Charlotte Cordonnier

Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration

Summary Cerebral small vessel disease (SVD) is a common accompaniment of ageing. Features seen on neuroimaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. SVD can present as a stroke or cognitive decline, or can have few or no symptoms. SVD frequently coexists with neurodegenerative disease, and can exacerbate cognitive deficits, physical disabilities, and other symptoms of neurodegeneration. Terminology and definitions for imaging the features of SVD vary widely, which is also true for protocols for image acquisition and image analysis. This lack of consistency hampers progress in identifying the contribution of SVD to the pathophysiology and clinical features of common neurodegenerative diseases. We are an international working group from the Centres of Excellence in Neurodegeneration. We completed a structured process to develop definitions and imaging standards for markers and consequences of SVD. We aimed to achieve the following: first, to provide a common advisory about terms and definitions for features visible on MRI; second, to suggest minimum standards for image acquisition and analysis; third, to agree on standards for scientific reporting of changes related to SVD on neuroimaging; and fourth, to review emerging imaging methods for detection and quantification of preclinical manifestations of SVD. Our findings and recommendations apply to research studies, and can be used in the clinical setting to standardise image interpretation, acquisition, and reporting. This Position Paper summarises the main outcomes of this international effort to provide the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE).

Cerebral microbleeds a guide to detection and interpretation

Cerebral microbleeds (CMBs) are increasingly recognised neuroimaging findings in individuals with cerebrovascular disease and dementia, and in normal ageing. There has been substantial progress in the understanding of CMBs in recent years, particularly in the development of newer MRI methods for the detection of CMBs and the application of these techniques to population-based samples of elderly people. In this Review, we focus on these recent developments and their effects on two main questions: how CMBs are detected, and how CMBs should be interpreted. The number of CMBs detected depends on MRI characteristics, such as pulse sequence, sequence parameters, spatial resolution, magnetic field strength, and image post-processing, emphasising the importance of taking into account MRI technique in the interpretation of study results. Recent investigations with sensitive MRI techniques have indicated a high prevalence of CMBs in community-dwelling elderly people. We propose a procedural guide for identification of CMBs and suggest possible future approaches for elucidating the role of these common lesions as markers for, and contributors to, small-vessel brain disease.

Medical management with or without interventional therapy for unruptured brain arteriovenous malformations (ARUBA): a multicentre, non-blinded, randomised trial.

BACKGROUND The clinical benefit of preventive eradication of unruptured brain arteriovenous malformations remains uncertain. A Randomised trial of Unruptured Brain Arteriovenous malformations (ARUBA) aims to compare the risk of death and symptomatic stroke in patients with an unruptured brain arteriovenous malformation who are allocated to either medical management alone or medical management with interventional therapy. METHODS Adult patients (≥18 years) with an unruptured brain arteriovenous malformation were enrolled into this trial at 39 clinical sites in nine countries. Patients were randomised (by web-based system, in a 1:1 ratio, with random permuted block design [block size 2, 4, or 6], stratified by clinical site) to medical management with interventional therapy (ie, neurosurgery, embolisation, or stereotactic radiotherapy, alone or in combination) or medical management alone (ie, pharmacological therapy for neurological symptoms as needed). Patients, clinicians, and investigators are aware of treatment assignment. The primary outcome is time to the composite endpoint of death or symptomatic stroke; the primary analysis is by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00389181. FINDINGS Randomisation was started on April 4, 2007, and was stopped on April 15, 2013, when a data and safety monitoring board appointed by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health recommended halting randomisation because of superiority of the medical management group (log-rank Z statistic of 4·10, exceeding the prespecified stopping boundary value of 2·87). At this point, outcome data were available for 223 patients (mean follow-up 33·3 months [SD 19·7]), 114 assigned to interventional therapy and 109 to medical management. The primary endpoint had been reached by 11 (10·1%) patients in the medical management group compared with 35 (30·7%) in the interventional therapy group. The risk of death or stroke was significantly lower in the medical management group than in the interventional therapy group (hazard ratio 0·27, 95% CI 0·14-0·54). No harms were identified, other than a higher number of strokes (45 vs 12, p<0·0001) and neurological deficits unrelated to stroke (14 vs 1, p=0·0008) in patients allocated to interventional therapy compared with medical management. INTERPRETATION The ARUBA trial showed that medical management alone is superior to medical management with interventional therapy for the prevention of death or stroke in patients with unruptured brain arteriovenous malformations followed up for 33 months. The trial is continuing its observational phase to establish whether the disparities will persist over an additional 5 years of follow-up. FUNDING National Institutes of Health, National Institute of Neurological Disorders and Stroke.

European Stroke Organisation (ESO) guidelines for the management of spontaneous intracerebral hemorrhage

Background Intracerebral hemorrhage (ICH) accounted for 9% to 27% of all strokes worldwide in the last decade, with high early case fatality and poor functional outcome. In view of recent randomized controlled trials (RCTs) of the management of ICH, the European Stroke Organisation (ESO) has updated its evidence-based guidelines for the management of ICH. Method A multidisciplinary writing committee of 24 researchers from 11 European countries identified 20 questions relating to ICH management and created recommendations based on the evidence in RCTs using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results We found moderate- to high-quality evidence to support strong recommendations for managing patients with acute ICH on an acute stroke unit, avoiding hemostatic therapy for acute ICH not associated with antithrombotic drug use, avoiding graduated compression stockings, using intermittent pneumatic compression in immobile patients, and using blood pressure lowering for secondary prevention. We found moderate-quality evidence to support weak recommendations for intensive lowering of systolic blood pressure to <140 mmHg within six-hours of ICH onset, early surgery for patients with a Glasgow Coma Scale score 9–12, and avoidance of corticosteroids. Conclusion These guidelines inform the management of ICH based on evidence for the effects of treatments in RCTs. Outcome after ICH remains poor, prioritizing further RCTs of interventions to improve outcome.

Prevalence and severity of microbleeds in a memory clinic setting

Objective: To determine prevalence and severity of microbleeds (MBs) in a large cohort of patients attending a memory clinic. Methods: The authors consecutively included patients attending their memory clinic between January 2002 and April 2005. They analyzed prevalence and number of MBs according to demographic, diagnostic, and MRI data. Results: The authors included 772 patients (53% men, age 66 ± 11). One hundred twenty-seven patients (17%) exhibited at least one MB. The prevalence differed according to diagnostic groups (p < 0.0001): Sixty-five percent of patients with vascular dementia exhibited MBs vs 18% of Alzheimer disease patients, 20% of mild cognitive impairment patients, and 10% of patients with subjective complaints. The presence of MBs was associated with age, white matter hyperintensities, lacunar infarcts, and infarcts. Conclusion: The prevalence of microbleeds (MBs) in a large cohort of patients attending a memory clinic is higher than previously described in community samples and lower than reported in stroke patients. This finding of a relatively high proportion of MBs in Alzheimer disease and mild cognitive impairment provides further evidence for the involvement of vascular factors in neurodegenerative diseases such as Alzheimer disease.

Brain microbleeds and Alzheimer’s disease: innocent observation or key player?

Brain microbleeds are small dot-like lesions appearing as hyposignals on gradient echo magnetic resonance sequences. In Alzheimers disease, brain microbleeds are of special interest as they may play a crucial role in the pathophysiology. They may be a missing link between two important theories on the neuropathogenesis of Alzheimers disease-the amyloid cascade hypothesis and the vascular hypothesis. Moreover, they may affect the clinical course of the disease and may have therapeutic consequences. The aim of this article is to review available data to understand the meaning of brain microbleeds in clinical terms and underlying pathology in the context of Alzheimers disease. We also review the available evidence and highlight the pitfalls of our current knowledge on brain microbleeds in the setting of clinical trials design.

Antithrombotic Drug Use, Cerebral Microbleeds, and Intracerebral Hemorrhage A Systematic Review of Published and Unpublished Studies

Background and Purpose— Cerebral microbleeds (MB) are potential risk factors for intracerebral hemorrhage (ICH), but it is unclear if they are a contraindication to using antithrombotic drugs. Insights could be gained by pooling data on MB frequency stratified by antithrombotic use in cohorts with ICH and ischemic stroke (IS)/transient ischemic attack (TIA). Methods— We performed a systematic review of published and unpublished data from cohorts with stroke or TIA to compare the presence of MB in: (1) antithrombotic users vs nonantithrombotic users with ICH; (2) antithrombotic users vs nonusers with IS/TIA; and (3) ICH vs ischemic events stratified by antithrombotic use. We also analyzed published and unpublished follow-up data to determine the risk of ICH in antithrombotic users with MB. Results— In a pooled analysis of 1460 ICH and 3817 IS/TIA, MB were more frequent in ICH vs IS/TIA in all treatment groups, but the excess increased from 2.8 (odds ratio; range, 2.3–3.5) in nonantithrombotic users to 5.7 (range, 3.4–9.7) in antiplatelet users and 8.0 (range, 3.5–17.8) in warfarin users (P difference=0.01). There was also an excess of MB in warfarin users vs nonusers with ICH (OR, 2.7; 95% CI, 1.6–4.4; P<0.001) but none in warfarin users with IS/TIA (OR, 1.3; 95% CI, 0.9–1.7; P=0.33; P difference=0.01). There was a smaller excess of MB in antiplatelet users vs nonusers with ICH (OR, 1.7; 95% CI, 1.3–2.3; P<0.001), but findings were similar for antiplatelet users with IS/TIA (OR, 1.4; 95% CI, 1.2–1.7; P<0.001; P difference=0.25). In pooled follow-up data for 768 antithrombotic users, presence of MB at baseline was associated with a substantially increased risk of subsequent ICH (OR, 12.1; 95% CI, 3.4–42.5; P<0.001). Conclusions— The excess of MB in warfarin users with ICH compared to other groups suggests that MB increase the risk of warfarin-associated ICH. Limited prospective data corroborate these findings, but larger prospective studies are urgently required.

Improving interrater agreement about brain microbleeds: development of the Brain Observer MicroBleed Scale (BOMBS)

Background and Purpose— If the diagnostic and prognostic significance of brain microbleeds (BMBs) are to be investigated and used for these purposes in clinical practice, observer variation in BMB assessment must be minimized. Methods— Two doctors used a pilot rating scale to describe the number and distribution of BMBs (round, low-signal lesions, <10 mm diameter on gradient echo MRI) among 264 adults with stroke or TIA. They were blinded to clinical data and their counterpart’s ratings. Disagreements were adjudicated by a third observer, who informed the development of a new Brain Observer MicroBleed Scale (BOMBS), which was tested in a separate cohort of 156 adults with stroke. Results— In the pilot study, agreement about the presence of ≥1 BMB in any location was moderate (&kgr;=0.44; 95% CI, 0.32-0.56), but agreement was worse in lobar locations (&kgr;=0.44; 95% CI, 0.30-0.58) than in deep (&kgr;=0.62; 95% CI, 0.48-0.76) or posterior fossa locations (&kgr;=0.66; 95% CI, 0.47-0.84). Using BOMBS, agreement about the presence of ≥1 BMB improved in any location (&kgr;=0.68; 95% CI, 0.49-0.86) and in lobar locations (&kgr;=0.78; 95% CI, 0.60-0.97). Conclusion— Interrater reliability concerning the presence of BMBs was moderate to good, and could be improved with the use of the BOMBS rating scale, which takes into account the main sources of interrater disagreement identified by our pilot scale.

Platelet transfusion versus standard care after acute stroke due to spontaneous cerebral haemorrhage associated with antiplatelet therapy (PATCH): a randomised, open-label, phase 3 trial

BACKGROUND Platelet transfusion after acute spontaneous primary intracerebral haemorrhage in people taking antiplatelet therapy might reduce death or dependence by reducing the extent of the haemorrhage. We aimed to investigate whether platelet transfusion with standard care, compared with standard care alone, reduced death or dependence after intracerebral haemorrhage associated with antiplatelet therapy use. METHODS We did this multicentre, open-label, masked-endpoint, randomised trial at 60 hospitals in the Netherlands, UK, and France. We enrolled adults within 6 h of supratentorial intracerebral haemorrhage symptom onset if they had used antiplatelet therapy for at least 7 days beforehand and had a Glasgow Coma Scale score of at least 8. With use of a secure web-based system that concealed allocation and used biased coin randomisation, study collaborators randomly assigned participants (1:1; stratified by hospital and type of antiplatelet therapy) to receive either standard care or standard care with platelet transfusion within 90 min of diagnostic brain imaging. Participants and local investigators giving interventions were not masked to treatment allocation, but allocation was concealed from outcome assessors and investigators analysing data. The primary outcome was shift towards death or dependence rated on the modified Rankin Scale (mRS) at 3 months, and analysed by ordinal logistic regression, adjusted for stratification variables and the Intracerebral Haemorrhage Score. The primary analysis was done in the intention-to-treat population and safety analyses were done in the intention-to-treat and as-treated populations. This trial is registered with the Netherlands Trial Register, number NTR1303, and is now closed. FINDINGS Between Feb 4, 2009, and Oct 8, 2015, 41 sites enrolled 190 participants. 97 participants were randomly assigned to platelet transfusion and 93 to standard care. The odds of death or dependence at 3 months were higher in the platelet transfusion group than in the standard care group (adjusted common odds ratio 2·05, 95% CI 1·18-3·56; p=0·0114). 40 (42%) participants who received platelet transfusion had a serious adverse event during their hospital stay, as did 28 (29%) who received standard care. 23 (24%) participants assigned to platelet transfusion and 16 (17%) assigned to standard care died during hospital stay. INTERPRETATION Platelet transfusion seems inferior to standard care for people taking antiplatelet therapy before intracerebral haemorrhage. Platelet transfusion cannot be recommended for this indication in clinical practice. FUNDING The Netherlands Organisation for Health Research and Development, Sanquin Blood Supply, Chest Heart and Stroke Scotland, French Ministry of Health.

Early seizures in intracerebral hemorrhage Incidence, associated factors, and outcome

Objective: In patients with spontaneous intracerebral hemorrhage (ICH), the occurrence of early seizures (ES) may be a prognostic marker. Therefore, we aimed to identify incidence, associated factors, and influence on outcome of ES in patients with ICH. Methods: Between November 2004 and March 2009, we prospectively recruited 562 consecutive adults with a spontaneous ICH (Prognosis of InTra-Cerebral Hemorrhage cohort). Patients with previous seizures (n = 40) were excluded. ES were defined as seizures occurring within 7 days of stroke onset, and their associated factors were identified with Cox regression. For a subgroup of onset seizures, we used logistic regression. Data influencing outcome (mortality at day 7 and month 6 and functional outcome at month 6) were studied using survival analyses. Results: ES occurred in 71 (14%; 95% confidence interval [CI] 11–17) of 522 patients (274 male; median age 72 years, interquartile range 58–79 years). The only factor associated with ES was cortical involvement of ICH (odds ratio [OR] = 2.06; 95% CI 1.28–3.31). Regarding onset seizures (n = 38) (7%; 95% CI 5–10), associated factors were previous ICH (OR = 4.76; 95% CI 1.53–14.84), cortical involvement (OR = 2.21; 95% CI 1.11–4.43), younger age (OR = 0.97 per 1 year increase; 95% CI 0.95–0.99), and severity of the neurologic deficit at admission (OR = 1.03 per 1 point increase in the National Institutes of Health Stroke Scale score; 95% CI 1.01–1.06). ES did not influence vital or functional outcome. Conclusions: ES are a frequent complication in patients with spontaneous ICH; however, their occurrence does not influence outcome at 6 months.