Leukoaraiosis and sex predict the hyperacute ischemic core volume

Leukoaraiosis in patients with tirofiban before endovascular thrombectomy: A post hoc analysis of a multicentre randomized clinical trial

BACKGROUND AND PURPOSE

To evaluate the effectiveness and safety of intravenous tirofiban before endovascular thrombectomy in subgroups of acute ischemic stroke patients with different degrees of leukoaraiosis (LA).

METHODS

Patients of the RESCUE BT trial whose LA grade could be assessed were included. Eligible patients were dichotomized into two strata according to the van Swieten scale (VSS) score, absent-to-moderate LA (VSS score <3) and severe LA (VSS score ≥3). Furthermore, patients were divided into tirofiban and placebo groups in each stratum. The primary outcome was the 90-day modified Rankin Scale (mRS) score. Safety outcome was radiological intracranial hemorrhage within 48 h.

RESULTS

861 patients were included, 439 patients with absent-to-moderate LA and 422 patients with severe LA. There were no significant differences in 90-day mRS score between the tirofiban and placebo groups in either stratum (absent-to-moderate LA: adjusted OR 0.92 (95%CI, 0.66-1.28), P = 0.62; severe LA: adjusted OR 0.99 (95% CI, 0.69-1.42), P = 0.96). In the severe LA stratum, the occurrence of radiologic intracranial hemorrhage was greater in the tirofiban group compared to the placebo group. (35.7% vs 26.4%; adjusted OR, 1.72 (95% CI, 1.12-2.66); P = 0.014). However, no difference was observed in the absent-to-moderate LA stratum (33.2% vs 29.3%; adjusted OR, 1.15 (95% CI, 0.76-1.75); P = 0.51).

CONCLUSION

There was no significant difference in disability severity at 90 days when treating AIS patients using intravenous tirofiban before endovascular therapy, in either absent-to-moderate or severe LA strata. It should be noted that intravenous tirofiban before endovascular therapy increases the incidence of radiologic intracranial hemorrhage in patients with severe LA.

Cerebral Small Vessel Disease and Infarct Growth in Acute Ischemic Stroke Treated with Intravenous Thrombolysis

We investigated relations between cerebral small vessel disease (cSVD) markers and evolution of the ischemic tissue from ischemic core to final infarct in people with acute ischemic stroke treated with intravenous thrombolysis. Data from the Stroke Imaging Repository (STIR) and Virtual International Stroke Trials Archive (VISTA) were used. Any pre-existing lacunar infarcts and white matter hyperintensities (WMH) were assessed on magnetic resonance (MR) before thrombolytic therapy. Acute ischemic core and final infarct volume were then assessed by two independent radiologists. The relationship among baseline markers of cSVD, acute ischemic core volume, final infarct volume, infarct growth (IG = final infarct - ischemic core), and infarct growth ratio (IGR = final infarct/ischemic core) was then assessed using linear and ordinal regression adjusted for age, sex, onset-to-treatment time, and stroke severity. We included 165 patients, mean (± SD) age 69.5 (± 15.7) years, 74 (45%) males, mean (± SD) ischemic core volume 25.48 (± 42.22) ml, final infarct volume 52.06 (± 72.88) ml, IG 26.58 (± 51.02) ml, IGR 8.23 (± 38.12). Seventy (42%) patients had large vessel occlusion, 20 (12%) acute small subcortical infarct. WMHs were present in 131 (79%) and lacunar infarcts in 61 (37%) patients. Final infarct volumes were 53.8 ml and 45.2 ml (WMHs/no WMHs), p = 0.139, and 24.6 ml and 25.9 ml (lacunar infarcts/no lacunar infarcts), p = 0.842. In linear and ordinal regression analyses, presence of lacunar infarcts was associated with smaller IG (β =  - 0.17; p = 0.024; cOR = 0.52; 95%CI = 0.28-0.96, respectively) and WMHs were associated with smaller IGR (β =  - 0.30; p = 0.004; cOR = 0.27; 95%CI = 0.11-0.69, respectively). In people with acute ischemic stroke treated with intravenous thrombolysis, cSVD features were associated with smaller growth of the acute ischemic area, suggesting less salvageable tissue at time of reperfusion therapy.

Regional brain aging: premature aging of the domain general system predicts aphasia severity

Premature brain aging is associated with poorer cognitive reserve and lower resilience to injury. When there are focal brain lesions, brain regions may age at different rates within the same individual. Therefore, we hypothesize that reduced gray matter volume within specific brain systems commonly associated with language recovery may be important for long-term aphasia severity. Here we show that individuals with stroke aphasia have a premature brain aging in intact regions of the lesioned hemisphere. In left domain-general regions, premature brain aging, gray matter volume, lesion volume and age were all significant predictors of aphasia severity. Increased brain age following a stroke is driven by the lesioned hemisphere. The relationship between brain age in left domain-general regions and aphasia severity suggests that degradation is possible to specific brain regions and isolated aging matters for behavior.

Nomogram to predict ventilator-associated pneumonia in large vessel occlusion stroke after endovascular treatment: a retrospective study

Background

Ventilator-Associated Pneumonia (VAP) severely impacts stroke patients' prognosis after endovascular treatment. Hence, this study created a nomogram to predict the occurrence of VAP after endovascular treatment.

Methods

The individuals with acute ischemic stroke and large vessel occlusion (AIS-LVO) who received mechanical ventilation and endovascular therapy between July 2020 and August 2023 were included in this retrospective study. The predictive model and nomogram were generated by performing feature selection optimization using the LASSO regression model and multifactor logistic regression analysis and assessed the evaluation, verification and clinical application.

Results

A total of 184 individuals (average age 61.85 ± 13.25 years, 73.37% male) were enrolled, and the rate of VAP occurrence was found to be 57.07%. Factors such as the Glasgow Coma Scale (GCS) score, duration of stay in the Intensive Care Unit (ICU), dysphagia, Fazekas scale 2 and admission diastolic blood pressure were found to be associated with the occurrence of VAP in the nomogram that demonstrating a strong discriminatory power with AUC of 0.862 (95% CI, 0.810-0.914), and a favorable clinical net benefit.

Conclusion

This nomogram, comprising GCS score, ICU duration, dysphagia, Fazekas scale 2 and admission diastolic blood pressure, can aid clinicians in predicting the identification of high-risk patients for VAP following endovascular treatment in large vessel occlusion stroke.

Higher High-Mobility Group Box-1 Levels are Associated with White Matter Lesions in Ischemic Stroke Patients

Background and Purpose

High-mobility group box-1 (HMGB1) is a useful biomarker for disease severity stratification and prognosis prediction. We aim to explore whether the circulating HMGB1 concentrations are associated with the white matter lesions (WMLs) burden in stroke patients.

Methods

Between 2022 June and December 2022, patients with acute ischemic stroke were prospectively enrolled. HMGB1 levels were measured by an enzyme-linked immunosorbent assay after admission for all patients. The WMLs severity was assessed by the Fazekas scale. We dichotomized patients into those with moderate-severe WMLs (Fazekas score 3-6) versus those with none-mild WMLs (Fazekas score 0-2). Furthermore, based on the severity of periventricular WMLs (PWMLs) and deep WMLs (DWMLs), patients were categorized as none-mild (Fazekas score 0-1) or moderate-severe (Fazekas score 2-3).

Results

A total of 287 participants (mean age: 64.9 years; 157 male) were analyzed. The median serum HMGB1 levels were 7.3 ng/mL (interquartile, 4.3 ng/mL-12.3 ng/mL). After adjustment for potential confounders, elevated HMGB1 levels were associated with the presence of moderate-severe WMLs (first quartile vs fourth quartile, odds ratio [OR], 4.101; 95% confidence interval [CI], 1.948-8.633; P = 0.001) and moderate-severe PWMLs (first quartile vs fourth quartile, OR, 9.181; 95% CI, 4.078-20.671; P = 0.001). Similar results were found when the HMGB1 levels were analyzed as a continuous variable.

Conclusion

This study demonstrated that increased HMGB1 levels were associated with the severity of WMLs, mainly in the periventricular region.

MRI-based risk stratification for recurrent ischemic stroke in embolic stroke of undetermined source

OBJECTIVE

Leukoaraiosis and other brain MRI-assessed parameters were shown to be associated with recurrent stroke in this population. We aimed to develop an MRI-based predictive tool for risk stratification of ESUS patients.

METHODS

We retrospectively assessed consecutive patients who were diagnosed with ESUS and underwent brain MRI and performed a multivariable analysis with the outcome of recurrent stroke/TIA. Based on the coefficient of each covariate, we generated an integer-based point scoring system. The discrimination and calibration of the score were assessed using the area under the receiver operator characteristic curve, net reclassification improvement, integrated discrimination improvement, calibration curve, and decision curve analysis. Also, we compared the new score with a previously published score (ALM score).

RESULTS

Among 176 patients followed for an overall period of 902.3 patient-years (median of 74 months), there were 39 recurrent ischemic stroke/TIAs (4.32 per 100 patient-years). Fazekas score (HR: 1.26, 95% CI: 1.03-1.54), enlarged perivascular space (EPVS) (HR: 2.76, 95% CI: 1.12-6.17), NIHSS at admission (HR: 1.11, 95% CI: 1.02-1.18), and infarct subtypes (HR: 2.88, 95% CI: 1.34-6.17) were associated with recurrent stroke/TIA. Accordingly, a score (FENS score) was developed with AUC-ROC values of 0.863, 0.788, and 0.858 for 1, 3, and 5 years, respectively. These were significantly better than the AUC-ROC of ALM score (0.635, 0.695, and 0.705, respectively). The FENS score exhibited better calibration and discrimination ability than the ALM score (Hosmer-Lemeshow test χ2 : 4.402, p = 0.819).

CONCLUSION

The MRI-based FENS score can provide excellent predictive performance for recurrent stroke/TIA and may assist in risk stratification of ESUS patients.

Determinants of cerebral collateral circulation in acute ischemic stroke due to large vessel occlusion

Introduction

Cerebral collateral circulation has a central role in ischemic stroke pathophysiology, and it is considered to correlate with infarct size, the success of reperfusion therapies, and clinical outcomes. Our aim was to study the factors influencing the development of collaterals in patients with acute ischemic stroke eligible for endovascular treatment.

Materials and methods

We enrolled patients with acute ischemic stroke and large vessel occlusion of anterior circulation potentially eligible for endovascular treatment. Included patients performed multiphase CT angiography to assess collaterals that were graded by the Menon Grading Score. We investigated the associations between clinical factors and collaterals and tested independent associations with logistic (good vs. poor collaterals) and ordinal (collateral grade grouped, Menon 0-2, 3, 4-5) regression analysis adjusting for age, sex, stroke severity, and onset to CT time (OCTT).

Results

We included 520 patients, the mean age was 75 (±13.6) years, 215 (41%) were men, and the median (IQR) NIHSS was 17 (11-22). Good collaterals were present in 323 (62%) patients and were associated with lower NIHSS (median 16 vs. 18; p < 0.001) and left hemisphere involvement (60% vs. 45%; p < 0.001), whereas previous stroke/TIA was more frequent in patients with poor collaterals (17 vs. 26%; p = 0.014). These results were confirmed in both logistic and ordinal regression analyses where good collaterals were associated with lower NIHSS (OR = 0.94; 95% CI = 0.91-0.96; cOR = 0.95; 95% CI = 0.92-0.97, respectively) and left hemisphere stroke (OR = 2.24; 95% CI = 1.52-3.28; cOR = 2.11; 95% CI = 1.46-3.05, respectively), while previous stroke/TIA was associated with poor collaterals (OR = 0.57; 95% CI = 0.36-0.90; cOR = 0.61; 95% CI = 0.40-0.94, respectively). Vascular risk factors, demographics, and pre-stroke treatments did not influence the collateral score.

Discussion

The results of our study suggest that risk factors and demographics do not influence the development of collateral circles, except for a negative relation with previous ischemic events. We confirm an already reported observation of a possible protective effect of collaterals on tissue damage assuming NIHSS as its surrogate. The association between left hemispheric stroke and better collaterals deserves to be further explored. Further efforts are needed to identify the factors that favor the development of collaterals.

Leukoaraiosis severity is related to increased risk of early neurological deterioration in acute ischemic stroke: a retrospective observational study

OBJECTIVES

The relationship between leukoaraiosis and early neurological deterioration in acute cerebral infarction patients remains controversial. We tried to determine whether an association existed between leukoaraiosis and early neurological deterioration in patients with acute ischemic stroke.

MATERIALS AND METHODS

We retrospectively enrolled acute cerebral infarction patients admitted to our our department within 4.5-72.0 h of symptom onset between January 2016 and March 2022. On the basis of the van Swieten scale, leukoaraiosis was evaluated as supratentorial white matter hypoattenuation on admission head CT and graded as 0 (absent), 1 (mild), 2 (moderate) and 3-4 (severe). Early neurological deterioration was defined as an increase in the National Institute of Health Stroke Scale score by >  = 2 points in the total score, or >  = 1 point in motor power within the first seven days after admission.

RESULTS

Among 736 patients, 522 (70.9%) patients had leukoaraiosis, and of these, 332 (63.6%) had mild leukoaraiosis, 41 (7.9%) had moderate leukoaraiosis, and 149 (28.5%) had severe leukoaraiosis. 118 (16.0%) patients experienced early neurological deterioration: 20 of the 214 (9.5%) patients without leukoaraiosis and 98 of the 522 (18.8%) patients with leukoaraiosis. In multiple regression analysis, we found van Swieten scale predicted early neurological deterioration independently (OR = 1.570; 95% CI: 1.226-2.012).

CONCLUSIONS

Leukoaraiosis is common in acute cerebral infarction patients and leukoaraiosis severity is related to increased risk of early neurological deterioration in the patients.

Impact of leukoaraiosis in patients with acute ischemic stroke treated with thrombectomy: a post hoc analysis of the DIRECT-MT trial

BACKGROUND

The influence of leukoaraiosis in patients with acute ischemic stroke (AIS) given intra-arterial treatment (IAT) with or without preceding intravenous thrombolysis (IVT) remains unknown.

OBJECTIVE

To assess the clinical and radiological outcomes of IAT in patients with or without leukoaraiosis.

METHODS

Patients of the direct mechanical thrombectomy trial (DIRECT-MT) whose leukoaraiosis grade could be assessed were included. DIRECT-MT was a randomized clinical trial performed in China to assess the effect of direct IAT compared with intravenous thrombolysis plus IAT. We employed the Age-Related White Matter Changes Scale for grading leukoaraiosis (ARWMC, 0 indicates no leukoaraiosis, 1-2 indicates mild-to-moderate leukoaraiosis, and 3 indicates severe leukoaraiosis) based on brain CT. The primary outcome was the score on the modified Rankin Scale (mRS) assessed at 90 days.

RESULTS

There were 656 patients in the trial, 649 patients who were included, with 432 patients without leukoaraiosis, and 217 (33.4%) patients with leukoaraiosis divided into mild-to-moderate (n=139) and severe groups (n=78). Leukoaraiosis was a predictor of a worse mRS score (adjusted OR (aOR)=0.7 (95% CI 0.5 to 0.8)) and higher mortality (aOR=1.4 (1.1 to 1.9)), but it was not associated with symptomatic intracranial hemorrhage (sICH) (aOR=0.9 (0.5 to 1.5)). IVT preceding IAT did not increase sICH risk for patients with no (aOR=1.4 (0.6 to 3.4)), mild-to-moderate (aOR=1.5 (0.3 to 7.8)), or severe (aOR=1.5 (0.1 to 21.3)) leukoaraiosis.

CONCLUSION

Patients with leukoaraiosis with AIS due to large vessel occlusion are at increased risk of a poor functional outcome after IAT but demonstrate similar sICH rates, and IVT preceding IAT does not increase the risk of sICH in Chinese patients with leukoaraiosis.

The contribution of white matter pathology, hypoperfusion, lesion load, and stroke recurrence to language deficits following acute subcortical left hemisphere stroke

Aphasia, the loss of language ability following damage to the brain, is among the most disabling and common consequences of stroke. Subcortical stroke, occurring in the basal ganglia, thalamus, and/or deep white matter can result in aphasia, often characterized by word fluency, motor speech output, or sentence generation impairments. The link between greater lesion volume and acute aphasia is well documented, but the independent contributions of lesion location, cortical hypoperfusion, prior stroke, and white matter degeneration (leukoaraiosis) remain unclear, particularly in subcortical aphasia. Thus, we aimed to disentangle the contributions of each factor on language impairments in left hemisphere acute subcortical stroke survivors. Eighty patients with acute ischemic left hemisphere subcortical stroke (less than 10 days post-onset) participated. We manually traced acute lesions on diffusion-weighted scans and prior lesions on T2-weighted scans. Leukoaraiosis was rated on T2-weighted scans using the Fazekas et al. (1987) scale. Fluid-attenuated inversion recovery (FLAIR) scans were evaluated for hyperintense vessels in each vascular territory, providing an indirect measure of hypoperfusion in lieu of perfusion-weighted imaging. We found that language performance was negatively correlated with acute/total lesion volumes and greater damage to substructures of the deep white matter and basal ganglia. We conducted a LASSO regression that included all variables for which we found significant univariate relationships to language performance, plus nuisance regressors. Only total lesion volume was a significant predictor of global language impairment severity. Further examination of three participants with severe language impairments suggests that their deficits result from impairment in domain-general, rather than linguistic, processes. Given the variability in language deficits and imaging markers associated with such deficits, it seems likely that subcortical aphasia is a heterogeneous clinical syndrome with distinct causes across individuals.

Diabetes is an Independent Growth Factor of Ischemic Stroke During Reperfusion Phase Leading to Poor Clinical Outcome

OBJECTIVES

Despite the success of recanalization by bridging therapy, about half of treated stroke patients remain disabled. While numerous reports propose clinical predictors of stroke clinical outcome in this context, we originally aimed to study pre-therapeutic factors influencing infarct growth (IG) and poor clinical outcome in strokes due to large vessel occlusion (LVO) successfully recanalized.

MATERIALS AND METHODS

We enrolled 87 consecutive successfully recanalized patients (mTICI: 2b/2c/3) by mechanical thrombectomy (±rt-PA) after stroke due to middle cerebral artery (M1) occlusion within 6 h according to AHA guidelines. IG was defined by subtracting the initial DWI volume to the final 24 h-TDM volume. Statistical associations between poor clinical outcome (mRS≥2), IG and pertinent clinico-radiological variables, were measured using logistic and linear regression models.

RESULTS

Among 87 enrolled patients (Age(y): 68.4 ± 17.5; NIHSS: 16.0 ± 5.4), 42/87 (48,28%) patients had a mRS ≥ 2 at 3 months. Diabetic history (OR: 3.70 CI95%[1.03;14.29] and initial NIHSS (/1 point: OR: 1.16 CI95%[1.05;1.27]) were independently associated with poor outcome. IG was significantly higher in stroke patients with poor outcome (+7.57 ± 4.52 vs -7.81 ± 1.67; p = 0.0024). Initial volumes were not significantly different (mRS≥2: 16.18 ± 2.67; mRS[0-1]: 14.70 ± 2.30; p = 0.6771). Explanatory variables of IG in linear regression were diabetic history (β: 21.26 CI95%[5.43; 37.09]) and NIHSS (β: 0.83 CI95%[0.02; 1.64]). IG was higher in diabetic stroke patients (23.54 ± 1.43 vs -6.20 ± 9.36; p = 0.0061).

CONCLUSIONS

We conclude that diabetes leads to continued IG after complete recanalization, conditioning clinical outcome in LVO strokes successfully recanalized by bridging therapy. We suggest that poor tissular reperfusion by diabetic microangiopathy could explain this result.

Relation of Pre-Stroke Aspirin Use With Cerebral Infarct Volume and Functional Outcomes

Objective

We investigated (1) the associations of pre‐stroke aspirin use with thrombus burden, infarct volume, hemorrhagic transformation, early neurological deterioration (END), and functional outcome, and (2) whether stroke subtypes modify these associations in first‐ever ischemic stroke.

Methods

This multicenter magnetic resonance imaging (MRI)‐based study included 5,700 consecutive patients with acute first‐ever ischemic stroke, who did not undergo intravenous thrombolysis or endovascular thrombectomy, from May 2011 through February 2014. Propensity score‐based augmented inverse probability weighting was performed to estimate adjusted effects of pre‐stroke aspirin use.

Results

The mean age was 67 years (41% women), and 15.9% (n = 907) were taking aspirin before stroke. Pre‐stroke aspirin use (vs nonuse) was significantly related to a reduced infarct volume (by 30%), particularly in large artery atherosclerosis stroke (by 45%). In cardioembolic stroke, pre‐stroke aspirin use was associated with a ~50% lower incidence of END (adjusted difference = −5.4%, 95% confidence interval [CI] = −8.9 to −1.9). Thus, pre‐stroke aspirin use was associated with ~30% higher likelihood of favorable outcome (3‐month modified Rankin Scale score < 3), particularly in large artery atherosclerosis stroke and cardioembolic stroke (adjusted difference = 7.2%, 95% CI = 1.8 to 12.5 and adjusted difference = 6.4%, 95% CI = 1.7 to 11.1, respectively). Pre‐stroke aspirin use (vs nonuse) was associated with 85% less frequent cerebral thrombus‐related susceptibility vessel sign (SVS) in large artery atherosclerosis stroke (adjusted difference = −1.4%, 95% CI = −2.1 to −0.8, p < 0.001) and was associated with ~40% lower SVS volumes, particularly in cardioembolic stroke (adjusted difference = −0.16 cm³, 95% CI = −0.29 to −0.02, p = 0.03). Moreover, pre‐stroke aspirin use was not significantly associated with hemorrhagic transformation (adjusted difference = −1.1%, p = 0.09).

Interpretation

Pre‐stroke aspirin use associates with improved functional independence in patients with first‐ever ischemic large arterial stroke by reducing infarct volume and/or END, likely by decreasing thrombus burden, without increased risk of hemorrhagic transformation. ANN NEUROL 2021;90:763–776

Vascular health and diffusion properties of normal appearing white matter in midlife

In this study, we perform a region of interest diffusion tensor imaging and advanced diffusion complexity analysis of normal appearing white matter to determine the impact of vascular health on these diffusivity metrics in midlife adults. 77 participants (26 black, 35 female) at year 30 visit in the Coronary Artery Risk Development in Young Adults longitudinal study were scanned with an advanced diffusion-weighted imaging and fluid-attenuated inversion recovery protocol. Fractional anisotropy and non-linear diffusion complexity measures were estimated. Cumulative measures across 30 years (9 study visits) of systolic blood pressure, body mass index, glucose, smoking and cholesterol were calculated as the area under the curve from baseline up to year 30 examination. Partial correlation analyses assessed the association between cumulative vascular health measures and normal appearing white matter diffusion metrics in these participants. Midlife normal appearing white matter diffusion properties were significantly associated (P < 0.05) with cumulative exposure to vascular risk factors from young adulthood over the 30-year time period. Higher cumulative systolic blood pressure exposure was associated with increased complexity and decreased fractional anisotropy. Higher cumulative body mass index exposure was associated with decreased fractional anisotropy. Additionally, in the normal appearing white matter of black participants (P < 0.05), who exhibited a higher cumulative vascular risk exposure, fractional anisotropy was lower and complexity was higher in comparison to normal appearing white matter in white participants. Higher burden of vascular risk factor exposure from young adulthood to midlife is associated with changes in the diffusion properties of normal appearing white matter in midlife. These changes which may reflect axonal disruption, increased inflammation and/or increased glial proliferation, were primarily observed in both anterior and posterior normal appearing white matter regions of the corpus callosum. These results suggest that microstructural changes in normal appearing white matter are sensitive to vascular health during young adulthood and are possibly therapeutic targets in interventions focused on preserving white matter health across life.

Cerebral Microbleeds Load and Long-Term Outcomes in Minor Ischemic Stroke

BACKGROUND AND PURPOSE

The association between the cerebral microbleed (CMB) count and outcomes in ischemic stroke has not been fully clarified. The aim of this study was to investigate the relationship between the CMBs count and functional outcomes in patients with a minor ischemic stroke treated with antiplatelet therapy METHODS: Non-cardiogenic minor ischemic stroke (NIHSS score < 4 on admission) patients who were treated with antiplatelet therapy were enrolled. The patients were divided into four groups based on the number of CMBs (absent, 1, 2-4, and > 4), and their clinical outcomes were compared. A poor outcome was defined as a modified Rankin scale (mRS) score of 3-6 90 days after symptom onset. Logistic regression analysis was performed to evaluate whether the CMBs count contributes to poor outcomes with well-known risk factors such as age, NIHSS score on admission, ischemic stroke recurrence, large artery atherosclerosis stroke subtype, and DWMHs.

RESULTS

A total of 240 patients were enrolled, and their pre mRS scores were matched based on CMB presence. A higher burden of CMBs was linearly correlated with the incidence of poor outcomes (4% in the absent group, 8% in the 1 CMB group, 13% in the 2-4 CMB group, and 20% in the > 4 CMB group, P = 0.002). Multivariate logistic regression analysis showed that CMBs count was one of the independent factor associated with poor outcomes (odds ratio 1.07, 95% confidence interval 1.02-1.12, P = 0.003).

CONCLUSION

The CMBs count contributes independently to poor outcomes in minor ischemic stroke patients treated with antiplatelet therapy.

Association of neuroimaging markers of cerebral small vessel disease with short-term outcomes in patients with minor cerebrovascular events

Background

Increasing evidences have showed that neuroimaging markers of SVD can predict the short-term outcome of acute ischemic stroke (AIS). It is unclear that whether neuroimaging markers of SVD are also associated with short-term outcomes of minor cerebrovascular events. In the present study, we investigate neuroimaging markers of SVD in order to explore their roles in prediction of short-term outcome in patients with minor cerebrovascular events.

Methods

Consecutive first-ever stroke patients (n = 546) from the Affiliated Jiangning Hospital of Nanjing Medical University were enrolled. A total of 388 patients were enrolled according to minor cerebrovascular events definition (National Institutes of Health Stroke Scale Score ≤ 3) and exclusion criteria. MRI scans were performed within 7 days of stroke onset, and then neuroimaging markers of SVD including WMH, lacunes, cerebral microbleeds (CMB), and perivascular spaces (PVS), SVD burden scores were assessed. We completed baseline characteristics and evaluated the relationships of short-term outcomes to SVD neuroimaging markers and SVD scores. The 90-day modified Rankin Scale (mRS) was thought as primary outcome and was dichotomized as good functional outcome (mRS 0–1) and poor outcome (mRS 2–6). Secondary outcomes were stroke progression and stroke recurrence.

Results

Higher age, National Institutes of Health Stroke Scale (NIHSS) upon admission, lipoprotein-associated phospholipase A2 (LP-PLA2) and lacunes, Fazekas score were correlated with poor functional outcome (P < 0.05), But after adjusting for confounding variables, among the neuroimaging markers of cerebral small vessel disease, only Fazekas score (OR, 1.343; 95% confidence interval, 1.020–1.770; P = 0.036) was found to be associated with poor outcome at 90 days. Higher Fazekas and SVD scores were not associated with stroke progression or stroke recurrence.

Conclusion

WMH can predict the poor functional outcome of minor cerebrovascular events. Adding other neuroimaging markers of SVD and total SVD burden score, however, does not improve the prediction, which indicated WMH can as neuroimaging markers for guiding the treatment of minor cerebrovascular events.

Impact of leukoaraiosis severity on the association of outcomes of mechanical thrombectomy for acute ischemic stroke: a systematic review and a meta-analysis

Background

Leukoaraiosis (LA) severity is associated with poor outcome after mechanical thrombectomy (MT) for acute ischemic stroke (AIS) caused by large vessel occlusion. This meta-analysis aimed to assess the association of LA severity with AIS-related risk factors and outcomes of MT.

Methods

PubMed, Web of Science, EMBASE, and Cochrane Collaboration Database was searched for studies on MT for AIS with LA. We conducted a random-effects meta-analysis for the prevalence of stroke risk factors and the MT outcome in the absent to moderate LA and severe LA groups.

Results

We included seven cohort studies involving 1294 participants (1019 with absent to moderate LA and 275 with severe LA). The absent to moderate LA group had a significantly lower prevalence of coronary artery disease (odds ratio [OR] 0.43; 95% CI 0.29–0.66), atrial fibrillation (OR, 0.26; 95% CI 0.17–0.38), hypertension (OR, 0.39; 95% CI 0.24–0.61), and ischemic stroke (OR, 0.27; 95% CI 0.15–0.50) than the severe LA group. There were no significant between-group differences in symptom onset to recanalization time (364.4 versus 356.2 min, mean difference 19.4; 95% CI − 28.3 to 67.2), final recanalization rate (modified thrombolysis in cerebral infarction score of 2b/3; OR, 0.87; 95% CI 0.55–1.38), and symptomatic intracranial hemorrhage (OR, 0.62; 95% CI 0.34–1.11). The absent to moderate LA group had a higher good functional outcome (modified Rankin Scale score of 0–2 at 90 days; OR, 4.55; 95% CI 3.20–6.47) and a lower mortality rate (179/1019 vs 108/275; OR, 0.28; 95% CI 0.20–0.39).

Conclusion

There are unique differences in the characteristics of risk factors and clinical outcomes of ischemic stroke across patients with LA of different severity. Patients with severe LA are more likely to be associated with risk factors for cerebrovascular disease and have a poor post-MT outcome.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10167-0) contains supplementary material, which is available to authorized users.

Gonadal hormones and stroke risk: PCOS as a case study

It is well known that stroke incidence and outcome is sex-dependent and influenced by age and gonadal hormones. In post-menopausal and/or aged females, declining estrogen levels increases stroke risk. However, women who experience early menopause also have an increase in stroke risk. This suggests that, regardless of age, gonadal hormones regulate stroke risk and severity. This review discusses prolonged gonadal hormone dysfunction in a common female endocrine disorder known as polycystic ovarian syndrome, PCOS, and the associated increased risk of stroke due to resulting hyperandrogenism and metabolic comorbidities.

Severe Leukoaraiosis Is Associated with Poor Outcome after Successful Recanalization of M1 Middle Cerebral Artery Occlusion Strokes

BACKGROUND

Severe leukoaraiosis (LA) is an established risk factor for poor outcome after mechanical thrombectomy (MT) for large vessel occlusion stroke. There is uncertainty whether this association also applies to successfully recanalized patients with M1 segment middle cerebral artery (MCA) occlusions.

METHODS

A retrospective single-centre study of patients with successful reperfusion (thrombolysis in cerebral infarction, TICI 2b or 3) after MT for an M1 MCA occlusion was performed over a 7-year period. LA score (LAS) was assessed using the age-related white matter change scale on pre-interventional brain imaging.

RESULTS

A total of 209 patients (median age 75.0 years) were included. LAS was assessed on pre-interventional imaging by computed tomography in 177 (84.7%) patients and magnetic resonance imaging in 32 (15.3%) patients. The median LAS was 1 (IQR 0-8), and severe LA consisted of the top 25 percentile, ranging from 9 to 24. Multivariable analysis demonstrated an association of severe LA (OR 0.32, 95% CI 0.12-0.88, p = 0.023), higher NIHSS on admission (OR 0.89, 95% CI 0.84-0.94, p < 0.001), advanced age (OR 0.97, 95% CI 0.95-1.00, p = 0.039), good leptomeningeal collaterals (OR 3.65, 95% CI 1.46-8.15, p = 0.001), and TICI 3 score (OR 3.26, 95% CI 10.52-7.01) with good clinical outcome after 3 months as measured with the modified Rankin scale.

CONCLUSION

Severe LA is associated with poor clinical outcome at 3 months in acute stroke patients undergoing MT due to emergent M1 MCA occlusion.

Association of FLAIR vascular hyperintensity and acute MCA stroke outcome changes with the severity of leukoaraiosis

PURPOSE

The clinical significance of FLAIR vascular hyperintensity (FVH), a marker of collateral circulation in ischaemic stroke, remains controversial. We hypothesised that the association between FVH and outcomes varies with the severity of leukoaraiosis (LA), another marker of collaterals, and that their combined significance may vary with time.

METHODS

We included 459 consecutive patients with middle cerebral artery (MCA) stroke. Proximal and distal FVHs were distinguished based on location. LA was divided into two grades, according to Fazekas scores of 0-2 and 3-6. Symptom-to-MRI time was divided into two categories: ≤ 14 days and ≥ 15 days.

RESULTS

We found no difference in FVH proportion according to LA grade. Multivariate analysis revealed that LA and FVH status were independently associated with unfavourable outcomes (modified Rankin scale ≥ 2) in patients with symptom-to-MRI times ≤ 14 days (P = 0.008), but not in those with symptom-to-MRI times ≥15 days (P = 0.61). In the group with symptom-to-MRI times ≤14 days, patients with LA 3-6 and FVH(+) (OR, 3.044; 95% CI, 1.116-8.305) were more likely to have unfavourable clinical outcomes compared with patients with LA 0-2 and FVH(+) but not compared with those with LA 0-2 and FVH(-) or LA 3-6 and FVH(-). In addition, FVH location did not influence the relationship between FVH and outcomes.

CONCLUSIONS

The association between FVH and outcomes was influenced by the degree of LA in the acute but not in the subacute and chronic stages of MCA infarction. FVH predicts clinical outcomes independently only in those with more extensive LA.

Leukoaraiosis and earlier neurological outcome after mechanical thrombectomy in acute ischemic stroke

BACKGROUND AND PURPOSE

The aim of the study was to evaluate whether leukoaraiosis (LA) severity is associated with earlier neurological outcome in acute stroke patients undergoing mechanical thrombectomy.

MATERIALS AND METHODS

In this retrospective multicenter study, we evaluated 273 acute stroke patients treated with mechanical thrombectomy. LA severity was graded as 0-2 (absent-to-moderate) versus 3-4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of early neurological improvement and early neurological deterioration. Early neurological improvement was defined as a decrease of≥4 points on the NIHSS, or an NIHSS score of zero 24hours after baseline assessment. Early neurological deterioration was defined as an increase of≥4 points on the NIHSS 24hours after baseline assessment.

RESULTS

There was a significantly lower early neurological improvement rate (17.1% versus 39.2%; P=0.006) and non-significantly higher early neurological deterioration rate (29.3% versus 17.7%; P=0.084) in patients with severe LA (sLA) compared with patients with absent-to-moderate LA. In multivariable analysis, sLA was inversely associated with early neurological improvement (OR, 0.31; 95% CI, 0.13-0.78; P=0.012). There was no significant association of sLA with early neurological deterioration. However, in patients without symptomatic intracranial hemorrhage, sLA was an independent predictor of early neurological deterioration (OR, 2.65; 95% CI, 1.09-6.45; P=0.032).

CONCLUSIONS

sLA is a significant negative predictor of early neurological improvement and is an independent predictor of early neurological deterioration in patients without symptomatic intracranial hemorrhage.

Diffusion Properties of Normal-Appearing White Matter Microstructure and Severity of Motor Impairment in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

The effect of white matter hyperintensities as measured by FLAIR MR imaging on functional impairment and recovery after ischemic stroke has been investigated thoroughly. However, there has been growing interest in investigating normal-appearing white matter microstructural integrity following ischemic stroke onset with techniques such as DTI.

MATERIALS AND METHODS

Fifty-two patients with acute ischemic stroke and 36 without stroke were evaluated with a DTI and FLAIR imaging protocol and clinically assessed for the severity of motor impairment using the Motricity Index within 72 hours of suspected symptom onset.

RESULTS

There were widespread decreases in fractional anisotropy and increases in mean diffusivity and radial diffusivity for the acute stroke group compared with the nonstroke group. There was a significant positive association between fractional anisotropy and motor function and a significant negative association between mean diffusivity/radial diffusivity and motor function. The normal-appearing white matter ROIs that were most sensitive to the Motricity Index were the anterior/posterior limb of the internal capsule in the infarcted hemisphere and the splenium of the corpus callosum, external capsule, posterior limb/retrolenticular part of the internal capsule, superior longitudinal fasciculus, and cingulum (hippocampus) of the intrahemisphere/contralateral hemisphere.

CONCLUSIONS

The microstructural integrity of normal-appearing white matter is a significant parameter to identify neural differences not only between those individuals with and without acute ischemic stroke but also correlated with the severity of acute motor impairment.

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.

Impact of Leukoaraiosis Severity on the Association of Time to Successful Reperfusion with 90-Day Functional Outcome After Large Vessel Occlusion Stroke

The chance for a favorable outcome after mechanical thrombectomy (MT) for large vessel occlusion stroke decreases with the symptom onset-to-reperfusion time (OTR). Patients with severe leukoaraiosis are at increased risk for a poor outcome after MT. However, whether leukoaraiosis modulates to the association between OTR and 90-day functional outcome is uncertain. We retrospectively analyzed 144 consecutive patients with successful (TICI ≥ 2b/3) MT for anterior circulation large vessel occlusion within 24 h form OTR between January 2012 to November 2016. Leukoaraiosis was dichotomized to absent-to-mild (van Swieten scale score 0-2) versus moderate-to-severe (3-4) as assessed on admission head CT. Multiple linear, logistic, and ordinal regression analyses were used to determine the association between leukoaraiosis, OTR, and 90-day modified Rankin Scale (mRS) score, after adjustment for pertinent covariates. Leukoaraiosis was independently associated with the OTR on multivariable linear regression (p = 0.003). The association between OTR and 90-day outcome depended on the degree of pre-existing leukoaraiosis burden as shown by a significant leukoaraiosis-by-OTR interaction on multivariable logistic regression (OR 0.76, 95% CI 0.58-0.98, p = 0.037) and multivariable ordinal regression (OR 0.87, 95% CI 0.78-0.97, p = 0.011). Pre-existing leukoaraiosis is associated with the 90-day functional outcome after successful reperfusion and impacts the association between the OTR and 90-day mRS among patients undergoing MT. Patients with high leukoaraiosis burden need to present earlier than patients with low leukoaraiosis burden for a similar favorable outcome. Pending confirmation, these results may have important implications for optimizing patient selection for acute stroke therapies.

Total MRI burden of cerebral vessel disease correlates with the progression in patients with acute single small subcortical strokes

BACKGROUND

The patients of single small subcortical strokes (SS) commonly have neurological worsening with risk factors, and mechanisms remain unclear. Asymptomatic lacunes, white matter lesions, cerebral microbleeds, and enlarged perivascular spaces are MRI markers of cerebral small vessel disease (cSVD). Previous studies mostly explored the association between the neurological deterioration and presence of above markers separately. The relationship between progressive single small SS and the simultaneous presence of multiple markers of cSVD has not been fully identified. We aimed to investigate whether total burden of cSVD detected with MRI was associated with progressive small SS in this study.

METHODS

Patients with single small SS (2.0 cm in diameter) were prospectively recruited during January 2016 and May 2018. Progression was defined as worsening by ≥1 point in National Institutes Health Stroke Scale (NIHSS) motor score within 72 hr from onset. The presence and burden of cSVD were determined by brain MRI, producing a score between 0 and 4. Besides, the patients' characteristics, clinical data, medical treatments during hospitalization stay were collected and statistically analyzed. Associations with progression were tested with forward stepwise regression analyses.

RESULTS

Fifty-seven (35.6%) patients underwent progression. No significant difference was observed in the distribution of any single vascular risk factor and its related laboratory data among these patients. After adjustment for age, sex, NIHSS score at admission, and time from stroke to MRI in separate models, severe WMHs (OR = 4.892; 95% CI = 2.011-11.904, p = 0.016), moderate- and high-grade basal ganglia EPVS (OR = 2.970; 95% CI = 1.861-6.121, p = 0.009), and total cSVD score (OR = 3.359; 95% CI = 2.016-5.599, p = 0.010) were associated with progression.

CONCLUSION

This study demonstrated that total MRI cSVD burden was independently associated with progression after single small subcortical strokes.

Cerebral White Matter Hyperintensities and Microbleeds in Acute Ischemic Stroke: Impact on Recanalization Therapies. A Review of the Literature

Cerebral white matter hyperintensities (WMH) and cerebral microbleeds (CMBs) are frequently seen on brain imaging acquired for acute ischemic stroke. Given the raising use of recanalization therapies - both intravenous and endovascular - the interest on the impact of WMH and CMBs on the risk of intracerebral hemorrhage and on functional outcome is growing. In this review, we will discuss the relevance of WMH and CMBs among patients with an acute ischemic stroke, focusing on the implications for recanalization therapies.

Leukoaraiosis severity and outcomes after mechanical thrombectomy with stent-retriever devices in acute ischemic stroke

Background and purpose

The aim of the study was to evaluate whether leukoaraiosis severity is associated with outcome in acute stroke patients undergoing mechanical thrombectomy with stent-retriever devices.

Methods

In this retrospective multicenter study, we evaluated 251 acute stroke patients (pretreatment National Institutes of Health Stroke Scale score ≥8) treated with stent-retriever devices. Leukoaraiosis severity was graded as 0–2 (absent-to-moderate) versus 3–4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of good functional outcome, defined as a modified Rankin Scale of 0–2 at 90 days.

Results

Significantly fewer patients in the severe LA group than in the absent-to-moderate LA group achieved a good functional outcome (18.4% vs 50.2%, P<0.001). In multivariable analysis, severe leukoaraiosis was a significant negative predictor of good functional outcome at 90 days (OR, 0.27; 95% CI 0.10–0.77; P=0.014).

Conclusions

The severity of leukoaraiosis is independently associated with 90-day functional outcome in acute stroke patients undergoing mechanical thrombectomy with stent-retriever devices.

Biomarkers of Stroke Recovery: Consensus-Based Core Recommendations from the Stroke Recovery and Rehabilitation Roundtable

The most difficult clinical questions in stroke rehabilitation are "What is this patient's potential for recovery?" and "What is the best rehabilitation strategy for this person, given her/his clinical profile?" Without answers to these questions, clinicians struggle to make decisions regarding the content and focus of therapy, and researchers design studies that inadvertently mix participants who have a high likelihood of responding with those who do not. Developing and implementing biomarkers that distinguish patient subgroups will help address these issues and unravel the factors important to the recovery process. The goal of the present paper is to provide a consensus statement regarding the current state of the evidence for stroke recovery biomarkers. Biomarkers of motor, somatosensory, cognitive and language domains across the recovery timeline post-stroke are considered; with focus on brain structure and function, and exclusion of blood markers and genetics. We provide evidence for biomarkers that are considered ready to be included in clinical trials, as well as others that are promising but not ready and so represent a developmental priority. We conclude with an example that illustrates the utility of biomarkers in recovery and rehabilitation research, demonstrating how the inclusion of a biomarker may enhance future clinical trials. In this way, we propose a way forward for when and where we can include biomarkers to advance the efficacy of the practice of, and research into, rehabilitation and recovery after stroke.

Brainstem leukoaraiosis independently predicts poor outcome after ischemic stroke

BACKGROUND AND PURPOSE

Increased supratentorial white matter hyperintensities volume (S-WMHV) has been reported to be a predictor of worse outcome in patients with acute ischemic stroke (AIS). However, few studies have focused on less common locations, such as brainstem white matter hyperintensities (B-WMH), and their relationship to S-WMHV. This study aimed to examine whether B-WMH affect clinical outcome after AIS or transient ischemic attack (TIA).

METHODS

Based on magnetic resonance imaging evidence, B-WMH were evaluated in 313 prospectively identified patients with AIS/TIA and registered as absent or present. Standardized S-WMHV was quantified using a validated volumetric image analysis and natural log-transformed (Log_S-WMHV). Poor outcome was defined as a modified Rankin Scale score of 3-6 at 3 months after the index event.

RESULTS

Brainstem white matter hyperintensities were detected in 57 (18.2%) patients. In unadjusted analyses for outcome, the presence of B-WMH was associated with worse outcome, compared with patients without B-WMH (P = 0.034). In multivariate analysis controlling for age, atrial fibrillation, stroke severity, reperfusion therapies and Log_S-WMHV, only B-WMH [odds ratio (OR), 2.46; P = 0.021] and stroke severity (OR, 1.23; P < 0.001) remained independently associated with unfavourable 90-day modified Rankin Scale score. Patients with B-WMH were older (OR, 1.06; P < 0.001) and tended to have more hyperlipidaemia (OR, 2.21; P = 0.023) and peripheral arterial disease (OR, 2.57; P = 0.031).

CONCLUSIONS

Brainstem white matter hyperintensities are an independent predictor of poor outcome after AIS/TIA and this relationship persists after adjustment for important prognostic factors. Our results also show that leukoaraiosis in this location identifies patients with a specific risk factor profile, suggesting differences in the underlying pathogenesis.

Biomarkers of stroke recovery: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation Roundtable

The most difficult clinical questions in stroke rehabilitation are "What is this patient's potential for recovery?" and "What is the best rehabilitation strategy for this person, given her/his clinical profile?" Without answers to these questions, clinicians struggle to make decisions regarding the content and focus of therapy, and researchers design studies that inadvertently mix participants who have a high likelihood of responding with those who do not. Developing and implementing biomarkers that distinguish patient subgroups will help address these issues and unravel the factors important to the recovery process. The goal of the present paper is to provide a consensus statement regarding the current state of the evidence for stroke recovery biomarkers. Biomarkers of motor, somatosensory, cognitive and language domains across the recovery timeline post-stroke are considered; with focus on brain structure and function, and exclusion of blood markers and genetics. We provide evidence for biomarkers that are considered ready to be included in clinical trials, as well as others that are promising but not ready and so represent a developmental priority. We conclude with an example that illustrates the utility of biomarkers in recovery and rehabilitation research, demonstrating how the inclusion of a biomarker may enhance future clinical trials. In this way, we propose a way forward for when and where we can include biomarkers to advance the efficacy of the practice of, and research into, rehabilitation and recovery after stroke.

Effects of hyperoxia on 18F-fluoro-misonidazole brain uptake and tissue oxygen tension following middle cerebral artery occlusion in rodents: Pilot studies

PURPOSE

Mapping brain hypoxia is a major goal for stroke diagnosis, pathophysiology and treatment monitoring. 18F-fluoro-misonidazole (FMISO) positron emission tomography (PET) is the gold standard hypoxia imaging method. Normobaric hyperoxia (NBO) is a promising therapy in acute stroke. In this pilot study, we tested the straightforward hypothesis that NBO would markedly reduce FMISO uptake in ischemic brain in Wistar and spontaneously hypertensive rats (SHRs), two rat strains with distinct vulnerability to brain ischemia, mimicking clinical heterogeneity.

METHODS

Thirteen adult male rats were randomized to distal middle cerebral artery occlusion under either 30% O2 or 100% O2. FMISO was administered intravenously and PET data acquired dynamically for 3hrs, after which magnetic resonance imaging (MRI) and tetrazolium chloride (TTC) staining were carried out to map the ischemic lesion. Both FMISO tissue uptake at 2-3hrs and FMISO kinetic rate constants, determined based on previously published kinetic modelling, were obtained for the hypoxic area. In a separate group (n = 9), tissue oxygen partial pressure (PtO2) was measured in the ischemic tissue during both control and NBO conditions.

RESULTS

As expected, the FMISO PET, MRI and TTC lesion volumes were much larger in SHRs than Wistar rats in both the control and NBO conditions. NBO did not appear to substantially reduce FMISO lesion size, nor affect the FMISO kinetic rate constants in either strain. Likewise, MRI and TTC lesion volumes were unaffected. The parallel study showed the expected increases in ischemic cortex PtO2 under NBO, although these were small in some SHRs with very low baseline PtO2.

CONCLUSIONS

Despite small samples, the apparent lack of marked effects of NBO on FMISO uptake suggests that in permanent ischemia the cellular mechanisms underlying FMISO trapping in hypoxic cells may be disjointed from PtO2. Better understanding of FMISO trapping processes will be important for future applications of FMISO imaging.

Recent Advances in Leukoaraiosis: White Matter Structural Integrity and Functional Outcomes after Acute Ischemic Stroke

Leukoaraiosis, a radiographic marker of cerebral small vessel disease detected on T2-weighted brain magnetic resonance imaging (MRI) as white matter hyperintensity (WMH), is a key contributor to the risk and severity of acute cerebral ischemia. Prior investigations have emphasized the pathophysiology of WMH development and progression; however, more recently, an association between WMH burden and functional outcomes after stroke has emerged. There is growing evidence that WMH represents macroscopic injury to the white matter and that the extent of WMH burden on MRI influences functional recovery in multiple domains following acute ischemic stroke (AIS). In this review, we discuss the current understanding of WMH pathogenesis and its impact on AIS and functional recovery.

Leukoaraiosis as an outcome predictor in the acute and subacute phases of stroke

INTRODUCTION

Leukoaraiosis (LA) is one of the neuroimaging features of cerebral small vessel disease and is associated with poor long-term prognosis. Areas covered: This narrative review focuses on the predictive role of LA on the evolution of the ischemic brain damage and on the clinical outcome in the subacute phase of stroke and in the short-term period afterwards. Expert commentary: LA predicts poorer tissue outcome and clinical prognosis also in acute and subacute stroke. In acute stroke, LA is associated with a less favorable fate of brain infarct and is a marker of increased risk of thrombolysis-related hemorrhagic transformation. The impaired cerebral microcirculation in LA patients may sustain the progression of ischemic lesion and enhance the bleeding risk. The short-term worse clinical outcome in ischemic stroke and intracranial hemorrhage patients with LA might be attributable to a state of altered brain connectivity. Endothelial failure, reduced micro-vessels density, and deficient collateral flow together with reduced functional reserve are some of the involved mechanisms. Future studies should aim at bridging the gap between the knowledge about LA pathophysiology and the therapeutic improvement of brain tissue perfusion and at producing data on early rehabilitation of stroke patients with LA at high disability risk.

Small vessel disease and clinical outcomes after IV rt-PA treatment

INTRODUCTION

Cerebral small vessel disease (SVD) contributes to dementia and disability in the elderly, and may negatively affect stroke outcomes. We aimed to evaluate to what extent single features and global burden of SVD detected with magnetic resonance (MR) are associated with worse outcomes in patients with ischaemic stroke treated with intravenous thrombolysis.

METHODS

We accessed anonymized data and MR images from the Stroke Imaging Repository (STIR) and the Virtual International Stroke Trials Archive (VISTA) Imaging. We described SVD features using validated scales and quantified the global burden of SVD with a combined score. Our mainoutcome was the modified Rankin Scale (mRS) at 90 days after stroke. We used logistic regression and ordinal regression models (adjusted for age, sex, stroke severity, onset to treatment time) to examine the associations between each SVD feature, SVD global burden and clinical outcomes.

RESULTS

A total of 259 patients had MR scans available at baseline (mean age±SD=68.7±15.5 years; 131 [49%] males). After adjustment for confounders, severe white matter changes were associated with disability (OR=5.14; 95%CI=2.30-11.48), functional dependency (OR=4.38; 95%CI=2.10-9.13) and worse outcomes in ordinal analysis (OR=2.71; 95%CI=1.25-5.85). SVD score was associated with disability (OR=1.66; 95%CI=1.03-2.66) and functional dependency (OR=1.47; 95%CI=1.00-2.45). Lacunes, enlarged perivascular spaces and brain atrophy showed no association with clinical outcomes.

CONCLUSION

Our results suggest that SVD negatively affects stroke outcomes after intravenous thrombolysis. Although white matter changes seem to be the major driver in relation to worse outcomes, global estimation of SVD is feasible and may provide helpful information.

White matter hyperintensity lesion burden is associated with the infarct volume and 90-day outcome in small subcortical infarcts

OBJECTIVES

Small subcortical infarcts (SSI) frequently coexist with brain white matter hyperintensity (WMH) lesions. We sought to determine whether preexisting WMH burden relates to SSI volume, SSI etiology, and 90-day functional outcome.

MATERIALS AND METHODS

We retrospectively studied 80 consecutive patients with acute SSI. Infarct volume was determined on diffusion weighted imaging, and WMH burden was graded on fluid-attenuated inversion recovery sequences according to the Fazekas scale. SSI etiology was categorized as small vessel disease (SVD) vs non-SVD related. Multivariable linear and logistic regression models were constructed to determine whether WMH burden was independently associated with the SSI volume and a poor 90-day outcome (modified Rankin scale [mRS] score >2), respectively.

RESULTS

In unadjusted analyses, patients with non-SVD-related SSI were older (P=.002) and more frequently had multiple infarcts (P<.001) than patients with SVD-related SSI. In the fully adjusted model, WMH severity (Coefficient 0.07; 95%-CI 0.029-0.117; P=.002) but not SSI etiology (P>.1) was independently associated with the SSI volume. On multivariable logistic regression, worse WMH (OR 2.28; 95%-CI 1.04-4.99; P=.040), SSI etiology (OR 9.20; 95%-CI 1.04-81.39; P=.046), preadmission mRS (OR 8.96; 95%-CI 2.65-30.27; P<.001), and SSI volume (OR 1.98; 95%-CI 1.14-3.44; P=.016) were associated with a poor 90-day outcome.

CONCLUSIONS

Greater WMH burden is independently associated with a larger SSI volume and a worse 90-day outcome.

Integrity of normal-appearing white matter and functional outcomes after acute ischemic stroke

OBJECTIVE

To characterize the effect of white matter microstructural integrity on cerebral tissue and long-term functional outcomes after acute ischemic stroke (AIS).

METHODS

Consecutive AIS patients with brain MRI acquired within 48 hours of symptom onset and 90-day modified Rankin Scale (mRS) score were included. Acute infarct volume on diffusion-weighted imaging (DWIv) and white matter hyperintensity volume (WMHv) on T2 fluid-attenuated inversion recovery MRI were measured. Median fractional anisotropy (FA), mean diffusivity, radial diffusivity, and axial diffusivity values were calculated within normal-appearing white matter (NAWM) in the hemisphere contralateral to the acute lesion. Regression models were used to assess the association between diffusivity metrics and acute cerebral tissue and long-term functional outcomes in AIS. Level of significance was set at p < 0.05 for all analyses.

RESULTS

Among 305 AIS patients with DWIv and mRS score, mean age was 64.4 ± 15.9 years, and 183 participants (60%) were male. Median NIH Stroke Scale (NIHSS) score was 3 (interquartile range [IQR] 1-8), and median normalized WMHv was 6.19 cm³ (IQR 3.0-12.6 cm³). Admission stroke severity (β = 0.16, p < 0.0001) and small vessel stroke subtype (β = -1.53, p < 0.0001), but not diffusivity metrics, were independently associated with DWIv. However, median FA in contralesional NAWM was independently associated with mRS score (β = -9.74, p = 0.02), along with age, female sex, NIHSS score, and DWIv.

CONCLUSIONS

FA decrease in NAWM contralateral to the acute infarct is associated with worse mRS category at 90 days after stroke. These data suggest that white matter integrity may contribute to functional recovery after stroke.

Leukoaraiosis is Associated with Worse Short-Term Functional and Cognitive Recovery after Minor Stroke

Whether leukoaraiosis burden retards short-term recovery after minor stroke is unclear. We investigated the association between leukoaraiosis and early recovery of neurological function after a first minor ischemic stroke in 217 acute stroke patients (National Institutes of Health Stroke Scale (NIHSS) score ≤5). Leukoaraiosis severity was graded according to the Fazekas scale and categorized into none to mild (0-2; n = 143) or severe (3-6; n = 74) groups. NIHSS and Minimum Mental State Examination (MMSE) were assessed at baseline and at 30 days. Univariate analysis revealed that the severe leukoaraiosis group was older in age (P < 0.001) and had fewer low MMSE patients than non-mild group at baseline (39.1% vs 55.9%, P = 0.003). However, the MMSE improved in none to mild group but not in the severe group at 30-day (15.4% vs 36.5%, P < 0.001). At 30-day, the severe leukoaraiosis group had higher NIHSS scores than the none-mild group (P = 0.04). Multiple linear regression analyses demonstrated that leukoaraiosis severity and admission NIHSS were independently associated with the NIHSS score on day 30 (P = 0.034, 95% CI 0.004-0.091 and P = 0.001, 95% CI 0.011-0.04). Binary regression analyses showed that leukoaraiosis severity and admission MMSE were significantly associated with MMSE (dichotomized) at 30-day (OR 2.1, P < 0.01, 95% CI 1.7-2.6 and OR 5.1, P < 0.01, 95% CI 2.1-12.8). Leukoaraiosis burden is an independent predictor of worse short-term functional and cognitive recovery after a minor ischemic stroke.

Normalised time-to-peak-distribution curves correlate with cerebral white matter hyperintensities - Could this improve early diagnosis?

Parameter-free assessment of the time-to-peak (TTP) histogram, termed 'TTP-distribution curve' (TDC), of dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) was introduced as a robust method to evaluate cerebral perfusion. TDC-assessment works fully automatically without the need of an arterial input function, thereby providing full comparability between different measurements. In the investigated sample of 106 patients, a strong dependency of TDC on the hemodynamic state of cerebral microvessels and the arterio-venous bolus-transit time [Formula: see text] was demonstrated. Accordingly, TDC-derived [Formula: see text] was 3.3-3.7 s for control patients and 4.4 s for cerebral small vessel disease patients. Measurements of associated bolus spread velocities ν and accelerations [Formula: see text] additionally revealed a direct effect from spin-spin relaxation time T₂-weighted white matter hyperintensity volume, considered to indicate microangiopathy in cerebral small vessel disease, on the TDC-measurements. This strongly supports the prevailing hypothesis that cerebral small vessel disease directly influences DSC-measurements, where the degree could be estimated from an analysis of TDC. While this may be used to correct DSC-parameters for undesirable effects from cerebral small vessel disease, it could also serve to potentially identify patients at risk for cerebral small vessel disease at an early stage, since a subset of patients without yet significant WHM-volume, but clearly altered hemodynamics in TDC-measurements, was identified in this study.

White Matter Hyperintensity-Adjusted Critical Infarct Thresholds to Predict a Favorable 90-Day Outcome

BACKGROUND AND PURPOSE

There is increasing interest in defining stroke lesion volume thresholds to predict poststroke outcome. However, there is a paucity of data on factors that impact the association between critical infarct thresholds volume and outcome. We sought to determine whether lesion thresholds best predicting outcome depend on the degree of preexisting white matter hyperintensity (WMH) lesion burden.

METHODS

Magnetic resonance imaging infarct volumes were quantified in 414 consecutive patients with anterior circulation ischemic strokes evaluated between January 2014 and December 2014. The WMH lesion volume was graded according to the Fazekas scale and dichotomized to absent to mild versus moderate to severe. Receiver operator characteristics curves were calculated to determine the infarct volume threshold best predicting the 90-day outcome. Multivariable logistic regression was used to determine whether the critical lesion thresholds independently predicted a favorable 90-day outcome after adjusting for pertinent confounders.

RESULTS

The infarct volumes thresholds predicting the 90-day outcome for the entire cohort (standard thresholds) were ≤29.5 mL (modified Rankin scale [mRS] 0-1), ≤29.9 mL (mRS 0-2), and ≤34.1 mL (mRS 0-3). For patients with absent-to-mild WMH lesion burden, WMH-adjusted critical infarct thresholds were significantly greater than the standard infarct thresholds. In the fully adjusted multivariable regression models, the WMH-adjusted infarct thresholds correctly predicted the outcome to a similar degree as the standard thresholds.

CONCLUSIONS

In this proof-of-concept study, the WMH lesion burden impacted the critical outcome-predicting infarct thresholds. If confirmed, using a WMH-adjusted infarct threshold could allow defining patients that have a favorable outcome despite having relatively large infarct volumes.

Impact of leukoaraiosis on parenchymal hemorrhage in elderly patients treated with thrombolysis

INTRODUCTION

Severity of vascular damage of white matter may predict hemorrhagic transformation (HT). We assess the relationship between leukoaraiosis (LA) severity and the type of hemorrhagic transformation in elderly patients treated with thrombolysis.

METHODS

We retrospectively analyzed the clinical data and pretreatment magnetic resonance imaging (MRI) of 180 consecutive ischemic stroke patients aged over 75 years. LA severity was graded according to the Fazekas scale, and acute diffusion-weighted-imaging (DWI) lesion volumes were semi-automatically outlined. Predictors of hemorrhagic infarction (HI) and parenchymal hemorrhage (PH) were identified using logistic regression analysis and exact multinomial logistic analysis.

RESULTS

HT occurred in 31 patients (17 %). Baseline National Institute of Health Stroke Score (NIHSS; p = 0.008), severe LA (p = 0.02), and diffusion lesion volume (p = 0.02) were predictors of HT in univariable logistic regression. Adjusted to lesion volume and baseline NIHSS score, exact multinomial logistic analysis showed that severe LA was the only independent predictor of parenchymal hemorrhage (p = 0.03).

CONCLUSION

In elderly patients, LA severity better predicts parenchymal hemorrhage than infarct size.

Association between Leukoaraiosis and Poor Outcome is not due to Reperfusion Inefficiency after Intravenous Thrombolysis

Leukoaraiosis (LA) is associated with structural and functional cerebrovascular impairment, which may compromise the capacity of ischemic tissue to maximize reperfusion after intravenous thrombolysis (IVT). We aimed to determine whether severe LA is correlated with reperfusion inefficiency, which contributes to infarct growth and poor functional outcome. We analyzed data from our consecutive acute ischemic stroke (AIS) patients who had acquired baseline and 24-h follow-up diffusion- and perfusion-weighted imaging. Reperfusion was defined as reduction of ≥70 % of hypoperfusion lesion at 24 h from baseline. Severe LA was defined as Fazekas score 2 or 3 on FLAIR images. We investigated the relationship between severity of LA and reperfusion status. Multivariate statistical analysis was carried out for modeling the independent predictors of reperfusion, infarct growth, and functional outcome. Finally, 79 patients were included, among them 30 (37.97 %) had severe LA. Reperfusion was observed in 41 (51.89 %) patients, the proportion of reperfusion was very similar in patients with and without severe LA (53.33 vs 51.02 %, p = 1.000). Large artery occlusion was the only independent unfavorable predictor for reperfusion (OR = 0.202, 95 % confidence interval, 0.060-0.673; p = 0.014). Multiple linear regression analysis revealed that severe LA was independently associated with infarct growth (standardized coefficients = 0.191, p = 0.040). Severe LA was also an independent predictor of poor outcome (mRS ≥ 3) (OR = 4.004, 95 % confidence interval, 1.267-12.656, p = 0.018) after adjusting for reperfusion and baseline severity of stroke. Severe LA was associated with infarct growth and poor outcome independent of reperfusion status, which may expand the notion that LA contributes the intrinsic vulnerability of brain tissue to acute ischemic insults. The burden of LA may not serve as an imaging indicator of reperfusion inefficiency after IVT for AIS patients.

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

BACKGROUND AND PURPOSE

Dilated Virchow-Robin spaces (dVRSs) were regarded as a phenotype of cerebral small-vessel disease (SVD). However, the clinical correlations of dVRS were still unclear. In this study, we aimed to investigate the topography and clinical correlations of dVRS in first-ever lacunar stroke patients.

METHODS

Patients with first-ever lacunar stroke were recruited and had magnetic resonance scans to identify the presence and degree of dVRS in the basal ganglia (BG-dVRS), dVRS in the central semiovale (CSO-dVRS), leukoaraiosis, and silent brain infarction (SBI). The neurological deficits after stroke onset and functional outcome after 1 year were evaluated using National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale, respectively. Clinical and radiological features were compared between patients with high and low degrees of dVRS, and between patients with favorable and unfavorable outcomes. Logistic regression models were constructed to identify the risk factors of unfavorable outcome.

RESULTS

The NIHSS scores were not statistically different between patients with high and low degrees of dVRS. More patients with high degrees of BG-dVRS had unfavorable outcomes than those with low degrees of BG-dVRS. Logistic regression showed that the degrees of BG-dVRS, leukoaraiosis, and SBIs were not independent risk factors for the unfavorable outcome, whereas the total burden of SVD was an independent risk factor for the unfavorable outcome.

CONCLUSION

The degrees of either BG-dVRS or CSO-dVRS were not associated with the severity of first lacunar stroke. BG-dVRS was related to the unfavorable 1-year outcome. This association might be based on the total severity of SVD.

Severe leukoaraiosis portends a poor outcome after traumatic brain injury

BACKGROUND AND PURPOSE

It is now well accepted that traumatic white matter injury constitutes a critical determinant of post-traumatic functional impairment. However, the contribution of preexisting white matter rarefaction on outcome following traumatic brain injury (TBI) is unknown. Hence, we sought to determine whether the burden of preexisting leukoaraiosis of presumed ischemic origin is independently associated with outcome after TBI.

METHODS

We retrospectively analyzed consecutive, prospectively enrolled patients of ≥50 years (n = 136) who were admitted to a single neurological/trauma intensive care unit. Supratentorial white matter hypoattenuation on head CT was graded on a 5-point scale (range 0-4) reflecting increasing severity of leukoaraiosis. Outcome was ascertained according to the modified Rankin Scale (mRS) and Glasgow outcome scale (GOS) at 3 and 12 months, respectively.

RESULTS

After adjustment for other factors, leukoaraiosis severity was significantly associated with a poor outcome at 3 and 12 months defined as mRS 3-6 and GOS 1-3, respectively. The independent association between leukoaraiosis and poor outcome remained when the analysis was restricted to patients who survived up to 3 months, had moderate-to-severe TBI [enrollment Glasgow Coma Scale (GCS) ≤12; p = 0.001], or had mild TBI (GCS 13-15; p = 0.002), respectively.

CONCLUSION

We provide first evidence that preexisting cerebral small vessel disease independently predicts a poor functional outcome after closed head TBI. This association is independent of other established outcome predictors such as age, comorbid state as well as intensive care unit complications and interventions. This knowledge may help improve prognostic accuracy, clinical management, and resource utilization.

White Matter Lesions Double the Risk of Post-Thrombolytic Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Cerebral white matter lesions (WMLs), a surrogate for small-vessel disease, are common in patients with stroke and may be related to an increased intracranial bleeding risk after intravenous thrombolysis in acute ischemic stroke. We aimed to investigate the risk of symptomatic intracerebral hemorrhage (sICH) in the presence of WMLs in a large cohort of ischemic stroke patients treated with intravenous thrombolysis.

METHODS

We included 2485 consecutive patients treated with intravenous thrombolysis at the Helsinki University Central Hospital. WMLs were scored according to 4 previously published computed tomography visual rating scales from all baseline head scans. A sICH was classified according to the European Cooperative Acute Stroke Study II criteria. The associations of sICH with nominal, ordinal, and continuous variables were analyzed in a univariate binary regression model and adjusted in multivariate binary regression models.

RESULTS

In univariate and multivariate regression analyses, all 4 tested visual WML rating scales (as continuous variables or dichotomized at different cutoff points) were associated with increased risk of sICH. In binary analyses, WML doubled the bleeding risk: the odds ratios of all 4 visual rating scales ranged from 2.22 (95% confidence interval, 1.49-3.30) to 2.70 (1.87-3.90) in univariable and from 2.00 (1.26-3.16) to 2.62 (1.71-4.02) in multivariable analyses. The multivariable-adjusted odds ratio for the association of high load of WMLs with remote parenchymal hemorrhage was 4.11 (2.38-7.10).

CONCLUSIONS

WMLs visible on computed tomography are associated with a more than doubled risk of sICH in patients treated with intravenous thrombolysis for acute ischemic stroke.

Prognostic Impact of Cerebral Small Vessel Disease on Stroke Outcome

Cerebral small vessel disease (SVD), which includes white matter hyperintensities (WMHs), silent brain infarction (SBI), and cerebral microbleeds (CMBs), develops in a conjunction of cumulated injuries to cerebral microvascular beds, increased permeability of blood-brain barriers, and chronic oligemia. SVD is easily detected by routine neuroimaging modalities such as brain computed tomography or magnetic resonance imaging. Research has revealed that the presence of SVD markers may increase the risk of future vascular events as well as deteriorate functional recovery and neurocognitive trajectories after stroke, and such an association could also be applied to hemorrhagic stroke survivors. Currently, the specific mechanistic processes leading to the development and manifestation of SVD risk factors are unknown, and further studies with novel methodological tools are warranted. In this review, recent studies regarding the prognostic impact of WMHs, SBI, and CMBs on stroke survivors and briefly summarize the pathophysiological concepts underlying the manifestation of cerebral SVD.