Plasma Inflammatory Biomarkers Are Associated With Poststroke Cognitive Impairment: The Nor-COAST Study.

BACKGROUND: Inflammation is proposed to be involved in the pathogenesis of poststroke cognitive impairment. The aim of this study was to investigate associations between concentrations of systemic inflammatory biomarkers after ischemic stroke and poststroke cognitive impairment. METHODS: The Nor-COAST study (Norwegian Cognitive Impairment After Stroke) is a prospective observational multicenter cohort study, including patients hospitalized with acute stroke between 2015 and 2017. Inflammatory biomarkers, including the TCC (terminal C5b-9 complement complex) and 20 cytokines, were analyzed in plasma, collected at baseline, 3-, and 18 months poststroke, using ELISA and a multiplex assay. Global cognitive outcome was assessed with the Montreal Cognitive Assessment (MoCA) scale. We investigated the associations between plasma inflammatory biomarkers at baseline and MoCA score at 3-, 18-, and 36-month follow-ups; the associations between inflammatory biomarkers at 3 months and MoCA score at 18- and 36-month follow-ups; and the association between these biomarkers at 18 months and MoCA score at 36-month follow-up. We used mixed linear regression adjusted for age and sex. RESULTS: We included 455 survivors of ischemic stroke. Higher concentrations of 7 baseline biomarkers were significantly associated with lower MoCA score at 36 months; TCC, IL (interleukin)-6, and MIP (macrophage inflammatory protein)-1α were associated with MoCA at 3, 18, and 36 months (P<0.01). No biomarker at 3 months was significantly associated with MoCA score at either 18 or 36 months, whereas higher concentrations of 3 biomarkers at 18 months were associated with lower MoCA score at 36 months (P<0.01). TCC at baseline and IL-6 and MIP-1α measured both at baseline and 18 months were particularly strongly associated with MoCA (P<0.01). CONCLUSIONS: Higher concentrations of plasma inflammatory biomarkers were associated with lower MoCA scores up to 36 months poststroke. This was most pronounced for inflammatory biomarkers measured in the acute phase following stroke. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02650531.

Stroke risk after transient ischemic attack in a Norwegian prospective cohort.

BACKGROUND: Transient ischemic attack (TIA) is a risk factor of stroke. Modern treatment regimens and changing risk factors in the population justify new estimates of stroke risk after TIA, and evaluation of the recommended ABCD2 stroke risk score. METHODS: From October, 2012, to July, 2014, we performed a prospective, multicenter study in Central Norway, enrolling patients with a TIA within the previous 2 weeks. Our aim was to assess stroke risk at 1 week, 3 months and 1 year after TIA, and to determine the predictive value of the dichotomized ABCD2 score (0-3 vs 4-7) at each time point. We used data obtained by telephone follow-up and registry data from the Norwegian Stroke Register. RESULTS: Five hundred and seventy-seven patients with TIA were enrolled of which 85% were examined by a stroke specialist within 24 h after symptom onset. The cumulative incidence of stroke within 1 week, 3 months and 1 year of TIA was 0.9% (95% CI, 0.37-2.0), 3.3% (95% CI, 2.1-5.1) and 5.4% (95% CI, 3.9-7.6), respectively. The accuracy of the ABCD2 score provided by c-statistics at 7 days, 3 months and 1 year was 0.62 (95% CI, 0.39-0.85), 0.62 (95% CI, 0.51-0.74) and 0.64 (95% CI, 0.54-0.75), respectively. CONCLUSIONS: We found a lower stroke risk after TIA than reported in earlier studies. The ABCD2 score did not reliably discriminate between low and high risk patients, suggesting that it may be less useful in populations with a low risk of stroke after TIA. TRIAL REGISTRATION: Unique identifier: NCT02038725 (retrospectively registered, January 16, 2014).

The Norwegian Cognitive impairment after stroke study (Nor-COAST): study protocol of a multicentre, prospective cohort study.

BACKGROUND: Early and late onset post-stroke cognitive impairment (PCI) contributes substantially to disability following stroke, and is a high priority within stroke research. The aetiology for PCI is complex and related to the stroke itself, brain resilience, comorbid brain diseases, prestroke vulnerability and complications during the hospital stay. The aim of the Norwegian Cognitive Impairment After Stroke study (Nor-COAST) is to quantify and measure levels of cognitive impairments in a general Norwegian stroke population and to identify biological and clinical markers associated with prognosis for cognitive disorders following incident stroke. The study will be organised within five work packages: 1) Incidence and trajectories 2) Pathological mechanisms 3) Development of a risk score 4) Impact of physical activity and 5) Adherence to secondary prevention. METHODS: Nor-COAST is an ongoing multicentre (five participating hospitals), prospective, cohort study with consecutive inclusion during the acute phase and with follow-up at three and 18 months, and at three years. Inclusion criteria are stroke defined according to the WHO criteria. During the recruitment period from 18.05.2015 to 31.03.2017, 816 participants have been included. Cognitive impairment will be classified according to the DSM-5 criteria using a consensus group. Cognitive function is assessed by a standardised neuropsychological test battery, the Montreal Cognitive Assessment, Trail making A and B, ten-word immediate and delayed recall test, the Controlled Oral Word Association, Global Deterioration Scale and proxy based information by and the Ascertain Dementia 8 item informant questionnaire. Biomarkers include magnetic resonance imaging, routine blood samples and bio-banking. Clinical assessments include characteristics of the stroke, comorbidity, delirium, frailty and tests for cognitive and physical function, sensor based activity monitoring and adherence to secondary prophylaxis. DISCUSSION: Nor-COAST is the first Norwegian multicentre study to quantify burden of PCI that will provide reliable estimates in a general stroke population. A multidisciplinary approach aiming to identify biomarkers and clinical markers of overall prognosis will add new knowledge about risk profiles, including pre-stroke vulnerability and modifiable factors such as physical activity and secondary prophylaxis of relevance for clinical practice and later intervention studies. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02650531 . Retrospectively registered January 8, 2016. First participant included May 18, 2015.

Hospital differences in motor activity early after stroke: a comparison of 11 Norwegian stroke units.

BACKGROUND: Activity levels in patients early after stroke vary across the world. The primary aim of this study was to assess the variation in motor activity in patients admitted to multiple Norwegian stroke units and to identify factors which explained the variation between hospitals. METHODS: Eligible patients were those less than 14 days after stroke, more than 18 years, not receiving palliative care. Activity levels, people present, and location were recorded by the use of a standard method of observation between 8 am and 5 pm. Hospital policy on serving meals in communal areas was also registered. Mixed general binomial model was used to analyze, which factors explained variation in activity levels between hospitals, after adjusting for age and stroke severity. RESULTS: A total of 393 patients from 11 stroke units were included. The patients spent 44.1% of the day in bed, 43.2% sitting out of bed, and 8.3% in higher motor activities (4.4% were not observed). Increased physical activity was associated with spending more time with a physical therapist, odds ratio (OR), 1.05 (95% confidence interval [CI], 1.03-1.08, P < .001) and admitted to a hospital serving the meals in communal areas, OR, 1.46 (95% CI, 1.09-1.95, P = .011). CONCLUSIONS: Despite variation between the hospitals, patients admitted to Norwegian stroke units spend most of the day out of bed. Time spent with a physical therapist and hospitals having a policy of serving meals in communal areas explained most of the variation in activity between hospitals.