Vascular aphasia outcome after intravenous recombinant tissue plasminogen activator thrombolysis for ischemic stroke

What does cognitive screening reveal about early cognitive performance following endovascular clot retrieval and intravenous thrombolysis in acute ischaemic stroke?

Background Little is known regarding cognitive outcomes following treatment with endovascular clot retrieval (ECR) and intravenous tissue plasminogen activator (t-PA). We aimed to determine if there were any differences on a measure of cognitive screening between patients treated with ECR, t-PA, and those who were managed conservatively. Methods The medical records of ischaemic stroke patients admitted to Monash Medical Centre between January 2019 and December 2019 were retrospectively reviewed. Information extracted from medical records included age, sex, National Institutes of Health Stroke Scale at presentation, location of occlusion, treatment type, medical history, and cognitive screening performance measured by the Montreal Cognitive Assessment (MoCA). Results Eighty-two patients met the inclusion criteria (mean age = 66.5 ± 13.9; 49 male, 33 female). Patients treated with ECR performed significantly better on the MoCA (n  = 36, 24.1 ± 4.3) compared to those who were managed conservatively (n  = 26, 20.7 ± 5.5). Performance for patients treated with t-PA (n  = 20, 23.9 ± 3.5) fell between the ECR and conservative management groups, but they did not significantly differ from either. Conclusion Our retrospective chart review found that ischaemic stroke patients treated with ECR appear to perform better on cognitive screening compared to patients who are managed conservatively. We also found that patients treated with ECR and t-PA appear to have similar cognitive screening performances in the acute stages following ischaemic stroke, although this finding is likely to have been impacted by group differences in stroke characteristics and may reflect the possibility that the ECR group performed better than expected based on their stroke severity.

Intravenous Thrombolysis After First-Ever Ischemic Stroke and Reduced Incident Dementia Rate

BACKGROUND AND PURPOSE

The use of intravenous thrombolysis is associated with improved clinical outcomes. Whether thrombolysis is associated with reduced incidence of poststroke dementia remains uncertain. We sought to estimate if the use of thrombolysis following first-ever ischemic stroke was associated with a reduced rate of incident dementia using a pragmatic observational design.

METHODS

We included first-ever ischemic stroke patients from the Ontario Stroke Registry who had not previously been diagnosed with dementia. The primary outcome was incident dementia ascertained by a validated diagnostic algorithm. We employed inverse probability of treatment-weighted Cox proportional hazard models to estimate the cause-specific hazard ratio for the association of thrombolysis and incident dementia at 1 and 5 years following stroke.

RESULTS

From July 2003 to March 2013, 7072 patients with ischemic stroke were included, 3276 (46.3%) were female and mean age was 71.0 (SD, 12.8) years. Overall, 38.2% of the cohort (n=2705) received thrombolysis, 77.2% (n=2087) of which was administered within 3 hours of stroke onset. In the first year following stroke, thrombolysis administration was associated with a 24% relative reduction in the rate of developing dementia (cause-specific hazard ratio, 0.76 [95% CI, 0.58-0.97]). This association remained significant at 5 years (cause-specific hazard ratio, 0.79 [95% CI, 0.66-0.91]) and at the end of follow-up (median 6.3 years; cause-specific hazard ratio, 0.79 [95% CI, 0.68-0.89]).

CONCLUSIONS

Thrombolysis administration following first-ever ischemic stroke was independently associated with a reduced rate of dementia. Incident dementia should be considered as a relevant outcome when evaluating risk/benefit of thrombolysis in ischemic stroke patients.

Association Between Early Cognitive Impairment and Midterm Functional Outcomes Among Chinese Acute Ischemic Stroke Patients: A Longitudinal Study

Background: Cognitive decline is common after stroke. The influence of early cognitive impairment on midterm functional outcomes among Chinese acute ischemic stroke (AIS) patients has not been fully studied. The aim of the study was to assess the association between early cognitive impairment and midterm functional outcomes among Chinese AIS patients.

Methods: A longitudinal survey focusing on Chinese AIS patients was conducted in three stroke centers in Shanghai, China (July to December 2016). A total of 185 eligible patients were interviewed at acute stage and at 1, 3, and 6 months after onset. Patients' functional outcomes were measured by modified Rankin Scale (mRS) and Barthel Index (BI) at each time point. Cognitive function was assessed using Montreal Cognitive Assessment, Changsha version (MoCA-CS), within 7 days after stroke onset. Covariates included patient's demographic characteristics, socioeconomic status, clinical characteristics of stroke, vascular risk factors, receiving rehabilitation after discharge from acute hospital, and recurrence. Generalized linear mixed models and general linear mixed models were applied.

Results: The prevalence of cognitive impairment at acute stage of stroke among these patients was 88.1%. The risk of disability (mRS 2–5) of all patients after stroke decreased over time (OR = 0.491, 95% CI = 0.401–0.603). The risk of disability among those with cognitive impairment increased compared with those with normal cognition (OR = 7.384, 95% CI = 1.041–52.407). The BI score of all patients increased over time after controlling for covariates (β = 1.51, p < 0.01). The BI score of those with cognitive impairment was lower than that with normal cognition over the follow-up period after controlling for other covariates (β = −8.11, p < 0.05).

Conclusions: This study showed that early cognitive impairment was associated with higher risk of disability and poor activity of daily living (ADL) among Chinese AIS patients. Further studies are needed to examine the linkage between multi-domain cognitive impairment and long-term disability and ADL among stroke survivors by using neuropsychological test batteries.

Aphasia and reperfusion therapies in hyper-acute settings: A scoping review

Purpose: Reperfusion therapies are medical treatments that restore blood flow either by surgical removal of a blood clot or with medications that dissolve clots. The introduction of reperfusion therapies has the potential to change the presentation of aphasia following acute ischaemic stroke (AIS). This scoping study will explore the relationship between aphasia and reperfusion therapies from a speech-language pathology perspective. Method: A systematic literature search was performed on studies published up until October 2016. Relevant studies that reported on aphasia and reperfusion therapy were assessed for quality and the relationship between the two. Results: Overall, 27 studies were identified, these studies were heterogeneous in nature. Despite speech-language pathologists filling a central role in management of aphasia, only seven of these studies mentioned involvement of speech-language pathologists, with minimal information about the precise nature of the involvement of speech-language pathology services. Conclusion: Based on this scoping review, reperfusion therapy appears to be impacting on the presentation of aphasia. A prospective study into reperfusion therapy and aphasia is required to inform speech-language pathologists on this patient population.

Imaging network level language recovery after left PCA stroke

Purpose: The neural mechanisms that support aphasia recovery are not yet fully understood. Our goal was to evaluate longitudinal changes in naming recovery in participants with posterior cerebral artery (PCA) stroke using a case-by-case analysis.

Methods: Using task based and resting state functional magnetic resonance imaging (fMRI) and detailed language testing, we longitudinally studied the recovery of the naming network in four participants with PCA stroke with naming deficits at the acute (0 week), sub acute (3–5 weeks), and chronic time point (5–7 months) post stroke. Behavioral and imaging analyses (task related and resting state functional connectivity) were carried out to elucidate longitudinal changes in naming recovery.

Results: Behavioral and imaging analysis revealed that an improvement in naming accuracy from the acute to the chronic stage was reflected by increased connectivity within and between left and right hemisphere “language” regions. One participant who had persistent moderate naming deficit showed weak and decreasing connectivity longitudinally within and between left and right hemisphere language regions.

Conclusions: These findings emphasize a network view of aphasia recovery, and show that the degree of inter- and intra- hemispheric balance between the language-specific regions is necessary for optimal recovery of naming, at least in participants with PCA stroke.

Recovery of orthographic processing after stroke: A longitudinal fMRI study

An intact orthographic processing system is critical for normal reading and spelling. Here we investigate the neural changes associated with impairment and subsequent recovery of the orthographic lexical processing system in an individual with an ischemic left posterior cerebral artery (PCA) stroke. This work describes a longitudinal case study of a patient, whose initials are MMY, with impairments in orthographic lexical processing for reading and spelling at stroke onset, and who recovered these skills within 1 year post stroke. We tested the hypothesis that this acute impairment to reading and spelling would be associated with a selective loss of neural activation in the left fusiform gyrus (FG), and that subsequent recovery would be associated with a gain of neural activation in this region. MMY's case provided a unique opportunity to assess the selectivity of neural changes because she demonstrated a behavioral recovery of naming as well; i.e., if there is neural recovery for reading and spelling, but not naming, then these neural changes are selective to the recovery of orthographic processing. To test our hypothesis, we examined longitudinal behavioral and functional magnetic resonance imaging (fMRI) data of reading, spelling, and visual object naming acquired acutely, 3 weeks, 5 months, and one year post stroke. In confirmation of our hypothesis, the loss and subsequent gain of orthographic lexical processing was associated with up-regulation of neural activation in areas previously associated with orthographic lexical processing: i.e., the left mid-FG and inferior frontal junction (IFJ). Furthermore, these neural changes were found to be selective to orthographic processing, as they were observed for reading and spelling, but not for visual object naming within the left mid-FG. This work shows that left PCA stroke can temporarily and selectively disrupt the orthographic lexical processing system, not only in the posterior region adjacent to the stroke, but also in relatively distant frontal orthographic processing regions.

Language improvement one week after thrombolysis in acute stroke

OBJECTIVES

Language recovery following acute stroke is difficult to predict due to several evaluation factors and time constraints. We aimed to investigate the predictors of aphasia recovery and to identify the National Institute of Health and Stroke Scale (NIHSS) items that best reflect linguistic performance, 1 week after thrombolysis.

MATERIALS AND METHODS

We retrieved data from a prospective registry of patients with aphasia secondary to left middle cerebral artery (MCA) stroke treated with intravenous thrombolysis. Complete recovery at day 7 (D7) was measured in a composite verbal score (CVS) (Σ Language+Questions+Commands NIHSS scores). Lesion size was categorized by the Alberta Stroke Program Early CT score (ASPECTS) and vascular patency by ultrasound. CVS was correlated with standardized aphasia testing if both were performed within a two-day interval.

RESULTS

Of 228 patients included (age average 67.32 years, 131 men), 72% presented some language improvement that was complete in 31%. Total recovery was predicted by ASPECTS (OR=1.65; 95% CI, 1.295-2.108; P < 0.00) and baseline aphasia severity (OR=0.439; 95% CI, 0.242-0.796; P < 0.007). CVS correlated better with standardized aphasia measures (aphasia quotient, severity, comprehension) than NIHSS_Language item.

CONCLUSIONS

Lesion size and initial aphasia severity are the main predictors of aphasia recovery one week after thrombolysis. A NIHSS composite verbal score seems to capture the global linguistic performance better than the language item alone.

Cognitive Outcomes following Thrombolysis in Acute Ischemic Stroke: A Systematic Review

BACKGROUND

Patients treated with thrombolytic therapy within 4.5 hours after stroke onset appear to have improved survival and functional outcomes. Poststroke cognitive impairment is associated with reduced quality of life and survival and needs to be reviewed in consideration of the administration of thrombolysis. This review aims to systematically evaluate literature exploring the effect of thrombolysis for ischemic stroke on cognition.

METHODS

An electronic search was conducted to identify articles and gray literature applying broad Medical Subject Heading terms. Literature was reviewed with a 2-step process against predetermined inclusion criteria. All relevant studies were included if they investigated global or individual cognitive domains.

RESULTS

Three studies satisfied the inclusion criteria but were diverse in outcome measures and duration, their heterogeneity limiting any possible pooled analysis. One study examined long-term treatment effects on global cognition and did not find a positive effect at 6 months. A positive treatment effect was reported in the acute phase in 1 study examining domains of visuoconstructive and perceptive abilities. One study retrospectively analyzed treatment effects on language and found improvement in the acute phase but not in the long term.

CONCLUSIONS

The limited existing evidence on the effects of thrombolytic therapy on long- and short-term cognition is varied in both outcome measures and diagnostic classifications, making it difficult to extrapolate results to a global stroke population. This review should be used to inform future research in stroke treatment outcomes and highlights the immediate need for larger, more robust studies in this area.