[show abstract][hide abstract] ABSTRACT: Given the rising number of strokes worldwide, and the large number of individuals left with disabilities after stroke, novel strategies to reduce disability, increase functions in the motor and the cognitive domains, and improve quality of life are of major importance. Physical activity is a promising intervention to address these challenges but, as yet, there is no study demonstrating definite outcomes. Our objective is to assess whether additional treatment in the form of physical fitness-based training for patients early after stroke will provide benefits in terms of functional outcomes, in particular gait speed and the Barthel Index (co-primary outcome measures) reflecting activities of daily living (ADL). We will gather secondary functional outcomes as well as mechanistic parameters in an exploratory approach.Methods/design: Our phase III randomised controlled trial will recruit 215 adults with moderate to severe limitations of walking and ADL 5 to 45 days after stroke onset. Participants will be stratified for the prognostic variables of "centre", "age", and "stroke severity", and randomly assigned to one of two groups. The interventional group receives physical fitness training delivered as supported or unsupported treadmill training (cardiovascular active aerobic training; five times per week, over 4 weeks; each session 50 minutes; total of 20 additional physical fitness training sessions) in addition to standard rehabilitation treatment. The control intervention consists of relaxation sessions (non-cardiovascular active; five times per week week, over 4 weeks; each session 50 minutes) in addition to standard rehabilitation treatment. Co-primary efficacy endpoints will be gait speed (in m/s, 10 m walk) and the Barthel Index (100 points total) at 3 months post-stroke, compared to baseline measurements. Secondary outcomes include standard measures of quality of life, sleep and mood, cognition, arm function, maximal oxygen uptake, and cardiovascular risk factors including blood pressure, pulse, waist-to-hip ratio, markers of inflammation, immunity and the insulin-glucose pathway, lipid profile, and others.
The goal of this endpoint-blinded, phase III randomised controlled trial is to provide evidence to guide post-stroke physical fitness-based rehabilitation programmes, and to elucidate the mechanisms underlying this intervention.Trial registration: Registered in ClinicalTrials.gov with the Identifier NCT01953549.
[show abstract][hide abstract] ABSTRACT: Physical activity is believed to exert a beneficial effect on functional and cognitive rehabilitation of patients with stroke. Although studies have addressed the impact of physical exercise in cerebrovascular prevention and rehabilitation, the underlying mechanisms leading to improvement are poorly understood. Training-induced increase of cerebral perfusion is a possible mediating mechanism. Our exploratory study aims to investigate training-induced changes in blood biomarker levels and magnetic resonance imaging in patients with subacute ischemic stroke.Methods/design: This biomarker-driven study uses an observational design to examine a subgroup of patients in the randomized, controlled PHYS-STROKE trial. In PHYS-STROKE, 215 patients with subacute stroke (hemorrhagic and ischemic) receive either 4 weeks of physical training (aerobic training, 5 times a week, for 50 minutes) or 4 weeks of relaxation sessions (5 times a week, for 50 minutes). A convenience sample of 100 of these patients with ischemic stroke will be included in BAPTISe and will receive magnetic resonance imaging (MRI) scans and an additional blood draw before and after the PHYS-STROKE intervention. Imaging scans will address parameters of cerebral perfusion, vessel size imaging, and microvessel density (the Q factor) to estimate the degree of neovascularization in the brain. Blood tests will determine several parameters of immunity, inflammation, endothelial function, and lipometabolism. Primary objective of this study is to evaluate differential changes in MRI and blood-derived biomarkers between groups. Other endpoints are next cerebrovascular events and functional status of the patient after the intervention and after 3 months assessed by functional scores, in particular walking speed and Barthel index (co-primary endpoints of PHYS-STROKE). Additionally, we will assess the association between functional outcomes and biomarkers including imaging results. For all endpoints we will compare changes between patients who received physical fitness training and patients who had relaxation sessions.
This exploratory study will be the first to investigate the effects of physical fitness training in patients with ischemic stroke on MRI-based cerebral perfusion, pertinent blood biomarker levels, and functional outcome. The study may have an impact on current patient rehabilitation strategies and reveal important information about the roles of MRI and blood-derived biomarkers in ischemic stroke.Trial registration: NCT01954797.
[show abstract][hide abstract] ABSTRACT: DSC-MRI is the most widely used method for perfusion imaging (PI) in brain, especially for stroke patients. However, the relationship between tracer concentration and signal change is only strictly valid for a network of capillaries and not in case of estimating the arterial input function (AIF). To investigate that impact, an analysis of 211 PI measurements regarding peak signal drop and relative concentration was performed. We found a descending linearity between the micro- and macrovascular signal with an increasing size of the AIF-defining artery. We conclude that in case of standard imaging techniques more distal arteries are preferable.
ISMRM 21st Annual Meeting & Exhibition, Salt Lake City; 04/2013
[show abstract][hide abstract] ABSTRACT: RATIONALE: In about 20% of acute ischemic stroke patients stroke occurs during sleep. These patients are generally excluded from intravenous thrombolysis. MRI can identify patients within the time-window for thrombolysis (≤4·5 h from symptom onset) by a mismatch between the acute ischemic lesion visible on diffusion weighted imaging (DWI) but not visible on fluid-attenuated inversion recovery (FLAIR) imaging. AIMS AND HYPOTHESIS: The study aims to test the efficacy and safety of MRI-guided thrombolysis with tissue plasminogen activator (rtPA) in ischemic stroke patients with unknown time of symptom onset, e.g., waking up with stroke symptoms. We hypothesize that stroke patients with unknown time of symptom onset with a DWI-FLAIR-mismatch pattern on MRI will have improved outcome when treated with rtPA compared to placebo. DESIGN: WAKE-UP is an investigator initiated, European, multicentre, randomized, double-blind, placebo-controlled clinical trial. Patients with unknown time of symptom onset who fulfil clinical inclusion criteria (disabling neurological deficit, no contraindications against thrombolysis) will be studied by MRI. Patients with MRI findings of a DWI-FLAIR-mismatch will be randomised to either treatment with rtPA or placebo. STUDY OUTCOME: The primary efficacy endpoint will be favourable outcome defined by modified Rankin Scale 0-1 at day 90. The primary safety outcome measures will be mortality and death or dependency defined by modified Rankin Scale 4-6 at 90 days. DISCUSSION: If positive, WAKE-UP is expected to change clinical practice making effective and safe treatment available for a large group of acute stroke patients currently excluded from specific acute therapy.
International Journal of Stroke 03/2013; · 2.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: Case reports have demonstrated complete early reversal of hyperintensities on diffusion-weighted imaging (DWI) after clinically diagnosed stroke. We aimed to investigate systematically the rate and characteristics of reversible diffusion hyperintensities (RDHs) in the first week after stroke. METHODS: Patients with clinical diagnosis of an acute cerebrovascular event and evidence of ischemia on DWI were included. MRI scans were performed on admission, on the following day, and 4 to 7 days after onset of symptoms with DWI and fluid-attenuated inversion recovery. Baseline and follow-up DWIs were coregistered and examined for individual RDHs. Characteristics of patients and of hyperintensities associated with early reversal were identified. RESULTS: We included 153 patients with a median National Institutes of Health Stroke Scale score of 4 (interquartile range, 2-8). In 3 patients (2%), MR images normalized completely. Thirty-seven patients (24%) displayed individual RDHs. Of 611 initial DWI hyperintensities, 97 (16%) reversed. Thirteen percent of the RDHs had corresponding abnormalities on fluid-attenuated inversion recovery images at the third measurement. Median size of the RDHs was 0.029 mL (interquartile range, 0.013-0.055). RDHs were associated with a multiple infarct pattern (odds ratio, 22.1; 95% confidence interval, 4.5-109.7) and symptomatic carotid stenosis (odds ratio, 5.5; 95% confidence interval, 1.4-21.5). Fifty-nine percent of the patients with RDHs had new additional lesions on follow-up DWI. RDHs were not associated with functional improvement on the National Institutes of Health Stroke Scale score. CONCLUSIONS: In this population of mainly minor to moderate stroke patients, complete normalization of MR images was rare. Complete reversal of individual DWI hyperintensities was limited to very small lesions and mostly occurred in embolic stroke patients.Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00715533.
[show abstract][hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: The so-called smoking-thrombolysis paradox of an improved outcome after thrombolysis was first described in smokers with myocardial infarction. We investigated whether reperfusion rates and clinical outcome differ between smokers and nonsmokers with ischemic stroke after intravenous tissue plasminogen activator. METHODS: Consecutive acute ischemic stroke patients, who had magnetic resonance imaging before and 1 day after thrombolysis, were included for analysis. All of the patients received intravenous tissue plasminogen activator within 4.5 hours. Reperfusion was defined as a 75% reduction in perfusion deficit (mean transit time >6 s) after thrombolysis compared with baseline. Magnetic resonance angiography was used to evaluate arterial stenosis and occlusion. Functional outcome was assessed 3 months after stroke using the modified Rankin Score. RESULTS: Of 148 patients, 21.6% were smokers (n=32). Smokers were younger (median, 61 years [SD, 9.4 years] versus 75 years [SD, 11.6 years]; P<0.001), less often women (28% versus 51%; P=0.03), had lower baseline glucose levels (median, 6.2 mmol/L [interquartile range, 5.7-6.8 mmol/L] versus 6.7 mmol/L [interquartile range, 6.1-8.2 mmol/L]; P<0.01) and higher baseline perfusion deficits (median, 53 mL [interquartile range, 13-141 mL] versus 17 mL [interquartile range, 2-66 mL]; P=0.04). In a backward stepwise regression analysis including age, sex, hypertension, glucose, perfusion deficit, and smoking, smoking had an odds ratio of 4 (95% confidence interval, 1-16; P=0.03) for reperfusion and 6 (95% confidence interval, 1-30; P=0.05) for recanalization (regression analysis for recanalization also included localization of arterial occlusion). Smokers had a better outcome (modified Rankin Score=0-2) than nonsmokers (77% versus 55%; P=0.05). CONCLUSIONS: Smoking is independently associated with recanalization and reperfusion, indicating that thrombolytic therapy acts more effectively in smokers; because of small numbers, these results should be considered preliminary.Clinical Trials Registration-NCT00715533 (http://www.clinicaltrials.gov/ct/show/NCT00715533).
[show abstract][hide abstract] ABSTRACT: Background and Purpose: Although the presence of cavitating lacunes on brain imaging may have prognostic implications, the modifiable risk factors underlying these frequently observed lesions are not completely understood. We sought to determine if fasting and post-challenge triglycerides associate with cavitating lacunes. Methods: All first ischemic stroke patients who completed a novel combined oral triglyceride and glucose tolerance test and MRI between January 2009 and June 2012 were included. Fluid-attenuated inversion recovery or T2 MRI sequences were used to visualize cavitating lacunes and white matter hyperintensities, which were graded using the Wahlund visual scale. Results: One hundred and ninety patients were included (median age 66, IQR 52-73; 33% female; median National Institute of Health Stroke Scale 2, IQR 1-4). A forward stepwise binary logistical regression analysis applying the Hosmer-Lemeshow goodness of fit test adjusted for parameters significant in univariate analyses (at the p < 0.10 level) revealed that Wahlund scores (Wahlund 0-4: reference; Wahlund 5-10: adjusted odds ratio, 5.1; 95% confidence interval, 1.3-20.0, p = 0.019; Wahlund>10: adjusted odds ratio 9.6; 95% CI, 1.55-59.35; p = 0.015) and the highest quartile of post-challenge triglycerides (>295 mg/dL; adjusted odds ratio, 7.36; 95% confidence interval 1.24-43.70; p = 0.028) independently associated with the presence of cavitating lacunes. Conclusion: Post-challenge serum triglycerides are independently associated with the presence of cavitating lacunes.
[show abstract][hide abstract] ABSTRACT: In acute ischemic stroke, time from symptom onset to intervention is a decisive prognostic factor. In order to reduce this time, prehospital thrombolysis at the emergency site would be preferable. However, apart from neurological expertise and laboratory investigations a computed tomography (CT) scan is necessary to exclude hemorrhagic stroke prior to thrombolysis. Therefore, a specialized ambulance equipped with a CT scanner and point-of-care laboratory was designed and constructed. Further, a new stroke identifying interview algorithm was developed and implemented in the Berlin emergency medical services. Since February 2011 the identification of suspected stroke in the dispatch center of the Berlin Fire Brigade prompts the deployment of this ambulance, a stroke emergency mobile (STEMO). On arrival, a neurologist, experienced in stroke care and with additional training in emergency medicine, takes a neurological examination. If stroke is suspected a CT scan excludes intracranial hemorrhage. The CT-scans are telemetrically transmitted to the neuroradiologist on-call. If coagulation status of the patient is normal and patient's medical history reveals no contraindication, prehospital thrombolysis is applied according to current guidelines (intravenous recombinant tissue plasminogen activator, iv rtPA, alteplase, Actilyse). Thereafter patients are transported to the nearest hospital with a certified stroke unit for further treatment and assessment of strokeaetiology. After a pilot-phase, weeks were randomized into blocks either with or without STEMO care. Primary end-point of this study is time from alarm to the initiation of thrombolysis. We hypothesized that alarm-to-treatment time can be reduced by at least 20 min compared to regular care.
[show abstract][hide abstract] ABSTRACT: OBJECTIVE: Beneficial effects of IV tissue plasminogen activator (tPA) in acute ischemic stroke are strongly time-dependent. In the Pre-Hospital Acute Neurological Treatment and Optimization of Medical care in Stroke (PHANTOM-S) study, we undertook stroke treatment using a specialized ambulance, the stroke emergency mobile unit (STEMO), to shorten call-to-treatment time. METHODS: The ambulance was staffed with a neurologist, paramedic, and radiographer and equipped with a CT scanner, point-of-care laboratory, and a teleradiology system. It was deployed by the dispatch center whenever a specific emergency call algorithm indicated an acute stroke situation. Study-specific procedures were restricted to patients able to give informed consent. We report feasibility, safety, and duration of procedures regarding prehospital tPA administration. RESULTS: From February 8 to April 30, 2011, 152 subjects were treated in STEMO. Informed consent was given by 77 patients. Forty-five (58%) had an acute ischemic stroke and 23 (51%) of these patients received tPA. The mean call-to-needle time was 62 minutes compared with 98 minutes in 50 consecutive patients treated in 2010. Two (9%) of the tPA-treated patients had a symptomatic intracranial hemorrhage and 1 of these patients (4%) died in hospital. Technical failures encountered were 1 CT dysfunction and 2 delayed CT image transmissions. CONCLUSIONS: The data suggest that prehospital stroke care in STEMO is feasible. No safety concerns have been raised so far. This new approach using prehospital tPA may be effective in reducing call-to-needle times, but this is currently being scrutinized in a prospective controlled study.
[show abstract][hide abstract] ABSTRACT: Purpose: To reduce the time from symptom onset to treatment with tissue plasminogen activator (tPA) in ischemic stroke, an ambulance was equipped with a CT scanner. We analyzed process and image quality of CT scanning during the pilot study regarding image quality and safety issues.Materials and Methods: The pilot study of a stroke emergency mobile unit (STEMO) ran over a period of 12 weeks on 5 weekdays from 7a. m. to 6:30 p. m. A teleradiological service for the justifying indication and reporting was established. The radiographer was responsible for the performance of the CT scan on the ambulance. 64 cranial CT scans and 1 intracranial CT angiography were performed. We compared times from ambulance alarm to treatment decision (time of last brain scan) with a cohort of 50 consecutive tPA treatments before implementation of STEMO.Results: 62 (95 %) of the 65 scans performed had sufficient quality for reading. Technical quality was not optimal in 45 cases (69 %) mainly caused by suboptimal positioning of patient or eye lense protection. Motion artefacts were observed in 8 exams (12 %). No safety issues occurred for team or patients. 23 patients were treated with thrombolysis. Time from alarm to last CT scan was 18 minutes shorter than in the tPA cohort before STEMO implementation.Conclusion: A teleradiological support for primary stroke imaging by CT on-site is feasible, quality-wise of diagnostic value and has not raised safety issues.
RöFo - Fortschritte auf dem Gebiet der R 10/2012; · 2.76 Impact Factor
[show abstract][hide abstract] ABSTRACT: In acute stroke magnetic resonance imaging, a 'mismatch' between visibility of an ischemic lesion on diffusion-weighted imaging (DWI) and missing corresponding parenchymal hyperintensities on fluid-attenuated inversion recovery (FLAIR) data sets was shown to identify patients with time from symptom onset ≤4.5 hours with high specificity. However, moderate sensitivity and suboptimal interpreter agreement are limitations of a visual rating of FLAIR lesion visibility. We tested refined image analysis methods in patients included in the previously published PREFLAIR study using refined visual analysis and quantitative measurements of relative FLAIR signal intensity (rSI) from a three-dimensional, segmented stroke lesion volume. A total of 399 patients were included. The rSI of FLAIR lesions showed a moderate correlation with time from symptom onset (r=0.382, P<0.001). A FLAIR rSI threshold of <1.0721 predicted symptom onset ≤4.5 hours with slightly increased specificity (0.85 versus 0.78) but also slightly decreased sensitivity (0.47 versus 0.58) as compared with visual analysis. Refined visual analysis differentiating between 'subtle' and 'obvious' FLAIR hyperintensities and classification and regression tree algorithms combining information from visual and quantitative analysis also did not improve diagnostic accuracy. Our results raise doubts whether the prediction of stroke onset time by visual image judgment can be improved by quantitative rSI measurements.Journal of Cerebral Blood Flow & Metabolism advance online publication, 10 October 2012; doi:10.1038/jcbfm.2012.129.
Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism 10/2012; · 5.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Patients waking up with stroke symptoms are generally excluded from intravenous thrombolysis. It was shown that magnetic resonance imaging (MRI) can identify patients within the time window for thrombolysis (≤ 4.5 h from symptom onset) by a mismatch between the acute ischemic lesion visible on diffusion-weighted imaging (DWI) but not visible on fluid-attenuated inversion recovery (FLAIR) imaging. The WAKE-UP trial is an investigator initiated, European, randomized, double-blind, placebo-controlled trial designed to test efficacy and safety of MRI-based thrombolysis with alteplase (tPA) in stroke patients with unknown time of symptom onset, e.g. due to symptom recognition on awakening. A total of 800 patients showing MRI findings of a DWI-FLAIR-mismatch will be randomized to either tPA or placebo. The primary efficacy endpoint will be favourable outcome defined by a modified Rankin scale score 0-1 at day 90. The primary safety outcome measures will be mortality and death or dependency defined by modified Rankin scale score 4-6 at 90 days. If positive the WAKE-UP trial is expected to change clinical practice and to make effective and safe treatment available for a large group of acute stroke patients currently excluded from specific acute treatment.
Der Nervenarzt 09/2012; 83(10):1241-51. · 0.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: To determine if severity of visually assessed white matter disease is associated with disability after ischemic stroke.
In this Berlin "Cream & Sugar" substudy, all first ischemic stroke patients who received magnetic resonance imaging and completed follow-up between January 2009 and December 2010, were enrolled. Severity of white matter disease was assessed on fluid-attenuated inversion recovery or T2-weighted sequences using the Wahlund and Fazekas visual scales. Functional outcome was assessed after 1 year using the modified Rankin Scale (follow-up [FU] modified Rankin Scale [mRS]).
Of 101 patients (37% female; median age, 67 years; interquartile range, 54-75; National Institutes of Health Stroke Scale score, 1; interquartile range, 0-2), median FU mRS was 1 (interquartile range, 0-2). Binary logistical regression adjusted for age (at 5-year intervals), acute National Institutes of Health Stroke Scale scores, fasting glucose, insulin, glycosylated hemoglobin, creatinine, C-reactive protein quartiles, waist circumference, and systolic blood pressure revealed that Fazekas scores of 2 and 3 independently associated with FU mRS (Fazekas score 2: adjusted odds ratio, 8.4; 95% confidence interval, 2.35-30.09; P=0.001; Fazekas score 3: adjusted odds ratio, 4.2; 95% confidence interval, 1.04-16.96; P=0.044). Wahlund scores >10 were significantly associated with FU mRS when fasting glucose levels were removed from the regression analysis (adjusted odds ratio, 12.17; 95% confidence interval, 1.91-77.54; P=0.008).
Severe white matter disease defined by standard criteria in acute ischemic stroke patients is associated with disability at 1 year and can be assessed quickly using visual rating scales. Clinical Trial Registration Information- URLs: http://www.clinicaltrials.gov and https://eudract.ema.europa.eu. Unique identifiers: NCT 01378468 and 2009-010356-97.
[show abstract][hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: Hyperintense vessels (HVs) have been observed in fluid-attenuated inversion recovery imaging of patients with acute ischemic stroke and been linked to slow flow in collateral arterial circulation. Given the potential importance of HV, we used a large, multicenter data set of patients with stroke to clarify which clinical and imaging factors play a role in HV. METHODS: We analyzed data of 516 patients from the previously published PRE-FLAIR study (PREdictive value of FLAIR and DWI for the identification of acute ischemic stroke patients ≤3 and ≤4.5 hours of symptom onset-a multicenter study) study. Patients were studied by MRI within 12 hours of symptom onset. HV were defined as hyperintensities in fluid-attenuated inversion recovery corresponding to the typical course of a blood vessel that was not considered the proximal, occluded main artery ipsilateral to the diffusion restriction. Presence of HV was rated by 2 observers and related to clinical and imaging findings. RESULTS: Presence of HV was identified in 240 of all 516 patients (47%). Patients with HV showed larger initial ischemic lesion volumes (median, 12.3 versus 4.9mL; P<0.001) and a more severe clinical impairment (median National Institutes of Health Stroke Scale 10.5 versus 6; P<0.001). In 198 patients with MR angiography, HVs were found in 80% of patients with vessel occlusion and in 17% without vessel occlusion. In a multivariable logistic regression model, vessel occlusion was associated with HV (OR, 21.7%; 95% CI, 9.6-49.9; P<0.001). HV detected vessel occlusion with a specificity of 0.86 (95% CI, 0.80-0.90) and sensitivity of 0.76 (95% CI, 0.69-0.83). CONCLUSIONS: HVs are a common finding associated with proximal arterial occlusions and more severe strokes. HVs predict arterial occlusion with high diagnostic accuracy.
[show abstract][hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: Absence of FLAIR hyperintensity within an acute infarct is associated with stroke onset <4.5 h. However, some patients rapidly develop FLAIR hyperintensity within this timeframe. We hypothesized that development of early infarct FLAIR hyperintensity would predict hemorrhagic transformation (HT) in sub-4.5 h tPA patients. METHODS: Consecutive acute stroke patients treated with IV tPA <4.5 h after onset who had MRI before and one day after thrombolysis were included. Two raters (blind to HT) independently identified FLAIR hyperintensity with reference to the DWI lesion. HT was assessed using T2* MRI at 24 h. Hemorrhagic infarction (HI) was defined as petechial HT without mass effect, and parenchymal hematoma (PH) as HT with mass effect. Multivariable logistic regression analysis for HT included FLAIR status, baseline NIHSS and DWI lesion volume, leukoaraiosis (Wahlund score), serum glucose and reperfusion. RESULTS: Of 109 patients, 33 (30%) had acute FLAIR hyperintensity. HT occurred in 17 patients (15.6%; 15 HI, 2 PH). HT was more common in FLAIR-positive patients than FLAIR-negative patients (33.3% vs. 9.2%, P = 0.009). Median time-to-scan and median time-to-thrombolysis did not differ significantly between patients with HT and without (97 IQR[68, 155] vs. 90 IQR[73, 119], P = 0.5; 120 IQR[99, 185] vs. 125 IQR[95, 150], P = 0.6, respectively). In multivariable analysis, only FLAIR hyperintensity was independently associated with HT after thrombolysis (OR: 18; 95% CI 2 to 175, P = 0.013). CONCLUSIONS: Early development of FLAIR hyperintensity within the area of diffusion-restriction is associated with increased risk of HT after thrombolysis in acute stroke patients.
European Journal of Neurology 08/2012; · 4.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Time from symptom onset to treatment is closely associated with the effectiveness of intravenous thrombolysis in acute ischemic stroke patients. Hospitals are encouraged to take every effort to shorten delay of treatment. Despite combined efforts to streamline procedures in hospitals to provide treatment as soon as possible, most patients receive tissue plasminogen activator with considerable delay and very few of them within 90 mins. Germany has an internationally acknowledged prehospital emergency care system with specially trained doctors on ambulances. We developed an ambulance equipped with a Computed Tomography (CT) scanner, point-of-care laboratory, teleradiological support, and an emergency-trained neurologist on board. In the Pre-Hospital Acute Neurological Therapy and Optimization of Medical care in Stroke Patients study, we aim at a reduction of the current alarm-to-needle time by prehospital use of tissue plasminogen activator in an ambulance.
We hypothesized that compared with regular care, we will reduce alarm-to-needle time by a minimum of 20 mins by implementation of the stroke emergency mobile unit.
Prospective study comparing randomly allocated periods with and without stroke emergency mobile unit availability.
Primary end point of the study is alarm-to-needle time. Secondary outcomes include thrombolysis treatment rates, modified Rankin scale after three-months, and alarm-to-imaging or alarm-to-laboratory time; safety aspects to be evaluated are mortality and rates of (symptomatic) intracerebral hemorrhage.
International Journal of Stroke 06/2012; 7(4):348-53. · 2.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: Recent innovations such as CT installation in ambulances may lead to earlier start of stroke-specific treatments. However, such technically complex mobile facilities require effective methods of correctly identifying patients before deployment. We aimed to develop and validate a new dispatcher identification algorithm for stroke emergencies.
Dispatcher identification algorithm for stroke emergencies was informed by systematic qualitative analysis of the content of emergency calls to ambulance dispatchers for patients with stroke or transient ischemic attack (N=117) and other neurological (N=39) and nonneurological (N=51) diseases (Part A). After training of dispatchers, sensitivity and predictive values were determined prospectively in patients admitted to Charité hospitals by using the discharge diagnosis as reference standard (Part B).
Part A: Dysphasic/dysarthric symptoms (33%), unilateral symptoms (22%) and explicitly stated suspicion of stroke (47%) were typically identified in patients with stroke but infrequently in nonstroke cases (all <10%). Convulsive symptoms (41%) were frequent in other neurological diseases but not strokes (3%). Pain (26%) and breathlessness (31%) were often expressed in nonneurological emergencies (6% and 7% in strokes). Part B: Between October 15 and December 16, 2010, 5774 patients were admitted by ambulance with 246 coded with final stroke diagnoses. Sensitivity of dispatcher identification algorithm for stroke emergencies for detecting stroke was 53.3% and positive predictive value was 47.8% for stroke and 59.1% for stroke and transient ischemic attack. Of all 275 patients with stroke dispatcher codes, 215 (78.5%) were confirmed with neurological diagnosis.
Using dispatcher identification algorithm for stroke emergencies, more than half of all patients with stroke admitted by ambulance were correctly identified by dispatchers. Most false-positive stroke codes had other neurological diagnoses.
[show abstract][hide abstract] ABSTRACT: We investigated if hyperintensities on fluid-attenuated inversion recovery (FLAIR) sequences in arteries and parenchyma are associated with poor outcome 3 months after thrombolysis.
Consecutive acute stroke patients with known time of symptom onset who had an MRI before and 1 day after thrombolysis were included in this study. Blinded to follow-up imaging and outcome, 2 raters independently judged the presence or absence of arterial and parenchymal FLAIR hyperintensities. Functional outcome (modified Rankin Scale) was assessed after 3 months.
Out of 90 patients, 22 had parenchymal FLAIR hyperintensities and 42 had hyperintense vessels. The combination of FLAIR hyperintensities in arteries and parenchyma occurred in 15 patients. Stepwise forward regression analysis revealed an adjusted odds ratio of 14.5 for a worse outcome (modified Rankin Scale score >2) in patients with FLAIR hyperintensities in arteries and parenchyma (95% confidence interval, 1.3-158.5; P=0.03).
FLAIR hyperintensities in arteries and parenchyma are an easy-to-use MRI feature in acute ischemic stroke associated with poor outcome 3 months after thrombolysis.