Transcranial Doppler sonography for detecting stenosis or occlusion of intracranial arteries in people with acute ischaemic stroke.

BACKGROUND: An occlusion or stenosis of intracranial large arteries can be detected in the acute phase of ischaemic stroke in about 42% of patients. The approved therapies for acute ischaemic stroke are thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA), and mechanical thrombectomy; both aim to recanalise an occluded intracranial artery. The reference standard for the diagnosis of intracranial stenosis and occlusion is intra-arterial angiography (IA) and, recently, computed tomography angiography (CTA) and magnetic resonance angiography (MRA), or contrast-enhanced MRA. Transcranial Doppler (TCD) and transcranial colour Doppler (TCCD) are useful, rapid, noninvasive tools for the assessment of intracranial large arteries pathology. Due to the current lack of consensus regarding the use of TCD and TCCD in clinical practice, we systematically reviewed the literature for studies assessing the diagnostic accuracy of these techniques compared with intra-arterial IA, CTA, and MRA for the detection of intracranial stenosis and occlusion in people presenting with symptoms of ischaemic stroke. OBJECTIVES: To assess the diagnostic accuracy of TCD and TCCD for detecting stenosis and occlusion of intracranial large arteries in people with acute ischaemic stroke. SEARCH METHODS: We limited our searches from January 1982 onwards as the transcranial Doppler technique was only introduced into clinical practice in the 1980s. We searched MEDLINE (Ovid) (from 1982 to 2018); Embase (Ovid) (from 1982 to 2018); Database of Abstracts of Reviews of Effects (DARE); and Health Technology Assessment Database (HTA) (from 1982 to 2018). Moreover, we perused the reference lists of all retrieved articles and of previously published relevant review articles, handsearched relevant conference proceedings, searched relevant websites, and contacted experts in the field. SELECTION CRITERIA: We included all studies comparing TCD or TCCD (index tests) with IA, CTA, MRA, or contrast-enhanced MRA (reference standards) in people with acute ischaemic stroke, where all participants underwent both the index test and the reference standard within 24 hours of symptom onset. We included prospective cohort studies and randomised studies of test comparisons. We also considered retrospective studies eligible for inclusion where the original population sample was recruited prospectively but the results were analysed retrospectively. DATA COLLECTION AND ANALYSIS: At least two review authors independently screened the titles and abstracts identified by the search strategies, applied the inclusion criteria, extracted data, assessed methodological quality (using QUADAS-2), and investigated heterogeneity. We contacted study authors for missing data. MAIN RESULTS: A comprehensive search of major relevant electronic databases (MEDLINE and Embase) from 1982 to 13 March 2018 yielded 13,534 articles, of which nine were deemed eligible for inclusion. The studies included a total of 493 participants. The mean age of included participants was 64.2 years (range 55.8 to 69.9 years). The proportion of men and women was similar across studies. Six studies recruited participants in Europe, one in south America, one in China, and one in Egypt. Risk of bias was high for participant selection but low for flow, timing, index and reference standard. The summary sensitivity and specificity estimates for TCD and TCCD were 95% (95% CI = 0.83 to 0.99) and 95% (95% CI = 0.90 to 0.98), respectively. Considering a prevalence of stenosis or occlusion of 42% (as reported in the literature), for every 1000 people who receive a TCD or TCCD test, stenosis or occlusion will be missed in 21 people (95% CI = 4 to 71) and 29 (95% CI = 12 to 58) will be wrongly diagnosed as harbouring an intracranial occlusion. However, there was substantial heterogeneity between studies, which was no longer evident when only occlusion of the MCA was considered, or when the analysis was limited to participants investigated within six hours. The performance of either TCD or TCCD in ruling in and ruling out a MCA occlusion was good. Limitations of this review were the small number of identified studies and the lack of data on the use of ultrasound contrast medium. AUTHORS' CONCLUSIONS: This review provides evidence that TCD or TCCD, administered by professionals with adequate experience and skills, can provide useful diagnostic information for detecting stenosis or occlusion of intracranial vessels in people with acute ischaemic stroke, or guide the request for more invasive vascular neuroimaging, especially where CT or MR-based vascular imaging are not immediately available. More studies are needed to confirm or refute the results of this review in a larger sample of stroke patients, to verify the role of contrast medium and to evaluate the clinical advantage of the use of ultrasound.

[Atrial fibrillation and dementia: not everything is clear ]. / Fibrillazione atriale e demenza: non tutto è chiaro...

The prevalence of dementia is ever increasing, as well as the prevalence of atrial fibrillation (AF). Several studies and systematic reviews evaluated the association between AF and dementia, highlighting an increased risk for dementia (with odds ratios from 1.4 to 1.6), with robust results in patients with previous stroke. In fact, not only vascular dementia, but also Alzheimer's disease seems more frequent in patients with AF, even though the very high heterogeneity of the results does not allow for solid conclusions. One of the mechanisms by which AF can cause dementia is the presence of silent embolic cerebral infarctions, and therefore treatment with oral anticoagulants could reduce the incidence of dementia. The results of several studies and systematic reviews show that this therapy, particularly with the new oral anticoagulants, is associated with a reduction of approximately one third of dementia. Rhythm control, obtained either with pharmacological therapy or catheter ablation, is associated with a reduction of dementia impact as well. The association between AF and cognitive deficit is therefore well documented, being more evident in patients with previous stroke but also present in cohorts of patients without prior vascular events. The development of dementia in AF patients can be due to cerebral infarctions, both clinically evident or silent, as well as by microembolism, microbleeds and hypoperfusion. Oral anticoagulation, particularly with the use of new oral anticoagulants, as well as a rhythm control strategy can reduce the incidence of dementia. More recently, it has been shown that atrial cardiomyopathy is significantly associated with the incidence of dementia, also in patients with no history of AF or stroke.

Sonothrombolysis for acute ischaemic stroke.

BACKGROUND: Sonothrombolysis is a promising but unproven tool for treating acute ischaemic stroke. There is an ongoing debate about the efficacy, safety, technical aspects of ultrasound administration and the possible potentiating effect of microbubbles. OBJECTIVES: To assess the effectiveness and safety of sonothrombolysis in patients with acute ischaemic stroke. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched in November 2011), the Cochrane Controlled Trials Register (The Cochrane Library 2011, Issue 12), MEDLINE (1950 to November 2011), EMBASE (1980 to November 2011), Database of Abstract and Review of Effects (DARE) (The Cochrane Library 2011, Issue 11), Stroke Trials Registry, Clinicaltrials.gov and Current Controlled Trials. We also searched the reference lists from relevant articles and reviews, and contacted colleagues, authors and researchers active in the field. Searching was completed in November 2011. SELECTION CRITERIA: Randomised trials of sonothrombolysis (any duration, any frequency of ultrasound, with or without microbubbles administration) started within 12 hours of symptom onset compared with intravenous tissue plasminogen activator (tPA) or conventional treatment.  DATA COLLECTION AND ANALYSIS: Two review authors selected trials for inclusion, assessed trial quality and extracted the data independently. We contacted study authors for missing data. MAIN RESULTS: We identified five eligible studies (233 patients). For the primary outcome (death or dependency at three months), five studies with a total number of 206 patients were available (four defined independence as a modified Rankin score of 0 to 2 and one used 0 to 1). Patients treated with sonothrombolysis were less likely to be dead or disabled at three months (odds ratio (OR) 0.50, 95% confidence interval (CI) 0.27 to 0.91). For the secondary outcomes, failure to recanalise was lower in the sonothrombolysis group (230 patients) (OR 0.28, 95% CI 0.16 to 0.50), no significant difference was found in mortality (206 patients) and in cerebral haemorrhage (233 patients). AUTHORS' CONCLUSIONS: Sonothrombolysis appears to reduce death or dependency at three months (although CIs are quite wide), and increases recanalisation without clear hazard. A larger clinical trial is warranted.

Sonothrombolysis for acute ischaemic stroke.

BACKGROUND: Sonothrombolysis is a promising but unproven tool for treating acute ischaemic stroke. There is an ongoing debate about the efficacy, safety, technical aspects of ultrasound administration and the possible potentiating effect of microbubbles. OBJECTIVES: To assess the effectiveness and safety of sonothrombolysis in patients with acute ischaemic stroke. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched in November 2011), the Cochrane Controlled Trials Register (The Cochrane Library 2011, Issue 12), MEDLINE (1950 to November 2011), EMBASE (1980 to November 2011), Database of Abstract and Review of Effects (DARE) (The Cochrane Library 2011, Issue 11), Stroke Trials Registry, Clinicaltrials.gov and Current Controlled Trials. We also searched the reference lists from relevant articles and reviews, and contacted colleagues, authors and researchers active in the field. Searching was completed in November 2011. SELECTION CRITERIA: Randomised trials of sonothrombolysis (any duration, any frequency of ultrasound, with or without microbubbles administration) started within 12 hours of symptom onset compared with intravenous tissue plasminogen activator (tPA) or conventional treatment.  DATA COLLECTION AND ANALYSIS: Two review authors selected trials for inclusion, assessed trial quality and extracted the data independently. We contacted study authors for missing data. MAIN RESULTS: We identified five eligible studies (233 patients). For the primary outcome (death or dependency at three months), five studies with a total number of 206 patients were available (four defined independence as a modified Rankin score of 0 to 2 and one used 0 to 1). Patients treated with sonothrombolysis were no more likely to be dead or disabled at three months (odds ratio (OR) 0.80, 95% confidence interval (CI) 0.45 to 1.44). For the secondary outcomes, failure to recanalise was lower in the sonothrombolysis group (230 patients) (OR 0.28, 95% CI 0.16 to 0.50), no significant difference was found in mortality (206 patients) and in cerebral haemorrhage (233 patients). AUTHORS' CONCLUSIONS: Sonothrombolysis did not reduce death or dependency at three months, but appeared to increase recanalisation without clear hazard. A larger clinical trial is warranted.