Umut Yilmaz

Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial.

BACKGROUND Only 2-5% of patients who have a stroke receive thrombolytic treatment, mainly because of delay in reaching the hospital. We aimed to assess the efficacy of a new approach of diagnosis and treatment starting at the emergency site, rather than after hospital arrival, in reducing delay in stroke therapy. METHODS We did a randomised single-centre controlled trial to compare the time from alarm (emergency call) to therapy decision between mobile stroke unit (MSU) and hospital intervention. For inclusion in our study patients needed to be aged 18-80 years and have one or more stroke symptoms that started within the previous 2·5 h. In accordance with our week-wise randomisation plan, patients received either prehospital stroke treatment in a specialised ambulance (equipped with a CT scanner, point-of-care laboratory, and telemedicine connection) or optimised conventional hospital-based stroke treatment (control group) with a 7 day follow-up. Allocation was not masked from patients and investigators. Our primary endpoint was time from alarm to therapy decision, which was analysed with the Mann-Whitney U test. Our secondary endpoints included times from alarm to end of CT and to end of laboratory analysis, number of patients receiving intravenous thrombolysis, time from alarm to intravenous thrombolysis, and neurological outcome. We also assessed safety endpoints. This study is registered with ClinicalTrials.gov, number NCT00153036. FINDINGS We stopped the trial after our planned interim analysis at 100 of 200 planned patients (53 in the prehospital stroke treatment group, 47 in the control group), because we had met our prespecified criteria for study termination. Prehospital stroke treatment reduced the median time from alarm to therapy decision substantially: 35 min (IQR 31-39) versus 76 min (63-94), p<0·0001; median difference 41 min (95% CI 36-48 min). We also detected similar gains regarding times from alarm to end of CT, and alarm to end of laboratory analysis, and to intravenous thrombolysis for eligible ischaemic stroke patients, although there was no substantial difference in number of patients who received intravenous thrombolysis or in neurological outcome. Safety endpoints seemed similar across the groups. INTERPRETATION For patients with suspected stroke, treatment by the MSU substantially reduced median time from alarm to therapy decision. The MSU strategy offers a potential solution to the medical problem of the arrival of most stroke patients at the hospital too late for treatment. FUNDING Ministry of Health of the Saarland, Germany, the Werner-Jackstädt Foundation, the Else-Kröner-Fresenius Foundation, and the Rettungsstiftung Saar.

Mobile stroke unit for diagnosis-based triage of persons with suspected stroke

Background: In this feasibility study, we tested whether prehospital diagnostic stroke workup enables rational decision-making regarding treatment and the target hospital in persons with suspected stroke. Methods: A mobile stroke unit that delivers imaging (including multimodal brain imaging with CT angiography and CT perfusion), point-of-care-laboratory analysis, and neurologic expertise directly at the emergency site was analyzed for its use in prehospital diagnosis-based triage of suspected stroke patients. Results: We present 4 complementary cases with suspected stroke who underwent prehospital diagnostic workup that enabled direct diagnosis-based treatment decisions and reliable triage regarding the most appropriate medical facility for that individual, e.g., a primary hospital vs specialized centers of a tertiary hospital. Conclusions: This preliminary report demonstrates the feasibility of prehospital diagnostic stroke workup for immediate etiology-specific decision-making regarding the necessary time-sensitive stroke treatment and the most appropriate target hospital.

Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke : The ReFlow (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke) Study

OBJECTIVES This study sought to assess the feasibility and safety of a recently described technique of mechanical recanalization with the help of a stent-like device. BACKGROUND In the special group of acute stroke patients with an intracranial large vessel occlusion, intravenous tissue-type plasminogen activator on its own leads to a good clinical outcome (mRS ≤ 2) in only 15% to 25% of cases. The aforementioned technique of mechanical recanalization showed very promising clinical results. METHODS Forty patients presenting within 6 h from stroke symptom onset were enrolled. Mechanical recanalization was performed using a Solitaire FR revascularization device. The primary endpoint of the study was the clinical outcome rated with the help of the modified Rankin Scale (mRS) after 90 days. RESULTS Twenty-four patients (60%) showed a good clinical outcome (mRS ≤ 2) at 90 days. One symptomatic hemorrhage was detected on follow-up computed tomography. The death rate was 12.5% (5 patients). Successful recanalization (Thrombolysis In Cerebral Infarction score ≥ 2b) of the target vessel was achieved in 95% of the patients with a mean of 1.8 runs with the device. CONCLUSIONS The ReFlow (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke) study shows that mechanical recanalization with flow restoration is highly effective in stroke patients with a large intracranial vessel occlusion presenting within 4.5 h after symptom onset. (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke [ReFlow]; NCT01210729).

Multifocal Signal Loss at Bridging Veins on Susceptibility-Weighted Imaging in Abusive Head Trauma

Identifying abusive head trauma (AHT) in infants is difficult because often there are no externally visible injuries and symptoms are nonspecific. The radiological finding that usually raises suspicion of AHT—especially when found with retinal hemorrhage and inappropriate history—is subdural hematoma (SDH). In addition to that, bridging vein thrombosis, assessed by imaging or autopsy, has been reported as a sign of the traumatic cause of SDH. Here we present two cases of AHT-associated SDH in infants, in which multifocal signal loss at bridging veins was present on susceptibility-weighted imaging without signs of venous infarction. As susceptibility-weighted imaging has been reported to be more sensitive for blood products than gradient-echo T2-weighted imaging, we propose that it might help to identify clot formation on injured bridging veins and therefore increase the sensitivity of imaging studies for a traumatic cause of SDH, helping to identify AHT that is considered to be caused by violent shaking.

Thrombus Attenuation Does Not Predict Angiographic Results of Mechanical Thrombectomy with Stent Retrievers

This article examines whether MCA clot attenuation on initial CT studies determines the outcome of endovascular recanalization. The study was performed in 70 patients and showed that there were no significant differences between thrombus attenuations and successful recanalizations or periprocedural clot fragmentations. This investigation differs from others in that clot attenuation did not predict recanalization. BACKGROUND AND PURPOSE: Mechanical thrombectomy with stent retrievers in acute stroke has emerged as a promising new technique, with the highest recanalization rate of the therapeutic procedures available thus far. However, in up to 20% of the cases, mechanical thrombectomy with stent retrievers results in poor angiographic outcomes, with Thrombolysis in Cerebral Infarction scores ≤2a. The purpose of this study was to investigate whether thrombus attenuation on the initial CT scan can predict the angiographic outcome of the recanalization procedure in MCA occlusions. MATERIALS AND METHODS: The data of 70 patients with acute MCA occlusions who underwent endovascular treatment with stent retrievers in our department were included. We analyzed thrombus attenuations, angiographic outcome, and periprocedural thrombus fragmentation. RESULTS: The mean thrombus attenuation was 49.8 ± 7.8 HU and the mean difference from the attenuation of the contralateral MCA was 9.9 ± 8.0 HU. There were no significant differences in the thrombus attenuations of occlusions that were successfully recanalized (modified Thrombolysis in Cerebral Infarction ≥2b) and those that were not. Neither were there significant correlations of thrombus attenuations and periprocedural thrombus fragmentations that occurred in 64.3%. We found a nonsignificantly higher rate of recanalizations with modified Thrombolysis in Cerebral Infarction ≥2b when the difference from the attenuation of the contralateral MCA was between 1–20 HU. CONCLUSIONS: In contrast to results of other revascularization procedures as published in a recent study, the angiographic result of mechanical thrombectomy with stent retrievers is not predicted by thrombus attenuation.

The Barrel stent: new treatment option for stent-assisted coiling of wide-necked bifurcation aneurysms—results of a single-center study

Purpose The Barrel stent is a laser cut stent designed for stent-assisted coil embolization of wide-necked bifurcation or branch aneurysms with a single device, with the purpose of lowering the metal-to-artery ratio and its inherent risk of thromboembolic complications of multiple stents. We report our early experiences with this device in 17 patients in this retrospective single-center analysis. Materials and methods 17 consecutive patients who underwent stent-assisted coil embolization of wide-necked bifurcation aneurysms with the Barrel stent were retrospectively identified. We analyzed the feasibility of successful deployment and post-treatment angiographic results. Adverse events, clinical outcome, and angiographic follow-up results were also analyzed. Results Aneurysms were located in the internal carotid artery (n=3), the middle cerebral artery (n=9), the anterior communicating artery (n=3), and the basilar artery (n=2). In the immediate post-treatment angiography, adequate occlusion (neck remnant or total occlusion) was observed in 16/17 (94.1%) of aneurysms. One patient experienced a transient ischemic attack. No permanent neurologic deficits were observed. 13/17 (76.5%) patients underwent short-term follow-up angiography after 3 months, all of which showed adequate occlusion of the aneurysm. Conclusions In this small retrospective single-center analysis we show that stent-assisted coiling with the Barrel stent is a safe and effective option for the endovascular treatment of intracranial wide-necked bifurcation aneurysms.

The Derivo Embolization Device, a Second-Generation Flow Diverter for the Treatment of Intracranial Aneurysms, Evaluated in an Elastase-Induced Aneurysm Model.

PurposeIn recent years, flow diverters have provided a promising alternative to treat complex intracranial aneurysms. In this study, we compare a second-generation flow-diverting device (Derivo Embolization Device) with its prototype flow diverter, in the treatment of elastase-induced aneurysms in New Zealand white rabbits.MethodsThe Derivo Embolization Device is a self-expanding stent consisting of 48 nitinol wires. The device was implanted across the necks of 17 elastase-induced aneurysms in New Zealand white rabbits. One additional device was implanted in the abdominal aorta of each animal covering the origin of lumbar arteries. Follow-up was performed after 3 months (n = 8) and 6 months (n = 9) under continuous double antiplatelet therapy. Statuses of angiographic and histological aneurysm occlusion as well as patency of branch arteries and neointimal growth were evaluated and compared with its prototype flow diverter.ResultsThe Derivo Embolization Device provided advanced visibility and flexibility, which led to more accurate navigation and placement. Complete aneurysm occlusion rates were noted in 15 cases (88 %), respectively, compared with 5 cases (28 %) with the first-generation device (p = 0.001). Neointimal growth and diameter stenosis were significantly less with the Derivo Embolization Device and declining after 6 months follow-up in the abdominal aorta. Extreme device oversizing led to distal occlusion of the parent vessel in three cases. Covered branch arteries remained patent throughout the entire period of observation.ConclusionsThe Derivo Embolization Device provides excellent occlusion of elastase-induced aneurysms while preserving branch arteries.

First Automated Stroke Imaging Evaluation via Electronic Alberta Stroke Program Early CT Score in a Mobile Stroke Unit.

Background: Recently, a mobile stroke unit (MSU) was shown to facilitate acute stroke treatment directly at the emergency site. The neuroradiological expertise of the MSU is improved by its ability to detect early ischemic damage via automatic electronic (e) evaluation of CT scans using a novel software program that calculates the electronic Alberta Stroke Program Early CT Score (e-ASPECTS). Methods: The feasibility of integrating e-ASPECTS into an ambulance was examined, and the clinical integration and utility of the software in 15 consecutive cases evaluated. Results: Implementation of e-ASPECTS onto the MSU and into the prehospital stroke management was feasible. The values of e-ASPECTS matched with the results of conventional neuroradiologic analysis by the MSU team. The potential benefits of e-ASPECTS were illustrated by three cases. In case 1, excluding early infarct signs supported the decision to directly perform prehospital thrombolysis. In case 2, in which stroke was caused by large-vessel occlusion, the high e-ASPECTS value supported the decision to initiate intra-arterial treatment and triage the patient to a comprehensive stroke center. In case 3, the e-ASPECTS value was 10, indicating the absence of early infarct signs despite pre-existing cerebral microangiopathy and macroangiopathy, a finding indicating the programs robustness against artefacts. Conclusions: This study on the integration of e-ASPECTS into the prehospital stroke management via a MSU showed for the first time that such integration is feasible, and aids both decision regarding the treatment option and the triage regarding the most appropriate target hospital.

Acute Occlusions of Dual-Layer Carotid Stents After Endovascular Emergency Treatment of Tandem Lesions

Background and Purpose— A new generation of carotid artery stents that uses a second micromesh layer to reduce embolic events during carotid artery stenting has recently been introduced. The purpose of this study was to compare acute occlusion rates of these new dual-layer stents with those of single-layer stents in the setting of emergency carotid artery stenting with intracranial mechanical thrombectomy in acute ischemic stroke. Methods— Consecutive patients with acute tandem (intra- and extracranial) lesions of the anterior circulation who were endovascularly treated at our institution were identified from our registry of neuroendovascular interventions. Clinical, angiographic, and neuroimaging data were analyzed. End points included acute occlusions of the carotid stents (within 72 hours after stenting) and symptomatic intracerebral hemorrhage. Results— Forty-seven patients were included. Dual-layer stents (n=20) had a significantly higher rate of acute occlusions than single-layer stents (n=27; 45% versus 3.7%; P=0.001; odds ratio, 21.3; 95% confidence interval, 2.4–188.4). There were no significant differences in the rates of patients who had any antiplatelet or dual antiplatelet medication before admission, in the rates of postinterventional symptomatic intracerebral hemorrhage, the mean National Institutes of Health Stroke Scale scores at admission, or the modified Rankin Scale scores at discharge. Conclusions— The recently introduced dual-layer stents have a higher risk of acute occlusion compared with single-layer stents in the treatment of acute stroke.

Tongue fasciculations in an infant with spinal muscular atrophy type 1.

Muscular hypotonia in infants may be associated with several conditions, such as spinal muscular atrophy (SMA). We report on an infant with tongue fasciculations and a rare mutation of the SMN1 gene. The presence of tongue fasciculations in combination with a thorough history may be suggestive of SMA.