Clinical correlates of infarct shape and volume in lacunar strokes: the Secondary Prevention of Small Subcortical Strokes trial

The impact of pre-stroke aspirin exposure on radiographic appearance and disability outcomes: A post-hoc analysis of the SPS3 trial: Aspirin Use and Small Subcortical Stroke

OBJECTIVES

The effect of pre-stroke use of aspirin on small subcortical infarct dimensions or outcomes is not well described. We aimed to bridge this knowledge gap amongst a well-described and heterogeneous patient population.

MATERIALS AND METHODS

We performed a post-hoc analysis of the Secondary Prevention of Small Subcortical Stroke (SPS3) trial. The primary exposure was aspirin use ≤7 days of index stroke. The primary outcomes were infarct dimensions. Functional outcomes by modified Rankin Scale (mRS) was a secondary outcome. Age restricted (≥55 years) subgroup analyses were performed as a sensitivity analysis. Descriptive statistical and regression modeling were performed for data analysis.

RESULTS

We included 1423 participants of which 453(31.8 %) used aspirin. Aspirin use was associated with more cardiovascular risk diagnoses. Maximal infarct diameter did not differ with pre-stroke aspirin use (11.3±4.2 mm versus 11.8±4.1 mm, p=0.057) however infarct area was smaller with exposure (126.4±90.0 mm2 versus 137.4±97.0 mm2, p=0.037) regardless of aspirin strength. Participants ≥55 years had smaller infarct diameters (11.1±4.2 mm versus 11.9±4.4 mm, p=0.019) and area (123.4±87.1 mm2 versus 130.6±93.2 mm2, p=0.037) with aspirin use. mRS did not significantly differ in our analyses.

CONCLUSIONS

In this post-hoc analysis of the SPS3 trial, pre-stroke aspirin use was associated with a smaller infarct area regardless of aspirin strength and without impact on functional outcomes. These findings were more pronounced in participants ≥55 years.

REGISTRATION

https://clinicaltrials.gov/study/NCT00059306?term= %22sps3 %22&rank=1.

Is the female sex associated with an increased risk for long-term cognitive decline after the first-ever lacunar stroke? Prospective study on small vessel disease cohort

Background

Sex is a significant determinant of survival and functional outcome after stroke. Long-term cognitive outcome after acute lacunar stroke in the context of sex differences has been rarely reported.

Methods

A cohort of small vessel disease (SVD) patients presenting with first-ever acute lacunar stroke and normal cognitive status has been evaluated 4 years after the qualifying event for the presence of cognitive impairment (CI) with a comprehensive neuropsychological battery. Differences in baseline clinical and neuroimaging characteristics were compared between sexes in relation to cognitive status.

Results

A total of 124 female and 150 male patients were analyzed. No difference was detected between the groups regarding age (p = 0.932) or frequency of common vascular risk factors (p > 0.1 for all). At the baseline assessment, women had more disabilities compared to men with a mean modified Rankin scale (mRS) score of 2.5 (1.5 in men, p < 0.0001). Scores of white matter hyperintensities (WMH) of presumed vascular origin and a total number of lacunes of presumed vascular origin on brain MRI were higher in women compared to men (p < 0.0001 for all). As many as 64.6% of patients had CI of any severity on follow-up, women more frequently (77.4%) than men (54.0%; p < 0.0001). Univariate logistic regression analysis showed that female sex, higher NIHSS and mRS scores, presence of depression, and increasing WMH severity were associated with an increased risk for CI. Multivariate regression analysis indicated that only depression (OR 1.74, 95%CI 1.25-2.44; p = 0.001) and WMH severity (OR 1.10, 95%CI 1.03-1.17; p = 0.004) were independently associated with the CI.

Conclusion

At the long-term follow-up, women lacunar stroke survivors, compared to men, more frequently had CI in the presence of more severe vascular brain lesions, but this association was dependent on the occurrence of depression and severity of WMH, and could not be explained by differences in common vascular risk factors.

Clinical and radiographic phenotypes of patients with multifocal subcortical versus cortical cerebral infarcts

BACKGROUND AND PURPOSE

Infarct topology is a key determinant in classification of a stroke as potentially embolic, with cortical and multifocal lesions being presumed embolic. Whether isolated subcortical multifocal infarcts are likely embolic has not been well studied.

METHODS

A prospective, single-center cohort study of consecutive patients with acute multifocal strokes confirmed on diffusion-weighting imaging (DWI) was queried, and patients compared according to the presence of isolated subcortical infarct topology versus cortical ± subcortical topology. Descriptive statistics and multivariable logistic regression were used to determine independent predictors of cryptogenic, subcortical infarcts.

RESULTS

Of 1739 patients screened, 743 had complete diagnostic testing with DWI evidence of acute infarction, 183 (24.6%) of whom had a multifocal stroke pattern. Isolated subcortical involvement was disproportionate among patients with ESUS (64.9%) when compared to patients with cardioembolic (24.3%) or large vessel disease (10.8%, p<0.01). Following multivariable adjustment, independent predictors of isolated subcortical multifocal infarction were milder strokes (OR 0.94, 95%CI 0.89-0.98) and higher grade Fazekas score (OR 2.32, 95%CI 1.02-5.29), while cardioembolism (OR 0.30, 95%CI 0.08-1.13) and large vessel disease (OR 0.27, 95%CI 0.08-0.91) remained inversely associated (as compared to ESUS).

CONCLUSIONS

These data suggest that multifocal subcortical infarctions are less likely to have an associated proximal embolic source than multifocal infarctions with cortical involvement. The strong association with chronic microvascular disease suggests this topology is more consistent with acute-on-chronic microvascular injury rather than an occult embolic source.

Association of stroke lesion shape with newly detected atrial fibrillation – Results from the MonDAFIS study

Paroxysmal Atrial fibrillation (AF) is often clinically silent and may be missed by the usual diagnostic workup after ischemic stroke. We aimed to determine whether shape characteristics of ischemic stroke lesions can be used to predict AF in stroke patients without known AF at baseline. Lesion shape quantification on brain MRI was performed in selected patients from the intervention arm of the Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS) study, which included patients with ischemic stroke or TIA without prior AF. Multiple morphologic parameters were calculated based on lesion segmentation in acute brain MRI data. Multivariate logistic models were used to test the association of lesion morphology, clinical parameters, and AF. A stepwise elimination regression was conducted to identify the most important variables. A total of 755 patients were included. Patients with AF detected within 2 years after stroke (n = 86) had a larger overall oriented bounding box (OBB) volume (p = 0.003) and a higher number of brain lesion components (p = 0.008) than patients without AF. In the multivariate model, OBB volume (OR 1.72, 95%CI 1.29–2.35, p < 0.001), age (OR 2.13, 95%CI 1.52–3.06, p < 0.001), and female sex (OR 2.45, 95%CI 1.41–4.31, p = 0.002) were independently associated with detected AF. Ischemic lesions in patients with detected AF after stroke presented with a more dispersed infarct pattern and a higher number of lesion components. Together with clinical characteristics, these lesion shape characteristics may help in guiding prolonged cardiac monitoring after stroke.

Imaging Patterns of Recurrent Infarction in the Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease (MyRIAD) Study

Introduction: While much is known about recurrent clinical events in patients with intracranial atherosclerotic disease (ICAD), there is limited data on characteristics of recurrent infarcts.

Methods: The NIH-funded MyRIAD prospective, observational study was designed to identify mechanisms of ischemia and predictors of recurrence in ICAD. Recurrent infarction was assessed on MRI at 6–8 weeks. We reviewed the DWI/ADC and FLAIR sequences in patients with recurrent stroke and characterized the number of infarcts, infarct location, size, and patterns based on whether they were borderzone (BZ), perforator (SC/P), cortical or territorial (C/T), and mixed. Temporal characteristics were delineated by ADC/FLAIR correlation.

Results: Of the 89 patients with 6–8 weeks MRI, 22 (24.7%) had recurrent infarcts in the territory of the symptomatic artery. Recurrent infarcts were evident on DWI in 63.6% and single infarcts in 54.5%. The median recurrent infarct volume was 2.0 cm³ compared to median index infarct volumes of 2.5 cm³. A mixed infarct pattern was most common (40.9%), followed by borderzone (22.7%), cortical or territorial (27.3%), while only 9.1% were in a perforator artery distribution. Amongst those with a mixed pattern, 8/9 had a borderzone distribution infarct as part of their mixed infarct pattern.

Conclusion: These findings provide novel data on the characteristics of early recurrent infarcts in patients with symptomatic ICAD.

Cilostazol Addition to Aspirin could not Reduce the Neurological Deterioration in TOAST Subtypes: ADS Post-Hoc Analysis

BACKGROUND

Our previous trial acute dual study (ADS) reported that dual antiplatelet therapy (DAPT) using cilostazol and aspirin did not reduce the rate of short-term neurological worsening in non-cardioembolic stroke patients. Present post-hoc analysis investigated whether the impact of combined cilostazol and aspirin differed among stroke subtypes and factors associated with neurological deterioration and/or stroke recurrence.

METHODS

Using the ADS registry, the rate of neurological deterioration, defined as clinical worsening and/or recurrent stroke, including transient ischemic attack was calculated. Stroke subtypes included large-artery atherosclerosis (LAA), small vessel occlusion (SVO), other determined etiology (Others), and undetermined etiology of stroke (Undetermined).

RESULTS

Data of 1022 patients were analyzed. Deterioration was seen in 104 (10%) patients, and the rates were not markedly different between patients treated with DAPT vs. aspirin in any stroke subtypes: LAA, 19% vs. 11%, (p=0.192); SVO, 10% vs. 10% (p=1.000); Others, 6% vs. 6% (p=1.000); Undetermined, 11% vs. 8% (p=0.590). Diabetes mellitus was the independent factor associated with deterioration (odds ratio 4.360, 95% confidence interval 1.139-16.691, p=0.032) in the LAA group. Age (1.030 [1.004-1.057], p=0.026), systolic blood pressure (1.012 [1.003-1.022], p=0.010), and infarct size (2.550 [1.488-4.371], p=0.001) were associated with deterioration in SVO group, and intracranial stenosis/occlusion was associated with it in the Undetermined group (3.744 [1.138-12.318], p=0.030).

CONCLUSIONS

Combined cilostazol and aspirin did not reduce the rate of short-term neurological deterioration in any clinical stroke subtype. The characteristics of patients whose condition deteriorates in the acute period may differ based on the stroke subtypes.

Infarct site and prognosis in small subcortical infarction: Role of the corticospinal tract and lentiform

OBJECTIVE

To determine the impact of infarct site combinations on prognosis of small subcortical infarction (SSI) by classifying the infarcted perforator area in relation to the anatomical structures that surround and/or involve the corticospinal tract.

METHODS

Consecutive patients with SSI ≤24 h from onset to initial magnetic resonance imaging (MRI) and ≤ 14 days from onset to second MRI were included. Infarct sites were defined as follows: caudate head, lentiform (L), corona radiata (CR), posterior limb and genu of the internal capsule (IC), thalamus, and brainstem with or without involvement of the corticospinal tract. An unfavorable outcome was defined as a modified Rankin Scale score of 2 to 6 at 3 months from onset. Infarct site combinations related to an unfavorable outcome were evaluated.

RESULTS

We screened 1558 consecutive patients with ischemic strokes, including 128 with SSI (99 [77%] male, median age 64 years). Of all, 29 (23%) had unfavorable outcomes. Factors associated with unfavorable outcomes were age (odds ratio (OR) 2.057, 95% confidence interval (CI) 1.230-3.493, p = 0.006), maximum infarct area (OR 1.094, 95% CI 1.030-1.163, p = 0.004), and infarct simultaneously involving the CR, IC, and L (OR 9.403, 95% CI 1.506-58.710, p = 0.016). Patients with simultaneous involvement of the CR, IC, and L were likely to have a higher subscore in the National Institutes of Health Stroke Scale item of arm motor impairment at discharge (OR 2.947, 95% CI 1.098-7.910, p = 0.032).

CONCLUSIONS

Infarcts involving the CR, IC, and L predict unfavorable outcomes in SSI.

Multiple versus fewer antiplatelet agents for preventing early recurrence after ischaemic stroke or transient ischaemic attack

BACKGROUND

Stroke is a leading cause of morbidity and mortality worldwide. Antiplatelet agents are considered to be the cornerstone for secondary prevention of stroke, but the role of using multiple antiplatelet agents early after stroke or transient ischaemic attack (TIA) to improve outcomes has not been established.

OBJECTIVES

To determine the effectiveness and safety of initiating, within 72 hours after an ischaemic stroke or TIA, multiple antiplatelet agents versus fewer antiplatelet agents to prevent stroke recurrence. The analysis explores the evidence for different drug combinations.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched 6 July 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 7 of 12, 2020) (last searched 6 July 2020), MEDLINE Ovid (from 1946 to 6 July 2020), Embase (1980 to 6 July 2020), ClinicalTrials.gov, and the WHO ICTRP. We also searched the reference lists of identified studies and reviews and used the Science Citation Index Cited Reference search for forward tracking of included studies.

SELECTION CRITERIA

We selected all randomised controlled trials (RCTs) that compared the use of multiple versus fewer antiplatelet agents initiated within 72 hours after stroke or TIA.

DATA COLLECTION AND ANALYSIS

We extracted data from eligible studies for the primary outcomes of stroke recurrence and vascular death, and secondary outcomes of myocardial infarction; composite outcome of stroke, myocardial infarction, and vascular death; intracranial haemorrhage; extracranial haemorrhage; ischaemic stroke; death from all causes; and haemorrhagic stroke. We computed an estimate of treatment effect and performed a test for heterogeneity between trials. We analysed data on an intention-to-treat basis and assessed bias for all studies. We rated the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 15 RCTs with a total of 17,091 participants. Compared with fewer antiplatelet agents, multiple antiplatelet agents were associated with a significantly lower risk of stroke recurrence (5.78% versus 7.84%, risk ratio (RR) 0.73, 95% confidence interval (CI) 0.66 to 0.82; P < 0.001; moderate-certainty evidence) with no significant difference in vascular death (0.60% versus 0.66%, RR 0.98, 95% CI 0.66 to 1.45; P = 0.94; moderate-certainty evidence). There was a higher risk of intracranial haemorrhage (0.42% versus 0.21%, RR 1.92, 95% CI 1.05 to 3.50; P = 0.03; low-certainty evidence) and extracranial haemorrhage (6.38% versus 2.81%, RR 2.25, 95% CI 1.88 to 2.70; P < 0.001; high-certainty evidence) with multiple antiplatelet agents. On secondary analysis of dual versus single antiplatelet agent therapy, benefit for stroke recurrence (5.73% versus 8.06%, RR 0.71, 95% CI 0.62 to 0.80; P < 0.001; moderate-certainty evidence) was maintained as well as risk of extracranial haemorrhage (1.24% versus 0.40%, RR 3.08, 95% CI 1.74 to 5.46; P < 0.001; high-certainty evidence). The composite outcome of stroke, myocardial infarction, and vascular death (6.37% versus 8.77%, RR 0.72, 95% CI 0.64 to 0.82; P < 0.001; moderate-certainty evidence) and ischaemic stroke (6.30% versus 8.94%, RR 0.70, 95% CI 0.61 to 0.81; P < 0.001; high-certainty evidence) were significantly in favour of dual antiplatelet therapy, whilst the risk of intracranial haemorrhage became less significant (0.34% versus 0.21%, RR 1.53, 95% CI 0.76 to 3.06; P = 0.23; low-certainty evidence).

AUTHORS' CONCLUSIONS

Multiple antiplatelet agents are more effective in reducing stroke recurrence but increase the risk of haemorrhage compared to one antiplatelet agent. The benefit in reduction of stroke recurrence seems to outweigh the harm for dual antiplatelet agents initiated in the acute setting and continued for one month. There is lack of evidence regarding multiple versus multiple antiplatelet agents. Further studies are required in different populations to establish comprehensive safety profiles and long-term outcomes to establish duration of therapy.

Within-lesion heterogeneity of subcortical DWI lesion evolution, and stroke outcome: A voxel-based analysis

The fate of subcortical diffusion-weighted imaging (DWI) lesions in stroke patients is highly variable, ranging from complete tissue loss to no visible lesion on follow-up. Little is known about within-lesion heterogeneity and its relevance for stroke outcome. Patients with subcortical stroke and recruited through the prospective DEDEMAS study (NCT01334749) were examined at baseline (n = 45), six months (n = 45), and three years (n = 28) post-stroke. We performed high-resolution structural MRI including DWI. Tissue fate was determined voxel-wise using fully automated tissue segmentation. Within-lesion heterogeneity at baseline was assessed by free water diffusion imaging measures. The majority of DWI lesions (66%) showed cavitation on six months follow-up but the proportion of tissue turning into a cavity was small (9 ± 13.5% of the DWI lesion). On average, 69 ± 25% of the initial lesion resolved without any visually apparent signal abnormality. The extent of cavitation at six months post-stroke was independently associated with clinical outcome, i.e. modified Rankin scale score at six months (OR = 4.71, p = 0.005). DWI lesion size and the free water-corrected tissue mean diffusivity at baseline independently predicted cavitation. In conclusion, the proportion of cavitating tissue is typically small, but relevant for clinical outcome. Within-lesion heterogeneity at baseline on advanced diffusion imaging is predictive of tissue fate.

Improving Clinical Detection of Acute Lacunar Stroke: Analysis From the IST-3

Supplemental Digital Content is available in the text.

We aim to identify factors associated with imaging-confirmed lacunar strokes and improve their rapid clinical identification early after symptom onset using data from the IST-3 (Third International Stroke Trial).

Dual Antiplatelet Therapy in Transient Ischemic Attack and Minor Stroke With Different Infarction Patterns: Subgroup Analysis of the CHANCE Randomized Clinical Trial

Importance

Infarction patterns may serve as important imaging markers to assess the probability of stroke recurrence in transient ischemic attack (TIA) and minor stroke. However, it is unclear whether patients with different infarction patterns benefit differently from dual antiplatelet therapy.

Objectives

To investigate whether infarction patterns can stratify the risk of recurrent stroke and whether the efficacy and safety of clopidogrel plus aspirin vs aspirin alone are consistent in different infarction patterns after TIA or minor stroke.

Design, Setting, and Participants

In this prespecified imaging substudy of the Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events (CHANCE) randomized clinical trial, a total of 1342 patients with noncardioembolic TIA or minor stroke at 45 sites of CHANCE from October 1, 2009, to July 30, 2012, were included in this substudy. The final analysis was conducted on July 30, 2016, and included 1089 patients with required magnetic resonance imaging sequences. Infarction patterns were grouped into multiple acute infarctions (MAIs), single acute infarction (SAI), and no acute infarction (NAI) according to diffusion-weighted imaging.

Main Outcomes and Measures

Primary and secondary efficacy outcomes were stroke recurrence and new clinical vascular event after 3 months, respectively. The safety outcome was moderate to severe bleeding risk after 3 months.

Results

Among 1089 patients, the mean (SD) age was 63.1 (10.7) years and 731 patients (65%) were men. Patients with MAIs (hazard ratio [HR], 5.8; 95% CI, 2.2-15.1; P < .001) and SAI (HR, 3.9; 95% CI, 1.5-10.5; P = .007) had higher risk of recurrent stroke than those with NAI after adjustment for potential confounders at 3-month follow-up. Stroke recurrence occurred in 15 (10.1%) and 25 (18.8%) of patients with MAIs administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 0.5; 95% CI, 0.3-0.96; P = .04), 24 (8.9%) and 24 (8.5%) of patients with SAI administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 1.1; 95% CI, 0.6-2.0; P = .71), and 3 (2.6%) and 2 (1.4%) of patients with NAI administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 1.7; 95% CI, 0.3-11.1; P = .56), with P = .04 for treatment × infarction pattern interaction effect. Clopidogrel plus aspirin did not increase moderate to severe bleeding risk.

Conclusions and Relevance

Infarction patterns can efficiently stratify the risk of recurrent stroke within 3 months of noncardioembolic TIA or minor ischemic stroke. Patients with MAIs received the most pronounced clinical benefit from dual antiplatelet therapy without increasing the risk of moderate to severe bleeding. However, even if after dual antiplatelet treatment, patients with MAIs still had a risk of stroke recurrence as high as those with SAI.

Trial Registration

clinicaltrials.gov Identifier: NCT00979589.

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

Background:

Recent small subcortical infarcts (RSSIs) mostly result from the occlusion of a single, small, brain artery due to intrinsic cerebral small-vessel disease (CSVD). Some RSSIs may be attributable to other causes such as cardiac embolism or large-artery disease, and their association with coexisting CSVD and vascular risk factors may vary with morphological magnetic resonance imaging (MRI) features.

Methods:

We retrospectively identified all inpatients with a single symptomatic MRI-confirmed RSSI between 2008 and 2013. RSSIs were rated for size, shape, location (i.e. anterior: basal ganglia and centrum semiovale posterior cerebral circulation: thalamus and pons) and MRI signs of concomitant CSVD. In a further step, clinical data, including detailed diagnostic workup and vascular risk factors, were analyzed with regard to RSSI features.

Results:

Among 335 RSSI patients (mean age 71.1 ± 12.1 years), 131 (39%) RSSIs were >15 mm in axial diameter and 66 (20%) were tubular shaped. Atrial fibrillation (AF) was present in 44 (13.1%) and an ipsilateral vessel stenosis > 50% in 30 (9%) patients. Arterial hypertension and CSVD MRI markers were more frequent in patients with anterior-circulation RSSIs, whereas diabetes was more prevalent in posterior-circulation RSSIs. Larger RSSIs occurred more frequently in the basal ganglia and pons, and the latter were associated with signs of large-artery atherosclerosis. Patients with concomitant AF had no specific MRI profile.

Conclusion:

Our findings suggest the contribution of different pathophysiological mechanisms to the occurrence of RSSIs in the anterior and posterior cerebral circulation. While there appears to be some general association of larger infarcts in the pons with large-artery disease, we found no pattern suggestive of AF in RSSIs.

Inter- and intra-rater reliability of computer-assisted planimetry in experimental stroke research

BACKGROUND

Computer-assisted planimetry is widely used in experimental stroke research to assess the size of the ischemic lesion or hemispheric volume.

NEW METHOD

Only insufficient data exist on the training required to achieve sufficient reliability in planimetry. Therefore, planimetry was performed over 15 months by two blinded raters who were initially inexperienced in the method. For inter-rater reliability, the hemispheric and lesional volume of 227 male Wistar Unilever rats subjected to middle cerebral artery occlusion were determined in diffusion- and T2-weighted sequences. For the intra-rater agreement, one investigator assessed the hemispheric and lesional volume in 87 T2-weighted sequences twice within a six-week interval. The correlation was calculated using Krippendorff's alpha and Bland-Altman plots illustrated the agreement.

RESULTS

Inter-rater agreement increased during the first seven weeks and remained at high values (Krippendorff's alpha > 0.88). For intra-rater agreement, Krippendorff's alpha was 0.84 for hemispheric and 0.85 for lesional volume. The Bland-Altman plot indicated solid agreement between raters in the absence of systematic errors.

COMPARISON WITH EXISTING METHODS

Simplified geometrical models or automated methods for planimetry can be used to determine lesional volume, but both approaches are inappropriate to assess hemispheric volume.

CONCLUSION

Computer-assisted planimetry can be an appropriate method to determine hemispheric or ischemic lesion volume in rodents but requires a sufficiently long learning period of approximately two months. Even an experienced investigator can generate data with serious variation. Inter- and intra-rater-dependent bias should be considered during the design and performance of respective studies.

[Small vessel cerebrovascular disease]

Small vessel vascular disease is a spectrum of different conditions that includes lacunar infarction, alteration of deep white matter, or microbleeds. Hypertension is the main risk factor, although the atherothrombotic lesion may be present, particularly in large-sized lacunar infarctions along with other vascular risk factors. MRI findings are characteristic and the lesions authentic biomarkers that allow differentiating the value of risk factors and defining their prognostic value.

Is the Occlusion Site of the Lenticulostriate Artery Identified on Admission Related to Clinical Prognosis in Patients with Lacunar Stroke?

BACKGROUND

The mechanism of lacunar stroke (LS) is rather speculative due to the lack of neuropathological evidence in clinical practice. To explore the significance of the occlusion site of the lenticulostriate artery (LSA) to this mechanism, we investigated the characteristics and prognosis of patients with LS with proximal occlusions.

MATERIALS AND METHODS

We studied 202 patients with acute LS in the region of the LSA. The presumed occlusion site of the LSA was assessed on coronal, diffusion-weighted magnetic resonance images. Based on the distance from the basal surface of the hemisphere to the proximal site of the lacunar infarct, patients were divided into 3 groups: proximal, middle, and distal site occlusions, and their characteristics and outcomes were compared.

RESULTS

White blood cell counts, blood glucose, hemoglobin A1c, low-density lipoprotein cholesterol, triglyceride, and admission National Institutes of Health Stroke Scale score were statistically different among the 3 groups. In multivariate analysis, both high levels of white blood cells (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.01-1.33) and triglyceride (OR, 1.31; 95% CI, 1.09-1.61) were positively related to the proximal occlusion site. Proximal occlusion (OR, 3.98; 95% CI, 1.06-16.11) was related to poor outcome at discharge.

CONCLUSIONS

Proximal occlusion of the LSA was independently related to elevated triglyceride and white blood cell counts. Patients with LS with proximal LSA occlusion had severe neurological deficits both on admission and at discharge.

Stroke subtype classification by geometrical descriptors of lesion shape

Background and purpose

Inference of etiology from lesion pattern in acute magnetic resonance imaging is valuable for management and prognosis of acute stroke patients. This study aims to assess the value of three-dimensional geometrical lesion-shape descriptors for stroke-subtype classification, specifically regarding stroke of cardioembolic origin.

Methods

Stroke Etiology was classified according to ASCOD in retrospectively selected patients with acute stroke. Lesions were segmented on diffusion-weighed datasets, and descriptors of lesion shape quantified: surface area, sphericity, bounding box volume, and ratio between bounding box and lesion volume. Morphological measures were compared between stroke subtypes classified by ASCOD and between patients with embolic stroke of cardiac and non-cardiac source.

Results

150 patients (mean age 77 years; 95% CI, 65–80 years; median NIHSS 6, range 0–22) were included. Group comparison of lesion shape measures demonstrated that lesions caused by small-vessel disease were smaller and more spherical compared to other stroke subtypes. No significant differences of morphological measures were detected between patients with cardioembolic and non-cardioembolic stroke.

Conclusion

Stroke lesions caused by small vessel disease can be distinguished from other stroke lesions based on distinctive morphological properties. However, within the group of embolic strokes, etiology could not be inferred from the morphology measures studied in our analysis.

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.

Cheiro-pedal syndrome: A revisit of etiology, localization and outcome

OBJECTIVE

Cheiro-pedal syndrome (CPS) is an incomplete sensory disorder confined to hand and foot and is generally considered a benign entity. However, knowledge comes from case report or case series only. The aim of this study is to clarify the etiology, localization and outcome of CPS.

PATIENT AND METHOD

A total of 21 CPS patients from our database and another 9 patients from literature were reviewed. CPS was classified into 4 types, namely unilateral and ipsilateral (Type I), bilateral (Type II), incomplete bilateral (Type III), and crossed (Type IV).

RESULTS

They were 20 men and 10 women; including 20 Type I patients, 9 Type II patients, 1 Type III patients, and 0 Type IV patient. Vascular disorders, non-vascular cervical disorder and polyneuropathy were the responsible causes in 18 patients, 7 patients, and 2 patients, respectively. Etiology was unknown in another 3 patients. Lesions were located at brain parenchyma in 16 patients, and cervical cord above C5 level in 9 patients. Disable motoroparesis occurred between 4days to 2 months in two-third of deteriorated patients. In three patients, their lesions were detected only on recurrence or exacerbation of CPS 4 months to 2 years later. Recovery, residual deficit and deterioration ensued in 44%, 28% and 28% patients, respectively. A 33.3% of brain involvement patients and 100.0% of spinal involvement patients terminated to residual deficit or deterioration. The sensitivity and specificity of prediction for deterioration was 77.8% and 100%, respectively, by type II or III CPS.

CONCLUSION

CPS is actually not a benign neurological disorder but a sensory alarm sign. A thorough examination of brain parenchyma and cervical spinal cord is urgent for identifying any treatable or preventable pathological lesions to reduce harmful consequence, especially in case of type II or III CPS.

Relationship Between Infarct Volume and Prothrombin Time-International Normalized Ratio in Ischemic Stroke Patients With Nonvalvular Atrial Fibrillation

BACKGROUND

In Japan, warfarin treatment at prothrombin time-international normalized ratio (PT-INR) of 1.60-2.60 is recommended for elderly patients with nonvalvular atrial fibrillation (NVAF). But it remains unknown whether PT-INR 1.60-1.99 has a similar effect on stroke severity as a value >2.0. The purpose of this study was to clarify the association between infarct volume and PT-INR levels.Methods and Results:The 180 patients (mean age, 76 years [SD, 10 years], 53% male) selected from 429 consecutive ischemic stroke patients admitted within 48 h of onset between 2004 and 2014 with NVAF were included. We classified them into 4 groups according to their PT-INR values on admission: no warfarin (NW), 129 patients; PT-INR <1.60 (poor control: PC), 29 patients; PT-INR 1.60-1.99 (low-intensity control: LC), 14 patients; and PT-INR ≥2.00 (high-intensity control: HC), 8 patients. Median (interquartile range: IQR) of infarct volume was 55 mL (IQR 14-175) in the NW, 42 mL (IQR 27-170) in the PC, 36 mL (IQR 6-130) in the LC, and 11 mL (IQR 0-39) in the HC groups. The infarct volume of the HC group was significantly smaller than in the other 3 groups, but no difference existed between the LC and PC groups or the LC and NW groups.

CONCLUSIONS

Warfarin control at PT-INR of 1.60-1.99 is not effective for reducing the severity of ischemic stroke in NVAF patients.

Examining Subcortical Infarcts in the Era of Acute Multimodality CT Imaging

BACKGROUND

Lacunar infarct has been characterized as small subcortical infarct. It is postulated to occur from "in situ microatheroma or lipohyalinosis" in small vessel or lacunar mechanism. Based on this idea, such infarcts by lacunar mechanism should not be associated with large area of perfusion deficits that extend beyond the subcortical region to the cortical region. By contrast, selected small subcortical infarcts, as defined by MR imaging in the subacute and chronic stage, may initially have large perfusion deficit or related large vessel occlusions. These infarcts with "lacunar" phenotype may also be caused by disease in the parent vessel and may have very different stroke mechanism from small vessel disease. Our aim is to describe differences in imaging characteristics between patients with small subcortical infarction with "lacunar phenotype" from those with lacunar mechanism.

MATERIALS AND METHODS

Patients undergoing acute CT perfusion/angiography (CTP/CTA) within 6 h of symptom onset and follow-up magnetic resonance imaging (MRI) for ischemic stroke were included (2009-2013). Lacunar infarct was defined as a single subcortical infarct ≤20 mm on follow-up MRI. Presence of perfusion deficits, vessel occlusion, and infarct dimensions was compared between lacunar infarcts and other topographical infarct types.

RESULTS

Overall, 182 patients (mean age 66.4 ± 15.3 years, 66% males) were included. Lacunar infarct occurred in 31 (17%) patients. Of these, 12 (39%) patients had a perfusion deficit compared with those with any cortical infarction (120/142, 67%), and the smallest lacunar infarct with a perfusion deficit had a diameter of <5 mm. The majority of patients with lacunar infarction (8/12, 66.7%) had a relevant vessel occlusion. A quarter of lacunar infarcts had a large artery stroke mechanism evident on acute CTP/CTA. Lacunar mechanism was present in 3/8 patients with corona radiata, 5/10 lentiform nucleus, 5/6 posterior limb of internal capsule (PLIC), 3/5 thalamic infarcts, 1/2 miscellaneous locations. There was a trend to significant with regards to finding lacunar mechanism among patients with thalamic and PLIC infarcts versus lentiform nucleus and corona radiata infarcts (p = 0.13).

CONCLUSION

Diverse stroke mechanisms were present among subcortical infarcts in different locations. When available acute CTP/CTA should be combined with subacute imaging of subcortical infarct to separate "lacunar phenotype" from those with lacunar mechanism.

Update on cerebral small vessel disease: a dynamic whole-brain disease

Cerebral small vessel disease (CSVD) is a very common neurological disease in older people. It causes stroke and dementia, mood disturbance and gait problems. Since it is difficult to visualise CSVD pathologies in vivo, the diagnosis of CSVD has relied on imaging findings including white matter hyperintensities, lacunar ischaemic stroke, lacunes, microbleeds, visible perivascular spaces and many haemorrhagic strokes. However, variations in the use of definition and terms of these features have probably caused confusion and difficulties in interpreting results of previous studies. A standardised use of terms should be encouraged in CSVD research. These CSVD features have long been regarded as different lesions, but emerging evidence has indicated that they might share some common intrinsic microvascular pathologies and therefore, owing to its diffuse nature, CSVD should be regarded as a 'whole-brain disease'. Single antiplatelet (for acute lacunar ischaemic stroke) and management of traditional risk factors still remain the most important therapeutic and preventive approach, due to limited understanding of pathophysiology in CSVD. Increasing evidence suggests that new studies should consider drugs that target endothelium and blood-brain barrier to prevent and treat CSVD. Epidemiology of CSVD might differ in Asian compared with Western populations (where most results and guidelines about CSVD and stroke originate), but more community-based data and clear stratification of stroke types are required to address this.

Predictors of clinical outcome in patients with acute perforating artery infarction

BACKGROUND AND PURPOSE

We aimed to determine the predictive factors for super-acute perforating artery infarctions (PAI) involving lenticulostriate arteries infarctions (LSAI), anterior pontine arteries infarctions (APAI) and thalamic arteries infarctions (TAI). Whether intravenous thrombolysis (iv-tPA) therapy would influence the clinical outcome was also studied.

METHODS

We analyzed 84 consecutive patients within 12h of stroke symptom onset from January 2008 to June 2015. All patients had an imaging-proven acute infarction in the perforating territory of LSA (n=53), TA (n=21) and APA (n=10). Favorable clinical outcome was defined as modified Rankin Scale ≤1 at 90days. Patients were divided into groups according to clinical outcome, lesion location and thrombolysis therapy. Baseline demographic data, past medical history, National Institutes of Health Stroke Scale (NIHSS) score and infarction volume were compared between groups.

RESULTS

Eighty-four patients were recruited (median age: 61y; 67.9% male). All patients with TAI (n=21), 34/53 (64.2%) patients with LSAI and 4/10 (40%) patients with APAI achieved favorable clinical outcome (mRS≤1). Ninety-day clinical outcome was associated with age, previous stroke, baseline NIHSS, infarct location, infarct volume. Intravenous thrombolysis improved 24h NIHSS, but was not significantly associated with favorable outcome at 90days. In multivariate analysis, only previous stroke/TIA (OR 0.09, 95%CI 0.01-0.68, p=0.020) and infarct volume (OR 0.64, 95%CI 0.43-0.96, p=0.032) were independently associated with the outcome of acute PAI at 90days.

CONCLUSIONS

Previous stroke/TIA, infarct location and infarct volume were independently associated with the short-term clinical outcome of acute PAI.

Features and Determinants of Lacune Shape: Relationship With Fiber Tracts and Perforating Arteries

BACKGROUND AND PURPOSE

Lacunes are a major manifestation of cerebral small vessel disease. Although still debated, the morphological features of lacunes may offer mechanistic insights. We systematically analyzed the shape of incident lacunes in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, a genetically defined small vessel disease.

METHODS

A total of 88 incident lacunes from 57 patients were segmented from 3-dimensional T1 magnetic resonance images and 3 dimensionally reconstructed. Anatomic location, diameter, volume, surface area, and compactness of lacunes were assessed. The shape was analyzed using a size, orientation, and position invariant spectral shape descriptor. We further investigated the relationship with perforating arteries and fiber tracts.

RESULTS

Lacunes were most abundant in the centrum semiovale and the basal ganglia. Diameter, volume, and surface area of lacunes in the basal ganglia and centrum semiovale were larger than in other brain regions. The spectral shape descriptor revealed a continuum of shapes with no evidence for distinct classes of lacunes. Shapes varied mostly in elongation and planarity. The main axis and plane of lacunes were found to align with the orientation of perforating arteries but not with fiber tracts.

CONCLUSIONS

Elongation and planarity are the primary shape principles of lacunes. Their main axis and plane align with perforating arteries. Our findings add to current concepts on the mechanisms of lacunes.

Infarct Size May Distinguish the Pathogenesis of Lacunar Infarction of the Middle Cerebral Artery Territory

Background

Lacunar infarctions are caused by small vessel disease (SVD) and branch atheromatous disease (BAD). Lacunar infarction may be classified as proximal vessel lacunar infarction (BAD) or distal vessel lacunar infarction (SVD) according to its location within the middle cerebral artery (MCA) territory in patients with normal MCA. Studies found that the lenticulostriate arteries may exist different ways and that the size of lacunar infarction may be dependent on the branching order. We investigated whether lacunar infarction size can differentiate between SVD and BAD in patients with normal MCA.

Material/Methods

We retrospectively studied 312 patients with lacunar infarction who had normal MCA on MR angiography. We found the normal flow void of the MCA on MR T2-weighted images, and the same layer on DWI was considered the level 0. The median of lowest layer of infarction lesions and the mean of lesion size were considered the cutoff point. We divided lacunar infarction into 2 groups according to cutoff point of lesion location and size. Data compared between the 2 groups included clinical information, radiography, and National Institutes of Health Stroke Scale score.

Results

Of all the 312 patients, the median of lowest layer of infarction lesions was the 3^rd level. Compared to patients with BAD, according to infarct location, patients with SVD were older, more often had a history of hypertension and smoking, and had more severe leukoaraiosis and smaller infarct lesions. The mean length of lesions was 11.1 mm on DWI images. Patients with SVD, according to infarct size, had lower NIHSS scores at admission. The mean lesion height was 12.26 mm on FLAIR images. Patients with SVD were more often male, had higher prevalence of smoking, and had more severe leukoaraiosis and lower NIHSS scores at admission. The lacunar infarction diameter on DWI and FLAIR images was negatively correlated with the level of lowest layer of infarction lesions.

Conclusions

Our data suggest that infarct lesion size may be used as a method to distinguish SVD and BAD in lacunar infarction patients with normal MCA.

Validity of shape as a predictive biomarker of final infarct volume in acute ischemic stroke

BACKGROUND AND PURPOSE

This study examines whether lesion shape documented on magnetic resonance diffusion-weighted imaging during acute stroke improves the prediction of the final infarct volume compared with lesion volume only.

METHODS

Diffusion-weighted imaging data and clinical information were retrospectively reviewed in 110 consecutive patients who underwent (n=67) or not (n=43) thrombolytic therapy for acute ischemic stroke. Three-dimensional shape analysis was performed on admission diffusion-weighted imaging data and 5 shape descriptors were developed. Final infarct volume was measured on T2-fluid-attenuated inversion recovery imaging data performed 30 days after stroke.

RESULTS

Shape analysis of acute ischemic lesion and more specifically the ratio of the bounding box volume to the lesion volume before thrombolytic treatment improved the prediction of the final infarct for patients undergoing thrombolysis (R(2)=0.86 in model with volume; R(2)=0.98 in model with volume and shape).

CONCLUSIONS

Our findings suggest that lesion shape contains important predictive information and reflects important environmental factors that might determine the progression of ischemia from the core.