Cognitive Recovery After Stroke: Memory

Mangiferin alleviated poststroke cognitive impairment by modulating lipid metabolism in cerebral ischemia/reperfusion rats

INTRODUCTION

Mangiferin is a Chinese herbal extract with multiple biological activities. Mangiferin can penetrate the blood‒brain barrier and has potential in the treatment of nervous system diseases. These findings suggest that mangiferin protects the neurological function in ischemic stroke rats by targeting multiple signaling pathways. However, little is known about the effect and mechanism of mangiferin in alleviating poststroke cognitive impairment.

METHODS

Cerebral ischemia/reperfusion (I/R) rats were generated via middle cerebral artery occlusion. Laser speckle imaging was used to monitor the cerebral blood flow. The I/R rats were intraperitoneally (i.p.) injected with 40 mg/kg mangiferin for 7 consecutive days. Neurological scoring, and TTC staining were performed to evaluate neurological function. Behavioral experiments, including the open field test, elevated plus maze, sucrose preference test, and novel object recognition test, were performed to evaluate cognitive function. Metabolomic data from brain tissue with multivariate statistics were analyzed by gas chromatography‒mass spectrometry and liquid chromatography‒mass spectrometry.

RESULTS

Mangiferin markedly decreased neurological scores, and reduced infarct areas. Mangiferin significantly attenuated anxiety-like and depression-like behaviors and enhanced learning and memory in I/R rats. According to the metabolomics results, 13 metabolites were identified to be potentially regulated by mangiferin, and the differentially abundant metabolites were mainly involved in lipid metabolism.

CONCLUSIONS

Mangiferin protected neurological function and relieved poststroke cognitive impairment by improving lipid metabolism abnormalities in I/R rats.

The autobiographical fluency task: Validity and reliability of a tool to assess episodic autobiographical memory and experience-near personal semantics

The assessment of autobiographical memory is challenging in clinical settings. The Autobiographical Fluency Task (AFT) - that is designed to test both Episodic Autobiographical Memory (EAM) and experience-near Personal Semantics (enPS) - may represent a feasible and rapid method to test access to autobiographical memories. Here we tested the reliability and the construct validity of the AFT. A total number of 51 individuals participated in the present study, with 24 included in Experiment 1 and 27 in Experiment 2. In Experiment 1, participants performed both the AFT and the Survey of Autobiographical Memory (SAM). In Experiment 2, participants completed the AFT and the Autobiographical Interview (AI). The AFT showed a moderate-to-high reliability. Also, EAM and enPS scores significantly correlated with the episodic subscale of the SAM. Results of Experiment 1 were replicated and expanded in Experiment 2. Again, the AFT showed a high reliability. Both EAM and enPS showed a significant correlation with the number of internal details produced during the AI; enPS also correlated with the number of external details. Overall, the present results show that the AFT may be a feasible instrument to assess autobiographical memory, especially for testing episodic autobiographical memory and experience-near personal semantics in clinical settings.

[Algorithms for the diagnosis and treatment of cognitive impairment and dysphagia in stroke patients]

Stroke is a socially significant neurological disease, the second most common cause of disability and mortality. A wide range of neurological problems that occur after stroke: cognitive, motor, speech, and language disfunction, neuropsychiatric, swallowing disorders and others, complicate rehabilitation, impair social and everyday adaptation, and reduce the quality of life of patients and their caregivers. Cognitive impairment (CI) is one of the most significant and common complications of stroke. Stroke increases the risk of their development by 5-8 times. Dysphagia is also a common symptom of stroke, the cause of aspiration complications (pneumonia), and nutritional imbalance. It increases the possibility of developing CI and dementia, and contributes to an increase in mortality. Older adults with CI are at a higher risk of developing dysphagia, therefore the early symptoms of dysphagia (presbyphagia) should be diagnosed. In recent years, the connection between CI and dysphagia has been actively studied. It is extremely important to identify CI and swallowing disorders as early as possible in patients both before and at all stages after stroke; as well as to develop combined multidisciplinary protocols for the rehabilitation of patients with these disorders with pharmacological support for the process.

Predictors of Cognitive Functions After Stroke Assessed Using the Wechsler Adult Intelligence Scale: A Retrospective Study

Background

The mechanism(s) of cognitive impairment remains complex, making it difficult to confirm the factors influencing poststroke cognitive impairment (PSCI).

Objective

This study quantitatively investigated the degree of influence and interactions of clinical indicators of PSCI.

Methods

Information from 270 patients with PSCI and their Wechsler Adult Intelligence Scale (WAIS-RC) scores, totaling 18 indicators, were retrospectively collected. Correlations between the indicators and WAIS scores were calculated. Multiple linear regression model(MLR), genetic algorithm modified Back-Propagation neural network(GA-BP), logistic regression model (LR), XGBoost model (XGB), and structural equation model were used to analyze the degree of influence of factors on the WAIS and their mediating effects.

Results

Seven indicators were significantly correlated with the WAIS scores: education, lesion side, aphasia, frontal lobe, temporal lobe, diffuse lesions, and disease course. The MLR showed significant effect of education, lesion side, aphasia, diffuse lesions, and frontal lobe on the WAIS. The GA-BP included five factors: education, aphasia, frontal lobe, temporal lobe, and diffuse lesions. LR predicted that the lesion side contributed more to mild cognitive impairment, while education, lesion side, aphasia, and course of the disease contributed more to severe cognitive impairment. XGB showed that education, side of the lesion, aphasia, and diffuse lesions contributed the most to PSCI. Aphasia plays a significant mediating role in patients with severe PSCI.

Conclusions

Education, lesion side, aphasia, frontal lobe, and diffuse lesions significantly affected PSCI. Aphasia is a mediating variable between clinical information and the WAIS in patients with severe PSCI.

CRTC1 is a potential target to delay aging-induced cognitive deficit by protecting the integrity of the blood-brain barrier via inhibiting inflammation

Aging can cause attenuation in the functioning of multiple organs, and blood-brain barrier (BBB) breakdown could promote the occurrence of disorders of the central nervous system during aging. Since inflammation is considered to be an important factor underlying BBB injury during aging, vascular endothelial cell senescence serves as a critical pathological basis for the destruction of BBB integrity. In the current review, we have first introduced the concepts related to aging-induced cognitive deficit and BBB integrity damage. Thereafter, we reviewed the potential relationship between disruption of BBB integrity and cognition deficit and the role of inflammation, vascular endothelial cell senescence, and BBB injury. We have also briefly introduced the function of CREB-regulated transcription co-activator 1 (CRTC1) in cognition and aging-induced CRTC1 changes as well as the critical roles of CRTC1/cyclooxygenase-2 (COX-2) in regulating inflammation, endothelial cell senescence, and BBB injury. Finally, the underlying mechanisms have been summarized and we propose that CRTC1 could be a promising target to delay aging-induced cognitive deficit by protecting the integrity of BBB through promoting inhibition of inflammation-mediated endothelial cell senescence.

Cognitive Deficits After Stroke

Cognition is a central feature of human existence and brain function. Cognitive deficits are common after stroke and may strongly impact functional outcome. Recent years have seen substantial advances in our understanding of cognitive functions in the healthy state, and this new body of knowledge promises to open new avenues for understanding and treating poststroke impairments, including cognitive deficits. The 5 reviews in this Focused Update from an international cast of experts provide excellent updates on cognitive syndromes that commonly contribute to poststroke disability: neglect, aphasia, apraxia, loss of executive function, and memory disorders. Cognitive impairment remains a major source of morbidity after stroke; these reviews approach this problem by considering clinical presentations, pathophysiology, measurement tools, and treatment approaches. In doing so, they highlight a number of key questions and critical gaps. A number of issues emerge as common across cognitive domains poststroke and are summarized herein. There is a need for improved methods to measure cognitive impairments, as well as for improved insights into pathophysiology of symptom onset and mechanisms of recovery after stroke, including validated biomarkers. These 5 state of the art summaries are sure to prove useful toward these goals.