Inflammation and cerebral small vessel disease: A systematic review

High-sensitivity C-reactive protein and all-cause mortality in four diverse populations: The CRONICAS Cohort Study

PURPOSE

To assess the association between all-cause mortality and hs-CRP, based mainly on the cumulative burden approach.

METHODS

Cohort study with adults ≥35 years from general population, using hs-CRP at two timepoints: at baseline and 30 months later to establish different exposures: change over time, cumulative, and weighted cumulative hs-CRP. The outcome was all-cause mortality assessed 7 years later. Cox models were generated to quantify the association.

RESULTS

Data from 3,119 participants (mean age 55.6 years, and 51.2% females), were analyzed. During follow-up, 164 (5.6%) deaths occurred over 20,314.5 person-years, indicating an overall mortality rate of 8.1 per 1,000 person-years. In multivariable model, hs-CRP at baseline was associated with high risk of mortality (HR = 1.77; 95%CI: 1.28-2.46). Similarly, hs-CRP change over time (HR = 2.50; 95%CI: 1.46-4.29), as well as cumulative and weighted cumulative hs-CRP (HR = 2.05; 95%CI: 1.31-3.20) were associated with greater risk of all-cause mortality. The weighted cumulative hs-CRP had the best goodness-of-fit for mortality prediction.

CONCLUSIONS

In this cohort across diverse geographical low-resource settings, high levels of hs-CRP were strongly associated with all-cause mortality. Two measurements of hs-CRP are better than one to predict mortality, and the weighted cumulative approach had the best prognostic fit.

Disrupted topological organization of resting-state functional brain networks in cerebral small vessel disease

We aimed to investigate alterations in functional brain networks and assess the relationship between functional impairment and topological network changes in cerebral small vessel disease (CSVD) patients with and without cerebral microbleeds (CMBs). We constructed individual whole‐brain, region of interest (ROI) level functional connectivity (FC) networks for 24 CSVD patients with CMBs (CSVD‐c), 42 CSVD patients without CMBs (CSVD‐n), and 36 healthy controls (HCs). Then, we used graph theory analysis to investigate the global and nodal topological disruptions between groups and relate network topological alterations to clinical parameters. We found that both the CSVD and control groups showed efficient small‐world organization in FC networks. However, compared to CSVD‐n patients and controls, CSVD‐c patients exhibited a significantly decreased clustering coefficient, global efficiency, and local efficiency and an increased shortest path length, indicating a disrupted balance between local specialization and global integration in FC networks. Although both the CSVD and control groups showed highly similar hub distributions, the CSVD‐c group exhibited significantly altered nodal betweenness centrality (BC), mainly distributed in the default mode network (DMN), attention, and visual functional areas. There were almost no global or regional alterations between CSVD‐n patients and controls. Furthermore, the altered nodal BC of the right anterior/posterior cingulate gyrus and left cuneus were significantly correlated with cognitive parameters in CSVD patients. These results suggest that CSVD patients with and without CMBs had segregated disruptions in the topological organization of the intrinsic functional brain network. This study advances our current understanding of the pathophysiological mechanisms underlying CSVD.

Adenosine A2A Receptor Suppressed Astrocyte-Mediated Inflammation Through the Inhibition of STAT3/YKL-40 Axis in Mice With Chronic Cerebral Hypoperfusion-induced White Matter Lesions

White matter lesions are an important pathological manifestation of cerebral small vessel disease, with inflammation playing a pivotal role in their development. The adenosine A2a receptor (ADORA2A) is known to inhibit the inflammation mediated by microglia, but its effect on astrocytes is unknown. Additionally, although the level of YKL-40 (expressed mainly in astrocytes) has been shown to be elevated in the model of white matter lesions induced by chronic cerebral hypoperfusion, the specific regulatory mechanism involved is not clear. In this study, we established in vivo and in vitro chronic cerebral hypoperfusion models to explore whether the ADORA2A regulated astrocyte-mediated inflammation through STAT3/YKL-40 axis and using immunohistochemical, western blotting, ELISA, PCR, and other techniques to verify the effect of astrocytes ADORA2A on the white matter injury. The in vivo experiments showed that activation of the ADORA2A decreased the expression of both STAT3 and YKL-40 in the astrocytes and alleviated the white matter injury, whereas its inhibition had the opposite effects. Similarly, ADORA2A inhibition significantly increased the expression of STAT3 and YKL-40 in astrocytes in vitro, with more proinflammatory cytokines being released by astrocytes. STAT3 inhibition enhanced the inhibitory effect of ADORA2A on YKL-40 synthesis, whereas its activation reversed the phenomenon. These results suggest that the activation of ADORA2A in astrocytes can inhibit the inflammation mediated by the STAT3/YKL-40 axis and thereby reduce white matter injury in cerebral small vessel disease.

Leukoaraiosis Mediates the Association of Total White Blood Cell Count With Post-Stroke Cognitive Impairment

Background and Purpose

The inflammatory response could play a key role in cognitive impairment. However, there has been limited research into the association between total white blood cell (WBC) count and post-stroke cognitive impairment (PSCI), and the significance of leukoaraiosis (LA) in this relationship is unknown. We aimed to examine the total WBC count in relation to PSCI and whether this association was mediated by LA.

Methods

Consecutive patients with first-ever ischemic stroke were prospectively enrolled from October 2020 to June 2021. The total WBC count was measured after admission. Cognitive function evaluations were performed at the 3-month follow-up using Mini-mental State Examination (MMSE). We defined the PSCI as an MMSE score <27.

Results

A total of 276 patients (mean age, 66.5 years; 54.7% male) were included in this analysis. Among them, 137 (49.6%) patients experienced PSCI. After adjustment for potential confounders, higher total WBC count was significantly correlated with an increased risk of LA [per 1-SD increase, odds ratio (OR), 1.39; 95% CI 1.06–1.82; p = 0.017] and PSCI (per 1-SD increase, OR, 1.51; 95% CI 1.12–2.04; p = 0.006). Furthermore, mediation analysis demonstrated that the association between total WBC count and PSCI was partly mediated by LA (the regression coefficient was changed by 9.7% for PSCI, and 12.4% for PSCI severity, respectively).

Conclusion

Increased total WBC count is a risk factor for PSCI. The presence of LA was partially responsible for the PSCI in patients who had a higher total WBC count.

Precision medicine in secondary prevention of ischemic stroke: how may blood-based biomarkers help in clinical routine? An expert opinion

PURPOSE OF REVIEW

One in eight patients unfortunately suffers a new stroke within 5 years of their first stroke, even today. Research in precision medicine could lead to a more individualized treatment allocation, possibly achieving lower recurrence rates of ischemic stroke. In this narrative review, we aim to discuss potential clinical implementation of several promising candidate blood biomarkers.

RECENT FINDINGS

We discuss specifically some promising blood-based biomarkers, which may improve the identification of underlying causes as well as risk stratification of patients according to their specific cerebrovascular risk factor pattern.

SUMMARY

Multimodal profiling of ischemic stroke patients by means of blood biomarkers, in addition to established clinical and neuroradiological data, may allow in the future a refinement of decision algorithms for treatment allocation in secondary ischemic stroke prevention.

The Potential Impact of Neuroimaging and Translational Research on the Clinical Management of Lacunar Stroke

Lacunar infarcts represent one of the most frequent subtypes of ischemic strokes and may represent the first recognizable manifestation of a progressive disease of the small perforating arteries, capillaries, and venules of the brain, defined as cerebral small vessel disease. The pathophysiological mechanisms leading to a perforating artery occlusion are multiple and still not completely defined, due to spatial resolution issues in neuroimaging, sparsity of pathological studies, and lack of valid experimental models. Recent advances in the endovascular treatment of large vessel occlusion may have diverted attention from the management of patients with small vessel occlusions, often excluded from clinical trials of acute therapy and secondary prevention. However, patients with a lacunar stroke benefit from early diagnosis, reperfusion therapy, and secondary prevention measures. In addition, there are new developments in the knowledge of this entity that suggest potential benefits of thrombolysis in an extended time window in selected patients, as well as novel therapeutic approaches targeting different pathophysiological mechanisms involved in small vessel disease. This review offers a comprehensive update in lacunar stroke pathophysiology and clinical perspective for managing lacunar strokes, in light of the latest insights from imaging and translational studies.

Serum Inflammatory Factors and Oxidative Stress Factors Are Associated With Increased Risk of Frailty and Cognitive Frailty in Patients With Cerebral Small Vessel Disease

Objective: To study the correlation between serum inflammatory factors, oxidative stress factors and frailty, and cognitive frailty in patients with cerebral small vessel disease (CSVD).

Methods: A total of 281 patients with CSVD were selected from Tianjin Huanhu Hospital and Inner Mongolia People's Hospital from March 2019 to March 2021. CSVD was diagnosed by MRI. The FRAIL scale was used to evaluate the frailty of patients. Patients with CSVD with frailty and MMSE score <27 were considered to have cognitive frailty. Patients with non-cognitive frailty were included in the control group. The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were used to evaluate the cognitive function of patients with CSVD. The serum interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase 3 (MMP-3), superoxide dismutase (SOD), and malondialdehyde (MDA) of patients with CSVD were detected. The correlation between blood inflammatory factors and oxidative stress factors with the frailty and cognitive frailty patients of CSVD were analyzed. Univariate and multivariate logistic regression were used to analyze the correlation between cognitive frailty and CSVD.

Results: Among the patients with CSVD selected in this study, female patients and older patients had a higher proportion of frailty (p < 0.001). In the Frail group, MoCA score and MMSE score were significantly lower than in the Pre-Frail and Robust groups, Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA) scores were significantly higher than the Pre-Frail and Robust groups, and the differences were statistically significant (p < 0.05). Serum CRP, IL-6, TNF-α, MMP-3, and MDA levels in the Frail group were higher, but SOD levels were lower. The levels of serum CRP, IL-6, TNF-α, MMP-3, and MDA in patients with CSVD in the Cognitive Frailty group were significantly higher than those of the Control group, while the levels of SOD were significantly lower than those of the Control group, and the differences were significant (p < 0.001). The results of univariate and multivariate logistic regression analysis showed that CRP, TNF-α, MMP-3, and MDA levels were associated with cognitive frailty in patients with CSVD (p < 0.05).

Conclusion: The increase of serum CRP, TNF-α, MMP-3, and MDA levels are significantly related to the increased risk of frailty and cognitive frailty in patients with CSVD.

Does previous stroke modify the relationship between inflammatory biomarkers and clinical endpoints in CKD patients?

Background

Chronic kidney disease (CKD) is an independent risk factor for stroke. Stroke is also an independent risk factor for worse CKD outcomes and inflammation may contribute to this bidirectional relationship. This study aims to investigate inflammatory biomarkers in patients with non-dialysis CKD (ND-CKD) with and without stroke.

Methods

A propensity matched sample from > 3000 Salford Kidney Study (SKS) patients, differentiated by previous stroke at study recruitment, had stored plasma analyzed for interleukin- 6 (IL-6), Von Willebrand Factor (VWF) and C-reactive protein (CRP). Multivariable cox regression analysis investigated associations between inflammation and death, end-stage renal disease (ESRD) and future non-fatal cardiovascular events (NFCVE).

Results

A total of 157 previous stroke patients were compared against 162 non-stroke patients. There were no significant differences in inflammatory biomarkers between the two groups. Previous stroke was associated with greater mortality risk, hazard ratio (HR) (95% CI) was 1.45 (1.07–1.97). Higher inflammatory biomarker concentrations were independently associated with death but not ESRD or NFCVE in the total population. For each 1 standard deviation (SD) increase in log IL-6, VWF and CRP, the HR for all-cause mortality were 1.35 (1.10–1.70), 1.26 (1.05–1.51) and 1.34 (1.12–1.61), respectively. CRP retained its independent association (HR 1.47 (1.15–1.87)) with death in the stroke population.

Conclusion

Previous stroke is an important determinant of mortality. However, the adverse combination of stroke and ND-CKD does not seem to be driven by higher levels of inflammation detected after the stroke event. Biomarkers of inflammation were associated with worse outcome in both stroke and non-stroke ND-CKD patients.

Trial registration

15/NW/0818.

A High Neutrophil-to-Lymphocyte Ratio Predicts Higher Risk of Poststroke Cognitive Impairment: Development and Validation of a Clinical Prediction Model

Objective

Poststroke cognitive impairment (PSCI) is a serious complication of stroke. The neutrophil-to-lymphocyte ratio (NLR) is a marker of peripheral inflammation. The relationship between the NLR and PSCI is far from well studied, and the thesis of this study was to assess the predictive value of the NLR in patients with PSCI, and establish and verify the corresponding prediction model based on this relationship.

Methods

A total of 367 stroke patients were included in this study. Neutrophils, lymphocytes, and NLRs were measured at baseline, and clinical and neuropsychological assessments were conducted 3 months after stroke. The National Institutes of Health Scale (NIHSS) was used to assess the severity of stroke. A Chinese version of the Mini Mental State Examination (MMSE) was used for the assessment of cognitive function.

Results

After three months of follow-up, 87 (23.7%) patients were diagnosed with PSCI. The NLR was significantly higher in PSCI patients than in non-PSCI patients (P &lt; 0.001). Patient age, sex, body mass index, NIHSS scores, and high-density lipoprotein levels also differed in the univariate analysis. In the logistic regression analysis, the NLR was an independent risk factor associated with the patients with PSCI after adjustment for potential confounders (OR = 1.67, 95%CI: 1.21–2.29, P = 0.002). The nomogram based on patient sex, age, NIHSS score, and NLR had good predictive power with an AUC of 0.807. In the validation group, the AUC was 0.816.

Conclusion

An increased NLR at admission is associated with PSCI, and the model built with NLR as one of the predictors can increase prognostic information for the early detection of PSCI.

Utility of white matter disease and atrophy on routinely acquired brain imaging for prediction of long-term delirium risk: population-based cohort study

Background

brain imaging done as part of standard care may have clinical utility beyond its immediate indication. Using delirium as an exemplar, we determined the predictive value of baseline brain imaging variables [white matter changes (WMC) and atrophy] for delirium risk on long-term follow-up after transient ischemic attack (TIA)/stroke in a population-based cohort study.

Methods

surviving TIA/stroke participants in the Oxford Vascular Study (OXVASC) were assessed prospectively for delirium during all hospitalisations over 6 months (2013–14). Using logistic regression, independent associations were determined between baseline OXVASC computed tomography or magnetic resonance brain imaging measures of WMC and cerebral atrophy (none/mild versus moderate/severe) and delirium adjusted for age, sex, baseline stroke severity, depression, illness severity and pre-admission cognition.

Results

among 1,565 TIA/stroke survivors with 194 hospital admissions (158 patients, mean/standard deviation age at admission = 79.2/11.5 years), delirium occurred in 59 (37%). WMC and atrophy on baseline imaging were associated with delirium [odds ratio (OR) = 3.41, 1.21–5.85, P = 0.001 and OR = 2.50, 1.23–5.08, P = 0.01 (unadjusted) and OR = 2.67, 1.21–5.85, P = 0.02 and OR = 2.18, 1.00–4.73, P = 0.05 (adjusted age and sex)]. Associations were strengthened when analyses were restricted to patients hospitalised within 5 years of baseline brain imaging [OR = 6.04, 2.39–15.24, P < 0.0001 and OR = 4.64, 1.46–14.82, P = 0.009 (unadjusted)] but only WMC remained significant after adjustment for all covariates including pre-admission cognition (OR = 4.83, 1.29–18.13, P = 0.02 for Mini-Mental State Examination and OR = 5.15, 1.26–21.09, P = 0.02 for Montreal Cognitive Assessment).

Conclusions

WMC and atrophy on brain imaging done up to 5 years earlier predicted delirium and may have clinical utility in risk stratification. Associations with WMC but not atrophy were independent of pre-admission cognitive impairment.

Altered Spontaneous Brain Activity Related to Neurologic Dysfunction in Patients With Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) encompasses several diseases affecting the small arteries, arterioles, venules, and capillaries of the brain and refers to several pathological processes and etiologies. Neuroimaging is considered the gold standard for detecting CSVD, which can present diverse features on MRI. Cerebral microbleeds (CMBs) in CSVD have been demonstrated to play a synergistic role in both cerebrovascular and neurodegenerative pathology. Considering previous studies on brain structural abnormalities in CSVD, in the present study, we aimed to explore altered spontaneous brain activity among CSVD patients using amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF) and regional homogeneity (ReHo) methods based on resting-state functional MRI. In this study, we recruited 24 CSVD patients with CMBs (CSVD-c), 42 CSVD patients without CMBs (CSVD-n) and 36 healthy controls from outpatient clinics in Shandong Provincial Hospital affiliated to Shandong First Medical University between September 2018 and June 2019. All subjects underwent 3-T MRI, including blood oxygen level-dependent (BOLD) and susceptibility-weighted imaging (SWI). Anatomic structures were segmented, ALFF/fALFF values were calculated, and ReHo maps were generated. Further statistical analysis was applied to study the difference in ALFF/fALFF/ReHo among the three groups and the association between ALFF/fALFF/ReHo changes in different brain regions and clinical characteristics. Twenty-four CSVD-c patients (age: 67.54 ± 6.00 years, 10 females), 42 CSVD-n patients (age: 66.33 ± 5.25 years, 22 females) and 36 healthy subjects (age: 64.14 ± 8.57 years, 19 females) were evaluated. Compared with controls, the CSVD-c group showed significantly increased ALFF values in the right insula, putamen and left precuneus; decreased fALFF values in the right precentral gyrus and postcentral gyrus; and increased ReHo values in the left precuneus, fusiform gyrus, right supplementary motor area (SMA), and superior frontal gyrus. Notably, the mean ALFF values of the right insula and putamen were not only significantly related to all clinical parameters but also demonstrated the best performance in Receiver Operating Characteristic (ROC) curve analysis. These findings reveal CSVD-c patients have dysfunctions in the default mode network, sensorimotor network and frontoparietal network, which may implicate the underlying neurophysiological mechanisms of intrinsic brain activity. The correlation between altered spontaneous neuronal activity and clinical parameters provides early useful diagnostic biomarkers for CSVD.

Total magnetic resonance imaging of cerebral small vessel disease burden predicts dysphagia in patients with a single recent small subcortical infarct

Background

This study was performed to identify the association between the total magnetic resonance imaging burden of small vessel disease and the occurrence of post-stroke dysphagia in patients with a single recent small subcortical infarct (RSSI).

Methods

We retrospectively identified all patients with a magnetic resonance imaging-confirmed single RSSI. The water-swallowing test and volume-viscosity swallow test were performed within the first 24 h following admission to assess swallowing. Demographic and clinical data were extracted from our stroke database. Based on brain magnetic resonance imaging, we independently rated the presence of cerebral microbleeds, lacunes, white matter hyperintensities and enlarged perivascular spaces. The presence of each small vessel disease feature was summed to determine the total small vessel disease burden, ranging from 0 to 4.

Results

In total, 308 patients with a single RSSI were enrolled. Overall, 54 (17.5%) were diagnosed with post-stroke dysphagia. The risk factors related to post-stroke dysphagia included the following: older age, higher National Institute of Health Stroke Scale scores, higher C-reactive protein level and higher fibrinogen level. Based on multiple logistic regression, National Institute of Health Stroke Scale scores and total small vessel disease burden were independent risk factors of post-stroke dysphagia in patients with a single RSSI, after adjusting for age, gender, history of hypertension, C-reactive protein level and fibrinogen level.

Conclusions

Dysphagia in patients with a single RSSI was associated with a more severe total small vessel disease burden as reflected by MRI. Total MRI of cerebral small vessel disease burden may predict dysphagia in these patients. Furthermore, more severe total small vessel disease burden was associated with systemic inflammation.

White matter changes, duration of hypertension, and age are associated with cerebral microbleeds in patients with different stages of hypertension

BACKGROUND

We aimed to investigate risk factors for the presence and number of cerebral microbleeds (CMBs) in patients with different stages of hypertension stages, with an emphasis on the relationship between white matter changes (WMCs) and CMBs.

METHODS

Since 2016, participants aged 40 years or more have been evaluated for the presence of CMBs using enhanced 3D multiecho GE T2*-weighted angiography (ESWAN) sequences. The Mann-Whitney U test and Pearson χ² test were used to compare the clinical characteristics between the CMB and no-CMB patient groups. Furthermore, we used Spearman's rank correlation analysis to examine the associations between the degree of CMB severity and other important factors.

RESULTS

CMBs were detected in 110 (36.7%) of 300 participants. Among patients with stage 2 hypertension, the majority also had CMBs (61.8%, 68/110). CMBs were positively correlated with age, hypertension stage, duration of hypertension, WMCs, and silent cerebral infarction. Patients with grade 3 WMCs were significantly more likely to have CMBs than those without WMCs; this association was true for both patients with stage 1 and those with stage 2 hypertension. In patients with stage 1 or stage 2 hypertension lasting longer than 20 years, the majority had CMBs (69.0%, 29/42; 69.1%, 47/68). The results of binary logistic regression indicated that a more severe hypertension stage, longer duration of hypertension, aging, having silent cerebral infarction and higher values of WMC increase the likelihood of the occurrence of CMBs.

CONCLUSIONS

CMBs detected in hypertensive patients were more likely to occur in deep structures, and the grade of WMCs and duration of hypertension were more closely associated with the CMB degree than with age.

Triglyceride glucose index is associated with cerebral small vessel disease burden and cognitive impairment in elderly patients with type 2 diabetes mellitus

OBJECTIVE

To investigate the relations of Triglyceride glucose (TyG) index with cerebral small vessel disease (CSVD) burden and cognitive function in aged patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 308 elderly patients with T2DM were included in this retrospective study. The standardized Chinese version of Mini-Mental State Examination was used to assess cognitive function. The total CSVD burden score was assessed by combining four imaging markers of CSVD, including the presence of white matter hyperintensity, cerebral microbleeds in the deep, lacunes and enlarged perivascular spaces in the basal ganglia. The TyG index was calculated as the formula of ln [fasting triglyceride (mg/dl) × fasting plasma glucose (mg/dl)/2]. We used logistic regression analysis and mediation analysis to investigate the relations of TyG index with CSVD and cognitive function.

RESULTS

Multivariate binary logistic regression analysis showed that increased TyG index (OR: 2.241; 95% Confidence Interval(CI): 1.439 to 3.490; P <0.001), or severe CSVD burden (OR: 2.198; 95% CI: 1.283 to 3.763; P = 0.004) was associated with an increased risk of cognitive impairment in elderly patients with T2DM after adjusting for potential confounders. In addition, TyG index was an independent risk factor of severe CSVD burden (OR: 1.472; 95% CI: 1.003 to 2.160; P = 0.048) after controlling for potential confounders. Compared with the lowest TyG index tertile, the multivariable-adjusted OR of the highest tertile was 3.298 (95% CI: 1.685 to 6.452; P for trend <0.001) for cognitive impairment, 1.933 (95% CI: 1.010 to 3.698; P for trend = 0.047) for severe CSVD burden. Mediation analysis found a significant moderating effect of the severe CSVD burden on the association between higher TyG index levels and cognitive impairment.

CONCLUSIONS

The increased TyG index is an independent risk factor for cognitive impairment and severe CSVD burden in clinical practice. A proportion of the effect of increased TyG index on cognitive impairment may be due to the aggravation of CSVD burden.

Cerebral Small Vessel Disease is Associated with Mild Cognitive Impairment in Type 2 Diabetes Mellitus

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is associated with cognitive impairment, but the underlying cerebral small vessel disease (CSVD)-related structural brain correlates are unclear. The aim of this study was to investigate the relationship between various imaging markers of CSVD and mild cognitive impairment (MCI) in patients with T2DM.

METHODS

A total of 228 eligible participants with T2DM who were divided into MCI group and normal cognitive group based on neuropsychological assessment were enrolled in this retrospective study. White matter hyperintensity (WMH), lacunes, cerebral microbleeds (CMBs) and enlarged perivascular spaces (EPVS) were evaluated based on brain magnetic resonance imaging (MRI). The total CSVD burden score was calculated by combining the above four markers of CSVD. Binary logistic regression analysis was used to evaluate the relationship between different imaging markers of CSVD and MCI in patients with T2DM. Kruskal-Wallis test and Jonckheere-Terpstra test were used to compare mean MoCA scores among individuals with varying CSVD markers.

RESULTS

In the multivariate binary logistic regression analyses, moderate or severe total CSVD burden (OR: 3.29, 95% CI: 1.63-7.38, P=0.004; OR: 10.97, 95% CI: 4.94-24.34, P<0.001, respectively), moderate dWMH (OR: 3.26, 95% CI: 1.43-7.41, P=0.005), extensive lacunes (OR: 4.97, 95% CI: 1.79-13.81, P=0.002), and moderate BG-EPVS (OR: 3.84, 95% CI: 1.81-8.13, P<0.001) were associated with MCI in patients with T2DM related to MCI after adjusting for potential confounders. There was a trend for significant decrease in MoCA scores with increase severity of dWMH, pWMH, lacunes, BG-EPVS, deep CMBs, or total CSVD burden (P for trend <0.05).

CONCLUSION

Different imaging markers of CSVD, particularly total CSVD burden, were associated with an increased risk of MCI and decline in MoCA scores in patients with T2DM. These findings may provide clues for future studies to explore early diagnostic imaging markers of cognitive impairment in relation to T2DM.

Related factors based on non-targeted metabolomics methods in minor ischaemic stroke

OBJECTIVE

This study aimed to identify potential biomarkers associated with the occurrence of minor ischaemic stroke.

METHODS

Four hundred patients hospitalized with minor ischaemic stroke were enrolled in the department of neurological internal medicine in Taiyuan Central Hospital, and 210 healthy subjects examined at the Taiyuan Central Hospital Medical Center during the same period were selected. We collected information on the general demographic characteristics and fasting blood samples of the subjects. We then used untargeted metabolomic assay to measure blood glucose, blood lipids, homocysteine, and high-sensitivity C-reactive protein.

RESULTS

There were statistically significant differences between the mild ischemic stroke group and the healthy control group in smoking, hypertension, and physical activity (P< 0.05). Compared with the healthy group, the minor ischaemic stroke group showed increased lactate, pyruvate, trimetlylamine oxide levels, and lactic acid, pyruvic acid, and trimethylamine N-oxidation (TMAO) levels were statistically significant (P< 0.001). In the minor ischaemic stroke risk model, hypertension, physical activity, smoking, and elevated TMAO levels influenced the occurrence of minor stroke.

CONCLUSION

Increased levels of lactic acid, pyruvate, and TMAO may be related to the pathophysiological changes in the minor ischaemic stroke population. High blood pressure, a lack of physical activity, smoking, and increased TMAO level were the influencing factors for the occurrence of minor ischaemic stroke. The serum metabolite TMAO may be associated with MS occurrence.

Inflammatory biomarkers and motoric cognitive risk syndrome: Multicohort survey

•

Raised IL-6 and CRP levels are associated with increased odds of MCR.

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IL-6 and CRP are involved in overlapping inflammatory, vascular, and neurological pathology.

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Establishing these pathways can guide interventions to prevent progression of MCR to dementia.

Background

Inflammation may play a role in Motoric Cognitive Risk (MCR) syndrome, a pre-dementia syndrome comprised of slow gait and cognitive complaints. Our objective was to examine associations of inflammatory biomarkers with MCR.

Methods

We examined association of interleukin-6 (IL-6) and C-reactive protein (CRP) with prevalent MCR using logistic regression in 3,101 older adults (52% female) from five cohorts (National Center for Geriatrics & Gerontology Study of Geriatric Syndromes [NCGG-SGS], Central Control of Mobility in Aging [CCMA], Tasmanian Study of Cognition and Gait [TASCOG], LonGenity, and Einstein Aging Study [EAS]). Associations were reported as odds ratios adjusted for sex, age, education, depressive symptoms, body mass index, and vascular diseases (aOR) with 95% confidence intervals (CI). Meta-analysis and analyses stratified by vascular disease were also done.

Results

Although associations between higher (worse) CRP and IL-6 tertiles and MCR were only seen in three out of the five cohorts (EAS, TASCOG, and LonGenity), when a pooled meta-analysis was performed, a robust association was demonstrated. In meta-analysis, highest tertiles of IL-6 (aOR 1.57, 95%CI 1.01- 2.44) and CRP (aOR 1.65, 95%CI 1.09–2.48) was associated with MCR versus lowest tertiles in the pooled sample. Higher CRP was associated with MCR among those with vascular disease in TASCOG and LonGenity cohorts, and among those without vascular disease in EAS.

Conclusions

IL-6 and CRP levels are associated with MCR in older adults, and this association varies by presence of vascular disease.

EP3 Receptor Deficiency Improves Vascular Remodeling and Cognitive Impairment in Cerebral Small Vessel Disease

Aging and hypertension are major risk factors for cerebral small vessel disease (CSVD). Anti-hypertensive therapy has achieved effective; however, incomplete results in treating CSVD, suggesting the need for additional treatments. Targeting abnormal inflammatory responses has become a topic of research interest. Small artery remodeling is the main pathological feature of CSVD. Inhibition of the E-prostanoid 3 (EP3) receptor has been shown to attenuate vascular remodeling in peripheral organs; however, little is known about its role in CSVD. Therefore, we investigated whether the deletion of EP3 attenuates the development of CSVD in an animal model-- stroke-prone renovascular hypertensive rat (RHRsp). We found that the cerebral small arteries of RHRsp exhibited increased EP3 expression. Despite no alleviation of hypertension, the deletion of EP3 still attenuated the cerebral small artery remodeling of RHRsp, as evidenced by reduced overexpression of extracellular matrix (ECM) in the vessel. In vitro experiments indicated that EP3 deletion regulated the expression of ECM by downregulating TGF-β1/Smad signaling. Furthermore, the Morris water maze test and magnetic resonance test demonstrated that EP3 knockout attenuated cognitive impairment of the RHRsp, possibly through increased cerebral blood flow. Together, our results indicate that the deletion of EP3 attenuates vascular remodeling and vascular cognitive impairment induced by hypertension, and blockade of the EP3 receptor may be a promising strategy for the treatment of CSVD.

Aerobic exercise in older people with subclinical sporadic cerebral small vessel disease: A randomized clinical trial

INTRODUCTION

The benefit and risk of aerobic exercise among older people harboring advanced cerebral small vessel disease (CSVD) upon cognition, mood, and motor functions are unknown.

METHODS

This rater-blind randomized trial examined effects of a 24-week aerobic exercise training (60 min/session, twice/week) upon clinical (cognition, mood, motor functions) and hemodynamic (pulse pressure [PP], blood pressure [BP], pulsatility index) measures in older people harboring moderate to severe CSVD, as evidenced by confluent white matter hyperintensity and/or ≥2 lacunes on magnetic resonance imaging. We further investigated interactions between treatment conditions and hemodynamics measures.

RESULTS

Fifty-three and 54 subjects were randomized into the active and control group, respectively. There was no between-group difference in any of the clinical outcomes. The active group had a greater between-group reduction in systolic BP and PP than the control group. Within-group comparison showed that global cognition of the active group remained similar at end of the study compared to baseline, whereas it declined significantly in the control group. We observed "diverging" interaction effects in that greater reduction in systolic BP/PP was associated with greater improvement in memory functions and global cognition but worsening in processing speed in the active group. Side effects were comparable between the two groups.

DISCUSSION

Future study should investigate the mechanisms of the diverging impacts of aerobic exercise upon different cognitive domains so that the benefit-risk ratio of aerobic exercise in older people harboring more advanced CSVD can be better defined.

Risk factors of cerebral small vessel disease: A systematic review and meta-analysis

BACKGROUND

Cerebral small vessel disease (CSVD) is a common neurological disease under the effect of multiple factors. Although some literature analyzes and summarizes the risk factors of CSVD, the conclusions are controversial. To determine the risk factors of CSVD, we conducted this meta-analysis.

METHODS

Five authoritative databases of PubMed, Embase, Cochrane Library, CNKI, and Wan Fang were searched to find related studies published before November 30, 2020. The literature was screened according to the inclusion and exclusion criteria. We used RevMan 5.4 software to analyze the data after extraction.

RESULTS

A total of 29 studies involving 16,587 participants were included. The meta-analysis showed that hypertension (odds ratio [OR] 3.16, 95% confidence interval [CI] 2.22-4.49), diabetes (OR 2.15, 95% CI 1.59-2.90), hyperlipidemia (OR 1.64, 95% CI 1.11-2.40), smoking (OR 1.47, 95% CI 1.15-1.89) were significantly related to the risk of lacune, while drinking (OR 1.03, 95% CI 0.87-1.23) was not. And hypertension (OR 3.31, 95% CI 2.65-4.14), diabetes (OR 1.66, 95% CI 2.65-1.84), hyperlipidemia (OR 1.88, 95% CI 1.08-3.25), smoking (OR 1.48, 95% CI 1.07-2.04) were significantly related to the risk of white matter hyperintensity, while drinking (OR 1.41, 95% CI 0.97-2.05) was not.

CONCLUSIONS

This study suggested that hypertension, diabetes, hyperlipidemia, and smoking are risk factors of CSVD, and we should take measures to control these risk factors for the purpose of preventing CSVD.

Association of Age and Sex With Multi-Modal Cerebral Physiology in Adult Moderate/Severe Traumatic Brain Injury: A Narrative Overview and Future Avenues for Personalized Approaches

The impact of age and biological sex on outcome in moderate/severe traumatic brain injury (TBI) has been documented in large cohort studies, with advanced age and male sex linked to worse long-term outcomes. However, the association between age/biological sex and high-frequency continuous multi-modal monitoring (MMM) cerebral physiology is unclear, with only sparing reference made in guidelines and major literature in moderate/severe TBI. In this narrative review, we summarize some of the largest studies associating various high-frequency MMM parameters with age and biological sex in moderate/severe TBI. To start, we present this by highlighting the representative available literature on high-frequency data from Intracranial Pressure (ICP), Cerebral Perfusion Pressure (CPP), Extracellular Brain Tissue Oxygenation (PbtO₂), Regional Cerebral Oxygen Saturations (rSO₂), Cerebral Blood Flow (CBF), Cerebral Blood Flow Velocity (CBFV), Cerebrovascular Reactivity (CVR), Cerebral Compensatory Reserve, common Cerebral Microdialysis (CMD) Analytes and their correlation to age and sex in moderate/severe TBI cohorts. Then we present current knowledge gaps in the literature, discuss biological implications of age and sex on cerebrovascular monitoring in TBI and some future avenues for bedside research into the cerebrovascular physiome after TBI.

Impaired dynamic cerebral autoregulation is associated with the severity of neuroimaging features of cerebral small vessel disease

Aims

Cerebral small vessel disease (CSVD) is characterized by functional and structural changes in small vessels. We aimed to elucidate the relationship between dynamic cerebral autoregulation (dCA) and neuroimaging characteristics of CSVD.

Methods

A case‐control study was performed. Cerebral blood flow velocity (CBFV) of bilateral middle cerebral arteries and spontaneous arterial blood pressure were simultaneously recorded. Transfer function analysis was used to calculate dCA parameters (phase, gain, and the rate of recovery of CBFV [RoRc]). Neuroimaging characteristics of CSVD patients were evaluated, including lacunes, white matter hyperintensities (WMH), cerebral microbleeds (CMBs), perivascular spaces (PVS), and the total CSVD burden.

Results

Overall, 113 patients and 83 controls were enrolled. Compared with the control group, the phase at low frequency and the RoRc in CSVD patients were lower, and the gain at very low and low frequencies were higher, indicating bilaterally impaired dCA. Total CSVD burden, WMH (total, periventricular and deep), severe PVS, and lobar CMBs were independently correlated with the phase at low frequency.

Conclusions

Our findings suggested that dCA was compromised in CSVD patients, and some specific neuroimaging characteristics (the total CSVD burden, WMH, severe PVS and lobar CMBs) might indicate more severe dCA impairment in CSVD patients.

The Predictive Role of Systemic Inflammation Response Index (SIRI) in the Prognosis of Stroke Patients

Purpose

Stroke is a disease associated with high mortality. Many inflammatory indicators such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR) and red blood cell distribution width (RDW) have been documented to predict stroke prognosis, their predictive power is limited. A novel inflammatory indicator called systemic inflammatory response index (SIRI) has been advocated to have an essential role in the prognostic assessment of cancer and infectious diseases. In this study, we attempted to assess the prognosis of stroke by SIRI. Moreover, we compared SIRI with other clinical parameters, including NLR, PLR, LMR and RDW.

Methods

This was a retrospective cohort study. We obtained data of 2450 stroke patients from the Multiparametric Intelligent Monitoring in Intensive Care III database. We used the Cox proportional hazards models to evaluate the relationship between SIRI and all-cause mortality and sepsis. Receiver operating curve (ROC) analysis was used to assess the predictive power of SIRI compared to NLR, PLR, LMR and RDW for the prognosis of stroke. We collected data of 180 patients from the First Affiliated Hospital of Wenzhou Medical University, which used the Pearson’s correlation coefficient to assess the relationship between SIRI and the National Institute of Health stroke scale (NIHSS).

Results

After adjusting multiple covariates, we found that SIRI was associated with all-cause mortality in stroke patients. Rising SIRI accompanied by rising mortality. Besides, ROC analysis showed that the area under the curve of SIRI was significantly greater than for NLR, PLR, LMR and RDW. Besides, Pearson’s correlation test confirmed a significant positive correlation between SIRI and NIHSS.

Conclusion

Elevated SIRI was associated with higher risk of mortality and sepsis and higher stroke severity. Therefore, SIRI is a promising low-grade inflammatory factor for predicting stroke prognosis that outperformed NLR, PLR, LMR, and RDW in predictive power.

Dysfunction of the Blood-brain Barrier in Cerebral Microbleeds: from Bedside to Bench

Cerebral microbleeds (CMBs) are a disorder of cerebral microvessels that are characterized as small (<10 mm), hypointense, round or ovoid lesions seen on T2*-weighted gradient echo MRI. There is a high prevalence of CMBs in community-dwelling healthy older people. An increasing number of studies have demonstrated the significance of CMBs in stroke, dementia, Parkinson's disease, gait disturbances and late-life depression. Blood-brain barrier (BBB) dysfunction is considered to be the event that initializes CMBs development. However, the pathogenesis of CMBs has not yet been clearly elucidated. In this review, we introduce the pathogenesis of CMBs, hypertensive vasculopathy and cerebral amyloid angiopathy, and review recent research that has advanced our understanding of the mechanisms underlying BBB dysfunction and CMBs presence. CMBs-associated risk factors can exacerbate BBB breakdown through the vulnerability of BBB anatomical and functional changes. Finally, we discuss potential pharmacological approaches to target the BBB as therapy for CMBs.

Hepatitis C Virus-Related Central and Peripheral Nervous System Disorders

Hepatitis C Virus (HCV), despite being a hepatotropic virus, is the causative agent of many systemic disorders, such as vasculitis, autoimmune diseases, lymphoproliferative disorders, and a broad spectrum of neurological and psychiatric manifestations. Although symptoms have been misdiagnosed or underdiagnosed, only recently, evidence of direct (inflammatory) or indirect (immune-mediated) HCV-dependent cerebral effects has been established. HCV infection can promote acute inflammatory response, pro-coagulative status and ischemic disorders, and neurodegeneration. These effects rely on cerebral HCV replication, possibly mediated by blood-brain barrier alterations. Further study is needed to better understand the HCV-related mechanisms of brain damage.

Study on the Correlation Between Ischemic Leukoaraiosis and Cerebral Large Artery Stenosis Using the Stages of the Preinfarction Period Based on the Result of Computed Tomography Perfusion

BACKGROUND AND OBJECTIVE

The influence of cerebral large artery stenosis (CLAS) on ischemic leukoaraiosis (LA) remains elusive. Based on the proposed stages of the preinfarction period, this study aimed to adopt the staging system to assess the correlation between ischemic LA and CLAS.

MATERIALS AND METHODS

Patients with unilateral CLAS ≥50% and without cerebral stroke were screened. The severity and distribution of stenosis were evaluated on computed tomography angiography images. The degree of regional cerebral perfusion was rated according to the stages of preinfarction period: 0=normal, 1=stage Ia, 2=stage Ib, 3=stage IIa, 4=stage IIb. Stage I included stage Ia and stage Ib. Stage II included stage IIa and stage IIb. LA was scored with Fazakas scale on T2-weighted image and/or fluid-attenuated inversion recovery sequences.

RESULTS

The cohort consisted of 212 patients (mean age, 66.89±11.39 y), including 145 (68.40%) males. CLAS severity and distribution did not differ between patients with and without LA (P>0.05). Normal, stage I, and stage II had significantly different incidences of LA and hemispheric LA scores in the left and right hemispheres (P<0.05). The degree of regional cerebral perfusion was independently associated with LA in the left (P=0.0094) and right hemispheres (P=0.0091).

CONCLUSIONS

Ischemic LA is not directly related to CLAS but is independently associated with the degree of CLAS-induced cerebral hypoperfusion. The stages of the preinfarction period are helpful in identifying people at high risk of LA progression.

Extracerebral microvascular dysfunction is related to brain MRI markers of cerebral small vessel disease: The Maastricht Study

BACKGROUND

Cerebral small vessel disease (cSVD) is a late consequence of cerebral microvascular dysfunction (MVD). MVD is hard to measure in the brain due to its limited accessibility. Extracerebral MVD (eMVD) measures can give insights in the etiology of cerebral MVD, as MVD may be a systemic process. We aim to investigate whether a compound score consisting of several eMVD measures is associated with structural cSVD MRI markers.

METHODS

Cross-sectional data of the population-based Maastricht Study was used (n = 1872, mean age 59 ± 8 years, 49% women). Measures of eMVD included flicker light-induced retinal arteriolar and venular dilation response (retina), albuminuria and glomerular filtration rate (kidney), heat-induced skin hyperemia (skin), and plasma biomarkers of endothelial dysfunction (sICAM-1, sVCAM-1, sE-selectin, and von Willebrand factor). These measures were standardized into z scores and summarized into a compound score. Linear and logistic regression analyses were used to investigate the associations between the compound score and white matter hyperintensity (WMH) volume, and the presence of lacunes and microbleeds, as measured by brain MRI.

RESULTS

The eMVD compound score was associated with WMH volume independent of age, sex, and cardiovascular risk factors (St β 0.057 [95% CI 0.010-0.081], p value 0.01), but not with the presence of lacunes (OR 1.011 [95% CI 0.803-1.273], p value 0.92) or microbleeds (OR 1.055 [95% CI 0.896-1.242], p value 0.52).

CONCLUSION

A compound score of eMVD is associated with WMH volume. Further research is needed to expand the knowledge about the role of systemic MVD in the pathophysiology of cSVD.

Cerebral Microbleed Burden in Ischemic Stroke Patients on Aspirin: Prospective Cohort of Intracranial Hemorrhage

Objective: This investigation aimed at studying the prevalence of cerebral microbleeds (CMBs), including risk factors and the correlation of CMBs to ischemic stroke (IS) patient end results.

Methods: Four hundred and fifty-nine acute IS cases were recruited between April 2014 and December 2016. Cerebral microbleeds were analyzed using susceptibility-weighted imaging (SWI) brain MRI scan. The enrolled patients with acute IS were followed up for 12–24 months, with a median follow-up time of 19 months. The follow-up endpoint events including recurrent ischemic stroke (RIS), intracranial hemorrhage (ICH), transient ischemic attack (TIA), mortality, and cardiovascular events. The associations between vascular risk factors and CMBs in IS patients were analyzed using univariate and multivariate logistic regression analysis. Cox regression model was employed for evaluating CMB impact on clinical outcome.

Results: Among 459 enrolled patients, 187 (40.7%) had CMBs and 272 (59.2%) had no CMB. In comparison with patients with no CMBs, age was higher and hypertension was more frequent in patients with CMBs. Multivariate logistic regression analyses revealed age and hypertension were independently associated with the presence of CMBs. Among the patient cohort, 450 cases completed the follow-up. During the follow-up period, 22 (4.9%) of patients developed ICH, 12 (2.7%) developed TIA, 68 (15.1%) developed RIS, cardiovascular events occurred in 20 (4.44%), and 13 (2.89%) cases were mortalities. Compared with patients without CMBs, IS patients with CMBs have an increased prevalence of ICH (p < 0.05). However, no statistically valid variations regarding other outcome incidences between both groups was identified (p > 0.05). The incidence of ICH was elevated in tandem with elevations in number of CMBs. Following adjusting for age, multivariate Cox proportional-hazards regression analysis revealed that CMBs ≥10 were independent predictors of ICH in acute IS patients.

Conclusion: Age and hypertension are independently associated with the presence of CMBs. Intracranial hemorrhage incidence rate was increased with the number of CMBs, and the number of CMBs ≥10 were independent predictors of ICH in acute stroke patients.

Long-Term Use of Metformin Is Associated With Reduced Risk of Cognitive Impairment With Alleviation of Cerebral Small Vessel Disease Burden in Patients With Type 2 Diabetes

Objective: Type 2 diabetes (T2D) is a risk factor for cognitive impairment and cerebral small vessel disease (CSVD). The relation of metformin use and cognitive impairment or CSVD is not clear. The objective of this study was to investigate the cross-sectional effects of long-term use of metformin on total CSVD burden and cognitive function in patients with T2D.

Methods: A total of 234 participants with T2D from the memory clinic in Hebei General Hospital were enrolled in this retrospective study. Duration of metformin use and dosage were recorded. Along with cerebral magnetic resonance imaging (MRI) examination, Mini-Mental State Examination (MMSE) was also performed to assess their cognitive status. We determined the validated total CSVD score (ranging from 0–4) by combining four markers of CSVD that were visually rated. We used binary logistic regression analysis, ordinal logistic regression analysis and mediation analysis to assess the relation of long-term use of metformin with CSVD burden and cognitive function.

Results: Binary logistic regression analysis showed long-term use of metformin was associated with reducing the risk of cognitive impairment (OR: 0.446; 95% Confidence Interval (CI): 0.249 to 0.800; P = 0.007), after adjustment of potential confounders, such as total CSVD burden score, age, HbA1c, hypertension, history of stroke, homocysteine, body mass index, TG and HDL-C. Ordinal logistic regression analysis suggested that long-term use of metformin was associated with alleviation of total CSVD burden score (OR: 0.583; 95% CI: 0.359 to 0.943; P = 0.027), after adjusting for age, HbA1c, hypertension, history of stroke, homocysteine, body mass index, TG and HDL-C. Mediation analysis showed significant mediation by the presence of severe CSVD burden score for long-term use of metformin in relation to cognitive impairment.

Conclusion: Long-term use of metformin was associated with lower rates of cognitive impairment and lower total CSVD burden score in patients with T2D. A proportion of the relation between long-term use of metformin and cognitive impairment may be attributable to alleviation of CSVD burden.

Inhibition of the Immunoproteasome Subunit LMP7 Ameliorates Cerebral White Matter Demyelination Possibly via TGFβ/Smad Signaling

Objectives

Chronic cerebral hypoperfusion induces white matter ischemic injury and cognitive impairment, whereas the mechanism remains unclear. Immunoproteasomes have been implicated in the pathogenesis of acute ischemia stroke and multiple sclerosis. However, the expression and role of immunoproteasomes in the brain of chronic cerebral hypoperfusion remain to be clarified.

Methods

Chronic white matter ischemic injury mice models were induced by bilateral carotid artery stenosis (BCAS). A selective immunoproteasome subunit low-molecular-mass peptide-7 (LMP7) inhibitor PR957 was administered to mice. Cognitive function, white matter integrity, and potential pathways were assessed after BCAS.

Results

The present study found that chronic cerebral hypoperfusion following BCAS induced cerebral white matter demyelination and cognitive impairment, accompanied with elevated expression of the immunoproteasomes LMP2 and LMP7, activation of astrocytes and microglia, and increased production of inflammatory cytokines (e.g., interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-10, transforming growth factor-β1 (TGFβ1), and insulin-like growth factor-1 (IGF-1)). However, inhibition of LMP7 with the specific proteasome inhibitor PR957 significantly mitigated the histological damage of the white matter, suppressed inflammatory response, and paralleled by an improvement of cognitive function. Furthermore, treatment of PR957 significantly upregulated the level of TGFβ1, the total expression level, and the phosphorylation level of Smad2/3 and promoted brain remyelination. Surprisingly, PR957 alone had no effects on the neuroinflammation response and the activation of TGFβ/Smad signaling in the sham-operated (BCAS-nonoperated) mice.

Conclusions

The possible mechanism underlying this was attributed to that the immunoproteasome regulates TGFβ/Smad signaling-mediated neuroinflammation and oligodendrocyte remyelination.

White Matter Microstructural Differences in Youth With Classical Congenital Adrenal Hyperplasia

CONTEXT

Gray matter morphology in the prefrontal cortex and subcortical regions, including the hippocampus and amygdala, are affected in youth with classical congenital adrenal hyperplasia (CAH). It remains unclear if white matter connecting these aforementioned brain regions is compromised in youth with CAH.

OBJECTIVE

To examine brain white matter microstructure in youth with CAH compared to controls.

DESIGN

A cross-sectional sample of 23 youths with CAH due to 21-hydroxylase deficiency (12.9 ± 3.5 year; 61% female) and 33 healthy controls (13.1 ± 2.8 year; 61% female) with 3T multishell diffusion-weighted magnetic resonance brain scans.

MAIN OUTCOME MEASURES

Complementary modeling approaches, including diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), to examine in vivo white matter microstructure in six white matter tracts that innervate the prefrontal and subcortical regions.

RESULTS

DTI showed CAH youth had lower fractional anisotropy in both the fornix and stria terminalis and higher mean diffusivity in the fornix compared to controls. NODDI modeling revealed that CAH youth have a significantly higher orientation dispersion index in the stria terminalis compared to controls. White matter microstructural integrity was associated with smaller hippocampal and amygdala volumes in CAH youth.

CONCLUSIONS

These patterns of microstructure reflect less restricted water diffusion likely due to less coherency in oriented microstructure. These results suggest that white matter microstructural integrity in the fornix and stria terminalis is compromised and may be an additional related brain phenotype alongside affected hippocampus and amygdala neurocircuitry in individuals with CAH.

Identification of the clinical and neuroimaging characteristics in children with neuromyelitis optica spectrum disorders: a case series

BACKGROUND

Childhood neuromyelitis optica spectrum disorders (NMOSDs) may cause visual impairment and brain or spinal cord damage, and the effects may be permanent if left untreated. Since the incidence of NMOSD cases in children is relatively low, the understanding of NMOSD among children is inadequate.

METHODS

This investigation examined the clinical and neuroimaging characteristics of childhood NMOSD. We retrospectively analyzed the clinical information of 11 NMOSD patients admitted to our centre from 2012 to 2021. The disease status was assessed by the Expanded Disability Status Scale (EDSS) score.

RESULTS

The two major symptoms observed in the study cohort were optic neuritis (ON) (9/11) and encephalopathy (7/11). Antibody tests were performed on 8 children, 2 of whom showed serum aquaporin 4 (AQP4) antibody positivity, and another 2 presented with serum myelin oligodendrocyte glycoprotein (MOG) antibody positivity. All patients showed white matter hyperintensity on magnetic resonance imaging (MRI) scans. Interestingly, a rare radiological sign, enlarged perivascular space (PVS), which is more commonly observed in the elderly or adults, was found in 4 participants with more severe clinical manifestations.

CONCLUSIONS

While NMOSD in children is less commonly diagnosed through clinical evaluations, the symptoms of ON and encephalopathy should raise the possibility of the disease. As the diagnosis of NMOSD in children is relatively difficult, enlarged PVS may represent a promising biomarker for the diagnosis and evaluation of NMOSD.

Consistent patterns in the inconsistent associations of Insulin-like growth factor 1 (IGF-1), C-Reactive Protein (C-RP) and Interleukin 6 (IL-6) levels with delirium in surgical populations. A systematic review and meta-analysis

BACKGROUND

Biomarkers for delirium could increase diagnostic accuracy and may help to identify pathological pathways. Until now study findings concerning cytokine levels have been inconsistent.

AIMS

Systematic review and meta-analysis investigating the association between peripheral levels of Insulin-like Growth Factor-1 (IGF-1), C-Reactive Protein (C-RP) and Interleukin-6 (IL-6) and delirium in surgical patients, and to explore if there are distinct/specific patterns that may potentially explain inconsistent results.

METHODS

PubMed, Scopus, CINAHL, Cochrane, and EMBASE databases were searched. Inclusion criteria were: prospective studies, surgical populations excluding preoperative delirium, available data. The following were collected: type of operation (orthopaedic, abdominal, etc), the timing of operation (acute, elective, both), demographics, number of participants with delirium, time of preoperative blood withdrawal, and preoperative levels of each biomarker.

RESULTS

Low levels of IGF-1 (n = 7 studies) are significantly associated with post-operative delirium in abdominal surgical samples. High levels of C-RP (n = 9) are associated with delirium in acute orthopaedic and elective abdominal operations. IL-6 (n = 14) is a significant predictor of post-operative delirium in a variety of surgical conditions (elective or acute).

DISCUSSION

A common pattern exists in the otherwise conflicting reported findings. This similarity may reflect different underling mechanisms and predisposing factors like cachexia and catabolic stages. It seems that delirium in abdominal surgery is triggered by IGF-1 disturbances, while in other surgeries by an inflammatory reaction.

CONCLUSIONS

Despite the contradictory results concerning the association of IGF-1, C-RP and IL-6 with postoperative delirium, the present meta-analysis shows that there are certain patterns. IL-6 seems a consistent predictor for delirium in surgical samples.

Plasma soluble TREM2 is associated with white matter lesions independent of amyloid and tau

Cerebral small vessel disease is one of the most common causes of cognitive decline and stroke. While several lines of evidence have established a relationship between inflammation and cerebrovascular pathology, the mechanistic link has not yet been elucidated. Recent studies suggest activation of immune mediators, including the soluble form of triggering receptor expressed on myeloid cells 2 (TREM2), may be critical regulators. In this study, we compared the plasma levels of soluble TREM2 and its correlations with neuroimaging markers and cerebral amyloid load in ten patients with Alzheimer's disease and 66 survivors of spontaneous intracerebral haemorrhage with cerebral amyloid angiopathy or hypertensive small vessel disease, two of the most common types of sporadic small vessel disease. We performed brain MRI and 11C-Pittsburgh compound B PET for all participants to evaluate radiological small vessel disease markers and cerebral amyloid burden, and 18F-T807 PET in a subgroup of patients to evaluate cortical tau pathology. Plasma soluble TREM2 levels were comparable between patients with Alzheimer's disease and small vessel disease (P=0.690). In patients with small vessel disease, plasma soluble TREM2 was significantly associated with white matter hyperintensity volume (P<0.001), but not with cerebral amyloid load. Among patients with Alzheimer's disease and cerebral amyloid angiopathy, plasma soluble TREM2 was independently associated with a tau-positive scan (P=0.001) and white matter hyperintensity volume (P=0.013), but not amyloid load (P=0.221). Our results indicate plasma soluble TREM2 is associated with white matter hyperintensity independent of amyloid and tau pathology. These findings highlight the potential utility of plasma soluble TREM2 as a strong predictive marker for small vessel disease-related white matter injury and hold clinical implications for targeting the innate immune response when treating this disease.

Cardiovascular co-morbidities, inflammation and cerebral small vessel disease

Cerebral small vessel disease (cSVD) is the most common cause of vascular cognitive impairment and affects all levels of the brain's vasculature. Features include diverse structural and functional changes affecting small arteries and capillaries that lead to a decline in cerebral perfusion. Due to an aging population, incidence of cerebral small vessel disease (cSVD) is continually rising. Despite its prevalence and its ability to cause multiple debilitating illnesses, such as stroke and dementia, there are currently no therapeutic strategies for the treatment of cSVD. In the healthy brain, interactions between neuronal, vascular and inflammatory cells are required for normal functioning. When these interactions are disturbed, chronic pathological inflammation can ensue. The interplay between cSVD and inflammation has attracted much recent interest and this review discusses chronic cardiovascular diseases, particularly hypertension, and explores how the associated inflammation may impact on the structure and function of the small arteries of the brain in cSVD. Molecular approaches in animal studies are linked to clinical outcomes in patients and novel hypotheses regarding inflammation and cSVD are proposed that will hopefully stimulate further discussion and study in this important area.

Attenuating vascular stenosis-induced astrogliosis preserves white matter integrity and cognitive function

BACKGROUND

Chronic cerebral hypoperfusion (CCH) causes white matter damage and cognitive impairment, in which astrogliosis is the major pathology. However, underlying cellular mechanisms are not well defined. Activation of Na+/H+ exchanger-1 (NHE1) in reactive astrocytes causes astrocytic hypertrophy and swelling. In this study, we examined the role of NHE1 protein in astrogliosis, white matter demyelination, and cognitive function in a murine CCH model with bilateral carotid artery stenosis (BCAS).

METHODS

Sham, BCAS, or BCAS mice receiving vehicle or a selective NHE1 inhibitor HOE642 were monitored for changes of the regional cerebral blood flow and behavioral performance for 28 days. Ex vivo MRI-DTI was subsequently conducted to detect brain injury and demyelination. Astrogliosis and demyelination were further examined by immunofluorescence staining. Astrocytic transcriptional profiles were analyzed with bulk RNA-sequencing and RT-qPCR.

RESULTS

Chronic cerebral blood flow reduction and spatial working memory deficits were detected in the BCAS mice, along with significantly reduced mean fractional anisotropy (FA) values in the corpus callosum, external capsule, and hippocampus in MRI DTI analysis. Compared with the sham control mice, the BCAS mice displayed demyelination and axonal damage and increased GFAP+ astrocytes and Iba1+ microglia. Pharmacological inhibition of NHE1 protein with its inhibitor HOE642 prevented the BCAS-induced gliosis, damage of white matter tracts and hippocampus, and significantly improved cognitive performance. Transcriptome and immunostaining analysis further revealed that NHE1 inhibition specifically attenuated pro-inflammatory pathways and NADPH oxidase activation.

CONCLUSION

Our study demonstrates that NHE1 protein is involved in astrogliosis with pro-inflammatory transformation induced by CCH, and its blockade has potentials for reducing astrogliosis, demyelination, and cognitive impairment.

N. BP, Mohamed Ibrahim N, Mustapha M. Aberrant Neurogliovascular Unit Dynamics in Cerebral Small Vessel Disease: A Rheological Clue to Vascular Parkinsonism

The distinctive anatomical assemble and functionally discrete multicellular cerebrovasculature dynamics confer varying rheological and blood-brain barrier permeabilities to preserve the integrity of cerebral white matter and its neural microenvironment. This homeostasis intricately involves the glymphatic system that manages the flow of interstitial solutes, metabolic waste, and clearance through the venous circulation. As a physiologically integrated neurogliovascular unit (NGVU) serving a particularly vulnerable cerebral white matter (from hypoxia, metabolic insults, infection, and inflammation), a likely insidious process over a lifetime could inflict microenvironment damages that may lead to pathological conditions. Two such conditions, cerebral small vessel disease (CSVD) and vascular parkinsonism (VaP), with poorly understood pathomechanisms, are frequently linked to this brain-wide NGVU. VaP is widely regarded as an atypical parkinsonism, described by cardinal motor manifestations and the presence of cerebrovascular disease, particularly white matter hyperintensities (WMHs) in the basal ganglia and subcortical region. WMHs, in turn, are a recognised imaging spectrum of CSVD manifestations, and in relation to disrupted NGVU, also include enlarged perivascular spaces. Here, in this narrative review, we present and discuss on recent findings that argue for plausible clues between CSVD and VaP by focusing on aberrant multicellular dynamics of a unique integrated NGVU-a crossroad of the immune-vascular-nervous system-which may also extend fresher insights into the elusive interplay between cerebral microvasculature and neurodegeneration, and the potential therapeutic targets.

Microglial activation and blood-brain barrier permeability in cerebral small vessel disease

Cerebral small vessel disease (SVD) is a major cause of stroke and dementia. The underlying pathogenesis is poorly understood, but both neuroinflammation and increased blood-brain barrier permeability have been hypothesized to play a role, and preclinical studies suggest the two processes may be linked. We used PET magnetic resonance to simultaneously measure microglial activation using the translocator protein radioligand 11C-PK11195, and blood-brain barrier permeability using dynamic contrast enhanced MRI. A case control design was used with two disease groups with sporadic SVD (n = 20), monogenic SVD (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, CADASIL), and normal controls (n = 20) were studied. Hotspots of increased glial activation and blood-brain barrier permeability were identified as values greater than the 95th percentile of the distribution in controls. In sporadic SVD there was an increase in the volume of hotspots of both 11C-PK11195 binding (P = 0.003) and blood-brain barrier permeability (P = 0.007) in the normal appearing white matter, in addition to increased mean blood-brain barrier permeability (P < 0.001). In CADASIL no increase in blood-brain barrier permeability was detected; there was a non-significant trend to increased 11C-PK11195 binding (P = 0.073). Hotspots of 11C-PK11195 binding and blood-brain barrier permeability were not spatially related. A panel of 93 blood biomarkers relating to cardiovascular disease, inflammation and endothelial activation were measured in each participant; principal component analysis was performed and the first component related to blood-brain barrier permeability and microglial activation. Within the sporadic SVD group both hotspot and mean volume blood-brain barrier permeability values in the normal appearing white matter were associated with dimension 1 (β  =  0.829, P = 0.017, and β  =  0.976, P = 0.003, respectively). There was no association with 11C-PK11195 binding. No associations with blood markers were found in the CADASIL group. In conclusion, in sporadic SVD both microglial activation and increased blood-brain barrier permeability occur, but these are spatially distinct processes. No evidence of increased blood-brain barrier permeability was found in CADASIL.

Fibrinogen is an Independent Risk Factor for White Matter Hyperintensities in CADASIL but not in Sporadic Cerebral Small Vessel Disease Patients

The relationship between fibrinogen and white matter hyperintensities (WMHs) are inconsistent. Whether there are different relationships between WMHs and fibrinogen in disparate subtypes of cerebral small vessel disease (CSVD) remains unknown. Here, we investigated the roles of plasma fibrinogen in sporadic CSVD (sCSVD) and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) patients. We performed a cross-sectional study that included 74 CSVD patients (19 CADASIL and 55 sporadic) and 74 age- and gender-matched healthy controls (HCs). Plasma fibrinogen was determined, and the severity of WMHs in CSVD patients was rated according to Fazekas scales. Univariate analysis and ordinal logistic regression were performed to evaluate the relationship between fibrinogen and the severity of WMHs in CSVD. Both CADASIL and sCSVD patients showed significantly higher plasma fibrinogen levels than HCs. No significant difference in the plasma fibrinogen level was observed between CADASIL and sCSVD. Univariate analysis and ordinal logistic regression indicated that fibrinogen is an independent risk factor for the severity of WMHs in CADASIL patients (odds ratio [OR] =1.064; 95% Confidence interval (CI, 1.004-1.127); p =0.037). However, age (odds ratio [OR] =1.093; 95% CI (1.033-1.156); P = 0.002), but not fibrinogen (odds ratio [OR] =1.004; 95% CI (0.997-1.011); P=0.262), is an independent risk factor for the severity of WMHs in sCSVD patients. Our results suggest that high levels of plasma fibrinogen are associated with the severity of WMHs in CADASIL but not in sCSVD patients, indicating that the role of fibrinogen may be different in disparate subtypes of CSVD. A better understanding of fibrinogen may yield insights into the pathogenesis of CSVD.

Emerging Concepts in Vascular Dementia: A Review

OBJECTIVE

Vascular dementia (VaD) is the second most common cause of dementia and a major health concern worldwide. A comprehensive review on VaD is warranted for better understanding and guidance for the practitioner. We provide an updated overview of the epidemiology, pathophysiological mechanisms, neuroimaging patterns as well as current diagnostic and therapeutic approaches.

MATERIALS AND METHODS

A narrative review of current literature in VaD was performed based on publications from the database of PubMed, Scopus and Google Scholar up to January, 2021.

RESULTS

VaD can be the result of ischemic or hemorrhagic tissue injury in a particular region of the brain which translates into clinically significant cognitive impairment. For example, a cerebral infarct in the speech area of the dominant hemisphere would translate into clinically significant impairment as would involvement of projection pathways such as the arcuate fasciculus. Specific involvement of the angular gyrus of the dominant hemisphere, with resultant Gerstman's syndrome, could have a pronounced effect on functional ability despite being termed a "minor stroke". Small vessel cerebrovascular disease can have a cumulate effect on cognitive function over time. It is unfortunately well recognized that "good" functional recovery in acute ischemic or haemorrhagic stroke, including subarachnoid haemorrhage, does not necessarily translate into good cognitive recovery. The victim may often be left unable to have gainful employment, drive a car safely or handle their affairs independently.

CONCLUSIONS

This review should serve as a compendium of updated information on VaD and provide guidance in terms of newer diagnostic and potential therapeutic approaches.

Cerebral microbleeds in vascular dementia from clinical aspects to host-microbial interaction

Vascular dementia is the second leading cause of dementia after Alzheimer's disease in the elderly population worldwide. Cerebral microbleeds (CMBs) are frequently observed in MRI of elderly subjects and considered as a possible surrogate marker. The number and location of CMBs reflect the severity of diseases and the underlying pathologies may involve cerebral amyloid angiopathy or hypertensive vasculopathy. Accumulating evidence demonstrated the clinicopathological discrepancies of CMBs, the clinical significance of CMBs associated with other MRI markers of cerebral small vessel disease, cognitive impairments, serum, and cerebrospinal fluid biomarkers. Moreover, emerging evidence has shown that genetic factors and gene-environmental interactions might shed light on the underlying etiologies of CMBs, focusing on blood-brain-barrier and inflammation. In this review, we introduce recent genetic and microbiome studies as a cutting-edge approach to figure out the etiology of CMBs through the "microbe-brain-oral axis" and "microbiome-brain-gut axis." Finally, we propose novel concepts, "microvascular matrisome" and "imbalanced proteostasis," which may provide better perspectives for elucidating the pathophysiology of CMBs and future development of therapeutics for vascular dementia using CMBs as a surrogate marker.

Dexmedetomidine Mitigated NLRP3-Mediated Neuroinflammation via the Ubiquitin-Autophagy Pathway to Improve Perioperative Neurocognitive Disorder in Mice

Background: Surgery and anesthesia-induced perioperative neurocognitive disorder (PND) are closely related to NOD-like receptors (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome microglia inflammatory response. Inhibiting the occurrence of neuroinflammation is an important treatment method to improve postoperative delirium. Fewer NLRP3-targeting molecules are currently available in the clinic to reduce the incidence of postoperative delirium. Dexmedetomidine (DEX), an α2 adrenergic receptor agonist has been shown to have antioxidant and anti-inflammatory activities. The present study showed that DEX reduced the production of cleaved caspase1 (CASP1) and destroyed the NLRP3–PYD And CARD Domain Containing (PYCARD)–CASP1 complex assembly, thereby reducing the secretion of IL-1β interleukin beta (IL-1β). DEX promoted the autophagy process of microglia and reduced NLRP3 expression. More interestingly, it promoted the ubiquitination and degradation of NLRP3. Thus, this study demonstrated that DEX reduced NLRP3-mediated inflammation through the activation of the ubiquitin-autophagy pathway. This study provided a new mechanism for treating PND using DEX.

Methods: C57BL/6 mice were pre-administered DEX 3 days in advance, and an abdominal exploration model was used to establish a perioperative neurocognitive disorder model. The anti-inflammatory effect of DEX was explored in vivo by detecting NLRP3-CASP1/IL-1β protein expression and behavioral testing. Primary microglia were stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in vitro, the expression of CASP1 and IL-1β was detected in the supernatant of cells, and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) and sequestosome 1 (SQSTM1) was examined in the cytoplasm. Meanwhile, Co-immunoprecipitation (Co-IP) was used to detect NLRP3 protein ubiquitination so as to clarify the new mechanism underlying the anti-inflammatory effect of DEX.

Results: Pre-administration of DEX reduced the protein expression of NLRP3, CASP1, and IL-1β in the hippocampus of mice induced by surgery and also improved the impairment of learning and memory ability. At the same time, DEX also effectively relieved the decrease in spine density of the hippocampal brain induced by surgery. DEX decreased the cleaved CASP1 expression, blocked the assembly of NLRP3–PYCARD–CASP1 complex, and also reduced the secretion of mature IL-1β in vitro. Mechanically, it accelerated the degradation of NLRP3 inflammasome via the autophagy–ubiquitin pathway and reduced the green fluorescent protein/red fluorescent protein MAP1LC3B ratio, which was comparable to the effect when using the autophagy activator rapamycin (Rapa). Furthermore, it increased the ubiquitination of NLRP3 after LPS plus ATP stimulated microglia.

Conclusion: DEX attenuated the hippocampal brain inflammation by promoting NLRP3 inflammasome degradation via the autophagy–ubiquitin pathway, thus improving cognitive impairment in mice.

Pro-inflammatory Monocyte Phenotype During Acute Progression of Cerebral Small Vessel Disease

Background: The etiology of cerebral small vessel disease (SVD) remains elusive, though evidence is accumulating that inflammation contributes to its pathophysiology. We recently showed retrospectively that pro-inflammatory monocytes are associated with the long-term progression of white matter hyperintensities (WMHs). In this prospective high-frequency imaging study, we hypothesize that the incidence of SVD progression coincides with a pro-inflammatory monocyte phenotype.

Methods: Individuals with SVD underwent monthly magnetic resonance imaging (MRI) for 10 consecutive months to detect SVD progression, defined as acute diffusion-weighted imaging-positive (DWI+) lesions, incident microbleeds, incident lacunes, and WMH progression. Circulating inflammatory markers were measured, cytokine production capacity of monocytes was assessed after ex vivo stimulation, and RNA sequencing was performed on isolated monocytes in a subset of participants.

Results: 13 out of 35 individuals developed SVD progression (70 ± 6 years, 54% men) based on incident lesions (n = 7) and/or upper quartile WMH progression (n = 9). Circulating E-selectin concentration (p < 0.05) and the cytokine production capacity of interleukin (IL)-1β and IL-6 (p < 0.01) were higher in individuals with SVD progression. Moreover, RNA sequencing revealed a pro-inflammatory monocyte signature including genes involved in myelination, blood–brain barrier, and endothelial–leukocyte interaction.

Conclusions: Circulating monocytes of individuals with progressive SVD have an inflammatory phenotype, characterized by an increased cytokine production capacity and a pro-inflammatory transcriptional signature.

Association of Serum IL-6 (Interleukin 6) With Functional Outcome After Intracerebral Hemorrhage

BACKGROUND AND OBJECTIVES

IL-6 (interleukin 6) is a proinflammatory cytokine and an established biomarker in acute brain injury. We sought to determine whether admission IL-6 levels are associated with severity and functional outcome after spontaneous intracerebral hemorrhage (ICH).

METHODS

We performed an exploratory analysis of the recombinant activated FAST trial (Factor VII for Acute ICH). Patients with admission serum IL-6 levels were included. Regression analyses were used to assess the associations between IL-6 and 90-day modified Rankin Scale. In secondary analyses, we used linear regression to evaluate the association between IL-6 and baseline ICH and perihematomal edema volumes.

RESULTS

Of 841 enrolled patients, we included 552 (66%) with available admission IL-6 levels (mean age 64 [SD 13], female sex 203 [37%]). IL-6 was associated with poor outcome (modified Rankin Scale, 4-6; per additional 1 ng/L, odds ratio, 1.30 [95% CI, 1.04-1.63]; P=0.02) after adjustment for known predictors of outcome after ICH and treatment group. IL-6 was associated with ICH volume after adjustment for age, sex, and ICH location, and this association was modified by location (multivariable interaction, P=0.002), with a stronger association seen in lobar (β, 12.51 [95% CI, 6.47-18.55], P<0.001) versus nonlobar (β 5.32 [95% CI, 3.36-7.28], P<0.001) location. IL-6 was associated with perihematomal edema volume after adjustment for age, sex, ICH volume, and ICH location (β 1.22 [95% CI, 0.15-2.29], P=0.03). Treatment group was not associated with IL-6 levels or outcome.

CONCLUSIONS

In the FAST trial population, higher admission IL-6 levels were associated with worse 90-day functional outcome and larger ICH and perihematomal edema volumes.

A Proposed Hypothesis on Dementia: Inflammation, Small Vessel Disease, and Hypoperfusion Is the Sequence That Links All Harmful Lifestyles to Cognitive Impairment

There is growing consensus that certain lifestyles can contribute to cognitive impairment and dementia, but the physiological steps that link a harmful lifestyle to its negative impact are not always evident. It is also unclear whether all lifestyles that contribute to dementia do so through the same intermediary steps. This article will focus on three lifestyles known to be risk factors for dementia, namely obesity, sedentary behavior, and insufficient sleep, and offer a unifying hypothesis proposing that lifestyles that negatively impact cognition do so through the same sequence of events: inflammation, small vessel disease, decline in cerebral perfusion, and brain atrophy. The hypothesis will then be tested in a recently identified risk factor for dementia, namely hearing deficit. If further studies confirm this sequence of events leading to dementia, a significant change in our approach to this debilitating and costly condition may be necessary, possible, and beneficial.

Association between white matter hyperintensity load and grey matter atrophy in mild cognitive impairment is not unidirectional

Neuroimaging measures of Alzheimer's disease (AD) include grey matter volume (GMV) alterations in the Default Mode Network (DMN) and Executive Control Network (ECN). Small-vessel cerebrovascular disease, often visualised as white matter hyperintensities (WMH) on MRI, is often seen in AD. However, the relationship between WMH load and GMV needs further examination. We examined the load-dependent influence of WMH on GMV and cognition in 183 subjects. T1-MRI data from 93 Mild Cognitive Impairment (MCI) and 90 cognitively normal subjects were studied and WMH load was categorized into low, medium and high terciles. We examined how differing loads of WMH related to whole-brain voxel-wise and regional DMN and ECN GMV. We further investigated how regional GMV moderated the relationship between WMH and cognition. We found differential load-dependent effects of WMH burden on voxel-wise and regional atrophy in only MCI. At high load, as expected WMH negatively related to both ECN and DMN GMV, however at low load, WMH positively related to ECN GMV. Additionally, negative associations between WMH and memory and executive function were moderated by regional GMV. Our results demonstrate non-unidirectional relationships between WMH load, GMV and cognition in MCI.

Prevalence and risk factors for brain white matter changes in young and middle-aged participants with Brain Dock (brain screening): a registry database study and literature review

This study aimed to determine the prevalence and risk factors for brain white matter changes in normal young and middle-aged participants who underwent Brain Dock (brain screening). We analyzed 5,000 consecutive healthy participants from the Brain Dock registry between August to December 2018. Age, sex, body mass index (BMI), medical history, deep subcortical white matter high intensity (DSWMH), periventricular high intensity (PVH), and enlargement of perivascular space (EPVS) were investigated in relation to age. The prevalence of DSWMH, PVH, and EPVS were 35.3%, 14.0%, and 17.8%, respectively. Multivariate logistic regression analyses for brain white matter changes were conducted. The significant risk factors in participants aged < 50 years were: age (OR:1.09, 95% CI:1.07-1.12), the female sex (1.29, 1.03-1.60), BMI obesity (1.86, 1.12-3.08), and hypertension (1.67, 1.18-2.35) for DSWMH; age (1.08, 1.04-1.13) and the female sex (1.56, 1.03-2.36) for PVH; and age (1.07, 1.05-1.10) and the female sex (0.77, 0.60-1.00) for EPVS. In conclusion, age was consistently identified as a significant risk factor in young and middle-aged participants. Some risk factors for brain white matter changes were identified even in young and middle-aged participants in this study. Further longitudinal studies should be done in the future.

Association of Trimethylamine N-Oxide and Its Precursor With Cerebral Small Vessel Imaging Markers

Background: High plasma levels of trimethylamine N-oxide (TMAO) and its precursor choline have been linked to stroke; however, their association with cerebral small vessel disease remains unclear. Here we evaluated the association of plasma levels of TMAO and choline with imaging markers of cerebral small vessel disease, including white matter hyperintensities, lacunes, and cerebral microbleeds.

Methods: We performed a baseline cross-sectional analysis of a multicenter hospital-based cohort study from 2015 to 2018. The data were collected from 30 hospitals in China and included 1,098 patients with ischemic stroke/transient ischemic attack aged ≥18 years. White matter hyperintensities, lacunes, and cerebral microbleeds were evaluated with the patients' demographic, clinical, and laboratory information removed. White matter hyperintensities were rated using the Fazekas visual grading scale, while the degree of severity of the lacunes and cerebral microbleeds was defined by the number of lesions.

Results: Increased TMAO levels were associated with severe white matter hyperintensities [adjusted odds ratio (aOR) for the highest vs. lowest quartile, 1.5; 95% confidence interval (CI), 1.0–2.1, p = 0.04]. High TMAO levels were more strongly associated with severe periventricular white matter hyperintensities (aOR for the highest vs. lowest quartile, 1.6; 95% CI, 1.1–2.3, p = 0.009) than deep white matter hyperintensities (aOR for the highest vs. lowest quartile, 1.3; 95% CI, 0.9–1.9, p = 0.16). No significant association was observed between TMAO and lacunes or cerebral microbleeds. Choline showed trends similar to that of TMAO in the association with cerebral small vessel disease.

Conclusions: In patients with ischemic stroke or transient ischemic attack, TMAO and choline appear to be associated with white matter hyperintensities, but not with lacunes or cerebral microbleeds; TMAO and choline were associated with increased risk of a greater periventricular, rather than deep, white matter hyperintensities burden.

Differential Effects of Serum Lipoprotein-Associated Phospholipase A2 on Periventricular and Deep Subcortical White Matter Hyperintensity in Brain

Background and Purpose: Serum level of lipoprotein-associated phospholipase A2 (Lp-PLA2) was associated with white matter hyperintensity (WMH). There were differences in the anatomical structure and pathophysiological mechanism between periventricular WMH (PVWMH) and deep subcortical WMH (DSWMH). In this study, we aimed to investigate the effects of serum Lp-PLA2 on the PVWMH and DSWMH. Methods: In total, 711 Chinese adults aged ≥45 years with cranial magnetic resonance imaging (MRI) were recruited in this cross-sectional study, who had received physical examinations in the Department of Neurology, the Affiliated Jiangning Hospital of Nanjing Medical University due to dizziness and headaches between January 2016 and July 2019. Enzyme linked immunosorbent assay (ELISA) was utilized to determine the serum Lp-PLA2. Fazekas scale was used to measure the severity of PVWMH (grade 0-3) and DSWMH (grade 0-3) on MRI scans. Ordinal regression analysis was carried out to investigate the relationship between serum Lp-PLA2 and PVWMH or DSWMH. Results: Finally, 567 cases were included in this study. The average level of serum Lp-PLA2 was 213.35±59.34 ng/ml. There were statistical differences in the age, hypertension, diabetes mellitus, atrial fibrillation, lacunar infarction, Lp-PLA2 grade, creatinine, Hcy, and H-CRP (P < 0.05) in PVWMH groups. Ordinal regression analysis indicated that there was a lower risk of PVWMH in the patients with normal and moderately elevated serum Lp-PLA2 compared with those with significantly elevated serum Lp-PLA2 after adjusting age, hypertension, diabetes mellitus, atrial fibrillation, lacunar infarction, Cr, Hcy, and H-CRP. In addition, PVWMH was correlated to advanced age, hypertension, diabetes mellitus, and lacunar infarction. After adjusting for confounding factors, DSWMH was correlated to advanced age and lacunar infarction. There was no correlation between serum Lp-PLA2 and DSWMH. Conclusions: Serum Lp-PLA2 was closely associated with the pathogenesis of PVWMH rather than DSWMH. There might be different pathological mechanisms between PVWMH and DSWMH.