34 research outputs found

    Systematic approach towards reliable estimation of abdominal aortic aneurysm size by ultrasound imaging and CT

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    Background: The management of abdominal aortic aneurysm (AAA) is fully dictated by AAA size, but there are no uniform measurement guidelines, and systematic differences exist between ultrasound- and CT-based size estimation. The aim of this study was to devise a uniform ultrasound acquisition and measurement protocol, and to test whether harmonization of ultrasound and CT readings is feasible. Methods: A literature review was undertaken to evaluate evidence for ultrasound-based measurement of AAA. A protocol for measuring AAA was then developed, and intraobserver and interobserver reproducibility was tested. Finally, agreement between ultrasound readings and CT-based AAA diameters was evaluated. This was an observational study of patients with a small AAA who participated in two pharmaceutical intervention trials. Results: Based on a literature review, an ultrasound acquisition and reading protocol was devised. Evaluation of the protocol showed an intraobserver repeatability of 1.6 mm (2s.d.) and an interobserver intraclass correlation coefficient (ICC) of 0.97. Comparison of protocolled ultrasound readings and local CT readings indicated a good correlation (r = 0.81), but a systematic +4.1-mm difference for CT. Harmonized size readings for ultrasound imaging and CT increased the correlation (r = 0.91) and reduced the systematic difference to +1.8 mm by CT. Interobserver reproducibility of protocolized CT measurements showed an ICC of 0.94 for the inner-to-inner method and 0.96 for the outer-to-outer method. Conclusion: The absence of harmonized size acquisition and reading guidelines results in overtreatment and undertreatment of patients with AAA. This can be avoided by the implementation of standardized ultrasound acquisition and a harmonized reading protocol for ultrasound- and CT-based readings

    Behavioural intervention in medication overuse headache: a concealed double-blind randomized controlled trial

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    Background and purpose Medication overuse headache is a prevalent disorder, with a strong biobehavioural component. Hence, behavioural interventions might effectuate reduction of the overused medication. We assessed in a double-blind manner the efficacy of a behavioural intervention during medication withdrawal therapy. Methods In this concealed, double-blind, randomized controlled trial in medication overuse headache, conducted at the Leiden University Medical Centre, we compared the effect of maximal versus minimal behavioural intervention by a headache nurse during withdrawal therapy. Maximal intervention consisted of an intensive contact schedule, comprising education, motivational interviewing, and value-based activity planning during 12 weeks of withdrawal therapy. Minimal intervention consisted of a short contact only. Patients were unaware of the existence of these treatment arms, as the trial was concealed in another trial investigating botulinum toxin A. Endpoints were successful withdrawal and monthly days of acute medication use after the withdrawal period. Results We enrolled 179 patients (90 maximal, 89 minimal intervention). At Week 12, most patients achieved withdrawal in both groups (82/90 [93%] maximal intervention vs. 75/89 [86%] minimal intervention, odds ratio = 2.44, 95% confidence interval [CI] = 0.83-7.23, p = 0.107). At Week 24, patients in the maximal intervention group had fewer medication days (mean difference = -2.23, 95% CI = -3.76 to -0.70, p = 0.005). This difference receded over time. Change in monthly migraine days did not differ between groups (-6.75 vs. -6.22). Conclusions This trial suggests modest benefit of behavioural intervention by a headache nurse during withdrawal therapy for medication overuse headache, to reduce acute medication use during and shortly after intervention, but extension seems warranted for a prolonged effectParoxysmal Cerebral Disorder

    Large-scale plasma metabolome analysis reveals alterations in HDL metabolism in migraine

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    Objective To identify a plasma metabolomic biomarker signature for migraine. Methods Plasma samples from 8 Dutch cohorts (n = 10,153: 2,800 migraine patients and 7,353 controls) were profiled on a 1H-NMR-based metabolomics platform, to quantify 146 individual metabolites (e.g., lipids, fatty acids, and lipoproteins) and 79 metabolite ratios. Metabolite measures associated with migraine were obtained after single-metabolite logistic regression combined with a random-effects meta-analysis performed in a nonstratified and sex-stratified manner. Next, a global test analysis was performed to identify sets of related metabolites associated with migraine. The Holm procedure was applied to control the family-wise error rate at 5% in single-metabolite and global test analyses. Results Decreases in the level of apolipoprotein A1 (β −0.10; 95% confidence interval [CI] −0.16, −0.05; adjusted p = 0.029) and free cholesterol to total lipid ratio present in small high-density lipoprotein subspecies (HDL) (β −0.10; 95% CI −0.15, −0.05; adjusted p = 0.029) were associated with migraine status. In addition, only in male participants, a decreased level of omega-3 fatty acids (β −0.24; 95% CI −0.36, −0.12; adjusted p = 0.033) was associated with migraine. Global test analysis further supported that HDL traits (but not other lipoproteins) were associated with migr

    Acute withdrawal and botulinum toxin A in chronic migraine with medication overuse: a double-blind randomized controlled trial

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    Development and application of statistical models for medical scientific researc

    Intra- and multicenter reproducibility of pulsed, continuous and pseudo-continuous arterial spin labeling methods for measuring cerebral perfusion

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    Intra- and multicenter reproducibility of currently used arterial spin labeling (ASL) methods were assessed at three imaging centers in the Netherlands, equipped with Philips 3TMR scanners. Six healthy participants were scanned twice at each site. The imaging protocol consisted of continuous ASL (CASL), pseudo-continuous ASL (p-CASL) with and without background suppression, pulsed ASL (PASL) with single and multiple inversion times (TIs), and selective ASL for segmentation. Reproducibility was expressed in terms of the coefficient of repeatability and the repeatability index. Voxelwise analysis of variance was performed, yielding brain maps that reflected regional variability. Intra- and multicenter reproducibility were comparable for all methods, except for single TI PASL, with better intracenter reproducibility (F-test of equality of two variances, P<0.05). Pseudo-continuous ASL and multi TI PASL varied least between sites. Variability maps of all methods showed most variability near brain-feeding arteries within sessions and in gray matter between sessions. On the basis of the results of this study, one could consider the use of reference values in clinical routine, with whole-brain p-CASL perfusion varying <20% over repeated measurements within the same individuals considered to be normal. Knowledge on regional variability allows for the use of perfusion-weighted images in the assessment of local cerebral pathology. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 1706-1715; doi:10.1038/jcbfm.2011.10; published online 9 February 201
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