Combining Early Ischemic Change and Collateral Extent for Functional Outcomes After Endovascular Therapy: An Analysis From AcT Trial.

BACKGROUND: Early ischemic change and collateral extent are colinear with ischemic core volume (ICV). We investigated the relationship between a combined score using the Alberta Stroke Program Early Computed Tomography Score and multiphase computed tomography angiography (mCTA) collateral extent, named mCTA-ACE score, on functional outcomes in endovascular therapy-treated patients. METHODS: We performed a post hoc analysis of a subset of endovascular therapy-treated patients from the Alteplase Compared to Tenecteplase trial which was conducted between December 2019 and January 2022 at 22 centers across Canada. Ten-point mCTA collateral corresponding to M2 to M6 regions of the Alberta Stroke Program Early Computed Tomography Score grid was evaluated as 0 (poor), 1 (moderate), or 2 (normal) and additively combined with the 10-point Alberta Stroke Program Early Computed Tomography Score to produce a 20-point mCTA-ACE score. We investigated the association of mCTA-ACE score with modified Rankin Scale score ≤2 and return to prestroke level of function at 90 to 120 days using mixed-effects logistic regression. In the subset of patients who underwent baseline computed tomography perfusion imaging, we compared the mCTA-ACE score and ICV for outcome prediction. RESULTS: Among 1577 intention-to-treat population in the trial, 368 (23%; 179 men; median age, 73 years) were included, with Alberta Stroke Program Early Computed Tomography Score, mCTA collateral, and combination of both (mCTA-ACE score: median [interquartile range], 8 [7-10], 9 [8-10], and 17 [16-19], respectively). The probability of modified Rankin scale score ≤2 and return to prestroke level of function increased for each 1-point increase in mCTA-ACE score (odds ratio, 1.16 [95% CI, 1.06-1.28] and 1.22 [95% CI, 1.06-1.40], respectively). Among 173 patients in whom computed tomography perfusion data was assessable, the mCTA-ACE score was inversely correlated with ICV (ρ=-0.46; P<0.01). The mCTA-ACE score was comparable to ICV to predict a modified Rankin scale score ≤2 and return to prestroke level of function (C statistics 0.71 versus 0.69 and 0.68 versus 0.64, respectively). CONCLUSIONS: The mCTA-ACE score had a significant positive association with functional outcomes after endovascular therapy and had a similar predictive performance as ICV.

Effect of Endovascular Thrombectomy for Acute Ischemic Stroke on Cognitive Outcomes: A Secondary Analysis of the ESCAPE Trial.

BACKGROUND AND OBJECTIVES: The effect of endovascular therapy (EVT) for large vessel occlusion stroke on cognitive outcomes is not well understood. We evaluated the effect of EVT on cognitive function in the Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE) trial. METHODS: Patient data from the ESCAPE randomized trial were analyzed. Cognitive assessments completed at 90 days after stroke were the Montreal Cognitive Assessment (MoCA), the Sunnybrook Neglect Assessment Procedure (SNAP), the Boston Naming Test (BNT), Trail-making test A (Trails A), and Trail-making test B (Trails B). We used logistic regression to evaluate the association between EVT and favorable cognitive outcome on the 5 separate tests, adjusting for demographic and clinical factors. We used generalized estimating equations and ordinal regression to determine the odds of favorable outcome with EVT on global cognition incorporating the 5 tests. We added final infarct volume (FIV) to the models to assess the relationship of FIV with cognitive outcome. RESULTS: The ESCAPE trial included 315 patients, 165 randomized to EVT and 150 randomized to control. There was higher odds of favorable outcome with EVT for MoCA (adjusted odds ratio [aOR] 2.32, 95% CI 1.30-4.16), SNAP (aOR 3.85, 95% CI 2.00-7.45), BNT (aOR 2.33, 95% CI 1.30-4.17), trails A (aOR 3.50, 95% CI 1.93-6.36), and trails B (aOR 2.56, 95% CI 1.46-4.48). There was higher odds of favorable outcome with EVT on global binary (aOR 2.57, 95% CI 1.67-3.94) and ordinal analyses (aOR 2.83, 95% CI 1.68-4.76) of cognitive function. After adding FIV to the models, both FIV and EVT were significantly associated with cognitive outcome. There was a significant correlation between global cognitive performance and mRS at day 90 (r = -0.78, p < 0.001), with the largest reductions in favorable cognitive outcome from mRS score 4 to 5 and from mRS 2 to 3. DISCUSSION: In this secondary analysis of the ESCAPE trial, EVT was associated with favorable outcome on 5 separate cognitive tests and in global analyses of cognitive benefit. These results provide novel evidence for the effect of EVT on cognition and support the global benefit of treatment with EVT. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with acute ischemic stroke due to intracranial internal carotid artery (ICA) or M1 segment MCA occlusion, including tandem extracranial ICA occlusions, EVT compared with best medical therapy increased odds of favorable cognitive outcome.

Link among apolipoprotein E E4, gait, and cognition in neurodegenerative diseases: ONDRI study.

INTRODUCTION: Apolipoprotein E E4 allele (APOE E4) and slow gait are independently associated with cognitive impairment and dementia. However, it is unknown whether their coexistence is associated with poorer cognitive performance and its underlying mechanism in neurodegenerative diseases. METHODS: Gait speed, APOE E4, cognition, and neuroimaging were assessed in 480 older adults with neurodegeneration. Participants were grouped by APOE E4 presence and slow gait. Mediation analyses were conducted to determine if brain structures could explain the link between these factors and cognitive performance. RESULTS: APOE E4 carriers with slow gait had the lowest global cognitive performance and smaller gray matter volumes compared to non-APOE E4 carriers with normal gait. Coexistence of APOE E4 and slow gait best predicted global and domain-specific poorer cognitive performances, mediated by smaller gray matter volume. DISCUSSION: Gait slowness in APOE E4 carriers with neurodegenerative diseases may indicate extensive gray matter changes associated with poor cognition. HIGHLIGHTS: APOE E4 and slow gait are risk factors for cognitive decline in neurodegenerative diseases. Slow gait and smaller gray matter volumes are associated, independently of APOE E4. Worse cognition in APOE E4 carriers with slow gait is explained by smaller GM volume. Gait slowness in APOE E4 carriers indicates poorer cognition-related brain changes.

Neuropsychiatric symptoms and brain morphology in patients with mild cognitive impairment, cerebrovascular disease and Parkinson disease: A cross sectional and longitudinal study.

OBJECTIVES: Neuropsychiatric symptoms (NPS) increase risk of developing dementia and are linked to various neurodegenerative conditions, including mild cognitive impairment (MCI due to Alzheimer's disease [AD]), cerebrovascular disease (CVD), and Parkinson's disease (PD). We explored the structural neural correlates of NPS cross-sectionally and longitudinally across various neurodegenerative diagnoses. METHODS: The study included individuals with MCI due to AD, (n = 74), CVD (n = 143), and PD (n = 137) at baseline, and at 2-years follow-up (MCI due to AD, n = 37, CVD n = 103, and PD n = 84). We assessed the severity of NPS using the Neuropsychiatric Inventory Questionnaire. For brain structure we included cortical thickness and subcortical volume of predefined regions of interest associated with corticolimbic and frontal-executive circuits. RESULTS: Cross-sectional analysis revealed significant negative correlations between appetite with both circuits in the MCI and CVD groups, while apathy was associated with these circuits in both the MCI and PD groups. Longitudinally, changes in apathy scores in the MCI group were negatively linked to the changes of the frontal-executive circuit. In the CVD group, changes in agitation and nighttime behavior were negatively associated with the corticolimbic and frontal-executive circuits, respectively. In the PD group, changes in disinhibition and apathy were positively associated with the corticolimbic and frontal-executive circuits, respectively. CONCLUSIONS: The observed correlations suggest that underlying pathological changes in the brain may contribute to alterations in neural activity associated with MBI. Notably, the difference between cross-sectional and longitudinal results indicates the necessity of conducting longitudinal studies for reproducible findings and drawing robust inferences.

Sex-Based Analysis of Workflow and Outcomes in Acute Ischemic Stroke Patients Treated With Alteplase Versus Tenecteplase.

BACKGROUND: Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase). METHODS: AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes. RESULTS: Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes. CONCLUSIONS: Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Infarct Evolution on MR-DWI After Thrombectomy in Acute Stroke Patients Randomized to Nerinetide or Placebo: The REPERFUSE-NA1 Study

BACKGROUND AND OBJECTIVES: The neuroprotectant nerinetide has shown promise in reducing infarct volumes in primate models of ischemia reperfusion. We hypothesized that early secondary infarct growth after endovascular therapy (EVT) (1) may be a suitable surrogate biomarker for testing neuroprotective compounds, (2) is feasible to assess in the acute setting using sequential MRI, and (3) can be modified by treatment with nerinetide. METHODS: REPERFUSE-NA1 was a prospective, multisite MRI substudy of the randomized controlled trial ESCAPE-NA1 (ClinicalTrials.gov NCT02930018) that involved patients with acute disabling large vessel occlusive stroke undergoing EVT within 12 hours of onset who were randomized to receive intravenous nerinetide or placebo. Patients enrolled in REPERFUSE-NA1 underwent sequential MRI <5 hours post-EVT (day 1) and at 24 hours (day 2). The primary outcome was total diffusion-weighted MRI infarct growth early after EVT, defined as the lesion volume difference between day 2 and day 1. The secondary outcome was region-specific infarct growth in different brain tissue compartments. Statistical analyses were performed using the Mann-Whitney U test and multiple linear regression. RESULTS: Sixty-seven of 71 patients included had MRI of sufficient quality. The median infarct volume post-EVT was 12.98 mL (IQR, 5.93-28.08) in the nerinetide group and 10.80 mL (IQR, 3.11-24.45) in the control group (p = 0.59). Patients receiving nerinetide showed a median early secondary infarct growth of 5.92 mL (IQR, 1.09-21.30) compared with 10.80 mL (interquartile range [IQR], 2.54-21.81) in patients with placebo (p = 0.30). Intravenous alteplase modified the effect of nerinetide on region-specific infarct growth in white matter and basal ganglia compartments. In patients with no alteplase, the infarct growth rate was reduced by 120% (standard error [SE], 60%) in the white matter (p = 0.03) and by 340% (SE, 140%) in the basal ganglia (p = 0.02) in the nerinetide group compared with placebo after adjusting for confounders. DISCUSSION: This study highlights the potential of using MR imaging as a biomarker to estimate the effect of a neuroprotective agent in acute stroke treatment. Patients with acute large vessel occlusive stroke exhibited appreciable early infarct growth both in the gray matter and the white matter after undergoing EVT. Acknowledging relatively small overall infarct volumes in this study, treatment with nerinetide was associated with slightly reduced percentage infarct growth in the white matter and basal ganglia compared with placebo in patients not receiving intravenous alteplase and had no effect on the total early secondary infarct growth. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov NCT02930018. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with acute large vessel ischemic stroke undergoing EVT, nerinetide did not significantly decrease early post-EVT infarct growth compared with placebo.

Intravenous tenecteplase compared with alteplase for minor ischaemic stroke: a secondary analysis of the AcT randomised clinical trial.

BACKGROUND: In ischaemic stroke, minor deficits (National Institutes of Health Stroke Scale (NIHSS) ≤5) at presentation are common but often progress, leaving patients with significant disability. We compared the efficacy and safety of intravenous thrombolysis with tenecteplase versus alteplase in patients who had a minor stroke enrolled in the Alteplase Compared to Tenecteplase in Patients With Acute Ischemic Stroke (AcT) trial. METHODS: The AcT trial included individuals with ischaemic stroke, aged >18 years, who were eligible for standard-of-care intravenous thrombolysis. Participants were randomly assigned 1:1 to intravenous tenecteplase (0.25 mg/kg) or alteplase (0.9 mg/kg). Patients with minor deficits pre-thrombolysis were included in this post-hoc exploratory analysis. The primary efficacy outcome was the proportion of patients with a modified Rankin Score (mRS) of 0-1 at 90-120 days. Safety outcomes included mortality and symptomatic intracranial haemorrhage (sICH). RESULTS: Of the 378 patients enrolled in AcT with an NIHSS of ≤5, the median age was 71 years, 39.7% were women; 194 (51.3%) received tenecteplase and 184 (48.7%) alteplase. The primary outcome (mRS score 0-1) occurred in 100 participants (51.8%) in the tenecteplase group and 86 (47.5 %) in the alteplase group (adjusted risk ratio (RR) 1.14 (95% CI 0.92 to 1.40)). There were no significant differences in the rates of sICH (2.9% in tenecteplase vs 3.3% in alteplase group, unadjusted RR 0.79 (0.24 to 2.54)) and death within 90 days (5.5% in tenecteplase vs 11% in alteplase group, adjusted HR 0.99 (95% CI 0.96 to 1.02)). CONCLUSION: In this post-hoc analysis of patients with minor stroke enrolled in the AcT trial, safety and efficacy outcomes with tenecteplase 0.25 mg/kg were not different from alteplase 0.9 mg/kg.

Advance Consent in Acute Stroke Trials: Survey of Canadian Stroke Physicians.

Advance consent presents a potential solution to the challenge of obtaining informed consent for participation in acute stroke trials. Clinicians in stroke prevention clinics are uniquely positioned to identify and seek consent from potential stroke trial participants. To assess the acceptability of advance consent to Canadian stroke clinic physicians, we performed an online survey. We obtained 58 respondents (response rate 35%): the vast majority (82%) expressed comfort with obtaining advance consent and 92% felt that doing so would not be a significant disruption to clinic workflow. These results support further study of advance consent for acute stroke trials.

Advance Consent in Acute Stroke Trials: Survey of Canadian Research Ethics Board Chairs.

Advance consent could allow individuals at high risk of stroke to provide consent before they might become eligible for enrollment in acute stroke trials. This survey explores the acceptability of this novel technique to Canadian Research Ethics Board (REB) chairs that review acute stroke trials. Responses from 15 REB chairs showed that majority of respondents expressed comfort approving studies that adopt advance consent. There was no clear preference for advance consent over deferral of consent, although respondents expressed significant concern with broad rather than trial-specific advance consent. These findings shed light on the acceptability of advance consent to Canadian ethics regulators.

Safety and efficacy of tenecteplase versus alteplase in stroke patients with carotid tandem lesions: Results from the AcT trial.

BACKGROUND: Carotid tandem lesions ((TL) ⩾70% stenosis or occlusion) account for 15-20% of acute stroke with large vessel occlusion. AIMS: We investigated the safety and efficacy of intravenous tenecteplase (0.25 mg/kg) versus intravenous alteplase (0.9 mg/kg) in patients with carotid TL. METHODS: This is a substudy of the alteplase compared with the tenecteplase trial. Patients with ⩾70% stenosis of the extracranial internal carotid artery (ICA) and concomitant occlusion of the intracranial ICA, M1 or M2 segments of the middle cerebral artery on baseline computed tomography angiography (CTA) were included. Primary outcome was 90-day-modified Rankin Scale (mRS) 0-1. Secondary outcomes were mRS 0-2, mortality, and symptomatic ICH (sICH). Angiographic outcomes were successful recanalization (revised Arterial Occlusive Lesion (rAOL) 2b-3) on first and successful reperfusion (eTICI 2b-3) on final angiographic acquisitions. Multivariable mixed-effects logistic regression was performed. RESULTS: Among 1577 alteplase versus tenecteplase randomized controlled trial (AcT) patients, 128 (18.8%) had carotid TL. Of these, 93 (72.7%) underwent intravenous thrombolysis plus endovascular thrombectomy (IVT + EVT), while 35 (27.3%) were treated with IVT alone. In the IVT + EVT group, tenecteplase was associated with higher odds of 90-day-mRS 0-1 (46.0% vs. 32.6%, adjusted OR (aOR) 3.21; 95% CI = 1.06-9.71) compared with alteplase. No statistically significant differences in rates of mRS 0-2 (aOR 1.53; 95% CI = 0.51-4.55), initial rAOL 2b-3 (16.3% vs. 28.6%), final eTICI 2b-3 (83.7% vs. 85.7%), and mortality (18.0% vs. 16.3%) were found. SICH only occurred in one patient. There were no differences in outcomes between thrombolytic agents in the IVT-only group. CONCLUSION: In patients with carotid TL treated with EVT, intravenous tenecteplase may be associated with similar or better clinical outcomes, similar angiographic reperfusion rates, and safety outcomes as compared with alteplase.

Association of plasma biomarkers with cognition, cognitive decline, and daily function across and within neurodegenerative diseases: Results from the Ontario Neurodegenerative Disease Research Initiative.

INTRODUCTION: We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases. METHODS: Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aß)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD). RESULTS: GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aß42/40 . DISCUSSION: GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.

Sex Differences in Obstructive Sleep Apnea after Stroke.

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea (OSA) is prevalent after stroke and associated with recurrent stroke, prolonged hospitalization, and decreased functional recovery. Sex differences in post-stroke OSA remain underexplored. The objective of this study was to evaluate sex differences in functional outcomes, stroke and OSA severity, and clinical manifestations of OSA in stroke patients with OSA. METHODS: We retrospectively evaluated data from three previously conducted studies. Study patients had an imaging-confirmed stroke and had been found to have OSA (apnea-hypopnea index [AHI] ≥ 5) on either in-laboratory polysomnography or home sleep apnea testing performed within 1 year of their stroke. Linear regression models were used to evaluate study outcomes. RESULTS: In total, 171 participants with post-stroke OSA (117 males [68.4%] and 54 females [31.6%]) were included. Female sex was an independent predictor for greater functional impairment (ß = 0.37, 95% CI 0.029-0.71, p = 0.03), increased stroke severity (ß = 1.009, 95% CI 0.032-1.99, p = 0.04), and greater post-stroke depressive symptoms (ß = 3.73, 95% CI 0.16-7.29, p = 0.04). Female sex was associated with lower OSA severity, as measured by the AHI (ß = -5.93, 95% CI -11.21- -0.66). Sex was not an independent predictor of specific symptoms of OSA such as daytime sleepiness, snoring, tiredness, and observed apneas. CONCLUSION: Females with post-stroke OSA had poorer functional outcomes and more severe strokes compared to males, despite having lower OSA severity. Females with post-stroke OSA also exhibited more depressive symptoms. Understanding sex differences in patients with post-stroke OSA will likely facilitate better recognition of OSA and potentially improve clinical outcomes.

Effect of Time to Thrombolysis on Clinical Outcomes in Patients With Acute Ischemic Stroke Treated With Tenecteplase Compared to Alteplase: Analysis From the AcT Randomized Controlled Trial.

BACKGROUND: The AcT (Alteplase Compared to Tenecteplase) randomized controlled trial showed that tenecteplase is noninferior to alteplase in treating patients with acute ischemic stroke within 4.5 hours of symptom onset. The effect of time to treatment on clinical outcomes with alteplase is well known; however, the nature of this relationship is yet to be described with tenecteplase. We assessed whether the association of time to thrombolysis treatment with clinical outcomes in patients with acute ischemic stroke differs by whether they receive intravenous tenecteplase versus alteplase. METHODS: Patients included were from AcT, a pragmatic, registry-linked, phase 3 randomized controlled trial comparing intravenous tenecteplase to alteplase in patients with acute ischemic stroke. Eligible patients were >18 years old, with disabling neurological deficits, presenting within 4.5 hours of symptom onset, and eligible for thrombolysis. Primary outcome was modified Rankin Scale score 0 to 1 at 90 days. Safety outcomes included 24-hour symptomatic intracerebral hemorrhage and 90-day mortality rates. Mixed-effects logistic regression was used to assess the following: (a) the association of stroke symptom onset to needle time; (b) door (hospital arrival) to needle time with outcomes; and (c) if these associations were modified by type of thrombolytic administered (tenecteplase versus alteplase), after adjusting for age, sex, baseline stroke severity, and site of intracranial occlusion. RESULTS: Of the 1538 patients included in this analysis, 1146 (74.5%; 591 tenecteplase and 555 alteplase) presented within 3 hours versus 392 (25.5%; 196: TNK and 196 alteplase) who presented within 3 to 4.5 hours of symptom onset. Baseline patient characteristics in the 0 to 3 hours versus 3- to 4.5-hour time window were similar, except patients in the 3- to 4.5-hour window had lower median baseline National Institutes of Health Stroke Severity Scale (10 versus 7, respectively) and lower proportion of patients with large vessel occlusion on baseline CT angiography (26.9% versus 18.7%, respectively). Type of thrombolytic agent (tenecteplase versus alteplase) did not modify the association between continuous onset to needle time (Pinteraction=0.161) or door-to-needle time (Pinteraction=0.972) and primary clinical outcome. Irrespective of the thrombolytic agent used, each 30-minute reduction in onset to needle time was associated with a 1.8% increase while every 10 minutes reduction in door-to-needle time was associated with a 0.2% increase in the probability of achieving 90-day modified Rankin Scale score 0 to 1, respectively. CONCLUSIONS: The effect of time to tenecteplase administration on clinical outcomes is like that of alteplase, with faster administration resulting in better clinical outcomes. REGISTRATION: URL: https://classic. CLINICALTRIALS: gov; Unique identifier: NCT03889249.

Perivascular spaces mediate a relationship between diabetes and other cerebral small vessel disease markers in cerebrovascular and neurodegenerative diseases.

Type 2 diabetes mellitus (T2DM) and hypertension are risk factors for cerebral small vessel disease (SVD); however, few studies have characterised their relationships with MRI-visible perivascular spaces (PVS). MRI was used to quantify deep (d) and periventricular (p) white matter hyperintensities (WMH), lacunes, PVS in the white matter (wmPVS) or basal ganglia (bgPVS), and diffusion metrics in white matter. Patients with T2DM had greater wmPVS volume and there were greater wmPVS volumes in patients with T2DM and hypertension together. Counterfactual moderated mediation models found indirect effects of T2DM on volumes of other SVD and diffusion markers that were mediated by wmPVS: pWMH, dWMH, periventricular lacunes, and deep lacunes, and progression of deep lacunes over 1 year, in patients with hypertension, but not in patients without hypertension. Studying the regulation of cortical perivascular fluid dynamics may reveal mechanisms that mediate the impact of T2DM on cerebral small vessels.

ROOD-MRI: Benchmarking the robustness of deep learning segmentation models to out-of-distribution and corrupted data in MRI.

Deep artificial neural networks (DNNs) have moved to the forefront of medical image analysis due to their success in classification, segmentation, and detection challenges. A principal challenge in large-scale deployment of DNNs in neuroimage analysis is the potential for shifts in signal-to-noise ratio, contrast, resolution, and presence of artifacts from site to site due to variances in scanners and acquisition protocols. DNNs are famously susceptible to these distribution shifts in computer vision. Currently, there are no benchmarking platforms or frameworks to assess the robustness of new and existing models to specific distribution shifts in MRI, and accessible multi-site benchmarking datasets are still scarce or task-specific. To address these limitations, we propose ROOD-MRI: a novel platform for benchmarking the Robustness of DNNs to Out-Of-Distribution (OOD) data, corruptions, and artifacts in MRI. This flexible platform provides modules for generating benchmarking datasets using transforms that model distribution shifts in MRI, implementations of newly derived benchmarking metrics for image segmentation, and examples for using the methodology with new models and tasks. We apply our methodology to hippocampus, ventricle, and white matter hyperintensity segmentation in several large studies, providing the hippocampus dataset as a publicly available benchmark. By evaluating modern DNNs on these datasets, we demonstrate that they are highly susceptible to distribution shifts and corruptions in MRI. We show that while data augmentation strategies can substantially improve robustness to OOD data for anatomical segmentation tasks, modern DNNs using augmentation still lack robustness in more challenging lesion-based segmentation tasks. We finally benchmark U-Nets and vision transformers, finding robustness susceptibility to particular classes of transforms across architectures. The presented open-source platform enables generating new benchmarking datasets and comparing across models to study model design that results in improved robustness to OOD data and corruptions in MRI.

Safety and Efficacy of Tenecteplase Compared With Alteplase in Patients With Large Vessel Occlusion Stroke: A Prespecified Secondary Analysis of the ACT Randomized Clinical Trial.

Importance: It is unknown whether intravenous thrombolysis using tenecteplase is noninferior or preferable compared with alteplase for patients with acute ischemic stroke. Objective: To examine the safety and efficacy of tenecteplase compared to alteplase among patients with large vessel occlusion (LVO) stroke. Design, Setting, and Participants: This was a prespecified analysis of the Intravenous Tenecteplase Compared With Alteplase for Acute Ischaemic Stroke in Canada (ACT) randomized clinical trial that enrolled patients from 22 primary and comprehensive stroke centers across Canada between December 10, 2019, and January 25, 2022. Patients 18 years and older with a disabling ischemic stroke within 4.5 hours of symptom onset were randomly assigned (1:1) to either intravenous tenecteplase or alteplase and were monitored for up to 120 days. Patients with baseline intracranial internal carotid artery (ICA), M1-middle cerebral artery (MCA), M2-MCA, and basilar occlusions were included in this analysis. A total of 1600 patients were enrolled, and 23 withdrew consent. Exposures: Intravenous tenecteplase (0.25 mg/kg) vs intravenous alteplase (0.9 mg/kg). Main Outcomes and Measures: The primary outcome was the proportion of modified Rankin scale (mRS) score 0-1 at 90 days. Secondary outcomes were an mRS score from 0 to 2, mortality, and symptomatic intracerebral hemorrhage. Angiographic outcomes were successful reperfusion (extended Thrombolysis in Cerebral Infarction scale score 2b-3) on first and final angiographic acquisitions. Multivariable analyses (adjusting for age, sex, National Institute of Health Stroke Scale score, onset-to-needle time, and occlusion location) were carried out. Results: Among 1577 patients, 520 (33.0%) had LVO (median [IQR] age, 74 [64-83] years; 283 [54.4%] women): 135 (26.0%) with ICA occlusion, 237 (45.6%) with M1-MCA, 117 (22.5%) with M2-MCA, and 31 (6.0%) with basilar occlusions. The primary outcome (mRS score 0-1) was achieved in 86 participants (32.7%) in the tenecteplase group vs 76 (29.6%) in the alteplase group. Rates of mRS 0-2 (129 [49.0%] vs 131 [51.0%]), symptomatic intracerebral hemorrhage (16 [6.1%] vs 11 [4.3%]), and mortality (19.9% vs 18.1%) were similar in the tenecteplase and alteplase groups, respectively. No difference was noted in successful reperfusion rates in the first (19 [9.2%] vs 21 [10.5%]) and final angiogram (174 [84.5%] vs 177 [88.9%]) among 405 patients who underwent thrombectomy. Conclusions and Relevance: The findings in this study indicate that intravenous tenecteplase conferred similar reperfusion, safety, and functional outcomes compared to alteplase among patients with LVO.

Rare neurovascular genetic and imaging markers across neurodegenerative diseases.

INTRODUCTION: Cerebral small vessel disease (SVD) is common in patients with cognitive impairment and neurodegenerative diseases such as Alzheimer's and Parkinson's. This study investigated the burden of magnetic resonance imaging (MRI)-based markers of SVD in patients with neurodegenerative diseases as a function of rare genetic variant carrier status. METHODS: The Ontario Neurodegenerative Disease Research Initiative study included 520 participants, recruited from 14 tertiary care centers, diagnosed with various neurodegenerative diseases and determined the carrier status of rare non-synonymous variants in five genes (ABCC6, COL4A1/COL4A2, NOTCH3/HTRA1). RESULTS: NOTCH3/HTRA1 were found to significantly influence SVD neuroimaging outcomes; however, the mechanisms by which these variants contribute to disease progression or worsen clinical correlates are not yet understood. DISCUSSION: Further studies are needed to develop genetic and imaging neurovascular markers to enhance our understanding of their potential contribution to neurodegenerative diseases.

Association of Dual-Task Gait Cost and White Matter Hyperintensity Burden Poststroke: Results From the ONDRI.

BACKGROUND: Acute change in gait speed while performing a mental task [dual-task gait cost (DTC)], and hyperintensity magnetic resonance imaging signals in white matter are both important disability predictors in older individuals with history of stroke (poststroke). It is still unclear, however, whether DTC is associated with overall hyperintensity volume from specific major brain regions in poststroke. METHODS: This is a cohort study with a total of 123 older (69 ± 7 years of age) participants with history of stroke were included from the Ontario Neurodegenerative Disease Research Initiative. Participants were clinically assessed and had gait performance assessed under single- and dual-task conditions. Structural neuroimaging data were analyzed to measure both, white matter hyperintensity (WMH) and normal appearing volumes. Percentage of WMH volume in frontal, parietal, occipital, and temporal lobes as well as subcortical hyperintensities in basal ganglia + thalamus were the main outcomes. Multivariate models investigated associations between DTC and hyperintensity volumes, adjusted for age, sex, years of education, global cognition, vascular risk factors, APOE4 genotype, residual sensorimotor symptoms from previous stroke and brain volume. RESULTS: There was a significant positive global linear association between DTC and hyperintensity burden (adjusted Wilks' λ = .87, P = .01). Amongst all WMH volumes, hyperintensity burden from basal ganglia + thalamus provided the most significant contribution to the global association (adjusted ß = .008, η2 = .03; P = .04), independently of brain atrophy. CONCLUSIONS: In poststroke, increased DTC may be an indicator of larger white matter damages, specifically in subcortical regions, which can potentially affect the overall cognitive processing and decrease gait automaticity by increasing the cortical control over patients' locomotion.

Rasch analyses of the Quick Inventory of Depressive Symptomatology Self-Report in neurodegenerative and major depressive disorders.

Background: Symptoms of depression are present in neurodegenerative disorders (ND). It is important that depression-related symptoms be adequately screened and monitored in persons living with ND. The Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) is a widely-used self-report measure to assess and monitor depressive severity across different patient populations. However, the measurement properties of the QIDS-SR have not been assessed in ND. Aim: To use Rasch Measurement Theory to assess the measurement properties of the Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) in ND and in comparison to major depressive disorder (MDD). Methods: De-identified data from the Ontario Neurodegenerative Disease Research Initiative (NCT04104373) and Canadian Biomarker Integration Network in Depression (NCT01655706) were used in the analyses. Five hundred and twenty participants with ND (Alzheimer's disease or mild cognitive impairment, amyotrophic lateral sclerosis, cerebrovascular disease, frontotemporal dementia and Parkinson's disease) and 117 participants with major depressive disorder (MDD) were administered the QIDS-SR. Rasch Measurement Theory was used to assess measurement properties of the QIDS-SR, including unidimensionality and item-level fit, category ordering, item targeting, person separation index and reliability and differential item functioning. Results: The QIDS-SR fit well to the Rasch model in ND and MDD, including unidimensionality, satisfactory category ordering and goodness-of-fit. Item-person measures (Wright maps) showed gaps in item difficulties, suggesting poor precision for persons falling between those severity levels. Differences between mean person and item measures in the ND cohort logits suggest that QIDS-SR items target more severe depression than experienced by the ND cohort. Some items showed differential item functioning between cohorts. Conclusion: The present study supports the use of the QIDS-SR in MDD and suggest that the QIDS-SR can be also used to screen for depressive symptoms in persons with ND. However, gaps in item targeting were noted that suggests that the QIDS-SR cannot differentiate participants falling within certain severity levels. Future studies would benefit from examination in a more severely depressed ND cohort, including those with diagnosed clinical depression.

User-centered design of feedback regarding health-related behaviors derived from wearables: An approach targeting older adults and persons living with neurodegenerative disease.

Objective: There has been tremendous growth in wearable technologies for health monitoring but limited efforts to optimize methods for sharing wearables-derived information with older adults and clinical cohorts. This study aimed to co-develop, design and evaluate a personalized approach for information-sharing regarding daily health-related behaviors captured with wearables. Methods: A participatory research approach was adopted with: (a) iterative stakeholder, and evidence-led development of feedback reporting; and (b) evaluation in a sample of older adults (n = 15) and persons living with neurodegenerative disease (NDD) (n = 25). Stakeholders included persons with lived experience, healthcare providers, health charity representatives and individuals involved in aging/NDD research. Feedback report information was custom-derived from two limb-mounted inertial measurement units and a mobile electrocardiography device worn by participants for 7-10 days. Mixed methods were used to evaluate reporting 2 weeks following delivery. Data were summarized using descriptive statistics for the group and stratified by cohort and cognitive status. Results: Participants (n = 40) were 60% female (median 72 (60-87) years). A total of 82.5% found the report easy to read or understand, 80% reported the right amount of information was shared, 90% found the information helpful, 92% shared the information with a family member or friend and 57.5% made a behavior change. Differences emerged in sub-group comparisons. A range of participant profiles existed in terms of interest, uptake and utility. Conclusions: The reporting approach was generally well-received with perceived value that translated into enhanced self-awareness and self-management of daily health-related behaviors. Future work should examine potential for scale, and the capacity for wearables-derived feedback to influence longer-term behavior change.