Intra-observer concordance of the Neuroradiologic Reviewing Committee in CT scan reviewing in MAST-E. Multicenter Acute Stroke Trial-Europe

Thrombolysis for acute ischaemic stroke

BACKGROUND

Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009.

OBJECTIVES

To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available.

MAIN RESULTS

We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke.

AUTHORS' CONCLUSIONS

Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.

Spontaneous motor cortex encephalocele presenting with simple partial seizures and progressive hemiparesis

Several cases of congenital or acquired temporal encephaloceles have been reported in the literature as the causative mechanism of simple and/or complex partial seizures. In this report the authors describe a rare case of spontaneous parietal encephalocele presenting with simple partial seizures and progressively increasing contralateral upper-extremity motor deficit. The unusual anatomical location of an encephalocele associated with seizures and the delayed seizure onset represent distinctive characteristics in this case. Preoperative imaging included surface electroencephalography, computerized tomography, and brain magnetic resonance imaging. Frameless neuronavigation and intraoperative cortical mapping were used to aid resection of the encephalocele, and the dural and bone defects were reconstructed. The surgical outcome in this case was excellent, and the patient has remained seizure free. The pertinent literature is reviewed in this report.

Early Signs of Brain Infarction at CT: Observer Reliability and Outcome after Thrombolytic Treatment—Systematic Review

PURPOSE

To review systematically all reported early computed tomographic (CT) signs in acute ischemic stroke to determine interobserver agreement and the relationship between early CT signs and patient outcome with or without thrombolysis.

MATERIALS AND METHODS

A systematic review of the literature was conducted by using Cochrane Stroke Group methodology to identify studies published between 1990 and 2003 that were performed to assess interobserver agreement about early signs of infarction on CT scans obtained within 6 hours after onset of stroke symptoms and determine the relation of early signs of infarction to clinical outcome, including any interactive effect of thrombolysis. Interobserver agreement was measured with the kappa statistic, sensitivity, and specificity. The relation of early signs to clinical outcome with or without thrombolysis was assessed with calculated odds ratios and 95% confidence intervals.

RESULTS

In 15 studies of interobserver agreement (median of 30 CT scans and six raters), the prevalence of all early infarction signs was 61% +/- 21 (standard deviation). Interobserver agreement (kappa statistics) ranged from 0.14 to 0.78 for any early infarction sign. The mean sensitivity and specificity for detection of early infarction signs with CT were 66% (range, 20%-87%) and 87% (range, 56%-100%), respectively. Experience improved detection, but knowledge of symptoms did not. In 15 studies of early infarction signs and outcome (including seven thrombolysis trials) in 3468 patients, any early infarction sign increased the risk of poor outcome (odds ratio, 3.11; 95% confidence interval: 2.77, 3.49). Two studies that sought interaction between early infarction signs and thrombolysis found no evidence that thrombolysis given in the presence of early infarction signs resulted in worse outcome than that due to early signs alone.

CONCLUSION

Further work is required to determine which signs are most reliably detected, whether scoring systems help to improve detection, and whether any early infarction sign should influence decisions concerning thrombolysis.

The NIH Stroke Scale is unreliable in untrained hands

BACKGROUND AND PURPOSE

The NIH (National Institutes of Health) Stroke Scale helps to define candidates for thrombolytic treatment and other important clinical decisions. We evaluated its use by last-year medical students who had no specific training in use of this scale.

METHODS

The scale (principles, utilization, methods for scoring, main pitfalls) was presented between 2 stroke lectures. Following a 30-minute study period, a case from the NIH training videotape (case 1, tape 2, total score 4) was presented, and the 13 items were scored by 42 voluntary students. The analysis focused on possible errors of potential clinical relevance.

RESULTS

Only 15 students (36%) scored all items correctly. Twenty (48%) gave results at least 2 points apart from the correct total score, and 14 students had scores > or = 6, which could lead to the inappropriate use of recombinant tissue-type plasminogen activator (rt-PA). At least 10% of the students made mistakes in most (8 of 13) items of the scale.

CONCLUSIONS

Graduating medical students are not ready to use the NIH Stroke Scale without specific training. The magnitude of the mistakes found in this study is enough to inappropriately include or exclude patients from rt-PA treatment. Training programs should be considered a sine qua non for qualification for rt-PA use in daily clinical practice.

Hemorrhagic transformation in acute ischemic stroke. The MAST-E study. MAST-E Group

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is the most critical complication of thrombolytics in clinical trials in acute stroke. The aim of this study was to determine the rates and the predictors of HT in the Multicenter Acute Stroke Trial-Europe (MAST-E) study.

METHODS

We performed a post hoc analysis of MAST-E data designed to assess the safety and efficacy of streptokinase administered intravenously within 6 hours of stroke onset. HT included all intracerebral hemorrhages and symptomatic hemorrhages (SHT) associated with clinical worsening. The predictors of HT and SHT were determined using multivariate modeling.

RESULTS

Among the 310 patients included, 159 patients had HT and 37 SHT (97 and 33 in the streptokinase group and 62 and 4 in the placebo group, respectively). Patients with SHT had significantly more atrial fibrillation, diabetes mellitus, no heparin use, streptokinase treatment, and early CT signs. In the multivariate analysis, HT was predicted by early CT signs and streptokinase treatment. SHT was predicted by diabetes mellitus, early CT signs, streptokinase treatment, and the interaction between streptokinase treatment and decreased level of consciousness. Among the streptokinase-treated patients, the same predictors remained.

CONCLUSIONS

The relative risks of HT after streptokinase were in the same range in MAST-E as in other streptokinase and tPA trials. Early CT signs were strong predictors of both HT and SHT, stressing that these patients are at high risk of bleeding. In our study, the predictors of HT and SHT were similar to those of tPA trials in acute stroke.