Early time course of FLAIR signal intensity differs between acute ischemic stroke patients with and without hyperintense acute reperfusion marker.

BACKGROUND: In animal models of stroke, the time course of blood-brain barrier (BBB) disruptions has been elaborately studied. In human patients, leakage of gadolinium into cerebrospinal fluid (CSF) space, visualized on MRI fluid attenuated inversion recovery (FLAIR) images, is considered a sign of BBB disruptions. It was termed 'hyperintense acute reperfusion marker' (HARM) and was associated with hemorrhages. However, the time course of the leakage is unknown and difficult to study in human patients. Also, the association of HARM with signal intensities and enhancement in the parenchyma on FLAIR images has not been thoroughly researched. METHODS: We analyzed imaging data of acute ischemic stroke patients who underwent repetitive MRI examinations within the first 36 h after the time of symptom onset. HARM was evaluated on FLAIR images. Regions of interest (ROI) of the hyperintensities on diffusion-weighted imaging (DWI) were determined for each time point and mirrored to the contralateral side. The ROI were furthermore corrected for CSF-filled space, using apparent diffusion coefficient (ADC) images. The corrected ROI were used to determine mean signal intensities of the lesions relative to the contralateral side on FLAIR, ADC and B0 images for each time point. RESULTS: The 18 included patients (5 females; median age: 69 years; median NIHSS score: 5) received 3-5 MRI examinations on the first day and 1-2 examinations on day 2 after stroke. Eight of the patients (44.4%) showed HARM on at least 1 examination. In 6 of these patients, HARM was already seen at the second examination, at the earliest 3.5 h after symptom onset. The HARM-positive patients had higher relative signal intensities (rSI) on FLAIR images in the parenchyma corresponding to the DWI-positive tissue compared with the HARM-negative patients. This difference between groups was statistically significant for the 2nd and 3rd examination (medians of 4.31 and 6.37 h from symptom onset, p < 0.001 and p = 0.005, respectively). No significant difference in rSI between groups was seen for ADC or B0 images. CONCLUSION: HARM does not only represent a contrast medium leakage from the pial system into the CSF space. It is accompanied by a markedly increased rSI in the early ischemic lesion on FLAIR images, which is likely due to parenchymal enhancement. The lack of differences on B0 images excludes a pure T2 effect.

Prediction of vascular risk after stroke - protocol and pilot data of the Prospective Cohort with Incident Stroke (PROSCIS).

RATIONALE: Long-term risk of vascular disease is substantially increased after stroke with several models proposed to predict subsequent stroke and other vascular events after an index event. However, recent validation studies demonstrate limited predictive properties of available prognostic models. AIMS: We aim to determine prediction models of different complexity for the combined vascular end-point of stroke, myocardial infarction, and vascular death at three-years after first-ever stroke. An independent external validation of the developed models will be performed. DESIGN: Prospective observational hospital-based cohort study of patients after first-ever stroke. METHODS: The new predictive models will be developed using the following steps: (1) Development of a basic score based on clinical history data (e.g. hypertension, myocardial infarction, and atrial fibrillation); (2) Development of an advanced score including additional factors such as blood-based biomarkers and results of vascular imaging; (3) Comparing the models fit using different methods (discrimination, calibration); (4) Assessment of clinical utility of an advanced score using methods based on reclassification tables (e.g. net reclassification improvement, integrated discrimination improvement, decision curve analysis); and (5) Investigation of external validity. OUTCOMES: Primary outcome is a combined vascular end-point composed of stroke, myocardial infarction, and vascular death at three-years after stroke. Furthermore, each component of the composite end-point will be investigated individually and the patterns and time points of risk transitions between vascular end-points and stroke sub-types will be determined.

Gender differences in knowledge of stroke in patients with atrial fibrillation.

BACKGROUND: A limiting factor for immediate initiation of stroke therapy is delayed hospital arrival. We assessed general knowledge on and behavior during an acute stroke with particular emphasis on prehospital temporal delays and a focus on the high-risk group of patients with atrial fibrillation (AF). METHODS: As part of the Berlin Acute Stroke Study (BASS), we interviewed patients admitted to hospital with symptoms of stroke using a standardized questionnaire. Cardiac rhythm was assessed by ECG and Holter monitor. Data analysis included additional stratification for age and gender. RESULTS: Of a total of 558 patients (66.8 +/- 13.5 years; 45% female) diagnosed with TIA or stroke 28% interpreted their own symptoms correctly as due to stroke. Female patients reporting cardiac arrhythmias and having AF more often correctly interpreted their symptoms as stroke (P = 0.03), considered their symptoms urgent (P = 0.02), considered stroke a medical emergency (P < 0.05) and had shorter prehospital delay times (P = 0.001) compared to female patients not reporting cardiac arrhythmias. Male, younger (< 65 years) and older patient groups showed no such effect, respectively. CONCLUSION: Females who know to have AF demonstrate better knowledge of stroke symptoms compared to females unaware or without this risk factor. This better knowledge translates into more appropriate behavior during an acute stroke.