Dilated Virchow-Robin Spaces in First-Ever Lacunar Stroke Patients: Topography and Clinical Correlations

Small vessel disease burden predicts functional outcomes in patients with acute ischemic stroke using machine learning

AIMS

Our purpose is to assess the role of cerebral small vessel disease (SVD) in prediction models in patients with different subtypes of acute ischemic stroke (AIS).

METHODS

We enrolled 398 small-vessel occlusion (SVO) and 175 large artery atherosclerosis (LAA) AIS patients. Functional outcomes were assessed using the modified Rankin Scale (mRS) at 90 days. MRI was performed to assess white matter hyperintensity (WMH), perivascular space (PVS), lacune, and cerebral microbleed (CMB). Logistic regression (LR) and machine learning (ML) were used to develop predictive models to assess the influences of SVD on the prognosis.

RESULTS

In the feature evaluation of SVO-AIS for different outcomes, the modified total SVD score (Gain: 0.38, 0.28) has the maximum weight, and periventricular WMH (Gain: 0.07, 0.09) was more important than deep WMH (Gain: 0.01, 0.01) in prognosis. In SVO-AIS, SVD performed better than regular clinical data, which is the opposite of LAA-AIS. Among all models, eXtreme gradient boosting (XGBoost) method with optimal index (OI) has the best performance to predict excellent outcome in SVO-AIS. [0.91 (0.84-0.97)].

CONCLUSIONS

Our results revealed that different SVD markers had distinct prognostic weights in AIS patients, and SVD burden alone may accurately predict the SVO-AIS patients' prognosis.

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.

Associations of Vascular Risk Factors and APOE Genotype With Perivascular Spaces Among Community-Dwelling Older Adults

Background Evidence suggests that enlarged perivascular spaces (PVSs) may represent a marker for cerebral small-vessel disease. We investigated whether vascular risk factors are correlated with visible PVS in older adults. Methods and Results This population-based study included 530 participants (age ≥60 years) who were free from dementia and functional dependence, derived from the Swedish National study on Aging and Care in Kungsholmen (2001-2003). We collected data on demographics, vascular risk factors, and health conditions through interviews, clinical examinations, laboratory tests, and patient registers. Cerebral PVSs and white matter hyperintensities on magnetic resonance images were visually assessed with semiquantitative visual rating scales. Data were analyzed using the general linear regression models. After controlling for demographics and cardiovascular disease, very high blood pressure (≥160/100 mm Hg) was significantly associated with global PVS score (β-coefficient, 1.30; 95% CI, 0.06-2.53) and orthostatic hypotension was associated with PVS score in the basal ganglia (β-coefficient 0.37; 0.03-0.70), but the associations became non-significant when adjusting for white matter hyperintensity load. Orthostatic hypotension was significantly associated with global and lobar PVS scores in carriers but not in noncarriers of the APOE ε4 allele. Global or regional PVS score was not significantly associated with other traditional vascular risk factors such as smoking, diabetes mellitus, physical inactivity, and overweight or obesity. Conclusions This study provides limited evidence supporting a correlation of magnetic resonance imaging-visible PVS with traditional vascular risk factors in older adults. The association of orthostatic hypotension with lobar PVS among APOE ε4 carriers suggests that lobar PVS may be a marker for amyloid-associated small-vessel disease.

Association between Enlarged Perivascular Spaces and Internal Carotid Artery Stenosis: A Study in Patients Diagnosed by Digital Subtraction Angiography

OBJECTIVE

An enlarged perivascular space (EPVS) is an imaging marker of cerebral small vessel disease, and its relationship with large artery disease is elusive. We investigated the EPVS in patients with internal carotid artery stenosis (ICAS) with the use of digital subtraction angiography (DSA) and tested the relationship between the degree of EPVS and the degree of ICAS; as well as the relationship between the degree of EPVS and white matter hyperintensity (WMH).

METHOD

A total of 202 patients with or without ICAS diagnosed by DSA were enrolled. The maximal ICAS rates, the degrees of EPVS and WMH were measured. The patients' clinical characteristics and laboratory parameters were recorded. Univariable analysis and multivariable regression were used to test their correlations. In a unilateral stenosis subgroup, the EPVSs in the ipsilateral hemisphere of stenosis and in the contralateral hemisphere were compared.

RESULTS

According to univariable analysis, there were significant differences in age (P = .000), Hg1bc (P = .035) and folic acid (P = .008) among the subgroups based on the degrees of EPVS in the basal ganglia (BG). Age (P = .000) and the level of fibrinogen (P = .018) differed statistically among the subgroups based on the degrees of EPVS in the white matter (WM). The correlation between the degrees of WM-EPVS and the ICAS levels was tested with a gamma test: G = .280, P = .001. The ordinal multivariable regression model showed that age was independently associated with both BG-EPVSs and WM-EPVSs. A current smoker status was also independently associated with WM-EPVSs. ICAS level was associated with the severity of WM-EPVSs after adjusting for other risk factors. The degree of BG-EPVS was not correlated with the degree of stenosis. (P = .101). In 59 patients with unilateral ICAS, as tested by the Wilcoxon signed ranks test, the WM-EPVS scores in the ipsilateral hemisphere of stenosis were higher than those in the contralateral hemisphere. (P = .004), but there was no difference in BG-EPVSs (P = .070). Both BG-EPVSs and WM-EPVSs were independently correlated with WMH.

CONCLUSIONS

BG-EPVSs and WM-EPVSs have different risk factors. WM-EPVSs but not BG-EPVSs are correlated with ICAS.

Total Small Vessel Disease Burden Predicts Functional Outcome in Patients With Acute Ischemic Stroke

Background: Cerebral small vessel disease (SVD) is generally considered as a cause of stroke, disability, gait disturbances, vascular cognitive impairment, and dementia. The aim of this study was to investigate whether the total SVD burden can be used to predict functional outcome in patients with acute ischemic stroke.

Methods: From April 2017 to January 2018, consecutive patients with acute ischemic stroke who underwent baseline MRI scan were evaluated. The functional outcome was assessed using the modified Rankin Scale (mRS) at 90 days and defined as i) excellent outcome (mRS ≤ 1) and ii) good outcome (mRS ≤ 2). Brain MRI was performed and assessed for lacunes, white matter hyperintensities (WMH), and enlarged perivascular spaces (EPVS). The total SVD burden was calculated based on lacunes, WMH, and EPVS and then summed up to generate an ordinal “total SVD burden” (range 0–3). Bivariate logistic regression models were used to identify the association between SVD and functional outcome.

Results: A total of 416 patients were included in the final analysis; 44.0, 33.4, 19.2, and 3.4% of the patients had 0, 1, 2, and 3 features of SVD, respectively. In regard to individual SVD feature, lacunes (OR: 0.48, 95% CI: 0.32–0.71; OR: 0.49, 95% CI: 0.31–0.77) and WMH (OR: 0.53, 95% CI: 0.34–0.82; OR: 0.53, 95% CI: 0.33–0.85) were negatively associated with excellent outcome and good outcome. As to the total burden of SVD, three SVD features had strongest negative associations with functional outcomes (excellent outcome, OR: 0.13, 95% CI: 0.03–0.48; good outcome, OR: 0.18, 95% CI: 0.06–0.54). After adjustment for potential confounders, a high SVD burden (3 features, OR: 0.07, 95% CI: 0.01–0.41) and the score of total SVD burden (OR: 0.64, 95% CI: 0.44–0.93) remained negatively associated with excellent outcome.

Conclusion: Total SVD burden negatively associated with functional outcome at 3 months in patients with acute ischemic stroke and is superior to individual SVD feature in prediction of functional outcome. MRI-based assessment of total SVD burden is highly valuable in clinical management of stroke victims and could help guide the allocation of resources to improve outcome.

Perivascular spaces and their associations with risk factors, clinical disorders and neuroimaging features: A systematic review and meta-analysis

BACKGROUND

Perivascular spaces, visible on brain magnetic resonance imaging, are thought to be associated with small vessel disease, neuroinflammation, and to be important for cerebral hemodynamics and interstitial fluid drainage.

AIMS

To benchmark current knowledge on perivascular spaces associations with risk factors, neurological disorders, and neuroimaging lesions, using systematic review and meta-analysis.

SUMMARY OF REVIEW

We searched three databases for perivascular spaces publications, calculated odds ratios with 95% confidence interval and performed meta-analyses to assess adjusted associations with perivascular spaces. We identified 116 relevant studies (n = 36,108) but only 23 (n = 12,725) were meta-analyzable. Perivascular spaces assessment, imaging and clinical definitions varied. Perivascular spaces were associated (n; OR, 95%CI, p) with ageing (8395; 1.47, 1.28-1.69, p = 0.00001), hypertension (7872; 1.67, 1.20-2.31, p = 0.002), lacunes (4894; 3.56, 1.39-9.14, p = 0.008), microbleeds (5015; 2.26, 1.04-4.90, p = 0.04) but not WMH (4974; 1.54, 0.71-3.32, p = 0.27), stroke or cognitive impairment. There was between-study heterogeneity. Lack of appropriate data on other brain disorders and demographic features such as ethnicity precluded analysis.

CONCLUSIONS

Despite many studies, more are required to determine potential pathophysiological perivascular spaces involvement in cerebrovascular, neurodegenerative and neuroinflammatory disorders.

Association of Cerebral Small Vessel Disease Burden and Health-Related Quality of Life after Acute Ischemic Stroke

Objective: Cerebral small vessel disease (SVD) is associated with increased mortality, disability and cognitive decline, depression in stroke survivors. This study examined the association between SVD burden, defined by a combination of SVD markers, and health-related quality of life (HRQoL) in acute ischemic stroke. Methods: Patients admitted with acute ischemic stroke of any etiology were prospectively screened between January 2010 to December 2014 and enrolled in the study if they met study entry criteria. HRQoL was evaluated with the 12-item Stroke Specific Quality of Life (SSQoL) at 3 months after the onset of acute ischemic stroke. SVD was ascertained by the presence of any of the SVD markers including lacune, white matter hyperintensities (WMH), cerebral microbleeds (CMB) and enlarged perivascular spaces (EPVS) in the basal ganglia or their combinations on brain magnetic resonance imaging (MRI). The presence of each individual marker scored 1 point and was summed up to generate an ordinal "SVD score" (0-4) capturing total SVD burden. Linear regression was used to determine the associations between SVD burden and HRQoL. Results: Of the743 acute ischemic stroke patients that formed he study sample (mean age: 66.3 ± 10.6 years; 41.7% women), 49.3%, 22.5%, 16.0%, 9.2% and 3.1% had SVD scores of 0, 1, 2, 3 and 4, respectively. After adjusting for demographic, clinical and imaging variables, the SVD score was independently associated with lower overall score of SSQoL (B = -1.39, SE = 0.56, p = 0.01), and its domains of mobility (B = -0.41, SE = 0.10, p < 0.001) and vision (B = -0.12, SE = 0.06, p = 0.03). Acute infract volume (B = -1.44, SE = 0.54, p = 0.01), functional independence (B = 5.69, SE = 0.34, p < 0.001) and anxious (B = -1.13, SE = 0.23, p < 0.001) and depressive symptoms (B = -3.41, SE = 0.22, p < 0.001) were also the significant predictors of the overall score of SSQoL. Conclusion: The brain's SVD burden predicts lower HRQoL, predominantly in domains of mobility and vision at 3 months after acute ischemic stroke. The evaluation of SVD burden could facilitate developing individual treatment strategies.