Publications (55) View all
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Article: Complete Early Reversal of Diffusion-Weighted Imaging Hyperintensities After Ischemic Stroke Is Mainly Limited to Small Embolic Lesions.
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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.Stroke 02/2013; · 5.73 Impact Factor -
Article: Identifying the perfusion deficit in acute stroke with resting-state functional magnetic resonance imaging.
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ABSTRACT: Temporal delay in blood oxygenation level-dependent (BOLD) signals may be sensitive to perfusion deficits in acute stroke. Resting-state functional magnetic resonance imaging (rsfMRI) was added to a standard stroke MRI protocol. We calculated the time delay between the BOLD signal at each voxel and the whole-brain signal using time-lagged correlation and compared the results to mean transit time derived using bolus tracking. In all 11 patients, areas exhibiting significant delay in BOLD signal corresponded to areas of hypoperfusion identified by contrast-based perfusion MRI. Time delay analysis of rsfMRI provides information comparable to that of conventional perfusion MRI without the need for contrast agents. ANN NEUROL 2013.Annals of Neurology 01/2013; 73(1):136-40. · 11.09 Impact Factor -
Article: Prehospital thrombolysis in acute stroke: Results of the PHANTOM-S pilot study.
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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.Neurology 12/2012; · 8.31 Impact Factor -
Article: Ocular hyperintense acute reperfusion marker.
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ABSTRACT: Hyperintense signal within the subarachnoid space (SAS), visualized on delayed postcontrast fluid-attenuated inversion recovery (FLAIR) in MRI, is proposed to be caused by early blood-brain barrier (BBB) breakdown due to ischemia,(1) and must be differentiated from subarachnoid hemorrhage. Reperfusion is the strongest independent predictor of early BBB disruption following ischemia and the phenomenon is described as hyperintense acute reperfusion marker (HARM).(2) We present a case of hyperintense signal in the vitreous body on delayed postcontrast FLAIR of an eye with central retinal artery occlusion (CRAO).Neurology 09/2012; 79(15):1622-3. · 8.31 Impact Factor -
Article: Thrombolytic therapy in total mismatch with severe stroke after acute MCA-occlusion and negative DWI.
Clinical neurology and neurosurgery 08/2012; · 1.30 Impact Factor
