Using Standardized Measures to Meet the Challenge of Stroke Assessment:

Pericyte Microvesicles as Plasma Biomarkers Reflecting Brain Microvascular Signaling in Patients With Acute Ischemic Stroke

BACKGROUND

Blood-based biomarkers have the potential to reflect cerebrovascular signaling after microvascular injury; yet, the detection of cell-specific signaling has proven challenging. Microvesicles retain parental cell surface antigens allowing detection of cell-specific signaling encoded in their cargo. In ischemic stroke, the progression of pathology involves changes in microvascular signaling whereby brain pericytes, perivascular cells wrapping the microcapillaries, are one of the early responders to the ischemic insult. Intercepting the pericyte signaling response peripherally by isolating pericyte-derived microvesicles may provide not only diagnostic information on microvascular injury but also enable monitoring of important pathophysiological mechanisms.

METHODS

Plasma samples were collected from patients with acute ischemic stroke (n=39) at 3 time points after stroke onset: 0 to 6 hours, 12 to 24 hours, and 2 to 6 days, and compared with controls (n=39). Pericyte-derived microvesicles were isolated based on cluster of differentiation 140b expression and quantified by flow cytometry. The protein content was evaluated using a proximity extension assay, and vascular signaling pathways were examined using molecular signature hallmarks and gene ontology.

RESULTS

In this case-control study, patients with acute ischemic stroke showed significantly increased numbers of pericyte-derived microvesicles (median, stroke versus controls) at 12 to 24 hours (1554 versus 660 microvesicles/μL; P=0.0041) and 2 to 6 days after stroke (1346 versus 660 microvesicles/μL; P=0.0237). Their proteome revealed anti-inflammatory properties mediated via downregulation of Kirsten rat sarcoma virus and IL (interleukin)-6/JAK/STAT3 signaling at 0 to 6 hours, but proangiogenic as well as proinflammatory signals at 12 to 24 hours. Between 2 and 6 days, proteins were mainly associated with vascular remodeling as indicated by activation of Hedgehog signaling in addition to proangiogenic signals.

CONCLUSIONS

We demonstrate that the plasma of patients with acute ischemic stroke reflects (1) an early and time-dependent increase of pericyte-derived microvesicles and (2) changes in the protein cargo of microvesicles over time indicating cell signaling specifically related to inflammation and vascular remodeling.

Relationship between Alcohol Intake and Stroke Severity in Japanese Patients: a Sex- and Subtype-Stratified Analysis

OBJECTIVES

This study aims to clarify the association between alcohol intake and stroke severity at admission and discharge according to sex and stroke subtype in Japanese patients with acute stroke.

MATERIALS AND METHODS

We analyzed the data of 199,599 patients registered in the Japan Stroke Data Bank from 1999 to 2018, including sex, age, stroke subtypes (cardioembolic ischemic, noncardioembolic ischemic, hypertensive hemorrhagic, nonhypertensive hemorrhagic, and subarachnoid hemorrhagic), dates of onset and admission, National Institutes of Health Stroke Scale score at admission, modified Rankin Scale score at discharge, and alcohol intake. Multivariable logistic regression analysis adjusted for stroke-related factors was performed to estimate the odds ratios of alcohol intake for stroke severity.

RESULTS

In cardioembolic ischemic stroke, a significant protective effect of moderate intake on severity at admission was observed in both sexes. In noncardioembolic ischemic stroke, a significant protective effect on stroke severity at admission was found for each sex. At discharge, the results also showed a significant protective effect for each sex with moderate intake. For both subtypes of ischemic stroke, a J-shaped relationship between alcohol intake and stroke severity at admission and discharge was observed in women and men. In hypertensive hemorrhagic stroke, a significant protective effect was found in men at both admission and discharge. In women, heavy drinking had a significant harmful effect on stroke severity at admission.

CONCLUSIONS

Habitual alcohol intake is associated with stroke severity at admission and discharge regardless of sex.

Incidence of aphasia in ischemic stroke

INTRODUCTION

A decrease in ischemic stroke (IS) incidence has been observed in high income countries during the last decades. Whether this has influenced the occurrence of aphasia in IS is uncertain. We therefore examined the incidence rate and potentially related determinants of aphasia in IS.

METHODS

We prospectively examined consecutive patients admitted to hospital with first-ever acute IS between 1 March 2017 and 28 February 2018 as part of the Lund Stroke Register (LSR) Study, comprising patients from the uptake area of Skåne University Hospital, Lund, Sweden. Patients were assessed with National Institutes of Health Stroke Scale (NIHSS) at stroke onset. Presence of aphasia was evaluated with NIHSS item 9 (language). We registered IS subtypes and risk factors. To investigate possible temporal changes in aphasia incidence, we made comparisons with corresponding LSR data from 2005-2006. Incidence rates were calculated and adjusted to the European Standard Population and to the Swedish population.

RESULTS

Among 308 included IS patients, 30% presented with aphasia (n=91; 95%CI: 25-35) a proportion of aphasia in IS that was similar to 2005-2006. The incidence rate of aphasia was 31 per 100 000 person-years adjusted to the European Standard Population (95%CI: 25-38 per 100 000 person-years) corresponding to a significant decrease of 30% between 2005-2006 and 2017-2018. The decrease was significantly more pronounced in men. The initial severity of aphasia remained unchanged, with the majority of patients having severe to global aphasia. No significant differences between vascular stroke risk factors were noted among stroke patients with or without aphasia.

CONCLUSION

Even though the overall IS incidence rate has decreased during the first decades of the 21st century, the proportion of IS patients with aphasia at stroke onset remains stable at 30%. Aphasia continues to be an important symptom that needs to be considered in stroke care and rehabilitation.

Lesion-symptom mapping with NIHSS sub-scores in ischemic stroke patients

Background

Lesion-symptom mapping (LSM) is a statistical technique to investigate the population-specific relationship between structural integrity and post-stroke clinical outcome. In clinical practice, patients are commonly evaluated using the National Institutes of Health Stroke Scale (NIHSS), an 11-domain clinical score to quantitate neurological deficits due to stroke. So far, LSM studies have mostly used the total NIHSS score for analysis, which might not uncover subtle structure–function relationships associated with the specific sub-domains of the NIHSS evaluation. Thus, the aim of this work was to investigate the feasibility to perform LSM analyses with sub-score information to reveal category-specific structure–function relationships that a total score may not reveal.

Methods

Employing a multivariate technique, LSM analyses were conducted using a sample of 180 patients with NIHSS assessment at 48-hour post-stroke from the ESCAPE trial. The NIHSS domains were grouped into six categories using two schemes. LSM was conducted for each category of the two groupings and the total NIHSS score.

Results

Sub-score LSMs not only identify most of the brain regions that are identified as critical by the total NIHSS score but also reveal additional brain regions critical to each function category of the NIHSS assessment without requiring extensive, specialised assessments.

Conclusion

These findings show that widely available sub-scores of clinical outcome assessments can be used to investigate more specific structure–function relationships, which may improve predictive modelling of stroke outcomes in the context of modern clinical stroke assessments and neuroimaging.

Trial registration number

NCT01778335.

Structural integrity of white matter tracts as a predictor of acute ischemic stroke outcome

BACKGROUND AND PURPOSE

Clinical assessment scores in acute ischemic stroke are only moderately correlated with lesion volume since lesion location is an important confounding factor. Many studies have investigated gray matter indicators of stroke severity, but the understanding of white matter tract involvement is limited in the early phase after stroke. This study aimed to measure and model the involvement of white matter tracts with respect to 24-h post-stroke National Institutes of Health Stroke Scale (NIHSS).

MATERIAL AND METHODS

A total of 96 patients (50 females, mean age 66.4 ± 14.0 years, median NIHSS 5, interquartile range: 2-9.5) with follow-up fluid-attenuated inversion recovery magnetic resonance imaging data sets acquired one to seven days after acute ischemic stroke onset due to proximal anterior circulation occlusion were included. Lesions were semi-automatically segmented and non-linearly registered to a common reference atlas. The lesion overlap and tract integrity were determined for each white matter tract in the AALCAT atlas and used to model NIHSS outcomes using a supervised linear-kernel support vector regression method, which was evaluated using leave-one-patient-out cross validation.

RESULTS

The support vector regression model using the tract integrity and tract lesion overlap measurements predicted the 24-h NIHSS score with a high correlation value of r = 0.7. Using the tract overlap and tract integrity feature improved the modeling accuracy of NIHSS significantly by 6% (p < 0.05) compared to using overlap measures only.

CONCLUSION

White matter tract integrity and lesion load are important predictors for clinical outcome after an acute ischemic stroke as measured by the NIHSS and should be integrated for predictive modeling.

Depressive symptoms in stroke patients treated and non-treated with intravenous thrombolytic therapy: a 1-year follow-up study

INTRODUCTION

This is a prospective study, first to compare the frequency of depressive symptoms in stroke survivors treated, and non-treated, with intravenous thrombolysis and second, to explore relationships between post-stroke depression (PSD) and stroke treatment modalities, taking into account other possible determinants of PSD, including post-traumatic stress symptoms.

METHODS

Groups of 73 thrombolysed and 73 non-thrombolysed patients matched for age and gender were examined at 3 and 12 months after discharge. PSD was assessed using the Beck Depression Inventory. Post-traumatic stress symptoms (PTSS), disability and social support were assessed with the Impact of Event Scale-Revised, the Barthel Index and the Berlin Social Support Scale.

RESULTS

At 3 months, PSD was present in 23.3% of the thrombolysed and 31.5% in the non-thrombolysed groups (p = 0.265). At 12 months, the frequencies were 29.2 and 20.6% (p = 0.229). Logistic regression of the combined group of thrombolysed and non-thrombolysed patients indicated that at 3 months, the adjusted predictors of PSD were disability (OR 24.35), presence of PTSS (OR 9.32), low social support (OR 3.68) and non-thrombolytic treatment (OR 3.19). At 12 months, the predictors were disability (OR 15.78) and low education (OR 3.61).

LIMITATIONS

The use of a questionnaire for the detection of depression, the relatively small sample size and a significant drop-out rate could limit the interpretation of these results.

CONCLUSIONS

(1) Thrombolysed and non-thrombolysed stroke survivors had similar frequency of depressive symptoms although the thrombolysed patients had more severe neurological deficits in the acute phase. It can be assumed that if thrombolysis had not been used, depressive symptoms would have been more frequent. (2) Lack of the rt-PA treatment was associated with three-time greater odds of screening for PSD at 3 months post-stroke, after adjustment for other PSD correlates. (3) Therefore, thrombolytic therapy seems to have a positive, but indirect, effect on patients' mood, especially in the first months after stroke. (4) All stroke patients, irrespective of the method of treatment, should be monitored for the presence of depression.

Validity of measures of neurological status used for predicting functional independence in adults after a cerebrovascular accident: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

Are the measures of neurologic status that are used in adults who have had a cerebrovascular accident valid in predicting functional independence?More specifically, the objective of this review is to assess the predictive validity of functional independence of the National Institutes of Health Stroke Scale and the Canadian Neurological Scale.

Spontaneous Recovery of Upper Extremity Motor Impairment After Ischemic Stroke: Implications for Stem Cell-Based Therapeutic Approaches

Preclinical studies suggest that stem cell therapy (SCT) may improve sensorimotor recovery after stroke. Upper extremity motor impairment (UEMI) is common after stroke, often entailing substantial disability. To evaluate the feasibility of post-stroke UEMI as a target for SCT, we examined a selected sample of stroke patients potentially suitable for SCT, aiming to assess the frequency and recovery of UEMI, as well as its relation to activity limitations and participation restrictions. Patients aged 20–75 years with first-ever ischemic stroke, and National Institutes of Health Stroke Scale (NIHSS) scores 1–18, underwent brain diffusion-weighted MRI within 4 days of stroke onset (n = 108). Survivors were followed up after 3–5 years, including assessment with NIHSS, Fugl-Meyer assessment of upper extremity (FMA-UE), modified Rankin Scale (mRS), and Stroke Impact Scale (SIS). UEMI was defined as NIHSS arm/hand score ≥1. UEMI recovery was evaluated with change in NIHSS arm/hand scores between baseline and follow-up. Of 97 survivors, 84 were available to follow-up. Among 76 subjects (of 84) without recurrent stroke, 41 had UEMI at baseline of which 10 had residual UEMI at follow-up. The FMA-UE showed moderate-severe impairment in seven of 10 survivors with residual UEMI. UEMI was correlated to mRS (r_s = 0.49, p < 0.001) and the SIS social participation domain (r_s = −0.38, p = 0.001). Nearly 25% of the subjects with UEMI at baseline had residual impairment after 3–5 years, whereas about 75% showed complete recovery. Most of the subjects with residual UEMI had moderate-severe impairment, which correlated strongly to dependency in daily activities and social participation restrictions. Our findings suggest that SCT targeting post-stroke UEMI may be clinically valuable with significant meaningful benefits for patients but also emphasize the need of early prognostication to detect patients that will have residual impairment in order to optimize patient selection for SCT.

Patterns of Emergency Medical Services Use and Its Association With Timely Stroke Treatment

Background—

Prior studies found that only about half of stroke patients arrived at hospitals via emergency medical services (EMSs), yet since then, there have been efforts to increase public awareness that time is brain. Using contemporary Get With the Guidelines-Stroke data, we assessed nationwide EMS use by stroke patients.

Methods and Results—

We analyzed data from 204 591 patients with ischemic and hemorrhagic stroke admitted to 1563 Get With the Guidelines-Stroke participating hospitals with data on National Institute of Health Stroke Score and insurance status. Hospital arrival by EMSs was observed in 63.7% of patients. Older patients, those with Medicaid and Medicare insurance, and those with severe stroke were more likely to activate EMSs. In contrast, minority race and ethnicity and living in rural communities were associated with decreased odds of EMS use. EMS transport was independently associated with earlier arrival (onset-to-door time, ≤3 hours; adjusted odds ratio, 2.00; 95% confidence interval, 1.93–2.08), prompter evaluation (more patients with door-to-imaging time, ≤25 minutes; odds ratio, 1.89; 95% confidence interval, 1.78–2.00), more rapid treatment (more patients with door-to-needle time, ≤60 minutes; odds ratio, 1.44; 95% confidence interval, 1.28–1.63), and more eligible patients to be treated with tissue-type plasminogen activator if onset is ≤2 hours (67% versus 44%; odds ratio, 1.47; 95% confidence interval, 1.33–1.64).

Conclusions—

Although EMS use is independently associated with more rapid evaluation and treatment of stroke, more than one third of stroke patients fail to use EMSs. Interventions aimed at increasing EMS activation should target populations at risk, particularly younger patients and those of minority race and ethnicity.

Training speech-language pathology graduate clinicians to administer the National Institutes of Health Stroke Scale

Aims

The National Institutes of Health Stroke Scale (NIHSS) is an 11-item assessment measuring the severity of an individual's stroke. Though neurologists, emergency room physicians, nurses, occupational therapists and physical therapists have completed the certification process for NIHSS administration, no study to date has examined whether speech-language pathologists (SLPs), or those in training, can be certified to administer the NIHSS. The aim of this study was to examine whether SLP graduate student-clinicians could be certified to administer the NIHSS.

Methods

Twenty student clinicians achieved Group A certification from the NIHSS training DVD, then were subsequently tested on NIHSS scoring for six patient vignettes from Group B of the training DVD.

Findings

No student achieved certification for the Group B patients.

Conclusions

The results of this study suggest that basic NIHSS training is not sufficient to ensure certification. In addition, the minimum requirements for NIHSS certification may not be adequate for any individual to reliably and accurately administer the scale. Measures to facilitate certification are discussed, including the need for extensive clinical exposure to stroke patients.