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Background: Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and therefore have potential to be used for genetic risk prediction. We constructed a genetic risk score to (1) predict ASAH incidence and IA presence (combined set of unruptured IA and ASAH) and (2) assess its association with patient characteristics. Methods: A genetic risk score incorporating genetic association data for IA and 17 traits related to IA (so-called metaGRS) was created using 1161 IA cases and 407 392 controls from the UK Biobank population study. The metaGRS was validated in combination with risk factors blood pressure, sex, and smoking in 828 IA cases and 68 568 controls from the Nordic HUNT population study. Furthermore, we assessed association between the metaGRS and patient characteristics in a cohort of 5560 IA patients. Results: Per SD increase of metaGRS, the hazard ratio for ASAH incidence was 1.34 (95% CI, 1.20–1.51) and the odds ratio for IA presence 1.09 (95% CI, 1.01–1.18). Upon including the metaGRS on top of clinical risk factors, the concordance index to predict ASAH hazard increased from 0.63 (95% CI, 0.59–0.67) to 0.65 (95% CI, 0.62–0.69), while prediction of IA presence did not improve. The metaGRS was statistically significantly associated with age at ASAH (β=−4.82×10 −3 per year [95% CI, −6.49×10 −3 to −3.14×10 −3 ]; P =1.82×10 −8 ), and location of IA at the internal carotid artery (odds ratio=0.92 [95% CI, 0.86–0.98]; P =0.0041). Conclusions: The metaGRS was predictive of ASAH incidence, although with limited added value over clinical risk factors. The metaGRS was not predictive of IA presence. Therefore, we do not recommend using this metaGRS in daily clinical care. Genetic risk does partly explain the clinical heterogeneity of IA warranting prioritization of clinical heterogeneity in future genetic prediction studies of IA and ASAH.

Background and aimsTo investigate the prognostic value of blood neurofilament light chain protein (NfL) levels in the acute phase of coronavirus disease 2019 (COVID-19).MethodsWe conducted an individual participant data (IPD) meta-analysis after screening on MEDLINE and Scopus to May 23rd2022. We included studies with hospitalized adult COVID-19 patients without major COVID-19-associated central nervous system (CNS) manifestations and with a measurement of blood NfL in the acute phase as well as data regarding at least one clinical outcome including intensive care unit (ICU)admission, need of mechanical ventilation (MV) and death. We derived the age-adjusted measures NfL Z scores and conducted mixed-effects modelling to test associations between NfL Z scores and other variables, encompassing clinical outcomes. Summary receiver operating characteristic curves (SROCs) were used to calculate the area under the curve (AUC) for blood NfL.ResultsWe identified 382 records, of which 7 studies were included with a total of 669 hospitalized COVID-19 cases (mean age 66.2 ± 15.0years, 68.1% males). Median NfL Z score at admission was elevated compared to the age-corrected reference population (2.37, IQR: 1.13-3.06, referring to 99th percentile in healthy controls). NfL Z scores were significantly associated with disease duration and severity. Higher NfL Z scores were associated with ahigher likelihood of ICU admission, need ofMV, and death. SROCs revealed AUCs of 0.74, 0.80 and 0.71 for mortality, need ofMV and ICU admission, respectively.ConclusionsBlood NfL levels were elevated in the acute phase of COVID-19 patients without major CNS manifestations and associated with clinical severity and poor outcome. The marker might ameliorate the performance of prognostic multivariable algorithms in COVID-19.

Mechanical thrombectomy is now the standard treatment for acute ischaemic stroke with occlusion of a carotid or intercranial artery. With occlusions of this type, thrombolytic treatment often has limited effect. The therapeutic outcome with the use of thrombectomy is time-dependent, and a personalised approach to indication is always necessary. To achieve the best possible results, the main prerequisites are good clinical procedures, an optimal patient pathway, high neuroradiological competence and coordinated, interdisciplinary teams.

Background Empiric strategies for secondary prevention in cryptogenic stroke and cryptogenic TIA are lacking. The best therapy to prevent recurrence depends on the cause of stroke. Attempting a correct diagnosis is therefore the fundamental goal of stroke treatment. Further investigation into the source of embolism if suspected, and determination of the etiology, even if demanding, is the needed prerequisite for optimal secondary prevention and risk reduction. Aims This paper discusses evaluation and treatment of cryptogenic stroke in light of recent years’ clinical trials results and developments in cardiology and neuroradiology. No ethical approval was needed for this work. Results Cardioembolism due to paroxysmal atrial fibrillation, patent foramen ovale, or cardiomyopathy; occult atherosclerosis from unstable plaques and hypercoagulable conditions seem to be the most common underlying causes to be revealed by further investigations. Treatment of these conditions can reduce the stroke recurrence significantly. Conclusions An individual approach and targeted diagnostics using advanced medical technologies in selected patients, who may benefit from a tailored treatment regimen, can help reveal a probable cause in the majority of strokes and TIAs previously classified as cryptogenic.

Careful brain monitoring saves lives and is beneficial to patients' health. Nevertheless, Norway lacks guidelines for brain monitoring in hospitals.

In this letter-to-the-editor the Task Force on Gender and Diversity issues in Neurology founded under the auspices of the European Academy of Neurology (EAN) addresses various gender issues that are arising during the COVID-19 pandemic. These issues concern different aspects, spanning from gender disparities in health care workforce to gender differences amongst patients suffering from COVID-19, risk factors, occurrence of neurological complications and (outcomes of) management. Due to the continuous flow of COVID-19 related papers this review cannot be comprehensive. We attempted to select the most relevant literature on this topic.

Background and Purpose: Cardioembolic stroke due to paroxysmal atrial fibrillation (AF) may account for 1 out of 4 cryptogenic strokes (CS) and transient ischemic attacks (TIAs). The purpose of this pilot study was to search for biomarkers potentially predicting incident AF in patients with ischemic stroke or TIA. Methods: Plasma samples were collected from patients aged 18 years and older with ischemic stroke or TIA due to AF (n = 9) and large artery atherosclerosis (LAA) with ipsilateral carotid stenosis (n = 8) and age- and sex-matched controls (n = 10). Analyses were performed with the Olink technology simultaneously measuring 184 biomarkers of cardiovascular disease. For bioinformatics, acquired data were analyzed using gene set enrichment analysis (GSEA). Selected proteins were validated using ELISA. Individual receiver operating characteristic (ROC) curves and odds ratios from logistic regression were calculated. A randomForest (RF) model with out-of-bag estimate was applied for predictive modeling. Results: GSEA indicated enrichment of proteins related to inflammatory response in the AF group. Interleukin (IL)-6, growth differentiation factor (GDF)-15, and pentraxin-related protein PTX3 were the top biomarkers on the ranked list for the AF group compared to the LAA group and the control group. ELISA validated increased expression of all tested proteins (GDF-15, PTX3, and urokinase plasminogen activator surface receptor [U-PAR]), except for IL-6. 19 proteins had the area under the ROC curve (AUC) over 0.85 including all of the proteins with significant evolution in the logistic regression. AUCs were very discriminant in distinguishing patients with and without AF (LAA and control group together). GDF-15 alone reached AUC of 0.95. Based on RF model, all selected participants in the tested group were classified correctly, and the most important protein in the model was GDF-15. Conclusions: Our results demonstrate an association between inflammation and AF and that multiple proteins alone and in combination may potentially be used as indicators of AF in CS and TIA patients. However, further studies including larger samples sizes are needed to support these findings. In the ongoing NOR-FIB study, we plan further biomarker assessments in patients with CS and TIA undergoing long-term cardiac rhythm monitoring with insertable cardiac monitors.

There is emerging evidence of an increased risk of venous thromboembolism as well as several reports of cerebral venous thrombosis in COVID-19.A previously healthy man in his fifties was admitted due to sudden confusion and reduced consciousness. One month earlier the patient had symptoms with headache, fever, dry cough, vomiting and diarrhoea and reduced sense of taste and smell. He was diagnosed with COVID-19 and the symptoms were mainly resolved within three weeks. On admission the patient was disorientated with aphasia. Brain imaging revealed a haemorrhagic infarction in the left temporal lobe due to thrombosis of the left transverse sinus and low-molecular weight heparin was instituted. On follow-up four months later, there was clinical improvement with only slight problems with short term memory and concentration.This case illustrates the risk of serious neurological complications due to cerebral venous thrombosis in COVID-19.

Background and Purpose— Thrombolysis with alteplase has beneficial effect on outcome and is safe within 4.5 hours. The present study compares the efficacy and safety of tenecteplase and alteplase in patients treated 3 to 4.5 hours after ischemic stroke. Methods— The data are from a prespecified substudy of patients included in The NOR-TEST (Norwegian Tenecteplase Stroke Trial), a randomized control trial comparing tenecteplase with alteplase. Results— The median admission National Institutes of Health Stroke Scale for this study population was 3 (interquartile range, 2–6). In the intention-to-treat analysis, 57% of patients that received tenecteplase and 53% of patients that received alteplase reached good functional outcome (modified Rankin Scale score of 0–1) at 3 months (odds ratio, 1.19; 95% CI, 0.68–2.10). The rates of intracranial hemorrhage in the first 48 hours were 5.7% in the tenecteplase group and 6.7% in the alteplase group (odds ratio, 0.84; 95% CI, 0.26–2.70). At 3 months, mortality was 5.7% and 4.5%, respectively. After excluding stroke mimics and patients with modified Rankin Scale score of >1 before stroke, the proportion of patients with good functional outcome was 61% in the tenecteplase group and 57% in the alteplase group (odds ratio, 1.24; 95% CI, 0.65–2.37). Conclusions— Tenecteplase is at least as effective as alteplase to achieve a good clinical outcome in patients with mild stroke treated between 3 and 4.5 hours after ischemic stroke. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT01949948.

Persistent symptoms of dizziness may be due to inappropriate compensatory strategies following an episode of acute dizziness. Common symptoms are dizziness in an upright position that is aggravated by visual stimuli and passive movement. In the World Health Organization’s new disease classification, ICD-11, the condition has been named persistent postural-perceptual dizziness. It is important to recognise this condition in order to avoid unnecessary investigation and to initiate the correct treatment.

Background Soluble lectin‐like oxidized low‐density lipoprotein receptor‐1 ( sLOX ‐1) has been shown to be increased in patients with acute ischemic stroke. Here, we evaluated plasma sLOX ‐1 levels and vascular carotid plaque LOX ‐1 (ie, OLR 1 ) gene expression in patients with ischemic stroke and transient ischemic attack ( TIA ) with particular focus on their relation to time since symptom onset. Methods and Results Plasma sLOX ‐1 (n=232) and carotid plaque OLR 1 gene expression (n=146) were evaluated in patients who were referred to evaluation for carotid endarterectomy, as well as in healthy control plasma (n=81). Patients were categorized according to presence of acute ischemic stroke or transient ischemic attack (n=35) ≤7 days, >7 days ≤3 months (n=90), >3 months (n=40), or no reported symptoms before study inclusion (n=67). Our major findings were the following: (1) Patients with carotid atherosclerosis had increased plasma sLOX ‐1 levels as compared with controls. (2) Plaque OLR 1 mRNA levels were increased in carotid plaques (n=146) compared with nonatherosclerotic vessels (ie, common iliac arteries of organ donors, n=10). (3) There were no differences in sLOX plasma levels or OLR 1 gene expression when analyzed according to the time since relevant cerebral ischemic symptoms. (4) Also patients with severe carotid atherosclerosis without any previous ischemic events had raised sLOX ‐1 levels. (5) Immunostaining showed colocalization between LOX ‐1 and macrophages within the carotid plaques. (6) Also patients with acute stroke (within 7 days) caused by atrial fibrillation (n=22) had comparable raised sLOX ‐1 levels. Conclusions sLOX ‐1 levels are elevated in patients with ischemic stroke and transient ischemic attack independent of cause and time since the ischemic event.

Bakgrunn Migrene er en vanlig nevrologisk sykdom som medforer betydelig belastning for den enkelte som rammes, og store helseokonomiske kostnader for samfunnet. Migrene er forbundet med okt risiko for hjerneslag. Formalet med denne artikkelen er a gi en oversikt over sammenhengen mellom migrene og hjerneslag: bade hjerneinfarkt og hjerneblodning, mulige underliggende mekanismer, kliniske implikasjoner og behovet for videre forskning innen feltet. Kunnskapsgrunnlag Denne oversikten er basert pa litteratursok i PubMed med definert sokestreng supplert med et pyramidesok i sokemotoren McMaster PLUS med ordene «migraine» og «stroke», samt gjennomgang av artiklenes referanselister. Resultat Migrene med aura er assosiert med en dobling av risikoen for hjerneinfarkt, men det er ingen sikker okt risiko blant personer med migrene uten aura. Royking, p-pillebruk og hyppige migreneanfall oker risikoen. Det ser ogsa ut til a vaere en noe hoyere forekomst av hjerneblodning hos personer med migrene med og uten aura. Fortolkning Sammenhengen mellom migrene og hjerneslag er kompleks. Det er med bakgrunn i okt risiko for hjerneinfarkt ved migrene med aura anbefalt at modifiserbare risikofaktorer som royking, hypertensjon og p-pillebruk kartlegges grundig og behandles.

The use of new, direct anticoagulants is increasing. Data from both controlled trials and clinical practice have shown that these drugs are as efficacious and safe as warfarin for deep vein thrombosis and pulmonary embolism, and as stroke prophylaxis for patients with atrial fibrillation. But what if platelet inhibition is also indicated? In the following, the combination of antiplatelets and the new anticoagulants is discussed for various indications.

The Nord-Trøndelag Health Study (HUNT 3) performed in 2006-2008 is a replication of the cross-sectional survey from 1995 to 1997 (HUNT 2). The aim of the present study was to assess the sensitivity and specificity of questionnaire-based headache diagnoses using a personal interview by a neurologist as a gold standard. For the questionnaire-based status as headache sufferer, a sensitivity of 88%, a specificity of 86%, and a kappa statistic of 0.70 were found. Chronic headache, chronic tension-type headache (TTH), and medication overuse headache (MOH) were diagnosed with a specificity ofor =99%, and a kappa statistic ofor =0.73. Lower figures were found for the diagnoses of migraine and TTH. For individuals with headacheor =1 day per month, a sensitivity of 58% (migraine) and 96% (TTH), a specificity of 91 and 69%, and a kappa statistic of 0.54 and 0.44 were found, respectively. The specificity for migraine with aura was 95%. In conclusion, the HUNT 3-questionnaire is a valid tool for identifying headache sufferers, and diagnosing patients with chronic headache, including chronic TTH and MOH. The more moderate sensitivity for migraine and TTH makes the questionnaire-based diagnoses of migraine and TTH suboptimal for determining the prevalence. However, the high specificity of the questionnaire-based diagnosis of migraine, in particular for migraine with aura, makes the questionnaire a valid tool for diagnosing patients with migraine for genetic studies.

In patients with diabetes mellitus (DM), there are changes in vascular reactivity and nerve conduction that may be relevant for migraine pathophysiology. However, previous studies on the relationship between headache and DM have shown conflicting results. The aim of the present study was to investigate a possible association between headache and DM in a large population-based cross-sectional study. Associations were assessed in multivariate analyses, estimating prevalence odds ratios (ORs) with 95% confidence intervals (CIs). Prevalence OR of migraine was lower amongst persons with DM compared with those without DM, the OR being 0.4 (95% CI: 0.2-0.9) for type 1 and 0.7 (95% CI: 0.5-0.9) for type 2 DM. Furthermore, OR of headache were lower amongst those with duration of DM > or = 13 years compared with those who had got DM the last 3 years, OR 0.6 (95% CI: 0.4-0.9). The analyses revealed no clear associations between non-migrainous headache and DM. The reason for the inverse relationship between migraine and DM is unknown, but might be related to pathophysiological abnormalities in patients with DM that protect against migraine.

Flow diverter stents are new important tools in the treatment of large, giant, or wide-necked aneurysms. Their delivery and positioning may be difficult due to vessel tortuosity. Common adverse events include intracranial hemorrhage and ischemic stroke, which usually occurs within the same day, or the next few days after the procedure. We present a case where we encountered an unusual intracerebral complication several months after endovascular treatment of a large left internal carotid artery aneurysm, and where brain biopsy revealed foreign body reaction to hydrophilic polymer fragments distally to the stent site. Although previously described, embolization of polymer material from intravascular equipment is rare. We could not identify any other biopsy verified case in the literature, with this particular presentation of intracerebral polymer embolization – a multifocal inflammation spread out through the white matter of one hemisphere without hemorrhage or ischemic changes.

The aim of this study was to examine a possible association between smoking, alcohol and headache in a large population-based cross-sectional study. A total of 51,383 subjects completed a headache questionnaire and constituted the 'Head-HUNT' Study. Questionnaire-based information on smoking was available in 95% and on alcohol in 89% of the individuals. Associations were assessed in multivariate analyses, estimating prevalence odds ratios (ORs) with 95% confidence intervals (CI). Prevalence rates for headache were higher amongst smokers compared with never smokers, most evident for those under 40 years smoking more than 10 cigarettes per day (OR 1.5, 95% CI 1.3-1.6). Passive smoking was also associated with higher headache prevalence. For alcohol use, there was a tendency of decreasing prevalence of migraine with increasing amounts of alcohol consumption compared with alcohol abstinence. Only with regard to symptoms indicating alcohol overuse, a positive association with frequent headache was found. The association between headache and smoking found in the present study raises questions about a causal relationship, e.g. that smoking causes headache or that it allays stress induced by headache. The observed negative association between migraine and alcohol consumption is probably explained by the headache precipitating properties of alcohol.

Background Ultrasound accelerates thrombolysis with tPA (sonothrombolysis). Ultrasound in the absence of tPA also accelerates clot break-up (sonolysis). Adding intravenous gaseous microbubbles may potentiate the effect of ultrasound in both sonothrombolysis and sonolysis. The Norwegian Sonothrombolysis in Acute Stroke Study aims in a pragmatic approach to assess the effect and safety of contrast enhanced ultrasound treatment in unselected acute ischaemic stroke patients. Methods/Design Acute ischaemic stroke patients ≥18 years, with or without visible arterial occlusion on computed tomography angiography (CTA) and treatable ≤ 4½ hours after symptom onset, are included in NOR-SASS. NOR-SASS is superimposed on a separate trial randomising patients with acute ischemic stroke to either tenecteplase or alteplase (The Norwegian Tenecteplase Stroke Trial NOR-TEST). The NOR-SASS trial has two arms: 1) the thrombolysis-arms (NOR-SASS A and B) includes patients given intravenous thrombolysis (tenecteplase or alteplase), and 2) the no-thrombolysis-arm (NOR-SASS C) includes patients with contraindications to thrombolysis. First step randomisation of NOR-SASS A is embedded in NOR-TEST as a 1:1 randomisation to either tenecteplase or alteplase. Second step NOR-SASS randomisation is 1:1 to either contrast enhanced sonothrombolysis (CEST) or sham CEST. Randomisation in NOR-SASS B (routine alteplase group) is 1:1 to either CEST or sham CEST. Randomisation of NOR-SASS C is 1:1 to either contrast enhanced sonolysis (CES) or sham CES. Ultrasound is given for one hour using a 2-MHz pulsed-wave diagnostic ultrasound probe. Microbubble contrast (SonoVue®) is given as a continuous infusion for ~30 min. Recanalisation is assessed at 60 min after start of CEST/CES. Magnetic resonance imaging and angiography is performed after 24 h of stroke onset. Primary study endpoints are 1) major neurological improvement measured with NIHSS score at 24 h and 2) favourable functional outcome defined as mRS 0–1 at 90 days. Discussion NOR-SASS is the first randomised controlled trial designed to test the superiority of contrast enhanced ultrasound treatment given ≤4½ hours after stroke onset in an unselected acute ischaemic stroke population eligible or not eligible for intravenous thrombolysis, with or without a defined arterial occlusion on CTA. If a positive effect and safety can be proven, contrast enhanced ultrasound treatment will be an option for all acute ischaemic stroke patients. EudraCT No 201200032341; www.clinicaltrials.gov NCT01949961.

Background Vascular damage in the central hand knob area can mimic peripheral motor nerve deficits. Case presentation We describe the case of a woman presenting with apparent peripheral neuropathy. Brain magnetic resonance imaging and computed tomography angiography revealed an infarct in the precentral hand knob area, with significant stenosis in the right proximal middle cerebral artery trunk. Subsequent 3-Tesla magnetic resonance imaging of the brain suggested cerebral angiitis. The patient experienced improved hand function following combined glucocorticoid and cyclophosphamide treatment. Conclusion Vascular damage in the hand knob area should be considered when evaluating peripheral motor nerve deficits in the presence of normal nerve conduction velocities. The diagnosis of cerebral angiitis remains a major challenge for clinicians.

The aim of this study was to investigate a possible association between haemochromatosis (HFE) gene mutations and the prevalence of Parkinson's disease. The HFE gene encodes a protein that modulates iron absorption. Several studies have documented increased iron levels in the basal ganglia in patients with Parkinson's disease. In a study on patients with concurrent hereditary haemochromatosis and Parkinson's disease, abnormal deposition of iron in the basal ganglia was suggested as an inductor of Parkinson's disease. In this study, genotype frequencies of the HFE mutations C282Y, H63D and S65C were estimated in 388 patients with Parkinson's disease and compared with frequencies found in comparable studies. No significant differences were found in frequencies between the patients and comparable populations. This study does not indicate increased susceptibility to Parkinson's disease in HFE gene mutation carriers in Norway.

Objective The objective of this article is to see whether the effect of candesartan for migraine prevention, shown in one previous study, could be confirmed in a new study, and if so, whether the effect was comparable to that of propranolol (non-inferiority analysis), and whether adverse events were different. Methods In a randomised, triple-blind, double cross-over study, 72 adult patients with episodic or chronic migraine went through three 12-week treatment periods on either candesartan 16 mg, propranolol slow-release 160 mg, or placebo. The main outcome measures were days with migraine headache per four weeks (primary outcome), days with headache, hours with headache, proportion of responders (>50% reduction of migraine days from baseline), and adverse events. Results In the modified intention-to treat-analysis, candesartan and propranolol were both superior to placebo: 2.95 (95% confidence interval: 2.35–3.55%) and 2.91 (2.36–3.45%), versus 3.53 (2.98–4.08%) for migraine days per month ( p = 0.02 for both comparisons, Wilcoxon's paired signed rank test, blinded statistical analysis). Candesartan was non-inferior to propranolol (and vice versa). The proportion of responders was significantly higher on candesartan (43%) and propranolol (40%) than on placebo (23%) ( p = 0.025 and Conclusion It is confirmed that candesartan 16 mg is effective for migraine prevention, with an effect size similar to propranolol 160 mg, and with somewhat different adverse events. Trial registration: EUDRACT (2008-002312-7), ClinicalTrials.gov (NCT00884663).

More than 70,000 Norwegians have atrial fibrillation, which is a major risk factor for ischemic stroke. A large proportion of ischemic strokes caused by atrial fibrillation could be prevented if patients receive optimal prophylactic treatment. This article describes the risk for ischemic stroke in patients with atrial fibrillation, and discusses who should receive prophylactic treatment and which therapy provides the best prevention.The article is based on recently published European, American and Canadian guidelines, a search in PubMed and the authors' own clinical experience.The new risk score CHA2DS2-VASc is better than the CHADS2 score for identifying patients with atrial fibrillation who have a truly low risk of ischemic stroke and are not in need of antithrombotic treatment. Oral anticoagulation therapy is recommended for patients with two or more risk factors for thromboembolism in addition to atrial fibrillation (CHA2DS2-VASc ≥ 2). Patients with atrial fibrillation and a single additional risk factor (CHA2DS2-VASc =1) an individual assessment should be made as to who should receive oral anticoagulants, and for patients with CHA2DS2-VASc = 0 antithrombotic treatment is not recommended. New oral anticoagulants are at least as effective as warfarin for preventing ischemic stroke in patients with nonvalvular atrial fibrillation, they carry a lower risk of cerebral haemorrhage, especially intracranial haemorrhage and are more practical in use. Platelet inhibitors have a minimal role in stroke prevention in patients with atrial fibrillation.Risks stratifying patients using the CHA2DS2-VASc score is a better method for assessing which patients with atrial fibrillation who should receive oral anticoagulation. The introduction of new oral anticoagulants will simplify preventive treatment and hopefully lead to a more efficient anticoagulation treatment in a larger number of patients with atrial fibrillation.

In acute ischemic stroke, rapid revascularization of the cerebral 'penumbra volume' is the key to better patient outcome. The largest and most proximal cerebral thrombotic artery occlusions can in most cases only be opened by intra-arterial intervention. The use of intra-arterial revascularization is rapidly expanding throughout Europe and North America, despite the risk for serious complications and the fact that the benefit of this treatment has not yet been proven in large, randomized clinical trials. Oslo University Hospital has performed approximately 60 intra-arterial procedures annually in acute ischemic stroke during the last few years. In this paper, we discuss important clinical and ethical aspects learned from our own experience. The future of intra-arterial cerebral revascularization will depend on an accurate preintervention patient selection.

As clinic-based studies show an association between headache and both high and low levels of haemoglobin, we analysed this relationship in a population-based cross-sectional study (the HUNT Study). A total of 2385 women aged 20-55 years responded to a headache questionnaire and gave blood samples for measuring haemoglobin and ferritin. In the multivariate analyses, adjusting for age and education, there was a linear trend of decreasing prevalence of headache ( P = 0.02) and migraine ( P = 0.01) with decreasing haemoglobin. In particular, migraine was less likely among women with low haemoglobin (values < 11.5 g/dl) (odds ratio 0.4, confidence interval 0.2, 0.9). There was no correlation between headache prevalence and ferritin. The present findings may be relevant for the headache reported in polycythaemia and chronic altitude sickness.

Background: Alteplase is the only approved thrombolytic agent for acute ischaemic stroke. The overall benefit from alteplase is substantial, but some evidence indicates that alteplase also has negative effects on the ischaemic brain. Tenecteplase may be more effective and less harmfull than alteplase, but large randomised controlled phase 3 trials are lacking. The Norwegian Tenecteplase Stroke Trial (NOR-TEST) aims to compare efficacy and safety of tenecteplase vs. alteplase. Methods/Design: NOR-TEST is a multi-centre PROBE (prospective randomised, open-label, blinded endpoint) trial designed to establish superiority of tenecteplase 0.4 mg/kg (single bolus) as compared with alteplase 0.9 mg/kg (10% bolus + 90% infusion/60 minutes) for consecutively admitted patients with acute ischaemic stroke eligible for thrombolytic therapy, i.e. patients a) admitted

The aim of this study was to evaluate the effect of the screening question phrasing on the 1-year prevalence figures of headache disorders, including migraine. Of a random sample of 563 invited participants in the Nord-Trøndelag Health Survey 2006-2008 in Norway, 297 (53%) met to a face-to-face interview. There were 74.1% that reported having had headache during the last year, whereas only 31.0% stated that they had suffered from headache in the same period. The 1-year prevalence of migraine was 17.2% and of tension-type headache (TTH) 51.9%. Migraine was ten times more likely (OR = 9.96, 95% CI 4.75-20.91) among those who stated that they were headache sufferers than among those who were not. Only headache sufferers had chronic TTH or medication-overuse headache. Thus "Have you suffered from headache?" can be a useful screening question in population-based questionnaire studies if the goal is to identify most migraineurs and almost all individuals with chronic headache.