyhemoglobin concentration changes from the frontal cortex using functional near-infrared spectroscopy are recorded. NVC responses are significantly impaired during the 2-back task in aged participants, while the frontal networks are characterized by higher local and global connection strength, and dynamic FC (p < 0.05). Both impaired NVC and increased FC correlate with age-related decline in accuracy during the 2-back task. These findings suggest that task-related brain states in older adults require stronger functional connections to compensate for the attenuated NVC responses associated with working memory load.

Cerebral small vessel disease pathology in COVID-19 patients: A systematic review.

Cerebral small vessel disease (CSVD) is the leading cause of vascular cognitive impairment and is associated with COVID-19. However, contributing factors that often accompany CSVD pathology in COVID-19 patients may influence the incidence of cerebrovascular complications. Thus, a mechanism linking COVID-19 and CSVD has yet to be uncovered and differentiated from age-related comorbidities (i.e., hypertension), and medical interventions during acute infection. We aimed to evaluate CSVD in acute and recovered COVID-19 patients and to differentiate COVID-19-related cerebrovascular pathology from the above-mentioned contributing factors by assessing the localization of microbleeds and ischemic lesions/infarctions in the cerebrum, cerebellum, and brainstem. A systematic search was performed in December 2022 on PubMed, Web of Science, and Embase using a pre-established search criterion related to history of, or active COVID-19 with CSVD pathology in adults. From a pool of 161 studies, 59 met eligibility criteria and were included. Microbleeds and ischemic lesions had a strong predilection for the corpus callosum and subcortical/deep white matter in COVID-19 patients, suggesting a distinct CSVD pathology. These findings have important implications for clinical practice and biomedical research as COVID-19 may independently, and through exacerbation of age-related mechanisms, contribute to increased incidence of CSVD.

A review of the use and psychometric properties of the Cognitive Log (Cog-Log) amongst adults with acquired brain injury.

This Rehabilitation Measures Database summary provides a review of the psychometric properties of the Cog-Log in individuals with acquired brain injury. A full review of the Cog-Log as well as reviews of over 400 other instruments for patients with various health conditions can be found at www.sralab.org/rehabilitation-measures. (PsycINFO Database Record

The effect of perceptual reasoning abilities on confrontation naming performance: An examination of three naming tests.

INTRODUCTION: Confrontation naming tests are a common neuropsychological method of assessing language and a critical diagnostic tool in identifying certain neurodegenerative diseases; however, there is limited literature examining the visual-perceptual demands of these tasks. This study investigated the effect of perceptual reasoning abilities on three confrontation naming tests, the Boston Naming Test (BNT), Neuropsychological Assessment Battery (NAB) Naming Test, and Visual Naming Test (VNT) to elucidate the diverse cognitive functions underlying these tasks to assist with test selection procedures and increase diagnostic accuracy. METHOD: A mixed clinical sample of 121 veterans were administered the BNT, NAB, VNT, and Wechsler Adult Intelligence Scale-4th Edition (WAIS-IV) Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) as part of a comprehensive neuropsychological evaluation. RESULTS: Multiple regression indicated that PRI accounted for 23%, 13%, and 15% of the variance in BNT, VNT, and NAB scores, respectively, but dropped out as a significant predictor once VCI was added. Follow-up bootstrap mediation analyses revealed that PRI had a significant indirect effect on naming performance after controlling education, primary language, and severity of cognitive impairment, as well as the mediating effect of general verbal abilities for the BNT (B = 0.13; 95% confidence interval, CI [.07, .20]), VNT (B = 0.01; 95% CI [.002, .03]), and NAB (B = 0.03; 95% CI [.01, .06]). CONCLUSIONS: Findings revealed a complex relationship between perceptual reasoning abilities and confrontation naming that is mediated by general verbal abilities. However, when verbal abilities were statistically controlled, perceptual reasoning abilities were found to have a significant indirect effect on performance across all three confrontation naming measures with the largest effect noted with the BNT relative to the VNT and NAB Naming Test.