Lower glomerular filtration rate after mild stroke induces cognitive impairment by causing endothelial dysfunction

The incidence of post stroke cognitive impairment (PSCI) is high in patients with mild stroke (MIS), and the risk factors and mechanism are uncertain. Increased cystatin C (CysC) levels after stroke may reflect lower glomerular filtration rate (GFR) and renal impairment. Previous studies have suggested endothelial dysfunction (ED) is closely related to renal impairment and cognitive impairment, respectively. We aimed to observe whether lower GFR estimated by CysC after MIS leaded to a high incidence of PSCI, and the role of ED in this process. 256 patients were enrolled in this prospective observational study. Renal function was assessed using GFR estimated by serum CysC. Endothelial function was evaluated by reactive hyperemia index (RHI) which calculated automatically by peripheral arterial tonometry (PAT). The cognitive function at baseline and 3 months was evaluated by MoCA score, and MoCA score ≤ 26 indicates the presence of PSCI. Spearman correlation analysis and linear regression were conducted to explore the factors affecting ED. Univariate and multivariate analysis was used to identify the independent risk factors of PSCI. The receiver operating characteristic (ROC) curve was applied to explore the optimal cutoff value of the independent risk factors levels for predicting PSCI. A total of 141 patients (55.1%) suffered from ED. Multiple linear regression analysis showed that there was a strong linear correlation between eGFRcys and RHI (p < 0.001). At the three-month follow-up, a total of 150 (58.6%) patients had been diagnosed with PSCI. Multivariate logistic regression analysis showed that RHI was an independent factor affecting the occurrence of PSCI (p < 0.05). ROC curve showed that the area under the curve was 0.724, and the optimal cut-off value of RHI was 1.655, with the sensitivity and specificity for PSCI were 72.7% and 73.6%, respectively. The lower eGFRcys level after MIS was significantly associated with ED, and ED may mediate the higher incidence of PSCI at 3 months after MIS.

Intestinal epithelial stem cell transplants as a novel therapy for cerebrovascular stroke

Almost 2/3rds of stroke survivors exhibit vascular cognitive impairment and a third of stroke patients will develop dementia 1-3 years after stroke. These dire consequences underscore the need for effective stroke therapies. In addition to its damaging effects on the brain, stroke rapidly dysregulates the intestinal epithelium, resulting in elevated blood levels of inflammatory cytokines and toxic gut metabolites due to a 'leaky' gut. We tested whether repairing the gut via intestinal epithelial stem cell (IESC) transplants would also improve stroke recovery. Organoids containing IESCs derived from young rats transplanted into older rats after stroke were incorporated into the gut, restored stroke-induced gut dysmorphology and decreased gut permeability, and reduced circulating levels of endotoxin LPS and the inflammatory cytokine IL-17A. Remarkably, IESC transplants also improved stroke-induced acute (4d) sensory-motor disability and chronic (30d) cognitive-affective function. Moreover, IESCs from older animals displayed senescent features and were not therapeutic for stroke. These data underscore the gut as a critical therapeutic target for stroke and demonstrate the effectiveness of gut stem cell therapy.

High-Frequency rTMS Improves Cognitive Function by Regulating Synaptic Plasticity in Cerebral Ischemic Rats

Poststroke cognitive impairment (PSCI) is one of the most severe sequelae of stroke and lacks effective treatment. Previous studies have shown that high-frequency repetitive transcranial magnetic stimulation (rTMS) may be a promising PSCI therapeutic approach, but the underlying mechanism is unclear. To uncover the effect of rTMS on PSCI, a transient middle cerebral artery occlusion (tMCAO) model was established. Modified Neurological Severity Score (mNSS) test and Morris Water Maze (MWM) test were performed to assess the neurological and cognitive function of rats. Furthermore, to explore the underlying mechanism, differentially expressed genes (DEGs) in the hippocampus of rats in the rTMS group and tMCAO group were compared using RNA sequencing. Then, bioinformatics analysis, including gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein-protein interaction (PPI) network analysis, was conducted to elaborate these DEGs. Our results indicated that high-frequency rTMS could significantly improve neurological and cognitive function, according to mNSS and MWM tests. We found 85 DEGs, including 71 upregulated genes and 14 downregulated genes, between the rTMS group and tMCAO group. The major functional category was related to chemical synaptic transmission modulation and several DEGs were significantly upregulated in processes related to synaptic plasticity, such as glutamatergic synapses. Calb2, Zic1, Kcnk9, and Grin3a were notable in PPI analysis. These results demonstrate that rTMS has a beneficial effect on PSCI, and its mechanism may be related to the regulation of synaptic plasticity and functional genes such as Calb2, Zic1, Kcnk9, and Grin3a in the hippocampus.

Development and Validation of Neuro-Cognitive Assessment Battery for Stroke Patients (NCABS) in Pakistan

Background & Objective:

Post Stroke Cognitive Impairments (PSCI) occur frequently in stroke survivors resulting in devastating consequences affecting daily living of survivors. Currently, there exists scarcity of sound assessment tools for the evaluation of PSCI as most of the commonly used scales offer a number of clinical (requires motor and linguistic skills) and cultural limitations (requires academic exposure). Therefore, current study was aimed at evaluating the efficacy of Neuro-Cognitive Assessment Battery for Stroke patients (N-CABS) in Pakistan.

Methods:

The participants were randomized in two groups including clinical and non-clinical group. N-CABS was administered on 61 clinical and 60 non-clinical participants (mean age=45 years; SD=5.55). Both groups were matched on all demographic variables including; age, gender, education and occupation. The psychometric properties of N-CABS were established through a number of robust measures of validity (construct, concurrent and discriminant validity) and reliability (internal consistency and test retest reliability).

Results:

The factor analysis suggested a two-factor solution (labeled as Verbal Cognitive Abilities and Visual Cognitive Abilities) for N-CABS explaining 67% of total variance. A significant test-retest reliability was found (α = 0.92, ^***p<0.001). The findings of concurrent validity recommended a significant correlation between N-CABS and Montreal Cognitive Assessment (MoCA) (α = 0.82, ^***p<0.001). Similarly, discriminant validity also revealed significant group differences to exist on N-CABS (^***p<0.001) suggesting N-CABS be able to discriminate between patients and healthy controls.

Conclusion:

The results of the current study favor N-CABS as a psychometrically strong screening instrument to screen PSCI in our culture.

Serum miR-132 is a risk marker of post-stroke cognitive impairment

BACKGROUND/AIMS

Recently, it has been reported that the microRNA-132(miR-132) is linked with synaptic plasticity and cognitive impairment. The present study investigates that whether miR-132 is altered in circulating blood serum samples of post-stroke cognitive impairment (PSCI) patients.

METHODS

We collected samples from 39 subjects with PSCI, 37 subjects with post-stroke cognitive normality (PSCN), and 38 age-matched controls (AMC) for which ages, gender and education level were matched. MiR-132 was detected using a quantitative real-time PCR (qRT-PCR) method. To test the predictive value of miR-132 for PSCI, prediction capabilities were compared using the receiver operating characteristic (ROC) curves and area under curve (AUC) analysis.

RESULTS

The level of miR-132 in PSCI patient serum was significantly elevated compared to that of PSCN and AMC subjects. The ROC curve showed that miR-132 achieved an AUC of 0.961 (p<0.0001). Importantly, the miR-132 level was correlated with the Montreal Cognitive Assessment (MoCA) score in PSCI patients.

CONCLUSIONS

These results indicated that there was a substantial correlation between serum miR-132 expression and post-stroke cognitive functionality, suggesting that miR-132 may be a risk marker for PSCI. Because of the limitations of this study, the results should be treated with caution.