Repeated-root cyclic and negacyclic codes over a finite chain ring

AbstractWe show that repeated-root cyclic codes over a finite chain ring are in general not principally generated. Repeated-root negacyclic codes are principally generated if the ring is a Galois ring with characteristic a power of 2. For any other finite chain ring they are in general not principally generated. We also prove results on the structure, cardinality and Hamming distance of repeated-root cyclic and negacyclic codes over a finite chain ring

Effect of first pass reperfusion on outcome in patients with posterior circulation ischemic stroke

BACKGROUND: First pass reperfusion (FPR), that is, excellent reperfusion (expanded treatment in cerebral ischemia (eTICI) 2C-3) in one pass, after endovascular treatment (EVT) of an occluded artery in the anterior circulation, is associated with favorable clinical outcome, even when compared with multiple pass excellent reperfusion (MPR). In patients with posterior circulation ischemic stroke (PCS), the same association is expected, but currently unknown. We aimed to assess characteristics associated with FPR and the influence of FPR versus MPR on outcomes in patients with PCS. METHODS: We used data from the MR CLEAN Registry, a prospective observational study. The effect of FPR on 24-hour National Institutes of Health Stroke Scale (NIHSS) score, as percentage reduction, and on modified Rankin Scale (mRS) scores at 3 months, was tested with linear and ordinal logistic regression models. RESULTS: Of 224 patients with PCS, 45 patients had FPR, 47 had MPR, and 90 had no excellent reperfusion (eTICI <2C). We did not find an association between any of the patient, imaging, or treatment characteristics and FPR. FPR was associated with better NIHSS (-45% (95% CI: -65% to -12%)) and better mRS scores (adjusted common odds ratio (acOR): 2.16 (95% CI: 1.23 to 3.79)) compared with no FPR. Outcomes after FPR were also more favorable compared with MPR, but the effect was smaller and not statistically significant (NIHSS: -14% (95% CI: -51% to 49%), mRS acOR: 1.50 (95% CI: 0.75 to 3.00)). CONCLUSIONS: FPR in patients with PCS is associated with favorable clinical outcome in comparison with no FPR. In comparison with MPR, the effect of FPR was no longer statistically significant. Nevertheless, our data support the notion that FPR should be the treatment target to pursue in every patient treated with EVT

Endovascular Treatment for Acute Ischemic Stroke in Patients on Oral Anticoagulants: Results from the MR CLEAN Registry

Background and Purpose - The use of oral anticoagulants (OAC) is considered a contra-indication for intravenous thrombolytics as acute treatment of ischemic stroke. However, little is known about the risks and benefits of endovascular treatment in patients on prior OAC. We aim to compare outcomes after endovascular treatment between patients with and without prior use of OAC. Methods - Data of patients with acute ischemic stroke caused by an intracranial anterior circulation occlusion, included in the nationwide, prospective, MR CLEAN Registry between March 2014 and November 2017, were analyzed. Outcomes of interest included symptomatic intracranial hemorrhage and functional outcome at 90 days (modified Rankin Scale score). Outcomes between groups were compared with (ordinal) logistic regression analyses, adjusted for prognostic factors. Results - Three thousand one hundred sixty-two patients were included in this study, of whom 502 (16%) used OAC. There was no significant difference in the occurrence of symptomatic intracranial hemorrhage between patients with and without prior OACs (5% versus 6%; adjusted odds ratio, 0.63 [95% CI, 0.38-1.06]). Patients on OACs had worse functional outcomes than patients without OACs (common odds ratio, 0.57 [95% CI, 0.47-0.66]). However, this observed difference in functional outcome disappeared after adjustment for prognostic factors (adjusted common odds ratio, 0.91 [95% CI, 0.74-1.13]). Conclusions - Prior OAC use in patients treated with endovascular treatment for ischemic stroke is not associated with an increased risk of symptomatic intracranial hemorrhage or worse functional outcome compared with no prior OAC use. Therefore, prior OAC use should not be a contra-indication for endovascular treatment

White Matter Lesions and Outcomes After Endovascular Treatment for Acute Ischemic Stroke:MR CLEAN Registry Results

BACKGROUND: Cerebral white matter lesions (WMLs) have been associated with a greater risk of poor functional outcome after ischemic stroke. We assessed the relations between WML burden and radiological and clinical outcomes in patients treated with endovascular treatment in routine practice. METHODS: We analyzed data from the MR CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischaemic Stroke in the Netherlands)-a prospective, multicenter, observational cohort study of patients treated with endovascular treatment in the Netherlands. WMLs were graded on baseline noncontrast computed tomography using a visual grading scale. The primary outcome was the score on the modified Rankin Scale at 90 days. Secondary outcomes included early neurological recovery, successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2b), futile recanalization (modified Rankin Scale score ≥3 despite successful reperfusion), and occurrence of symptomatic intracranial hemorrhage. We used multivariable logistic regression models to assess associations between WML severity and outcomes, taking the absence of WML on noncontrast computed tomography as the reference category. RESULTS: Of 3180 patients included in the MR CLEAN Registry between March 2014 and November 2017, WMLs were graded for 3046 patients and categorized as none (n=1855; 61%), mild (n=608; 20%), or moderate to severe (n=588; 19%). Favorable outcome (modified Rankin Scale score, 0-2) was achieved in 838 patients (49%) without WML, 192 patients (34%) with mild WML, and 130 patients (24%) with moderate-to-severe WML. Increasing WML grades were associated with a shift toward poorer functional outcome in a dose-dependent manner (adjusted common odds ratio, 1.34 [95% CI, 1.13-1.60] for mild WML and 1.67 [95% CI, 1.39-2.01] for moderate-to-severe WML; Ptrend, <0.001). Increasing WML grades were associated with futile recanalization (Ptrend, <0.001) and were inversely associated with early neurological recovery (Ptrend, 0.041) but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage. CONCLUSIONS: An increasing burden of WML at baseline is associated with poorer clinical outcomes after endovascular treatment for acute ischemic stroke but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage

Assessment of collateral status by dynamic ct angiography in acute mca stroke: Timing of acquisition and relationship with final infarct volume

BACKGROUND AND PURPOSE: Dynamic CTA is a promising technique for visualization of collateral filling in patients with acute ischemic stroke. Our aim was to describe collateral filling with dynamic CTA and assess the relationship with infarct volume at follow-up. MATERIALS AND METHODS: We selected patients with acute ischemic stroke due to proximal MCA occlusion. Patients underwent NCCT, single-phase CTA, and whole-brain CT perfusion/dynamic CTA within 9 hours after stroke onset. For each patient, a detailed assessment of the extent and velocity of arterial filling was obtained. Poor radiologic outcome was defined as an infarct volume of\70 mL. The association between collateral score and follow-up infarct volume was analyzed with Poisson regression. RESULTS: Sixty-one patients with a mean age of 67 years were included. For all patients combined, the interval that contained the peak of arterial filling in both hemispheres was between 11 and 21 seconds after ICA contrast entry. Poor collateral status as assessed with dynamic CTA was more strongly associated with infarct volume of 70 mL (risk ratio, 1.9; 95% CI, 1.3-2.9) than with single-phase CTA (risk ratio, 1.4; 95% CI, 0.8-2.5). Four subgroups (good-versus-poor and fast-versus-sl

Comparing Pandemic to Seasonal Influenza Mortality: Moderate Impact Overall but High Mortality in Young Children

Background: We assessed the severity of the 2009 influenza pandemic by comparing pandemic mortality to seasonal influenza mortality. However, reported pandemic deaths were laboratory-confirmed - and thus an underestimation - whereas seasonal influenza mortality is often more inclusively estimated. For a valid comparison, our study used the same statistical methodology and data types to estimate pandemic and seasonal influenza mortality. Methods and Findings: We used data on all-cause mortality (1999-2010, 100% coverage, 16.5 million Dutch population) and influenza-like-illness (ILI) incidence (0.8% coverage). Data was aggregated by week and age category. Using generalized estimating equation regression models, we attributed mortality to influenza by associating mortality with ILI-incidence, while adjusting for annual shifts in association. We also adjusted for respiratory syncytial virus, hot/cold weather, other seasonal factors and autocorrelation. For the 2009 pandemic season, we estimated 612 (range 266-958) influenza-attributed deaths; for seasonal influen

qTICI: Quantitative assessment of brain tissue reperfusion on digital subtraction angiograms of acute ischemic stroke patients

Background: The Thrombolysis in Cerebral Infarction (TICI) scale is an important outcome measure to evaluate the quality of endovascular stroke therapy. The TICI scale is ordinal and observer-dependent, which may result in suboptimal prediction of patient outcome and inconsistent reperfusion grading. Aims: We present a semi-automated quantitative reperfusion measure (quantified TICI (qTICI)) using image processing techniques based on the TICI methodology. Methods: We included patients with an intracranial proximal large vessel occlusion with complete, good quality runs of anteroposterior and lateral digital subtraction angiography from the MR CLEAN Registry. For each vessel occlusion, we identified the target downstream territory and automatically segmented the reperfused area in the target downstream territory on final digital subtraction angiography. qTICI was defined as the percentage of reperfused area in target downstream territory. The value of qTICI and extended TICI (eTICI) in predicting favorable functional outcome (modified Rankin Scale 0–2) was compared using area under receiver operating characteristics curve and binary logistic regression analysis unadjusted and adjusted for known prognostic factors. Results: In total, 408 patients with M1 or internal carotid artery occlusion were included. The median qTICI was 78 (interquartile range 58–88) and 215 patients (53%) had an eTICI of 2C or higher. qTICI was comparable to eTICI in predicting favorable outcome with area under receiver operating characteristics curve of 0.63 vs. 0.62 (P = 0.8) and 0.87 vs. 0.86 (P = 0.87), for the unadjusted and adjusted analysis, respectively. In the adjusted regression analyses, both qTICI and eTICI were independently associated with functional outcome. Conclusion: qTICI provides a quantitative measure of reperfusion with similar prognostic value for functional outcome to eTICI score

Neurobiological basis and risk factors of persistent fatigue and concentration problems after COVID-19: study protocol for a prospective case–control study (VeCosCO)

Introduction: The risk factors for persistent fatigue and cognitive complaints after infection with SARS-CoV-2 and the underlying pathophysiology are largely unknown. Both clinical factors and cognitive-behavioural factors have been suggested to play a role in the perpetuation of complaints. A neurobiological aetiology, such as neuroinflammation, could be the underlying pathophysiological mechanism for persisting complaints. To unravel factors associated with persisting complaints, VeCosCO will compare individuals with and without persistent fatigue and cognitive complaints >3 months after infection with SARS-CoV-2. The study consists of two work packages. The first work package aims to (1) investigate the relation between persisting complaints and neuropsychological functioning; (2) determine risk factors and at-risk phenotypes for the development of persistent fatigue and cognitive complaints, including the presence of postexertional malaise and (3) describe consequences of persistent complaints on quality of life, healthcare consumption and physical functioning. The second work package aims to (1) determine the presence of neuroinflammation with [18F]DPA-714 whole-body positron emission tomography (PET) scans in patients with persisting complaints and (2) explore the relationship between (neuro)inflammation and brain structure and functioning measured with MRI. / Methods and analysis: This is a prospective case–control study in participants with and without persistent fatigue and cognitive complaints, >3 months after laboratory-confirmed SARS-CoV-2 infection. Participants will be mainly included from existing COVID-19 cohorts in the Netherlands covering the full spectrum of COVID-19 acute disease severity. Primary outcomes are neuropsychological functioning, postexertional malaise, neuroinflammation measured using [18F]DPA-714 PET, and brain functioning and structure using (f)MRI. / Ethics and dissemination: Work package 1 (NL79575.018.21) and 2 (NL77033.029.21) were approved by the medical ethical review board of the Amsterdam University Medical Centers (The Netherlands). Informed consent is required prior to participation in the study. Results of this study will be submitted for publication in peer-reviewed journals and shared with the key population