Post-Stroke Impairments of Manual Dexterity and Finger Proprioception: Their Contribution to Upper Limb Activity Capacity.

BACKGROUND: Knowing how impaired manual dexterity and finger proprioception affect upper limb activity capacity is important for delineating targeted post-stroke interventions for upper limb recovery. OBJECTIVES: To investigate whether impaired manual dexterity and finger proprioception explain variance in post-stroke activity capacity, and whether they explain more variance than conventional clinical assessments of upper limb sensorimotor impairments. METHODS: Activity capacity and hand sensorimotor impairments were assessed using clinical measures in N = 42 late subacute/chronic hemiparetic stroke patients. Dexterity was evaluated using the Dextrain Manipulandum to quantify accuracy of visuomotor finger force-tracking (N = 36), timing of rhythmic tapping (N = 36), and finger individuation (N = 24), as well as proprioception (N = 27). Stepwise multivariate and hierarchical linear regression models were used to identify impairments best explaining activity capacity. RESULTS: Dexterity and proprioceptive components significantly increased the variance explained in activity capacity: (i) Box and Block Test was best explained by baseline tonic force during force-tracking and tapping frequency (adjusted R2 = .51); (ii) Motor Activity Log was best explained by success rate in finger individuation (adjusted R2 = .46); (iii) Action Research Arm Test was best explained by release of finger force and proprioceptive measures (improved reaction time related to use of proprioception; adjusted R2 = .52); and (iv) Moberg Pick-Up test was best explained by proprioceptive function (adjusted R2 = .18). Models excluding dexterity and proprioception variables explained up to 19% less variance. CONCLUSIONS: Manual dexterity and finger proprioception explain unique variance in activity capacity not captured by conventional impairment measures and should be assessed when considering the underlying causes of post-stroke activity capacity limitations.URL: https://www.clinicaltrials.gov. Unique identifier: NCT03934073.

Late-onset vascular complications of radiotherapy for primary brain tumors: a case-control and cross-sectional analysis.

PURPOSE: Radiotherapy (RT) is a recognized risk factor for cerebrovascular (CV) disease in children and in adults with head and neck cancer. We aimed to investigate whether cerebral RT increases the risk of CV disease in adults with primary brain tumors (PBT). METHODS: We retrospectively identified adults with a supratentorial PBT diagnosed between 1975 and 2006 and with at least 10 years follow-up after treatment. We analyzed demographic, clinical, and radiological features with special attention to CV events. We also described CV events, vascular risk factors, and intracranial artery modifications in a cross-sectional study of irradiated patients alive at the time of the study. RESULTS: A total of 116 patients, treated with RT (exposed group), and 85 non-irradiated patients (unexposed group) were enrolled. Stroke was more frequent in irradiated PBT patients than in the unexposed group (42/116 (36%) vs 7/85 (8%); p < 0.001), with higher prevalence of both ischemic (27/116 (23%) vs 6/85 (7%); p = 0.004) and hemorrhagic (12/116 (10%) vs 1/85 (1%); p = 0.02) stroke. In the irradiated group, patients with tumors near the Willis Polygon were more likely to experience stroke (p < 0.016). Fourty-four alive irradiated patients were included in the cross-sectional study. In this subgroup, intracranial arterial stenosis was more prevalent (11/45, 24%) compared to general population (9%). CONCLUSIONS: Stroke prevalence is increased in long-surviving PBT patients treated with cranial RT. IMPLICATIONS FOR CANCER SURVIVORS: CV events are frequent in long survivors of PBT treated with cerebral RT. We propose a check list to guide management of late CV complications in adults treated with RT for PBT.

A translational roadmap for transcranial magnetic and direct current stimulation in stroke rehabilitation: Consensus-based core recommendations from the third stroke recovery and rehabilitation roundtable.

BACKGROUND AND AIMS: The purpose of this Third Stroke Recovery and Rehabilitation Roundtable (SRRR3) was to develop consensus recommendations to address outstanding barriers for the translation of preclinical and clinical research using the non-invasive brain stimulation (NIBS) techniques Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) and provide a roadmap for the integration of these techniques into clinical practice. METHODS: International NIBS and stroke recovery experts (N = 18) contributed to the consensus process. Using a nominal group technique, recommendations were reached via a five-stage process, involving a thematic survey, two priority ranking surveys, a literature review and an in-person meeting. RESULTS AND CONCLUSIONS: Results of our consensus process yielded five key evidence-based and feasibility barriers for the translation of preclinical and clinical NIBS research, which were formulated into five core consensus recommendations. Recommendations highlight an urgent need for (1) increased understanding of NIBS mechanisms, (2) improved methodological rigor in both preclinical and clinical NIBS studies, (3) standardization of outcome measures, (4) increased clinical relevance in preclinical animal models, and (5) greater optimization and individualization of NIBS protocols. To facilitate the implementation of these recommendations, the expert panel developed a new SRRR3 Unified NIBS Research Checklist. These recommendations represent a translational pathway for the use of NIBS in stroke rehabilitation research and practice.

A translational roadmap for transcranial magnetic and direct current stimulation in stroke rehabilitation: Consensus-based core recommendations from the third stroke recovery and rehabilitation roundtable.

BACKGROUND AND AIMS: The purpose of this Third Stroke Recovery and Rehabilitation Roundtable (SRRR3) was to develop consensus recommendations to address outstanding barriers for the translation of preclinical and clinical research using the non-invasive brain stimulation (NIBS) techniques Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) and provide a roadmap for the integration of these techniques into clinical practice. METHODS: International NIBS and stroke recovery experts (N = 18) contributed to the consensus process. Using a nominal group technique, recommendations were reached via a five-stage process, involving a thematic survey, two priority ranking surveys, a literature review and an in-person meeting. RESULTS AND CONCLUSIONS: Results of our consensus process yielded five key evidence-based and feasibility barriers for the translation of preclinical and clinical NIBS research, which were formulated into five core consensus recommendations. Recommendations highlight an urgent need for (1) increased understanding of NIBS mechanisms, (2) improved methodological rigor in both preclinical and clinical NIBS studies, (3) standardization of outcome measures, (4) increased clinical relevance in preclinical animal models, and (5) greater optimization and individualization of NIBS protocols. To facilitate the implementation of these recommendations, the expert panel developed a new SRRR3 Unified NIBS Research Checklist. These recommendations represent a translational pathway for the use of NIBS in stroke rehabilitation research and practice.

ASPECTS evolution after endovascular successful reperfusion in the early and extended time window.

BACKGROUND: The Alberta Stroke Program Early CT scan Score (ASPECTS) is a reliable imaging biomarker of infarct extent on admission but the value of 24-hour ASPECTS evolution in day-to-day practice is not well studied, especially after successful reperfusion. We aimed to assess the association between ASPECTS evolution after successful reperfusion with functional and safety outcomes, as well as to identify the predictors of ASPECTS evolution. METHODS: We used data from an ongoing prospective multicenter registry. Stroke patients with anterior circulation large vessel occlusion treated with endovascular therapy (EVT) and achieved successful reperfusion (modified thrombolysis in cerebral ischemia (mTICI) 2b-3) were included. ASPECTS evolution was defined as one or more point decrease in ASPECTS at 24 hours. RESULTS: A total of 2366 patients were enrolled. In a fully adjusted model, ASPECTS evolution was associated with lower odds of favorable outcome (modified Rankin Scale (mRS) score 0-2) at 90 days (adjusted odds ratio (aOR) = 0.46; 95% confidence interval (CI) = 0.37-0.57). In addition, ASPECTS evolution was a predictor of excellent outcome (90-day mRS 0-1) (aOR = 0.52; 95% CI = 0.49-0.57), early neurological improvement (aOR = 0.42; 95% CI = 0.35-0.51), and parenchymal hemorrhage (aOR = 2.64; 95% CI, 2.03-3.44). Stroke severity, admission ASPECTS, total number of passes, complete reperfusion (mTICI 3 vs. mTICI 2b-2c) and good collaterals emerged as predictors of ASPECTS evolution. CONCLUSION: ASPECTS evolution is a strong predictor of functional and safety outcomes after successful endovascular therapy. Higher number of EVT attempts and incomplete reperfusion are associated with ASPECTS evolution at day 1.

A single case neuroimaging study of tickertape synesthesia.

Reading acquisition is enabled by deep changes in the brain's visual system and language areas, and in the links subtending their collaboration. Disruption of those plastic processes commonly results in developmental dyslexia. However, atypical development of reading mechanisms may occasionally result in ticker-tape synesthesia (TTS), a condition described by Francis Galton in 1883 wherein individuals "see mentally in print every word that is uttered (…) as from a long imaginary strip of paper". While reading is the bottom-up translation of letters into speech, TTS may be viewed as its opposite, the top-down translation of speech into internally visualized letters. In a series of functional MRI experiments, we studied MK, a man with TTS. We showed that a set of left-hemispheric areas were more active in MK than in controls during the perception of normal than reversed speech, including frontoparietal areas involved in speech processing, and the Visual Word Form Area, an occipitotemporal region subtending orthography. Those areas were identical to those involved in reading, supporting the construal of TTS as upended reading. Using dynamic causal modeling, we further showed that, parallel to reading, TTS induced by spoken words and pseudowords relied on top-down flow of information along distinct lexical and phonological routes, involving the middle temporal and supramarginal gyri, respectively. Future studies of TTS should shed new light on the neurodevelopmental mechanisms of reading acquisition, their variability and their disorders.

Association between superior longitudinal fasciculus, motor recovery, and motor outcome after stroke: a cohort study.

Introduction: Parieto-frontal interactions are mediated by the superior longitudinal fasciculus (SLF) and are crucial to integrate visuomotor information and mediate fine motor control. In this study, we aimed to characterize the relation of white matter integrity of both parts of the SLF (SLF I and SLF II) to both motor outcome and recovery and its evolution over time in stroke patients with upper limb motor deficits. Materials and methods: Fractional anisotropy (FA) values over the SLF I, SLF II, and corticospinal tract (CST) and upper limb motor performance evaluated by both the upper limb Fugl-Meyer Assessment score and maximum grip strength were measured for 16 patients at 3 weeks, 6 weeks, and 12 weeks poststroke. FA changes were assessed over time using repeated-measures Friedman ANOVA, and correlations between motor recovery, motor outcome at 12 weeks, and FA values in the CST, SLF I, and SLF II at 3 weeks were performed using Spearman's rank-order correlation. Results: FA values in the affected hemisphere's SLF I and SLF II at 3 weeks correlated with motor recovery at 12 weeks when assessed by the Fugl-Meyer Assessment for upper limb extremity (rho: 0.502, p: 0.04 and rho: 0.510, p: 0.04, respectively) but not when assessed by grip strength. FA values in the SLF I and SLF II were not correlated with motor outcomes. FA values in the SLF II in the affected hemisphere changed significantly over time (p: 0.016). Conclusion: Both SLF I and SLF II appeared to participate in poststroke motor recovery of complex movements but not in the motor outcome. These results argue that visually/spatially oriented motor tasks as well as more complex motor tasks using parietal associative areas should be used for poststroke rehabilitation strategies.

Relevance of National Institutes of Health Stroke Scale subitems for best revascularization therapy in minor stroke patients with large vessel occlusion: An observational multicentric study.

BACKGROUND AND PURPOSE: The best management of acute ischemic stroke patients with a minor stroke and large vessel occlusion is still uncertain. Specific clinical and radiological data may help to select patients who would benefit from endovascular therapy (EVT). We aimed to evaluate the relevance of National Institutes of Health Stroke Scale (NIHSS) subitems for predicting the potential benefit of providing EVT after intravenous thrombolysis (IVT; "bridging treatment") versus IVT alone. METHODS: We extracted demographic, clinical, risk factor, radiological, revascularization and outcome data of consecutive patients with M1 or proximal M2 middle cerebral artery occlusion and admission NIHSS scores of 0-5 points, treated with IVT ± EVT between May 2005 and March 2021, from nine prospectively constructed stroke registries at seven French and two Swiss comprehensive stroke centers. Adjusted interaction analyses were performed between admission NIHSS subitems and revascularization modality for two primary outcomes at 3 months: non-excellent functional outcome (modified Rankin Scale score 2-6) and difference in NIHSS score between 3 months and admission. RESULTS: Of the 533 patients included (median age 68.2 years, 46% women, median admission NIHSS score 3), 136 (25.5%) initially received bridging therapy and 397 (74.5%) received IVT alone. Adjusted interaction analysis revealed that only facial palsy on admission was more frequently associated with excellent outcome in patients treated by IVT alone versus bridging therapy (odds ratio 0.47, 95% confidence interval 0.24-0.91; p = 0.013). Regarding NIHSS difference at 3 months, no single NIHSS subitem interacted with type of revascularization. CONCLUSIONS: This retrospective multicenter analysis found that NIHSS subitems at admission had little value in predicting patients who might benefit from bridging therapy as opposed to IVT alone. Further research is needed to identify better markers for selecting EVT responders with minor strokes.

Effects of weather conditions on endovascular treatment case volume for patients with ischemic stroke.

BACKGROUND: Weather conditions have been shown to influence the occurrence of cardiovascular events. We tested the hypothesis that weather parameters may be associated with variations of case volume of endovascular treatment (EVT) for acute ischemic stroke. METHODS: Individual data from the ETIS (Endovascular Treatment in Ischemic Stroke) French national registry were matched to local weather stations. Meteorological parameters (rainfall, humidity, atmospheric pressure, air temperature) were gathered from national online resources. Weather readings and EVT case volumes were annually standardized per weather station and EVT center, and their associations tested with non-parametric univariable and generalized linear statistical models. RESULTS: Between 2015 and 2021, 9913 EVT procedures addressed by 135 primary stroke units were matched to weather conditions. The mean daily case volume per center was 0.41 [StDev 0.33], and there was a median of 0.84 procedures daily linked to a weather station [StDev 0.47]. We found lower atmospheric pressure (ß estimate -0.04; 95%CI[-0.07;-0.03], p<0.001), higher humidity (ß estimate 0.07; 95%CI [0.05;0.09], p<0.001) and lower temperatures (ß estimate -0.08; 95%CI[-0.10;-0.06], p<0.001) to be associated with higher standardized EVT daily case volumes. These associations were stable when testing them across strata of binned EVT standardized case volumes. CONCLUSIONS: Our study suggests that lower ambient temperature, lower atmospheric pressure, and higher air humidity are associated with significantly more daily EVT cases in a European temperate country. These results may provide insight into both system of care optimization at times of climate change and intracranial LVO pathophysiology. REGISTRATION-URL: https://clinicaltrials.gov/ct2/show/NCT03776877.

Efficacy of interactive manual dexterity training after stroke: a pilot single-blinded randomized controlled trial.

OBJECTIVE: To compare the efficacy of Dextrain Manipulandum™ training of dexterity components such as force control and independent finger movements, to dose-matched conventional therapy (CT) post-stroke. METHODS: A prospective, single-blind, pilot randomized clinical trial was conducted. Chronic-phase post-stroke patients with mild-to-moderate dexterity impairment (Box and Block Test (BBT) > 1) received 12 sessions of Dextrain or CT. Blinded measures were obtained before and after training and at 3-months follow-up. Primary outcome was BBT-change (after-before training). Secondary outcomes included changes in motor impairments, activity limitations and dexterity components. Corticospinal excitability and short intracortical inhibition (SICI) were measured using transcranial magnetic stimulation. RESULTS: BBT-change after training did not differ between the Dextrain (N = 21) vs CT group (N = 21) (median [IQR] = 5[2-7] vs 4[2-7], respectively; P = 0.36). Gains in BBT were maintained at the 3-month post-training follow-up, with a non-significant trend for enhanced BBT-change in the Dextrain group (median [IQR] = 3[- 1-7.0], P = 0.06). Several secondary outcomes showed significantly larger changes in the Dextrain group: finger tracking precision (mean ± SD = 0.3 ± 0.3N vs - 0.1 ± 0.33N; P < 0.0018), independent finger movements (34.7 ± 25.1 ms vs 7.7 ± 18.5 ms, P = 0.02) and maximal finger tapping speed (8.4 ± 7.1 vs 4.5 ± 4.9, P = 0.045). At follow-up, Dextrain group showed significantly greater improvement in Motor Activity Log (median/IQR = 0.7/0.2-0.8 vs 0.2/0.1-0.6, P = 0.05). Across both groups SICI increased in patients with greater BBT-change (Rho = 0.80, P = 0.006). Comparing Dextrain subgroups with maximal grip force higher/lower than median (61.2%), BBT-change was significantly larger in patients with low vs high grip force (7.5 ± 5.6 vs 2.9 ± 2.8; respectively, P = 0.015). CONCLUSIONS: Although immediate improvements in gross dexterity post-stroke did not significantly differ between Dextrain training and CT, our findings suggest that Dextrain enhances recovery of several dexterity components and reported hand-use, particularly when motor impairment is moderate (low initial grip force). Findings need to be confirmed in a larger trial. Trial registration ClinicalTrials.gov NCT03934073 (retrospectively registered).

Longitudinal Monitoring of Microstructural Alterations in Cerebral Ischemia with in Vivo Diffusion-weighted MR Spectroscopy.

Background The time course of cellular damage after acute ischemic stroke (IS) is currently not well known, and specific noninvasive markers of microstructural alterations linked to inflammation are lacking, which hinders the monitoring of anti-inflammatory treatment. Purpose To evaluate the temporal pattern of neuronal and glial microstructural changes after stroke using in vivo single-voxel diffusion-weighted MR spectroscopy. Materials and Methods In this prospective longitudinal study, participants with IS and healthy volunteers (HVs) underwent MRI at 3.0 T. In participants with IS, apparent diffusion coefficients (ADCs) and concentrations of total N-acetyl-aspartate (tNAA), total creatine (tCr), and total choline (tCho) were measured in volumes of interest (VOIs), including the lesion VOI (VOIles) and the contralateral VOI (VOIcl) at 2 weeks, 1 month, and 3 months after IS. HVs were examined once, with VOIs located in the same brain regions as participants with IS. Within- and between-group differences and longitudinal changes were examined using linear mixed-effects models. Results Twenty participants with IS (mean age, 61 years ± 13 [SD]; 12 women) and 20 HVs (mean age, 59 years ± 13; 12 women) were evaluated. No differences in ADCs or concentrations were observed in VOIcl between HVs and participants with IS. In participants with IS, the ADC of tCr was higher in VOIles than in VOIcl at 1 month (+14.4%, P = .004) and 3 months after IS (+19.0%, P < .001), while the ADC of tCho was higher only at 1 month (+16.7%, P = .001). No difference in the ADC of tNAA was observed between the two VOIs at any time point. tNAA and tCr concentrations were lower in VOIles than in VOIcl and were stable over time (approximately -50% and -30%, respectively; P < .001). Conclusion High diffusivity of choline-containing compounds and total creatine (tCr) in the ischemic lesion 1 month after ischemic stroke (IS) indicates glial morphologic changes, suggesting that active inflammation is still ongoing at this time point. High tCr diffusivity up to 3 months after IS likely reflects the presence of astrogliosis at the chronic stage of cerebral ischemia. Clinical trial registration no. NCT02833961 © RSNA, 2022 Online supplemental material is available for this article.

Aspirin versus aggressive antiplatelet therapy for acute carotid stenting plus thrombectomy in tandem occlusions: ETIS Registry results.

BACKGROUND: Patients treated with acute carotid stenting (CAS) may have higher odds of a favorable outcome than those treated without CAS during thrombectomy in tandem occlusions. Antiplatelet therapy is associated with CAS to avoid stent thrombosis, which occurs in around 20% of patients and negatively impacts outcomes. In this study we compared two antiplatelet strategies in tandem occlusion strokes treated with CAS and intracranial thrombectomy in clinical practice. METHODS: The Endovascular Treatment in Ischemic Stroke Registry is an ongoing prospective observational study involving 21 comprehensive stroke centers performing thrombectomy in France. We analyzed patients with atherosclerotic tandem occlusions treated with acute CAS and intracranial thrombectomy who received at least one antiplatelet agent. Aggressive antiplatelet therapy included oral or intravenous glycoprotein (GP) IIb/IIIa or P2Y12 inhibitors. The primary outcome was cervical carotid artery patency at day 1 imaging follow-up. RESULTS: Among the 187 included patients, 124 (66.3%) received aspirin alone and 63 (33.7%) received aggressive antiplatelet therapy. There was no significant difference regarding safety outcomes, especially in symptomatic intracerebral hemorrhage, parenchymal hematoma, and procedural complications. There was a significantly higher rate of carotid stent patency at day 1 in the aggressive antiplatelet therapy group (81.7% vs 97.1%, aOR 17.49, 95% CI 1.10 to 277.2, p=0.042). Odds of favorable functional outcome (90-day modified Rankin Scale score 0-2) were similar between the groups (OR 3.04, 95% CI 0.64 to 14.25, p=0.158). CONCLUSIONS: In tandem occlusions treated with CAS plus thrombectomy, an aggressive antiplatelet regimen was associated with an increased rate of carotid stent patency at day 1 without safety concerns. Randomized trials are warranted to confirm these findings.

Influence of prior intravenous thrombolysis in patients treated with mechanical thrombectomy for M2 occlusions: insight from the Endovascular Treatment in Ischemic Stroke (ETIS) registry.

BACKGROUND: Intravenous thrombolysis (IVT) for patients treated with mechanical thrombectomy (MT) for proximal occlusions has recently been questioned through randomized trials. However, few patients with M2 occlusions were included. We investigated the influence of prior IVT for patients presenting M2 occlusions treated with MT in comparison with MT alone. METHODS: We conducted a retrospective analysis of the Endovascular Treatment in Ischemic Stroke (ETIS) registry, a multicenter observational study. Data from consecutive patients treated with MT for M2 occlusions between January 2015 and January 2022 at 26 comprehensive stroke centers were analyzed. The primary endpoint was 90-day modified Rankin Scale score of 0-2. Outcomes were compared using propensity score approaches. We also performed sensitivity analysis in relevant subgroups of patients. RESULTS: Among 1132 patients with M2 occlusions treated with MT, 570 received prior IVT. The two groups were comparable after propensity analysis. The rate of favorable functional outcome was significantly higher in the IVT+MT group compared with the MT alone group (59.8% vs 44.7%; adjusted OR 1.38, 95% CI 1.10 to 1.75, P=0.008). Hemorrhagic and procedural complications were similar in both groups. In sensitivity analysis excluding patients with anticoagulation treatment, favorable recanalization was more frequent in the IVT+MT group (OR 1.37, 95% CI 1.11 to 1.70, P=0.004). CONCLUSIONS: In cases of M2 occlusions, prior IVT combined with MT resulted in better functional outcome than MT alone, without increasing the rate of hemorrhagic or procedural complications. These results suggest the benefit of IVT in patients undergoing MT for M2 occlusions.

How does Tourette syndrome impact adolescents' daily living? A text mining study.

Tourette syndrome is a neurodevelopmental disease in which clinical manifestations are essentially present during childhood and adolescence, corresponding to one of the critical development phases. However, its consequences on the daily lives of young patients have been insufficiently investigated. Here, we aimed to investigate this using a statistical text mining approach, allowing for the analysis of a large volume of free textual data. Sixty-two adolescents with Tourette syndrome participated in an interview in which they discussed their daily life (i) in school, (ii) at home, and (iii) with strangers, (iv) the aspect of Tourette syndrome which caused the most difficulty, and (v) their thoughts regarding their future as adults. Following data pre-processing, these corpora were analyzed separately using the IRAMUTEQ software through factorial correspondence analysis to identify the most commonly recurring topics of each corpus, and their relations with clinical features. The main difficulty corpus was directly related to comorbidities of Tourette syndrome. Daily life at home was correlated with executive functioning. Difficulties at school were related to a higher severity of tics. Thoughts regarding future daily life were worst for the youngest patients and were correlated with executive functioning and a higher depression score. Taken altogether, our results highlighted that social stigma was a pervasive topic among our corpora. From a clinical standpoint, tic severity was especially related to difficulties at school, while comorbidities had a high impact on social daily living and cost for managing both tics and symptoms of comorbidities. TRIAL REGISTRATION: clinicaltrials.gov/ct2/show/NCT04179435.

Effect of intravenous thrombolysis before endovascular therapy on outcome according to collateral status: insight from the ETIS Registry.

BACKGROUND: It is unknown whether collateral status modifies the effect of pretreatment intravenous thrombolysis (IVT) on the outcomes of patients with large vessel occlusions treated with endovascular therapy (EVT). We aimed to assess whether collateral status modifies the effect of IVT on the outcomes of EVT in clinical practice. METHODS: We used data from the ongoing prospective multicentric Endovascular Treatment in Ischemic Stroke (ETIS) Registry in France. Patients with anterior circulation proximal large vessel occlusions treated with EVT within 6 hours of symptom onset were enrolled. Patients were divided into two groups based on pretreatment with IVT. The two groups were matched based on baseline characteristics. We tested the interaction between collateral status and IVT in unadjusted and adjusted models. RESULTS: A total of 1589 patients were enrolled in the study, of whom 55% received IVT. Using a propensity score matching method, 724 no IVT patients were matched to 549 IVT patients. In propensity score weighted analysis, IVT was associated with higher odds of early neurological improvement (OR 1.74; 95% CI 1.33 to 2.26), favorable functional outcome (OR 1.66; 95% CI 1.23 to 2.24), excellent functional outcome (OR 2.04; 95% CI 1.47 to 2.83), and successful reperfusion (OR 2.18; 95% CI 1.51 to 3.16). IVT was not associated with mortality or hemorrhagic complications. There was no interaction between collateral status and IVT association with any of the outcomes. CONCLUSIONS: Collateral status does not modify the effect of pretreatment IVT on the efficacy and safety outcomes of EVT.

Persistent perfusion abnormalities at day 1 correspond to different clinical trajectories after stroke.

BACKGROUND: Perfusion abnormalities after thrombolysis are frequent within and surrounding ischemic lesions, but their relative frequency is not well known. OBJECTIVE: To describe the different patterns of perfusion abnormalities observed at 24 hours and compare the characteristics of the patients according to their perfusion pattern. METHODS: From our thrombolysis registry, we included 226 consecutive patients with an available arterial spin labeling (ASL) perfusion sequence at day 1. We performed a blinded assessment of the perfusion status (hypoperfusion-h, hyperperfusion-H, or normal-N) in the ischemic lesion and in the surrounding tissue. We compared the time course of clinical recovery, the rate of arterial recanalization, and hemorrhagic transformations in the different perfusion profiles. RESULTS: We identified seven different perfusion profiles at day 1. Four of these (h/h, h/H, H/H, and H/N) represented the majority of the population (84.1%). The H/H profile was the most frequent (34.5%) and associated with 3-month good outcome (modified Rankin Scale (mRS): 63.5%). Patients with persistent hypoperfusion within and outside the lesion (h/h, 12.4%) exhibited worse outcomes after treatment (mRS score 0-2: 23.8%) than other patients, were less frequently recanalized (40.7%), and had more parenchymal hematoma (17.8%). The h/H profile had an intermediate clinical trajectory between the h/h profile and the hyperperfused profiles. CONCLUSION: ASL hypoperfusion within the infarct and the surrounding tissue was associated with poor outcome. A more comprehensive view of the mechanisms in the hypoperfused surrounding tissue could help to design new therapeutic approaches during and after reperfusion therapies.

Poor clinical outcome despite successful basilar occlusion recanalization in the early time window: incidence and predictors.

BACKGROUND: Endovascular treatment (EVT) for basilar artery occlusions (BAO) is associated with a higher rate of futile recanalization compared with anterior circulation procedures. We aimed to identify the incidence and predictors of poor clinical outcome despite successful reperfusion in current clinical practice. METHODS: We used data from the ETIS (Endovascular Treatment in Ischemic Stroke) registry, a prospective multicenter observational registry of stroke treated with EVT in France. Patients undergoing EVT for acute BAO from January 2014 to May 2019 successfully treated within 8 hours from onset were included. Predictors of 90-day poor outcome (modified Rankin Scale (mRS) 4-6) were researched within patients with successful (modified Thrombolysis In Cerebral Infarction (mTICI 2b-3)) and excellent (mTICI 2c-3) reperfusion. RESULTS: Among 242 patients treated within 8 hours, successful reperfusion was achieved in 195 (80.5%) and excellent reperfusion in 120 (49.5%). Poor outcome was observed in 107 (54.8%) and 60 (50%) patients, respectively. In patients with successful early reperfusion, age, higher initial National Institutes of Health Stroke Scale (NIHSS) score, lower posterior circulation Alberta Stroke Programme Early CT Score (pc-ASPECTS), and absence of prior intravenous thrombolysis were independent predictors of poor outcome. The only treatment factor with an independent predictive value was first-pass mTICI 2b-3 reperfusion (adjusted OR 0.13, 95% CI 0.05 to 0.37, p<0.001). In patients with excellent early reperfusion, independent predictors were age, initial NIHSS score, first-pass mTICI 2c-3 reperfusion, and hemorrhagic transformation on post-interventional imaging. CONCLUSIONS: Early successful reperfusion with EVT occurred in 80.5% of patients, and the only treatment-related factor predictive of clinical outcome was first pass mTICI 2b-3 reperfusion. Further research is warranted to identify the optimal techniques and devices associated with first pass reperfusion in the posterior circulation.

Thrombectomy in basilar artery occlusions: impact of number of passes and futile reperfusion.

BACKGROUND: The number of mechanical thrombectomy (MT) passes is strongly associated with angiographic reperfusion as well as clinical outcomes in patients with anterior circulation ischemic stroke. However, these associations have not been analyzed in patients with basilar artery occlusion (BAO). We investigated the influence of the number of MT passes on the degree of reperfusion and clinical outcomes, and compared outcome after ≤3 passes versus >3 passes. METHODS: We used data from the prospective multicentric Endovascular Treatment in Ischemic Stroke (ETIS) Registry at 18 sites in France. Patients with BAO treated with MT were included. The primary outcome was a favorable outcome, defined as a modified Rankin Scale score of 0-3 at 90 days. We fit mixed multiple regression models, with center as a random effect. RESULTS: We included 275 patients. Successful recanalization (modified Thrombolysis In Cerebral Infarction (mTICI) 2b-3) was achieved in 88.4%, and 41.8% had a favorable outcome. The odds ratio for favorable outcome with each pass above 1 was 0.41 (95% CI 0.23 to 0.73) and for recanalization (mTICI 2b-3) it was 0.70 (95% CI 0.57 to 0.87). In patients with ≤3 passes, the rate of favorable outcome in recanalized versus non-recanalized patients was 50.5% versus 10.0% (p=0.001), while in those with >3 passes it was 16.7% versus 15.2% (p=0.901). CONCLUSIONS: We found that BAO patients had a significant relationship between the number of MT passes and both recanalization and favorable functional outcome. We further found that the benefit of recanalization in BAO patients was significant only when recanalization was achieved within three passes, encouraging at least three passes before stopping the procedure.

Interpretable deep learning for the prognosis of long-term functional outcome post-stroke using acute diffusion weighted imaging.

Advances in deep learning can be applied to acute stroke imaging to build powerful and explainable prediction models that could supersede traditionally used biomarkers. We aimed to evaluate the performance and interpretability of a deep learning model based on convolutional neural networks (CNN) in predicting long-term functional outcome with diffusion-weighted imaging (DWI) acquired at day 1 post-stroke. Ischemic stroke patients (n = 322) were included from the ASTER and INSULINFARCT trials as well as the Pitié-Salpêtrière registry. We trained a CNN to predict long-term functional outcome assessed at 3 months with the modified Rankin Scale (dichotomized as good [mRS ≤ 2] vs. poor [mRS ≥ 3]) and compared its performance to two logistic regression models using lesion volume and ASPECTS. The CNN contained an attention mechanism, which allowed to visualize the areas of the brain that drove prediction. The deep learning model yielded a significantly higher area under the curve (0.83 95%CI [0.78-0.87]) than lesion volume (0.78 [0.73-0.83]) and ASPECTS (0.77 [0.71-0.83]) (p < 0.05). Setting all classifiers to the specificity as the deep learning model (i.e., 0.87 [0.82-0.92]), the CNN yielded a significantly higher sensitivity (0.67 [0.59-0.73]) than lesion volume (0.48 [0.40-0.56]) and ASPECTS (0.50 [0.41-0.58]) (p = 0.002). The attention mechanism revealed that the network learned to naturally attend to the lesion to predict outcome.