Are morphologic features of recent small subcortical infarcts related to specific etiologic aspects?

Correlation between enlarged perivascular space and brain white matter hyperintensities in patients with recent small subcortical infarct

BACKGROUND

This study aimed to investigate the correlation between enlarged perivascular space (EPVS) and white matter hyperintensities (WMH) at different locations in patients with recent small subcortical infarct (RSSI).

METHODS

Data were collected from patients with RSSI who were hospitalized at Changzhou Second People's Hospital between October 2020 and December 2021. All patients underwent cranial magnetic resonance imaging, and the grades of EPVS and WMH were assessed, including basal ganglia EPVS (BG-EPVS), centrum semiovale EPVS (CSO-EPVS), deep WMH (DWMH), and periventricular WMH (PWMH). The volumes of EPVS and WMH at different locations were quantified using 3D Slicer software. Patients were grouped according to the severity of BG-EPVS and CSO-EPVS. Univariate and multivariate analyses were used to analyze the relationship between EPVS and WMH.

RESULTS

A total of 215 patients with RSSI were included in the analysis. Patients with moderate-to-severe BG-EPVS had higher DWMH and PWMH severity than those with mild BG-EPVS, both in terms of volume and grade. There was no significant difference in WMH severity between patients with mild CSO-EPVS and those with moderate-to-severe CSO-EPVS. Multivariate analysis indicated that after adjustments were made for confounding factors, DWMH volume (β = 0.311; 95% CI, 0.089-0.400; p = .002) and PWMH volume (β = 0.296; 95% CI, 0.083-0.424; p = .004) were independently associated with BG-EPVS. Pearson correlation showed that PWMH volume (r = .589; p < .001) and DWMH volume (r = .596; p < .001) were positively related to BG-EPVS volume.

CONCLUSION

DWMH and PWMH are closely related to BG-EPVS in patients with RSSI.

Role of small acute hyperintense lesions in long-term progression of cerebral small vessel disease and clinical outcome: a 14-year follow-up study

BACKGROUND

Small hyperintense lesions are found on diffusion-weighted imaging (DWI) in patients with sporadic small vessel disease (SVD). Their exact role in SVD progression remains unclear due to their asymptomatic and transient nature. The main objective is to investigate the role of DWI+lesions in the radiological progression of SVD and their relationship with clinical outcomes.

METHODS

Participants with SVD were included from the Radboud University Nijmegen Diffusion tensor MRI Cohort. DWI+lesions were assessed on four time points over 14 years. Outcome measures included neuroimaging markers of SVD, cognitive performance and clinical outcomes, including stroke, all-cause dementia and all-cause mortality. Linear mixed-effect models and Cox regression models were used to examine the outcome measures in participants with a DWI+lesion (DWI+) and those without a DWI+lesion (DWI-).

RESULTS

DWI+lesions were present in 45 out of 503 (8.9%) participants (mean age: 66.7 years (SD=8.3)). Participants with DWI+lesions and at least one follow-up (n=33) had higher white matter hyperintensity progression rates (β=0.36, 95% CI=0.05 to 0.68, p=0.023), more incident lacunes (incidence rate ratio=2.88, 95% CI=1.80 to 4.67, p<0.001) and greater cognitive decline (β=-0.03, 95% CI=-0.05 to -0.01, p=0.006) during a median follow-up of 13.2 (IQR: 8.8-13.8) years compared with DWI- participants. No differences were found in risk of all-cause mortality, stroke or dementia.

CONCLUSION

Presence of a DWI+lesion in patients with SVD is associated with greater radiological progression of SVD and cognitive decline compared with patients without DWI+lesions.

Advances in Understanding the Pathogenesis of Lacunar Stroke: From Pathology and Pathophysiology to Neuroimaging

Lacunar stroke (LS) accounts for about one-quarter of all acute ischemic strokes, represents an important marker of cerebral small vessel disease (CSVD), and has prognostic significance in terms of recurrent vascular events and vascular cognitive impairment. Our understanding of the etiology and pathogenesis of LS is largely based on the meticulous postmortem work of C. Miller Fisher in the late 1960s, with scarce subsequent pathological analysis of the "lacunar hypothesis" and no reliable approaches for direct in vivo imaging of the small intracranial vessels. The recent development of high-resolution MRI, which allows both large-vessel wall and perforating arteries to be imaged in one setting, provides the opportunity to advance understandings of the clinical mechanisms, imaging characteristics, and pathogenesis of LS. Given accumulating evidence of endothelial dysfunction and blood-brain-barrier disruption as early features of CSVD-related LS, advanced imaging may allow various underlying pathogenetic mechanisms to be defined and for better targeting of therapeutic approaches in LS. In this review, progress in understanding the pathogenesis of LS is outlined, covering pathology, pathophysiology, and imaging characteristics, with a focus toward future directions in the complex entity of LS.

Susceptibility Vessel Sign in Deep Perforating Arteries in Patients with Recent Small Subcortical Infarcts

OBJECTIVES

Recent small subcortical infarcts (RSSI) are considered an acute manifestation of cerebral small vessel disease. Paramagnetic signals in perforating arteries supplying RSSI may be detected on T2*-relaxation derived sequences on MRI and is defined as susceptibility vessel sign (SVS). We aimed to study the prevalence of SVS in patients with RSSI, and explore whether its identification is related to cerebral small vessel disease markers.

MATERIALS AND METHODS

We selected patients with RSSI identified on MRI during admission from a single-center stroke registry. The main demographic and clinical features, including vascular risk factors, were collected. Radiological features of RSSI and cerebral small vessel disease [white matter hyperintensities in deep and periventricular regions, enlarged perivascular spaces, lacunae, microbleeds, and brain atrophy] were described using validated qualitative scores. The presence of SVS was assessed on T2*gradient-echo or other susceptibility-weighted imaging. We compared the clinical and radiological features of patients with or without SVS in uni- and multivariate models.

RESULTS

Out of 210 patients with an RSSI on an MRI, 35 (17%) showed SVS. The proportion of SVS+ patients was similar in different susceptibility imaging modalities (p=.64). Risk factor profiles and clinical course were similar in SVS+ and SVS- patients. SVS+ patients had a higher grade of deep white matter hyperintensities and brain atrophy, more lacunae (p=.001, p=.034, p=.022, respectively), and a similar degree of the rest of radiological variables, compared to SVS- patients. In the multivariate analysis, the grade of deep white matter hyperintensities was the only independent factor associated with SVS [OR 3.1 (95% CI, 1.5-6.4)].

CONCLUSIONS

SVS in patients with RSSI is uncommon and related to a higher grade of deep white matter hyperintensities. Pathophysiological mechanisms underlying the deposition of hemosiderin in the path of occluded perforating arteries are uncertain and might include endothelial dysfunction or embolic mechanisms.

Morphologic evolution of recent small sub-cortical infarcts and adjacent white matter in the basal ganglia in a Chinese cohort

Background

Data on the evolution of recent small sub-cortical infarcts are limited, especially in the Chinese. Previous studies have reported a large heterogeneity in cavitation and infarct location; therefore, the present study assessed the morphology of small sub-cortical infarcts in the basal ganglia in a Chinese cohort.

Methods

Patients who had experienced a recent, single, small sub-cortical infarct in the basal ganglia and received at least one follow-up magnetic resonance imaging (MRI) scan were retrospectively identified from January 2014 to June 2018. Time to follow-up imaging, baseline infarct size, vascular risk factors, and other clinical data, as well as the morphologic changes of the index infarct and surrounding white matter were recorded. Demographic, clinical and MRI characteristics were respectively compared among three groups (white matter hyper-intensitie [WMH] vs. cavitation vs. absent) and between with and without new WMH formation groups. In addition, logistic regression analyses were performed in investigating the determinate independent predictors for new WMH formation.

Results

Seventy-eight subjects were included with a median follow-up time of 304 days (range: 124–552 days). We found a significant reduction in infarct size at follow-up: 46 of 78 (59.0%) infarctions showed some degree of cavitation, 19 of 78 (24.4%) index lesions resembled non-cavitated WMH, and 13 of 78 (16.7%) infarcts had disappeared at follow-up MRI. No factors were found to be associated with differential outcomes of the infarcts. In addition, 8 of 78 (10.3%) patients demonstrated new WMH formation surrounding the index infarct; white matter progression (odds ratio = 15.95, 95% confidence interval = 1.65–153.99; P = 0.017) was an independent risk factor of new WMH formation.

Conclusions

More than half of the small sub-cortical infarcts in the basal ganglia progressed to cavities, demonstrating that these infarcts can be reduced and go undetected. The presence of new WMH around the infarct may be indicative of the worsening progression of cerebral small vessel diseases. Additionally, white matter progression is an independent risk factor, which may be a potential therapeutic target.

Factors Associated With the Occurrence and Evolution of Recent Small Subcortical Infarcts (RSSIs) in Different Locations

Recent small subcortical infarcts (RSSIs) can occur in different brain regions. Distinct etiologies might be involved for RSSIs in different locations and could further affect RSSI cavitation and functional outcomes. In this study, we aim to analyze the baseline clinical and imaging characteristics associated with the occurrence and cavitation of RSSIs in different locations. We retrospectively include patients who presented with RSSIs from a database for cerebral small vessel disease. Detailed information, including demographic, clinical, laboratory, and radiological data, were collected. We identify baseline RSSIs on diffusion-weighted images and divide them into brainstem, subcortical white matter, and basal ganglia region groups. Cavitation is evaluated on follow-up T2 fluid-attenuated inversion recovery (FLAIR) images. Statistical analysis is performed to determine factors associated with the occurrence and cavitation of RSSIs in different locations. We find that patients with brainstem RSSIs have a higher proportion of diabetes (64.1%) compared to patients with subcortical white matter (27.3%, P < 0.001) and basal ganglia region RSSIs (35.2%, P = 0.006) and have higher levels of HbA1c (7.20%) compared to patients with subcortical white matter (6.10%, P = 0.001) and basal ganglia region RSSIs (6.20%, P = 0.003). In addition, patients with brainstem RSSIs have higher NIHSS scores than patients with subcortical white matter RSSIs (2 vs 0, P = 0.001). Patients with subcortical white matter RSSIs have higher a white matter hyperintensity (WMH) burden compared to patients with basal ganglia region RSSIs (21.64 cm³ vs 11.10 cm³, P = 0.004). Follow-up analysis demonstrates that basal ganglia region RSSIs are less likely to cavitate than subcortical white matter RSSIs (61.4% vs 83.6%, P = 0.010), and contacting with WMH is associated with the cavitation of subcortical white matter RSSIs (OR: 101.760, P = 0.003). Our study demonstrates that RSSIs in different locations are associated with different clinical and imaging characteristics. Furthermore, cavitation of RSSIs might be affected by local lesion features and the surrounding environment rather than general demographic and clinical factors.