Inhomogeneous patient samples have been used in previous studies to determine the power of magnetic resonance imaging (MRI) for trial monitoring in multiple sclerosis (MS). These power-calculations might not be applicable to the active relapsing-remitting patient who is preferably included in trials. In order to reevaluate the power-calculations for MRI in the monitoring of treatment in strictly relapsing-remitting MS and to compare the power of different trial designs we studied 12 relapsing-remitting MS patients prospectively for a median period of 12 months using monthly clinical assessments and gadolinium-enhanced MRI. A median number of two clinical relapses/patient occurred of which a median of one was treated with steroids. A median of 1.59 new lesions/scan/patient was detected (range 0-8). The total number of new active lesions correlated significantly with study period relapses (SRCC = 0.72, P = 0.023). Computer simulations using the bootstrap technique yielded mostly lower power values for a parallel groups design than in previous studies except for short follow-periods in larger samples. In this-sample the open cross-over design was found to be between 20 and 40% more powerful. Results of power-calculations are clearly sample dependent implying that for treatment trial monitoring using MRI in relapsing-remitting MS conservative sample size estimates are to be used. In an active patient group open cross-over trial designs could be a very powerful alternative to parallel groups design.

Background and aim To investigate sex differences with respect to presence and location of atherosclerosis in acute ischemic stroke patients. Methods Participants with acute ischemic stroke were included from the Dutch acute stroke trial, a large prospective multicenter cohort study performed between May 2009 and August 2013. All patients received computed tomography/computed tomography-angiography within 9 h of stroke onset. We assessed presence of atherosclerosis in the intra- and extracranial internal carotid and vertebrobasilar arteries. In addition, we determined the burden of intracranial atherosclerosis by quantifying internal carotid and vertebrobasilar artery calcifications, resulting in calcium volumes. Prevalence ratios between women and men were calculated with Poisson regression analysis and adjusted prevalence ratio for potential confounders (age, hypertension, hyperlipidemia, diabetes, smoking, and alcohol use). Results We included 1397 patients with a mean age of 67 years, of whom 600 (43%) were women. Presence of atherosclerosis in intracranial vessel segments was found as frequently in women as in men (71% versus 72%, adjusted prevalence ratio 0.95; 95% CI 0.89–1.01). In addition, intracranial calcification volume did not differ between women and men in both intracranial internal carotid (large burden 35% versus 33%, adjusted prevalence ratio 0.93; 95% CI 0.73–1.19) and vertebrobasilar arteries (large burden 26% versus 40%, adjusted prevalence ratio 0.69; 95% CI 0.41–1.12). Extracranial atherosclerosis was less common in women than in men (74% versus 81%, adjusted prevalence ratio 0.86; 95% CI 0.81–0.92). Conclusions In patients with acute ischemic stroke the prevalence of intracranial atherosclerosis does not differ between women and men, while extracranial atherosclerosis is less often present in women compared with men.

Background and aim To investigate whether a striped occipital cortex and intragyral hemorrhage, two markers recently detected on ultra-high-field 7-tesla-magnetic resonance imaging in hereditary cerebral amyloid angiopathy (CAA), also occur in sporadic CAA (sCAA) or non-sCAA intracerebral hemorrhage (ICH). Methods We performed 7-tesla-magnetic resonance imaging in patients with probable sCAA and patients with non-sCAA-ICH. Striped occipital cortex (linear hypointense stripes perpendicular to the cortex) and intragyral hemorrhage (hemorrhage restricted to the juxtacortical white matter of one gyrus) were scored on T2*-weighted magnetic resonance imaging. We assessed the association between the markers, other CAA-magnetic resonance imaging markers and clinical features. Results We included 33 patients with sCAA (median age 70 years) and 29 patients with non-sCAA-ICH (median age 58 years). Striped occipital cortex was detected in one (3%) patient with severe sCAA. Five intragyral hemorrhages were found in four (12%) sCAA patients. The markers were absent in the non-sCAA-ICH group. Patients with intragyral hemorrhages had more lobar ICHs (median count 6.5 vs. 1.0), lobar microbleeds (median count >50 vs. 15), and lower median cognitive scores (Mini Mental State Exam: 20 vs. 28, Montreal Cognitive Assessment: 18 vs. 24) compared with patients with sCAA without intragyral hemorrhage. In 12 (36%) patients, sCAA diagnosis was changed to mixed-type small vessel disease due to deep bleeds previously unobserved on lower field-magnetic resonance imaging. Conclusion Whereas a striped occipital cortex is rare in sCAA, 12% of patients with sCAA have intragyral hemorrhages. Intragyral hemorrhages seem to be related to advanced disease and their absence in patients with non-sCAA-ICH could suggest specificity for CAA.

Background: Surgery and embolization may both be considered in ruptured superfi cial micro-AVMs. However, surgery may be challenged by poor recognition of the lesion and embolization by diffi culty in achieving complete obliteration and avoiding en passage feeders. Recent developments in AVM surgery and embolization techniques call for a reevaluation of these treatment options.Methods: Eight consecutive patients with superfi cial micro-AVMs are presented. All patients received an initial embolization attempt with either nBCA or ONYX. If complete obliteration was not obtained, either a second embolization or surgical resection was offered. At surgery, indocyanine green video angiography (ICG-VA) was used in all cases. Effectiveness and safety of all procedures were evaluated retrospectively. Functional outcome at 6 months was assessed by the modifi ed Ranking Score (mRS).Results: Patients had a mean age of 52±17 years and all presented with hemorrhage. The mean nidus size was 4 mm, and was localized supratentorially in 5 cases and infratentorially in 3. Initial embolization was successful in 2 patients (25%). One patient underwent a second, unsuccessful, embolization attempt and 1 patient did not receive further treatment. Consequently, fi ve patients underwent surgery, which was successful in four (80%). The unsuccessful case was successfully reoperated. The only two procedural complications were related to superselective embolization, but neither caused clinical sequelae. Mean clinical follow-up was 29 months (range, 4-75mo), with mRS 0 in 2, mRS 1 in 4 and mRS 3 in 2 cases. Conclusions:In a current case series, embolization of superfi cial micro-AVMs was associated with a lower success rate (25% vs 80%) than microsurgery and a higher procedural complication rate (minor complications: 22% vs 0%).

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