Atrial fibrillation in cryptogenic stroke and TIA patients in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Main results.

Introduction: Secondary stroke prevention depends on proper identification of the underlying etiology and initiation of optimal treatment after the index event. The aim of the NOR-FIB study was to detect and quantify underlying atrial fibrillation (AF) in patients with cryptogenic stroke (CS) or transient ischaemic attack (TIA) using insertable cardiac monitor (ICM), to optimise secondary prevention, and to test the feasibility of ICM usage for stroke physicians. Patients and methods: Prospective observational international multicenter real-life study of CS and TIA patients monitored for 12 months with ICM (Reveal LINQ) for AF detection. Results: ICM insertion was performed in 91.5% by stroke physicians, within median 9 days after index event. Paroxysmal AF was diagnosed in 74 out of 259 patients (28.6%), detected early after ICM insertion (mean 48 ± 52 days) in 86.5% of patients. AF patients were older (72.6 vs 62.2; p < 0.001), had higher pre-stroke CHA2DS2-VASc score (median 3 vs 2; p < 0.001) and admission NIHSS (median 2 vs 1; p = 0.001); and more often hypertension (p = 0.045) and dyslipidaemia (p = 0.005) than non-AF patients. The arrhythmia was recurrent in 91.9% and asymptomatic in 93.2%. At 12-month follow-up anticoagulants usage was 97.3%. Discussion and conclusions: ICM was an effective tool for diagnosing underlying AF, capturing AF in 29% of the CS and TIA patients. AF was asymptomatic in most cases and would mainly have gone undiagnosed without ICM. The insertion and use of ICM was feasible for stroke physicians in stroke units.

Underlying causes of cryptogenic stroke and TIA in the nordic atrial fibrillation and stroke (NOR-FIB) study - the importance of comprehensive clinical evaluation.

BACKGROUND: Cryptogenic stroke is a heterogeneous condition, with a wide spectrum of possible underlying causes for which the optimal secondary prevention may differ substantially. Attempting a correct etiological diagnosis to reduce the stroke recurrence should be the fundamental goal of modern stroke management. METHODS: Prospective observational international multicenter study of cryptogenic stroke and cryptogenic transient ischemic attack (TIA) patients clinically monitored for 12 months to assign the underlying etiology. For atrial fibrillation (AF) detection continuous cardiac rhythm monitoring with insertable cardiac monitor (Reveal LINQ, Medtronic) was performed. The 12-month follow-up data for 250 of 259 initially included NOR-FIB patients were available for analysis. RESULTS: After 12 months follow-up probable stroke causes were revealed in 43% patients, while 57% still remained cryptogenic. AF and atrial flutter was most prevalent (29%). In 14% patients other possible causes were revealed (small vessel disease, large-artery atherosclerosis, hypercoagulable states, other cardioembolism). Patients remaining cryptogenic were younger (p < 0.001), had lower CHA2DS2-VASc score (p < 0.001) on admission, and lower NIHSS score (p = 0.031) and mRS (p = 0.016) at discharge. Smoking was more prevalent in patients that were still cryptogenic (p = 0.014), while dyslipidaemia was less prevalent (p = 0.044). Stroke recurrence rate was higher in the cryptogenic group compared to the group where the etiology was revealed, 7.7% vs. 2.8%, (p = 0.091). CONCLUSION: Cryptogenic stroke often indicates the inability to identify the cause in the acute phase and should be considered as a working diagnosis until efforts of diagnostic work up succeed in identifying a specific underlying etiology. Timeframe of 6-12-month follow-up may be considered as optimal. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT02937077, EudraCT 2018-002298-23.

European Stroke Organisation (ESO) standard operating procedure for the preparation and publishing of guidelines.

The first European Stroke Organization (ESO) standard operating procedure (SOP) published in 2015 aimed at the implementation the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to provide evidence-based guidelines for stroke management. This second ESO-SOP is aiming at further increase of the practicability of ESO guidelines and its technical implications. Authors comprised of the members of the ESO guideline Board and ESO Executive Committee. The final document was agreed on by several internal reviews. The second SOP comprises of the following aspects: rational for the SOP, the introduction of expert consensus statements, types of guideline documents, structures involved and detailed description of the guideline preparation process, handling of financial and intellectual conflicts of interest (CoI), involvement of ESO members in the guideline process, review process, authorship and publication policy, updating of guidelines, cooperation with other societies, and dealing with falsified data. This second SOP supersedes the first SOP published in 2015.

Imaging of Patients with Suspected Large-Vessel Occlusion at Primary Stroke Centers: Available Modalities and a Suggested Approach.

The overwhelming benefit of endovascular therapy in patients with large-vessel occlusions suggests that more patients will be screened than treated. Some of those patients will be evaluated first at primary stroke centers; this type of evaluation calls for standardizing the imaging approach to minimize delays in assessing, transferring, and treating these patients. Here, we propose that CT angiography (performed at the same time as head CT) should be the minimum imaging approach for all patients with stroke with suspected large-vessel occlusion presenting to primary stroke centers. We discuss some of the implications of this approach and how to facilitate them.

Patient selection for intra-arterial cerebral revascularization in acute ischemic stroke.

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.

The influence of acetabular inclination angle on the penetration of polyethylene and migration of the acetabular component: a prospective, radiostereometric study on cemented acetabular components.

In this prospective study we studied the effect of the inclination angle of the acetabular component on polyethylene wear and component migration in cemented acetabular sockets using radiostereometric analysis. A total of 120 patients received either a cemented Reflection All-Poly ultra-high-molecular-weight polyethylene or a cemented Reflection All-Poly highly cross-linked polyethylene acetabular component, combined with either cobalt-chrome or Oxinium femoral heads. Femoral head penetration and migration of the acetabular component were assessed with repeated radiostereometric analysis for two years. The inclination angle was measured on a standard post-operative anteroposterior pelvic radiograph. Linear regression analysis was used to determine the relationship between the inclination angle and femoral head penetration and migration of the acetabular component. We found no relationship between the inclination angle and penetration of the femoral head at two years' follow-up (p = 0.9). Similarly, our data failed to reveal any statistically significant correlation between inclination angle and migration of these cemented acetabular components (p = 0.07 to p = 0.9).

In vitro testing of the deformation pattern and initial stability of a cementless stem coupled to an experimental femoral head, with increased offset and altered femoral neck angles.

The ability to vary femoral offset and neck angles in total hip arthroplasty increases the amount of flexibility in the mechanical reconstruction of the hip joint. The present study investigates the changes in strain pattern and bone-implant micromotion caused by increased femoral offset in combination with retroversion or reduced neck-shaft angle, made possible by a large experimental femoral head. A cementless femoral stem was inserted in 10 human cadaver femurs. Three femoral head configurations were tested: the standard situation, an increased offset combined with retroversion, and increased offset combined with reduced neck-shaft angle. The femurs were loaded in a hip simulator that was able to reproduce the conditions that correspond to one-legged stance and stair climbing. There was a statistically significant increase in strain for the experimental head at several strain gauge rosettes compared to the standard head. The largest significant increase in strain was 14.2 per cent on the anterior side of the femur. The largest mean total point motion was 44 microm in the distal coating area for the configuration with increased femoral offset and retroverted neck axis. The clinical relevance of the changes in strain distribution is uncertain. The femoral stem showed excellent initial stability for all test situations.

Headache, migraine and cardiovascular risk factors: the HUNT study.

BACKGROUND: Migraine with aura (MA) has been found to be a risk factor for cardiovascular disease including ischaemic stroke and myocardial infarction. Studies have also reported a higher prevalence of unfavourable cardiovascular risk factors amongst migraineurs, but results have been conflicting as to whether this is restricted to MA or also holds true for migraine without aura (MO). This study aims to examine the relation between headache and cardiovascular risk factors in a large cross-sectional population-based study. METHODS: A total of 48,713 subjects (age ≥ 20 years) completed a headache questionnaire and were classified according to the headache status in the Nord-Trøndelag Health Study in Norway 1995-1997 (HUNT 2). Framingham 10-year risk for myocardial infarction and coronary death could be calculated for 44,098 (90.5%) of these. Parameters measured were blood pressure, body mass index, serum total and high-density lipoprotein cholesterol. RESULTS: Compared to controls, Framingham risk score was elevated in non-migraine headache sufferers (OR 1.17, 95% CI 1.10-1.26), migraineurs without aura (OR 1.17, 95% CI 1.04-1.32) and most pronounced amongst migraineurs with aura (OR 1.54, 95% CI 1.21-1.95). Framingham risk score consistently increased with headache frequency. For non-migrainous headache and MO, the increased risk was accounted for by the lifestyle factors smoking, high BMI and low physical activity, whilst such factors did not explain the elevated risk associated with MA. CONCLUSIONS: Both MA, MO and non-migrainous headache are associated with an unfavourable cardiovascular risk profile, but different mechanisms seem to underlie the elevated risk in MA than in the other headache types.

Customised femoral stems in osteopetrosis and the development of a guiding system for the preparation of an intramedullary cavity: a report of two cases.

Traditional techniques for the insertion of femoral stems in arthroplasty of the hip in osteopetrosis carry a considerable risk of penetration of the femoral cortex and intra-operative fractures, due to obliteration of the intramedullary cavity and greatly increased stiffness and brittleness of the bone. In order to reduce the risk of such complications we manufactured a customised stem and a computer-based guiding device for the preparation of a cavity within the proximal femur. This system was used successfully in three hips in two patients. We describe the system and the operative technique.

Increased strain in the femoral neck following insertion of a resurfacing femoral prosthesis.

The cortical strains on the femoral neck and proximal femur were measured before and after implantation of a resurfacing femoral component in 13 femurs from human cadavers. These were loaded into a hip simulator for single-leg stance and stair-climbing. After resurfacing, the mean tensile strain increased by 15% (95% confidence interval (CI) 6 to 24, p = 0.003) on the lateral femoral neck and the mean compressive strain increased by 11% (95% CI 5 to 17, p = 0.002) on the medial femoral neck during stimulation of single-leg stance. On the proximal femur the deformation pattern remained similar to that of the unoperated femurs. The small increase of strains in the neck area alone would probably not be sufficient to cause fracture of the neck However, with patient-related and surgical factors these strain changes may contribute to the risk of early periprosthetic fracture.

An in vitro study of the strain distribution in human femora with anatomical and customised femoral stems.

Hydroxyapatite-coated standard anatomical and customised femoral stems are designed to transmit load to the metaphyseal part of the proximal femur in order to avoid stress shielding and to reduce resorption of bone. In a randomised in vitro study, we compared the changes in the pattern of cortical strain after the insertion of hydroxyapatite-coated standard anatomical and customised stems in 12 pairs of human cadaver femora. A hip simulator reproduced the physiological loads on the proximal femur in single-leg stance and stair-climbing. The cortical strains were measured before and after the insertion of the stems. Significantly higher strain shielding was seen in Gruen zones 7, 6, 5, 3 and 2 after the insertion of the anatomical stem compared with the customised stem. For the anatomical stem, the hoop strains on the femur also indicated that the load was transferred to the cortical bone at the lower metaphyseal or upper diaphyseal part of the proximal femur. The customised stem induced a strain pattern more similar to that of the intact femur than the standard, anatomical stem.

Comorbidity of headache and gastrointestinal complaints. The Head-HUNT Study.

Associations between headache, including migraine, and gastrointestinal (GI) symptoms were studied in a large questionnaire-based cross-sectional study (the Head-HUNT Study). The headache questionnaire was completed by 43,782 individuals, who answered all the questions concerning nausea, reflux symptoms, diarrhoea and constipation. In the multivariate analyses, adjusting for age, sex, educational level, medication use, depression and anxiety, a higher prevalence of headache was found in individuals with much reflux [odds ratio (OR) 2.4, 95% confidence interval (CI) 2.2, 2.6], diarrhoea (OR 2.4, 95% CI 2.1, 2.8), constipation (OR 2.1, 95% CI 1.9, 2.4) and nausea (OR 3.2, 95% CI 2.6, 3.8) compared with those without such complaints. All the GI symptoms investigated seemed to be approximately as common among persons with non-migrainous headache as among migraine sufferers, but the association between headache and GI complaints increased markedly with increasing headache frequency. This may suggest that headache sufferers generally are predisposed to GI complaints.

Headache prevalence related to diabetes mellitus. The Head-HUNT study.

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.

Headache prevalence related to smoking and alcohol use. The Head-HUNT Study.

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.

Palamed G compared with Palacos R with gentamicin in Charnley total hip replacement. A randomised, radiostereometric study of 60 HIPS.

We performed a randomised, radiostereometric study comparing two different bone cements, one of which has been sparsely clinically documented. Randomisation of 60 total hip replacements (57 patients) into two groups of 30 was undertaken. All the patients were operated on using a cemented Charnley total hip replacement, the only difference between groups being the bone cement used to secure the femoral component. The two cements used were Palamed G and Palacos R with gentamicin. The patients were followed up with repeated clinical and radiostereometric examinations for two years to assess the micromovement of the femoral component and the clinical outcome. The mean subsidence was 0.18 mm and 0.21 mm, and the mean internal rotation was 1.7 degrees and 2.0 degrees at two years for the Palamed G and Palacos R with gentamicin bone cements, respectively. We found no statistically significant differences between the groups. Micromovement occurred between the femoral component and the cement, while the cement mantle was stable inside the bone. The Harris hip score improved from a mean of 38 points (14 to 54) and 36 (10 to 57) pre-operatively to a mean of 92 (77 to 100) and 91 (63 to 100) at two years in the Palamed G and Palacos R groups, respectively. No differences were found between the groups. Both bone cements provided good initial fixation of the femoral component and good clinical results at two years.

Headache prevalence related to haemoglobin and ferritin. The HUNT Study.

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.

Mechanical stability of custom and anatomical femoral stems: an experimental study in human femora.

In this study we have compared the mechanical stability of custom (n=8) and anatomical (n=8) uncemented femoral components, following insertion into human cadaveric femurs, during simulated single leg stance and stair climbing. In the custom group two specimens were excluded from the study due to detachment of the greater trochanter during cyclical loading. As a consequence of their mechanical behaviour both types of stems could be divided into subgroups of "unstable" and "stable" implants. In the course of one thousand loading cycles three anatomical stems and one custom stem migrated more than 1 mm, which was interpreted as mechanical loosening. This difference in rate of mechanical loosening was not significant. However, the majority of the stems were remarkably stable and showed micromotion of less than 18 m and migration of less than 35 m at the proximal implant-bone interface. The corresponding figures for the tip of the stems were 243 m and 170 m, respectively. During torsional loading the custom stems showed less rotatory motion than the anatomical stem (p<0.05). There were no significant differences in the magnitude of cyclical micromotion or migration for the two types of femoral stems. (Hip International 2002; 12: 263-73).

Changes in proximal femoral strain after insertion of uncemented standard and customised femoral stems. An experimental study in human femora.

We have compared the changes in the pattern of the principal strains in the proximal femur after insertion of eight uncemented anatomical stems and eight customised stems in human cadaver femora. During testing we aimed to reproduce the physiological loads on the proximal femur and to simulate single-leg stance and stair-climbing. The strains in the intact femora were measured and there were no significant differences in principal tensile and compressive strains in the left and right femora of each pair. The two types of femoral stem were then inserted randomly into the left or right femora and the cortical strains were again measured. Both induced significant stress shielding in the proximal part of the metaphysis, but the deviation from the physiological strains was most pronounced after insertion of the anatomical stems. The principal compressive strain at the calcar was reduced by 90% for the anatomical stems and 67% for the customised stems. Medially, at the level of the lesser trochanter, the corresponding figures were 59% and 21%. The anatomical stems induced more stress concentration on the anterior aspect of the femur than did the customised stems. They also increased the hoop strains in the proximomedial femur. Our study shows a consistently more physiological pattern of strain in the proximal femur after insertion of customised stems compared with standard, anatomical stems.

Complications after LP related to needle type: pencil-point versus Quincke.

OBJECTIVES: We studied the incidence of complications after diagnostic lumbar puncture (LP) related to needle type. MATERIAL AND METHODS: A 5 months' observational study of routine diagnostic LP in 83 patients was conducted. RESULTS: Significantly more headache was observed after LP using thicker cutting needles (20G Quincke) compared with thinner cutting or non-cutting needles (22G Quincke or pencil-point). No significant difference in complications after LP was found between the 22G Quincke and pencil-point needles. CONCLUSION: The size of the needle and not the needle shape seems to be the main determinant for post-dural puncture headache (PDPH).