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Introduction: Visual field defects (VFDs) represent a debilitating poststroke complication, characterized by unseen parts of the visual field. Visual perceptual learning (VPL), involving repetitive visual training in blind visual fields, may effectively restore visual field sensitivity in cortical blindness. This current multicenter, double-blind, randomized, controlled clinical trial investigated the efficacy and safety of VPL-based digital therapeutics (Nunap Vision [NV]) for treating poststroke VFDs., Methods: Stroke outpatients with VFDs (>6 months after stroke onset) were randomized into NV (defective field training) or Nunap Vision-Control (NV-C, central field training) groups. Both interventions provided visual perceptual training, consisting of orientation, rotation, and depth discrimination, through a virtual reality head-mounted display device 5 days a week for 12 weeks. The two groups received VFD assessments using Humphrey visual field (HVF) tests at baseline and 12-week follow-up. The final analysis included those completed the study (NV, n = 40; NV-C, n = 35). Efficacy measures included improved visual area (sensitivity ≥6 dB) and changes in the HVF scores during the 12-week period., Results: With a high compliance rate, NV and NV-C training improved the visual areas in the defective hemifield (>72 degrees 2 ) and the whole field (>108 degrees 2 ), which are clinically meaningful improvements despite no significant between-group differences. According to within-group analyses, mean total deviation scores in the defective hemifield improved after NV training (p = .03) but not after NV-C training (p = .12)., Conclusions: The current trial suggests that VPL-based digital therapeutics may induce clinically meaningful visual improvements in patients with poststroke VFDs. Yet, between-group differences in therapeutic efficacy were not found as NV-C training exhibited unexpected improvement comparable to NV training, possibly due to learning transfer effects., (© 2024 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

A reciprocal relationship between perceptual learning and functional brain changes towards perceptual learning effectiveness has been demonstrated previously; however, the underlying neural correlates remain unclear. Further, visual perceptual learning (VPL) is implicated in visual field defect (VFD) recovery following chronic stroke. We investigated resting-state functional connectivity (RSFC) in the visual cortices associated with mean total deviation (MTD) scores for VPL-induced VFD recovery in chronic stroke. Patients with VFD due to chronic ischemic stroke in the visual cortex received 24 VPL training sessions over 2 months, which is a dual discrimination task of orientation and letters. At baseline and two months later, the RSFC in the ipsilesional, interhemispheric, and contralesional visual cortices and MTD scores in the affected hemi-field were assessed. Interhemispheric visual RSFC at baseline showed the strongest correlation with MTD scores post-2-month VPL training. Notably, only the subgroup with high baseline interhemispheric visual RSFC showed significant VFD improvement following the VPL training. The interactions between the interhemispheric visual RSFC at baseline and VPL led to improvement in MTD scores and largely influenced the degree of VFD recovery. The interhemispheric visual RSFC at baseline could be a promising brain biomarker for the effectiveness of VPL-induced VFD recovery., (© 2024. The Author(s).)

Background: Therapeutic-induced hypertension treatment (iHTN) is helpful for alleviating early neurological deterioration (END) in acute small vessel occlusive stroke. We examined the time parameters related to iHTN effectiveness in these patients., Methods: We retrospectively reviewed patients with acute small vessel occlusive stroke who underwent iHTN for END, defined as an increase of ≥2 points in total National Institutes of Health Stroke Scale (NIHSS) score or ≥1 point in motor items of NIHSS. The primary outcome was an early neurological improvement (ENI; a decrease of ≥2 points in total NIHSS score or ≥1 point in motor items of NIHSS), and the secondary outcome was any neurological improvement (a decrease of ≥1 point in the total NIHSS score). We conducted a multivariable logistic regression analysis, adjusting for demographics, risk factors, baseline clinical status, and intervention-related variables. We also generated a restricted cubic spline curve for the END-to-iHTN time cutoff., Results: Among the 1062 patients with small vessel occlusive stroke screened between 2017 and 2021, 136 patients who received iHTN within 24 hours from END were included. The mean age was 65.1 (±12.0) years, and 61.0% were male. Sixty-five (47.8%) patients showed ENI and 77 (56.6%) patients showed any neurological improvement. END-to-iHTN time was significantly shorter in patients with ENI (150 [49-322] versus 290 [97-545] minutes; P =0.018) or any neurological improvement (150 [50-315] versus 300 [130-573] minutes; P =0.002). A 10-minute increase in the time between END and iHTN decreased the odds of achieving ENI (odds ratio, 0.984 [95% CI, 0.970-0.997]; P =0.019) or any neurological improvement (odds ratio, 0.978 [95% CI, 0.964-0.992]; P =0.002). The restricted cubic spline curve showed that the odds ratio of ENI reached its minimum at ≈3 hours., Conclusions: Among patients with small vessel occlusive stroke with END, a shorter interval between END and the initiation of iHTN was associated with increased odds of achieving neurological improvement. The efficacy of iHTN may be limited to induction within the first 3 hours of END., Competing Interests: Disclosures None.

Introduction: Patients with atrial fibrillation-related stroke (AF-stroke) are prone to developing rapid ventricular response (RVR). We investigated whether RVR is associated with initial stroke severity, early neurological deterioration (END) and poor outcome at 3 months., Methods: We reviewed patients who had AF-stroke between January 2017 and March 2022. RVR was defined as having heart rate >100 beats per minute on initial electrocardiogram. Neurological deficit was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission. END was defined as increase of ≥2 in total NIHSS score or ≥1 in motor NIHSS score within first 72 h. Functional outcome was score on modified Rankin Scale at 3 months. Mediation analysis was performed to examine potential causal chain in which initial stroke severity may mediate relationship between RVR and functional outcome., Results: We studied 568 AF-stroke patients, among whom 86 (15.1%) had RVR. Patients with RVR had higher initial NIHSS score (p < 0.001) and poor outcome at 3 months (p = 0.004) than those without RVR. The presence of RVR [adjusted odds ratio (aOR) = 2.13; p = 0.013] was associated with initial stroke severity, but not with END and functional outcome. Otherwise, initial stroke severity [aOR = 1.27; p = <0.001] was significantly associated with functional outcome. Initial stroke severity as a mediator explained 58% of relationship between RVR and poor outcome at 3 months., Conclusion: In patients with AF-stroke, RVR was independently associated with initial stroke severity but not with END and functional outcome. Initial stroke severity mediated considerable proportion of association between RVR and functional outcome., (© 2023 S. Karger AG, Basel.)

Background:  We investigated the association between the reaction time (R), a thromboelastography (TEG) parameter for hypercoagulability, and functional outcomes based on the occurrence of hemorrhagic transformation (HT) and early neurological deterioration (END)., Methods:  We enrolled ischemic stroke patients and performed TEG immediately after the patients' arrival. The baseline characteristics, occurrence of HT and END, stroke severity, and etiology were compared according to the R. END was defined as an increase of ≥1 point in motor or ≥2 points in the total National Institute of Health Stroke Scale within 3 days after admission. The outcome was the achievement of functional independence (modified Rankin scale [mRS]: 0-2) at 3 months after stroke. Logistic regression analyses were performed to verify the association between R and outcome., Results:  HT and END were frequently observed in patients with an R of <5 minutes compared with the group with an R of ≥5 minutes (15 [8.1%] vs. 56 [21.0%], p  < 0.001; 16 [8.6%] vs. 65 [24.3%], p  = 0.001, respectively). In multivariable analysis, an R of <5 minutes was associated with decreased odds of achieving functional independence (0.58 [0.34-0.97], p  = 0.038). This association was maintained when the outcome was changed to disability free (mRS 0-1) and when mRS was analyzed as an ordinal variable., Conclusion:  Hypercoagulability on TEG (R <5 minutes) may be a negative predictor for functional outcome of stroke after 3 months, with more frequent HT, END, and different stroke etiologies. This study highlights the potential of TEG parameters as biomarkers for predicting functional outcomes in ischemic stroke patients., Competing Interests: None declared., (Thieme. All rights reserved.)

Early neurological deterioration (END) in lenticulostriate artery (LSA) infarction is associated with perforating artery hypoperfusion. As middle cerebral artery (MCA) tortuosity may alter hemodynamics, we investigated the association between MCA tortuosity and END in LSA infarction. We reviewed patients with acute LSA infarction without significant MCA stenosis. END was defined as an increase of ≥ 2 or ≥ 1 in the National Institutes of Health Stroke Scale (NIHSS) total or motor score, respectively, within first 72 h. The MCA tortuosity index (actual /straight length) was measured. Stroke mechanisms were categorized as branch atheromatous disease (BAD; lesions > 10 mm and 4 axial slices) and lipohyalinotic degeneration (LD; lesion smaller than BAD). Factors associated with END in LD and BAD were investigated. END occurred in 104/390 (26.7%) patients. A high MCA tortuosity index (adjusted odds ratio, aOR 10.63, 95% confidence interval [2.57-44.08], p = 0.001) was independently associated with END. In patients with BAD, high initial NIHSS score (aOR 1.40 [1.03-1.89], p = 0.031) and presence of parental artery disease (stenosis < 50%; aOR 10.38 [1.85-58.08], p = 0.008) were associated with END. In patients with LD, high MCA tortuosity (aOR 41.78 [7.37-237.04], p < 0.001) was associated with END. The mechanism causing END in patients with LD and BAD may differ., (© 2023. The Author(s).)

Background and Purpose: Stenting is an important treatment for preventing stroke. However, the effect of vertebrobasilar stenting (VBS) might be limited because of relatively high periprocedural risks. Silent brain infarcts (SBIs) are known as a predictor for future stroke. Because of anatomical differences, factors for SBIs might be different between carotid artery stenting (CAS) and VBS. We compared the characteristics of SBIs between VBS and CAS., Methods: We included patients who underwent elective VBS or CAS. Diffusion-weighted imaging was performed pre- and post-procedure to detect new SBIs. Clinical variables, occurrence of SBIs, and procedure-related factors were compared between CAS and VBS. Moreover, we investigated predictors of SBIs in each group separately., Results: Ninety-two (34.2%) out of 269 patients had SBIs. SBIs were more frequently observed in VBS (29 [56.6%] vs. 63 [28.9%], p<.001). The risk of SBIs outside the stent-inserted vascular territory was higher in VBS compared to CAS (14 [48.3%] vs. 8 [12.7%], p<.001). Larger-diameter stents (odds ratio: 1.28, 95% confidence interval: 1.06-1.54, p = .012) and prolonged procedure time (1.01, [1.00-1.03], p = .026) increased the risk of SBIs in CAS, whereas only age increased the risk of SBIs in VBS (1.08 [1.01-1.16], p = .036)., Conclusions: Compared to CAS, VBS was associated with longer procedure time, more residual stenosis, and more SBIs, especially outside the stent-inserted vascular territory. The risk of SBIs after CAS was associated with stent size and procedural difficulty. Only age was associated with SBIs in VBS. The pathomechanism of SBIs after VBS and CAS may be different., (© 2023 American Society of Neuroimaging.)

Background: Thromboelastography (TEG) is a useful for predicting hemorrhagic transformation, early neurological deterioration, and functional outcome after stroke. We aimed to investigate whether TEG value could also be useful in predicting functional outcome via various intraprocedural and postprocedural factors in patients with acute large vessel occlusive stroke who underwent intraarterial thrombectomy (IAT)., Methods: Patients with ischemic stroke who underwent IAT between March 2018 and March 2020 at two tertiary hospitals were included. The association between reaction time (R) and functional outcome was evaluated. The primary outcome was the achievement of functional independence defined as the achievement of a modified Rankin Scale (mRS) score of 0-2 at 3 months after the index stroke., Results: Among a total of 160 patients (mean age, 70.6 ± 12.3 years; 103 [64.4 %] men), 79 (49.3 %) achieved functional independence at 3 months. R, both as a continuous (odds ratio [OR]: 1.45, 95 % confidence interval [95 % CI]: 1.09-1.92, P = 0.011) and dichotomized parameters (R < 5 min [OR: 0.37, 95 % CI: 0.16-0.82, P = 0.014]), were inversely associated with increased odds of achieving functional independence (mRS score 0-2) after multivariable analysis. The association was still consistent when the outcome was the achievement of disability free (mRS score 0-1) or mRS score analyzed as an ordinal variable., Conclusions: Decreased R, especially R < 5 min, was inversely associated with functional outcome pf stroke after EVT., Competing Interests: Declaration of competing interest The authors have no financial conflicts of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Propensity for lesion lateralization in atrial fibrillation-related cardiac embolic stroke (AF-stroke) remains controversial. In this study, we compared the hemispheric differences among patients with AF-stroke and identified factors associated with lesion laterality., Methods: We retrospectively reviewed patients with acute AF-stroke admitted from January, 2017 to March, 2022. Patients were grouped based on whether lesions were right or left hemispheric in the anterior circulation territory, based on diffusion-weighted imaging. Factors associated with right-side propensity were analyzed., Results: Among 385 patients, the mean age was 74±11 years and 52.5 % were male. Right and left hemispheric lesions were observed in 189 (49.1 %) and 196 (50.9%) patients, respectively. In the multivariate analysis, enlarged left atrium (LA) (adjusted odds ratio [aOR]=1.03, 95% confidential interval [CI], 1.007-1.061; p=0.013) and single confluent lesion pattern (aOR= 1.55, 95% CI, 1.012-2.381; p=0.044) were associated with right hemispheric lesions., Conclusions: Enlarged LA and single confluent lesion pattern were strongly related to right-sided propensity in patients with AF-stroke., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Purpose: Endovascular thrombectomy (EVT) has benefits in selected patients 6-24 h after stroke onset. However, the response to EVT >24 h after stroke onset is still unclear. We compared the early response to EVT in patients with different time windows., Methods: Patients who underwent EVT in an emergency setting were enrolled and categorized according to when EVT was performed: within 6 (early), 6-24 (late), and >24 h (very late) after stroke onset. Early neurological improvement (ENI) and deterioration (END) were defined as improvement and worsening, respectively, of National Institutes of Health Stroke Scale (NIHSS) score by ≥4 points after EVT. The three groups' clinical characteristics and response to EVT were compared. We also investigated factors associated with ENI and END., Results: During study period, 274 patients underwent EVT (109 early, 104 late, and 61 very late). Patients who underwent EVT very late were younger (p = 0.007), had smaller ischemic cores, and had lower initial NIHSS scores (8 ± 5) than those who underwent EVT early (14 ± 6) and late (13 ± 7; p < 0.001). Stroke mechanisms also differed according to the time window (p < 0.001): cardioembolism was more common after early EVT, whereas large-artery atherosclerosis was more prevalent among patients who underwent EVT very late. ENI was significantly more common after early (60.6%) and late EVT (51.0%) than after very late EVT (29.5%; p = 0.001); however, rates of END did not differ (11.0%, 13.5%, and 4.9%, respectively). ENI was independently associated with male, higher NIHSS score, and early and late EVT. END was associated with failure of recanalization., Conclusions: ENI was more observed and associated with early and late EVT. Highly selected patients receiving very late EVT may not benefit from ENI but may still have a chance to prevent END. The occurrence of END was associated not with time window but with failure of recanalization., (© 2022 S. Karger AG, Basel.)

Background and Purpose: Treatment of acute ischemic stroke is heavily contingent upon time, as there is a strong relationship between time clock and tissue progression. Work has established imaging biomarker assessments as surrogates for time since stroke (TSS), namely, by comparing signal mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) imaging. Our goal was to develop an automatic technique for determining TSS from imaging that does not require subspecialist radiology expertise., Methods: Using 772 patients (66 ± 9 years, 319 women), we developed and externally evaluated a deep learning network for classifying TSS from MR images and compared algorithm predictions to neuroradiologist assessments of DWI-FLAIR mismatch. Models were trained to classify TSS within 4.5 hours and performance metrics with confidence intervals were reported on both internal and external evaluation sets., Results: Three board-certified neuroradiologists' DWI-FLAIR mismatch assessments, based on majority vote, yielded a sensitivity of .62, a specificity of .86, and a Fleiss' kappa of .46 when used to classify TSS. The deep learning method performed similarly to radiologists and outperformed previously reported methods, with the best model achieving an average evaluation accuracy, sensitivity, and specificity of .726, .712, and .741, respectively, on an internal cohort and .724, .757, and .679, respectively, on an external cohort., Conclusion: Our model achieved higher generalization performance on external evaluation datasets than the current state-of-the-art for TSS classification. These results demonstrate the potential of automatic assessment of onset time from imaging without the need for expertly trained radiologists., (© 2022 American Society of Neuroimaging.)

Two different stroke mechanisms are involved in small vessel disease: branch atheromatous disease (BAD) and lipohyalinotic degeneration (LD). We compared mechanisms of stroke in lenticulostriate arteries (LSA) vs. anterior pontine arteries (APA) and verified factors associated with stroke mechanisms, including shape of middle cerebral artery (MCA) and basilar artery (BA). We retrospectively reviewed patients with acute ischemic stroke with penetrating artery territory confirmed by MRI. The mechanisms of stroke were categorized based on diffusion-weighted imaging; BAD was defined as lesion larger than 10 mm in LSA and lesions involving basal pontine in APA. Other lesions were classified as LD. The shapes of MCA and BA were classified as straight, with one angle, or with two angles (U, C or S shape, respectively) using anterior-posterior view. The study included 221 patients. LD was more common in LSA infarcts, but BAD was more common in APA infarcts (p < 0.001). Low initial National Institutes of Health Stroke Scale [Adjusted Odds ratio (aOR) = 0.78; p < 0.001], absence of hyperlipidemia [aOR = 0.31; p = 0.002], previous statin use [aOR = 4.35; p = 0.028] LSA infarcts [reference = APA territory; aOR = 11.07; p < 0.001], and S-shaped vessels (reference = straight shaped vessels; aOR = 3.51; p = 0.004) were independently associated with LD. Angulations in the mother vessels may be more associated with true small vessel disease more with LD than BAD., (© 2022. The Author(s).)

Background: The effect of cholesterol on the functional outcome after endovascular thrombectomy (EVT) is still controversial. This study aimed to investigate whether the lipid profile is associated with the EVT prognosis., Methods: We retrospectively analyzed patients with emergent large vessel occlusion who underwent EVT. The blood lipid levels were measured in the fasting state, 1 day after admission. We divided patients into terciles of serum total cholesterol (TC) levels and compared the clinical characteristics among the groups. The factors associated with a good outcome at 3 months (modified Rankin scale 0-2) were investigated, considering the stroke mechanism and recanalization status., Results: Among 274 patients, good outcomes were observed in 108 (39.4%) patients. Low initial severity (odds ratio (OR), 0.91, 95% confidence interval (CI), 0.858-0.954; p < 0.001) and high TC level (1.35, 1.034-1.758; p = 0.041) were associated with good outcomes. In patients with cardioembolism, young age (0.95, 0.915-0.991; p = 0.021), low initial severity (0.92, 0.857-0.988; p = 0.024), and high TC level (1.60, 1.019-2.499; p = 0.036) were associated with good outcomes. The lipid profile was not associated with a functional outcome in those with large artery atherosclerosis. In patients with complete recanalization, young age (0.97, 0.941-0.994; p = 0.016), low initial severity (0.91, 0.864-0.961; p = 0.001), absence of diabetes (0.45, 0.218-0.947; p = 0.035) or any hemorrhage (0.33, 0.142-0.760; p = 0.009), and high TC level (1.40, 1.031-1.879; p = 0.031) were associated with good outcomes., Conclusions: A high TC level was associated with favorable outcomes after EVT, especially in patients with cardioembolism and complete recanalization., (© 2022. Fondazione Società Italiana di Neurologia.)

Objective: Chronic kidney disease (CKD) increases blood pressure variability (BPV) and affects stroke outcomes. However, the effect of BPV on early neurological deterioration (END) may be different according to the renal function., Methods: We enrolled ischemic stroke patients with a National Institutes of Health Stroke Scale of ≤5. END was defined as worsening of ≥1 point in motor power or ≥2 points in total score. BPV was calculated with BP measured during the first 5 days and presented as standard deviation (SD) and coefficient of variation (CoV). Renal function was classified using the Kidney Disease Improving Global Outcomes (KDIGO) classification of CKD. Variables were compared between those with (KDIGO classification: moderate- to very-high-risk) and without renal impairment (KDIGO classification: low-risk) and factors associated with END were investigated., Results: Among the 290 patients (136 [46.9%] renal impairment), END was observed in 59 (20.3%) patients. BPV parameters and the risk of END increased as renal function was impaired. Renal function and systolic BP (SBP) mean, SD, CoV, and diastolic BP (DBP) mean, SD were independently associated with END. We found no association between BPV parameters and END in normal renal function patients; however, among impaired renal function patients, SBP SD (odds ratio [OR]: 1.20, 95% confidence interval [CI]: 1.09-1.32, P<0.001) and CoV (1.30 [1.12-1.50], P<0.001) were associated with END., Conclusions: The association between END and BPV parameters differs according to renal function in minor ischemic stroke; BPV was associated with END in patients with renal impairment, but less in those with normal renal function., Competing Interests: The authors have declared that no competing interests exist.

Background Which type of recurrent stroke is associated with pulse pressure (PP) remains uncertain in ischemic stroke with cerebral microbleeds or intracerebral hemorrhage. Methods and Results The PICASSO (Prevention of Cardiovascular Events in Ischemic Stroke Patients With High Risk of Cerebral Hemorrhage) database involving 1454 subjects was analyzed. Subjects were stratified into quartiles according to the distribution of mean PP (mm Hg) during follow-up (mean, 1.9 years): <47 (first quartile), 48 to 53 (second quartile), 54 to 59 (third quartile), and ≥60 mm Hg (fourth quartile). The primary end point was hemorrhagic stroke, and the secondary end points were ischemic stroke, stroke of any type, and major adverse cardiovascular events. Adjusted time-dependent area under the receiver operating characteristic curve analysis was performed to assess the prediction accuracy of mean PP. The mean frequency of visit for blood pressure checkup was 9.4±5.5 times. The stroke incidence rate per 100 person-years was 3.14, 2.24, 5.52, and 6.22, respectively in increasing quartile of mean PP, and the rate of major adverse cardiovascular events was 3.82, 2.84, 6.37, and 7.14, respectively. In the presence of mean arterial pressure, hemorrhagic stroke risk was higher in the highest quartile (adjusted hazard ratio, 6.03; 95% CI, 1.04-34.99) versus the lowest quartile, which was evident at higher mean systolic blood pressure. Higher mean PP as a continuous variable was also a predictor of hemorrhagic stroke (1.09, 1.03-1.15). The time-dependent area under the receiver operating characteristic curve for hemorrhagic stroke was 0.79. Conclusions Long-term elevated PP with higher systolic blood pressure confers a greater risk of subsequent hemorrhagic stroke among stroke patients with cerebral microbleeds or intracerebral hemorrhage. Registration URL: https://www.clinicaltrials.gov; Unique identifier, NCT01013532.

Background: Clinical-diffusion mismatch (CDM) and perfusion-diffusion mismatch (PDM) are used to select patients for endovascular thrombectomy (EVT) in the late-window period. As CDM well reflects true penumbra, we hypothesized that patients with CDM and PDM would respond better to EVT than those with PDM only at the late-window period., Methods: Acute ischemic stroke patients who received EVT 6-24 h after stroke onset were included. PDM (perfusion-/diffusion-weighted image (DWI) lesion volume >1.8) was used to select candidates for EVT in this time-period in our center. CDM was defined according to the DAWN trial criteria. Response to EVT was compared between patients with and without CDM. Early neurological improvement (ENI) was defined as improvement >4 points on National Institutes of Health Stroke Scale (NIHSS) score 1 day after EVT. Multivariable analysis was performed to investigate independent factors associated with ENI. The correlation between DWI lesion volume and NIHSS score was investigated in those with and without CDM., Results: Among 94 patients enrolled, all patients had PDM and 44 (46.3%) had CDM. Forty-eight patients (51.1%) showed ENI. The prevalence of hypertension, initial NIHSS score, improvement in NIHSS score after EVT, and prevalence of ENI were greater in patients with CDM than those without. ENI was independently associated with onset-to-door time (odds ratio [95% confidence interval]: 0.998 [0.997-1.000]; p = 0.042), complete recanalization (23.912 [2.238-255.489]; p = 0.009), initial NIHSS score (1.180 [1.012-1.377]; p = 0.034), and the presence of CDM (5.160 [1.448-18.386]; p = 0.011). The correlation between DWI lesion volume and initial NIHSS score was strong in patients without CDM (r = 0.731) but only moderate in patients with CDM (r = 0.355)., Conclusion: Patients with both CDM and PDM had a better response to late-window EVT than those with PDM only., (© 2021 S. Karger AG, Basel.)

Treating acute ischemic stroke (AIS) patients is a time-sensitive endeavor, as therapies target areas experiencing ischemia to prevent irreversible damage to brain tissue. Depending on how an AIS is progressing, thrombolytics such as tissue-plasminogen activator (tPA) may be administered within a short therapeutic window. The underlying conditions for optimal treatment are varied. While previous clinical guidelines only permitted tPA to be administered to patients with a known onset within 4.5 hours, clinical trials demonstrated that patients with signal intensity differences between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) sequences in an MRI study can benefit from thrombolytic therapy. This intensity difference, known as DWI-FLAIR mismatch, is prone to high inter-reader variability. Thus, a paradigm exists where onset time serves as a weak proxy for DWI-FLAIR mismatch. In this study, we sought to detect DWI-FLAIR mismatch in an automated fashion, and we compared this to assessments done by three expert neuroradiologists. Our approach involved training a deep learning model on MRI to classify tissue clock and leveraging time clock as a weak proxy label to supplement training in a semi-supervised learning (SSL) framework. We evaluate our deep learning model by testing it on an unseen dataset from an external institution. In total, our proposed framework was able to improve detection of DWI-FLAIR mismatch, achieving a top ROC-AUC of 74.30%. Our study illustrated that incorporating clinical proxy information into SSL can improve model optimization by increasing the fidelity of unlabeled samples included in the training process.

Objectives: The prognosis of a cerebral artery dissection is known to be benign, but the structural changes of vessel wall at follow-up are not well known. The natural course of an intracranial and extracranial artery dissection may differ due to structural differences. We aimed to figure out how stenosis and other wall features change, according to the dissection location.Materials and Methods: We retrospectively enrolled patients who suffered an ischemic stroke or transient ischemic attack due to a dissection and who had undergone both initial and follow-up high-resolution magnetic resonance imaging (HRMRI). Patients were dichotomized to intracranial or extracranial dissection group. The clinical and HRMRI characteristics of two groups were compared. Factors associated with stenosis changes were also investigated.Results: A total of 57 patients (intracranial, n = 43; and extracranial, n = 14) were enrolled. The mean age (45.6 vs. 32.2, p < 0.001) was higher and hypertension (37.2% vs. 7.1%, p = 0.04) was more frequent in the intracranial dissection group. In HRMRI analysis, stenosis improvement (27.9% vs. 85.7%, p < 0.001) were more frequent whereas residual wall enhancement (86.0% vs. 46.2%, p = 0.006) and intramural hematoma (62.8% vs. 21.4%, p = 0.007) were less frequent in the extracranial dissection group. Multivariate analysis indicated that extracranial location was the only independent factor (odds ratio 8.98, 95 % confidence interval 1.45-55.65; p = 0.02) associated with stenosis improvement.Conclusions: Younger age, stenosis improvement, disappearance of wall enhancement and intramural hematoma were more frequent in an extracranial dissection compared with an intracranial dissection. An extracranial location is independently associated with stenosis improvement in dissection patients. [ABSTRACT FROM AUTHOR]