Enlarged perivascular spaces are associated with health-related quality of life in patients with acute ischemic stroke

Brain Enlarged Perivascular Spaces as Imaging Biomarkers of Cerebrovascular Disease: A Clinical Narrative Review

Perivascular spaces or Virchow-Robin spaces form pathways along the subarachnoid spaces that facilitate the effective clearance of brain metabolic by-products through intracellular exchange and drainage of cerebrospinal fluid. Best seen on magnetic resonance imaging of the brain, enlarged perivascular spaces (EPVSs) are increasingly recognized as potential imaging biomarkers of neurological conditions. EPVSs are an established subtype of cerebral small-vessel disease; however, their associations with other cerebrovascular disorders are yet to be fully understood. In particular, there has been great interest in the association between the various parameters of EPVSs, such as number, size, and topography, and vascular neurological conditions. Studies have identified cross-sectional and longitudinal relationships between EPVS parameters and vascular events, such as ischemic stroke (both clinical and silent), intracerebral hemorrhage, vascular risk factors, such as age and hypertension, and neurodegenerative processes, such as vascular dementia and Alzheimer disease. However, these studies are limited by heterogeneity of data and the lack of consistent results across studied populations. Existing meta-analyses also fail to provide uniformity of results. We performed a qualitative narrative review with an aim to provide an overview of the associations between EPVSs and cerebrovascular diseases, which may help recognize gaps in our knowledge, inform the design of future studies, and advance the role of EPVSs as imaging biomarkers.

Asymmetric distribution of enlarged perivascular spaces in centrum semiovale may be associated with epilepsy after acute ischemic stroke

Objective

To investigate the factors influencing enlarged perivascular space (EPVS) characteristics at the onset of acute ischemic stroke (AIS), and whether the PVS characteristics can predict later post‐stroke epilepsy (PSE).

Methods

A total of 312 patients with AIS were identified, of whom 58/312 (18.6%) developed PSE. Twenty healthy participants were included as the control group. The number of PVS in the basal ganglia (BG), centrum semiovale (CS), and midbrain (MB) was manually calculated on T₂‐weighted MRI. The scores and asymmetry index (AI) of EPVS in each region were compared among the enrolled participants. Other potential risk factors for PSE were also analyzed, including NIHSS at admission and stroke etiologies.

Results

The EPVS scores were significantly higher in the bilateral BG and CS of AIS patients compared to those of the control group (both p < 0.01). No statistical differences in EPVS scores in BG, CS, and MB were obtained between the PSE group and the nonepilepsy AIS group (all p > 0.01). However, markedly different AI scores in CS were found between the PSE group and the nonepilepsy AIS group (p = 0.004). Multivariable analysis showed that high asymmetry index of EPVS (AI≥0.2) in CS was an independent predictor for PSE (OR = 3.7, 95% confidence interval 1.5–9.1, p = 0.004).

Conclusions

Asymmetric distribution of EPVS in CS may be an independent risk factor and a novel imaging biomarker for the development of PSE. Further studies to understand the mechanisms of this association and confirmation with larger patient populations are warranted.

Direct Rating Estimation of Enlarged Perivascular Spaces (EPVS) in Brain MRI Using Deep Neural Network

In this article, we propose a deep-learning-based estimation model for rating enlarged perivascular spaces (EPVS) in the brain’s basal ganglia region using T2-weighted magnetic resonance imaging (MRI) images. The proposed method estimates the EPVS rating directly from the T2-weighted MRI without using either the detection or the segmentation of EVPS. The model uses the cropped basal ganglia region on the T2-weighted MRI. We formulated the rating of EPVS as a multi-class classification problem. Model performance was evaluated using 96 subjects’ T2-weighted MRI data that were collected from two hospitals. The results show that the proposed method can automatically rate EPVS—demonstrating great potential to be used as a risk indicator of dementia to aid early diagnosis.

Enlarged perivascular spaces and hemorrhagic transformation after acute ischemic stroke

Background

Enlarged perivascular spaces (EPVS) are considered to be neuroimaging markers of cerebral small vessel disease (CSVD). It remains unknown whether EPVS are associated with hemorrhagic transformation (HT) after acute ischemic stroke (AIS). We performed this retrospective cohort study to explore the associations of EPVS with clinical risk factors and other CSVD imaging features, and to investigate the relationship between EPVS and HT in patients with AIS.

Methods

AIS patients admitted within 24 hours of stroke onset between January 2016 and December 2017 were consecutively enrolled. EPVS, lacunes, and white matter hyperintensities (WMH) were rated with validated rating scales on magnetic resonance images after the stroke. HT was defined as hemorrhage determined by follow-up brain imaging during the patients' hospital stay. Logistic regression was used to determine the risk factors and associations with other CSVD markers of EPVS in the basal ganglia (BG) and centrum semiovale (CS) regions, and the impact of EPVS on HT was further explored.

Results

Among 494 included patients (mean age 66.4 years, 58.1% male), 81 (16.4%) experienced HT. In the multivariate logistic analyses, increasing age [odd ratio (OR) 1.041, 95% confidence interval (CI), 1.017-1.066], hypertension (OR 2.174, 95% CI, 1.338-3.532), lacunar stroke (OR 1.968, 95% CI, 1.169-3.314), CS-EPVS (OR 2.474, 95% CI, 1.796-3.407), and periventricular WMH (OR 2.140, 95% CI, 1.441-3.176) were significantly associated with BG-EPVS; whereas only BG-EPVS (OR 4.349, 95% CI, 2.281-8.291) were independently related to CS-EPVS. After adjustment for potential variables, neither BG-EPVS (OR 0.674, 95% CI, 0.336-1.350) nor CS-EPVS (OR 0.792, 95% CI, 0.334-1.879) was significantly associated with the occurrence of HT.

Conclusions

Our data showed that EPVS in the BG and CS regions were interrelated and had different risk factors in ischemic stroke patients. EPVS (particularly that in BG) were independently related to other CSVD markers. The presence or burden of EPVS was not significantly associated with HT after AIS.

Magnetic resonance imaging manifestations of cerebral small vessel disease: automated quantification and clinical application

The common cerebral small vessel disease (CSVD) neuroimaging features visible on conventional structural magnetic resonance imaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. The CSVD neuroimaging features have shared and distinct clinical consequences, and the automatic quantification methods for these features are increasingly used in research and clinical settings. This review article explores the recent progress in CSVD neuroimaging feature quantification and provides an overview of the clinical consequences of these CSVD features as well as the possibilities of using these features as endpoints in clinical trials. The added value of CSVD neuroimaging quantification is also discussed for researches focused on the mechanism of CSVD and the prognosis in subjects with CSVD.

Ischemia-related changes of fat-mass and obesity-associated protein expression in the gerbil hippocampus

Fat-mass and obesity-associated protein (Fto) plays important roles in energy metabolism. It also acts as a demethylase and is most abundantly found in the brain. In the present study, we examined the spatial and temporal changes of Fto immunoreactivity after five minutes of transient forebrain ischemia in the hippocampus. In the control group, Fto immunoreactivity was mainly observed in the nucleus of pyramidal cells in the CA1 and CA3 regions as well as the polymorphic layer, granule cell layer, and subgranular zone of the dentate gyrus. Fto immunoreactivity was transiently, but not significantly, increased in the hippocampal CA3 region and the dentate gyrus two days after ischemia compared to mice without ischemia in the sham-operated group. Four days after ischemia, low Fto immunoreactivity was observed in the stratum pyramidale of the CA1 region because of neuronal death, but Fto immunoreactive cells were abundantly detected in the stratum pyramidale of the CA3 region, which is relatively resistant to ischemic damage. Thereafter, Fto immunoreactivity progressively decreased in the hippocampal CA1 and CA3 regions and the dentate gyrus until ten days after ischemia. At this time-point, Fto immunoreactivity was significantly lower in the hippocampal CA1 and CA3 regions and the dentate gyrus compared to that in the sham-operated group. The reduction of Fto immunoreactive structures in the hippocampus may be associated with impairments in Fto-related hippocampal function.

Association Between Behavioral Dysexecutive Syndrome and the Health-Related Quality of Life Among Stroke Survivors

AIM

Behavioral dysexecutive syndrome (BDES) is one common neuropsychiatric comorbidity after stroke. Despite evidences suggesting the adverse effect of BDES on the survivors' outcome, little is known about the association between BDES and the health-related quality of life (HRQoL) among stroke survivors and how BDES impacts the HRQoL. This study aimed to address these questions.

METHODS

This study included 219 patients with acute ischemic stroke consecutively admitted to a regional hospital in Hong Kong. BDES was defined as a Chinese version of the Dysexecutive Questionnaire (DEX) score of ≥20 assessed at three months after stroke. The HRQoL was assessed with the Chinese version of the Stroke-Specific Quality of Life (SSQoL) questionnaire encompassing 12 domains. Multivariate linear regression models were employed to examine the association between BDES symptoms and the SSQoL total and domain scores. Structural equation model (SEM) was further constructed to delineate the linking pathways linking BDES and the HRQoL.

RESULTS

The study sample compromised mainly older patients with mild to moderate ischemic stroke. Compared with patients without BDES, those with BDES exhibited poorer performances regarding with the summarized SSQoL (226.2 ± 18.8 vs. 200.3 ± 29.8, p < 0.001) and almost all domains. The BDES symptoms were independently contributed to the whole HRQoL (SSQoL total score) (β = -0.20, p = 0.002), specifically to the domains in personality (β = -0.34, p < 0.001), language (β = -0.22, p = 0.01), and work/productivity (β = -0.32, p < 0.001), after adjusting demographic and clinical characteristics in linear models. The impacts of the BDES symptoms on the HRQoL were mainly explained by the indirect path mediated by depression and anxiety (path coefficient = -0.27, p < 0.05) rather than physical disability, while the resting was elucidated by the path directly linking BDES to the HRQoL (path coefficient = -0.17, p < 0.05).

CONCLUSION

The present study preliminarily demonstrated a potential association between BDES and a lower level of the HRQoL, predominantly in domains of personality, language, and work/productivityafter acute ischemic stroke. This study also offered insights into the underlying mechanisms linking BDES and the HRQoL, implicating that integrative psychological therapies were urged to achieve better HRQoL after stroke.

Cerebral Small Vessel Disease Burden Is Associated With Accelerated Poststroke Cognitive Decline: A 1-Year Follow-Up Study

OBJECTIVE

This study investigated the association between small vessel disease (SVD) burden, a combination of multiple SVD markers and cognitive dysfunction after stroke.

METHODS

The study sample comprised 451 patients with first-ever acute ischemic stroke. Cognitive functions were assessed with the Mini-Mental State Examination (MMSE) at 3, 9, and 15 months after the index stroke. Cognitive impairment was defined as an MMSE score of ≤26. A total SVD score, indicating SVD burden, was constructed by summing the scores of the 4 SVD markers (white matter hyperintensities [WMHs], lacunes, cerebral microbleeds, and perivascular spaces) ascertained by magnetic resonance imaging (range: 0-4). The association between SVD burden and cognitive dysfunction was assessed with linear mixed models or generalized estimating equation models, as appropriate.

RESULTS

The majority of patients had mild-to-moderate stroke and at least one identifiable SVD marker. Cognitive impairment was found in about one-third of patients. After adjusting for confounding factors, the SVD burden was associated with MMSE scores (β = -0.37, P = .003) and cognitive impairment (odds ratio [OR] = 1.20, 95% confidence interval [CI] = 1.02-1.42). SVD burden was specifically associated with the performance of MMSE subscores including orientation to place and time, calculation, and word recall. Of the SVD markers, WMHs was the most robust predictor of decrease in MMSE scores (β = -0.25, P = .01) and cognitive impairment (OR = 1.14, 95% CI = 1.01-1.29).

CONCLUSION

Cerebral SVD burden is associated with decreased MMSE scores, suggesting cognitive dysfunction during the first year after mild-to-moderate acute ischemic stroke.

Enlarged perivascular spaces are associated with health-related quality of life in patients with acute ischemic stroke

AIMS

This study explored the association between enlarged perivascular spaces (EPVS) and the health-related quality of life (HRQoL) in patients with acute ischemic stroke.

METHODS

This was an observational study of consecutively screened patients with acute ischemic stroke from March 2010 to March 2015. EPVS were rated in the basal ganglia and the centrum semiovale with a validated scale. The HRQoL was assessed 3 months after the stroke onset using the Stroke-Specific Quality of Life (SSQoL). Linear regression models were used to study the association between EPVS and HRQoL.

RESULTS

The study included 648 patients (mean age 65.8 years; 40.0% women) with mild to moderately severe stroke (median NIHSS score 2), of whom 640 (98.8%) exhibited signs of small vessel disease. The median EPVS scores in the basal ganglia and the centrum semiovale were 1 each. In linear regression analysis, EPVS in the basal ganglia were associated with a lower total SSQoL score (P = 0.02) and lower mobility (P = 0.01), mood (P = 0.03), and self-care (P < 0.01). EPVS in the centrum semiovale were associated only with a lower SSQoL work/productivity subscore (P = 0.002).

CONCLUSIONS

EPVS are associated with lower HRQoL in patients with mild to moderate acute ischemic stroke. Early identification and intervention of EPVS may improve HRQoL in stroke survivors.