Mona Laible

Prevalence of atrial fibrillation and association of previous antithrombotic treatment in patients with cerebral microbleeds.

Cerebral microbleeds (CMBs) are associated with an increased risk of intracerebral hemorrhage. The impact of oral anticoagulation (OAC) on CMBs is not well characterized. Our aim was to assess the prevalence of CMBs in stroke and transient ischaemic attack (TIA) patients with atrial fibrillation (AF) and to analyze the implications of previous treatment with OAC.

Prevalence of renal dysfunction in ischaemic stroke and transient ischaemic attack patients with or without atrial fibrillation

Chronic kidney disease (CKD) is associated with a higher risk of stroke and atrial fibrillation (AF). There are limited data on the comorbidity of renal dysfunction and AF in stroke patients. Our aim was to determine the frequency of kidney dysfunction in ischaemic stroke patients with and without AF.

3-T high-b-value diffusion-weighted MR imaging in hyperacute ischemic stroke.

BACKGROUND AND PURPOSE In patients with hyperacute ischemic stroke, early demonstration of infarction is essential. Diffusion weighted imaging (DWI) is the key method for detecting hyperacute infarction. The value of high b-value DWI in hyperacute ischemic stroke is controversial at 1.5 T, and is unknown at 3 T. The aim of this study is to explore the value of high b-value versus standard b-value DWI at 3T in hyperacute stroke with quantitative and qualitative analysis. MATERIAL AND METHODS This study prospectively included 104 consecutive patients with hyperacute stroke. At 3 T, conventional MR sequences and DWI were performed. The examination included a standard DWI (b = 1000 s/mm(2)) and two high b-value DWI (b = 3000 s/mm(2) and b = 5000 s/mm(2)). Qualitative and quantitative analysis was performed. RESULTS With increasing b value, DW images appeared noisier. The number of detected lesions was significantly higher on b = 3000 images than on the other DW images and higher on b = 5000 images than on b = 1000 images. The number of lesions greater than 1 cm was not significantly different. Lesion conspicuity was higher, boundary better seen, lesion extent bigger, and estimation of final infarct size was better on high b-value than on standard b-value DWI. Contrast-to-noise-ratio (CNR) and signal-to-noise-ratio (SNR) decreased and contrast ratio (CR) increased on high b-value DWI compared to standard b-value DWI. CONCLUSION At 3 T, high b-value DWI was superior to standard b-value DWI in detection of hyperacute infarction and prediction of final infarct size in spite of increasing imaging artifacts.

3-T high-b-value diffusion-weighted MR imaging of hyperacute ischemic stroke in the vertebrobasilar territory

BACKGROUND AND PURPOSE Diffusion-weighted imaging (DWI) is the key method for diagnosing acute ischemic stroke. Applied b values in stroke diffusion studies are usually in the range of 800-1500 s/mm², but progress in magnetic resonance (MR) technology now permits higher b values. However, it is uncertain whether high-b-value DW sequences improve the detection of acute and hyperacute ischemic lesions. The aim of this study is to explore the sensitivity of high b values vs standard b values at 3T in hyperacute stroke in the vertebrobasilar territory. MATERIAL AND METHODS 3-T DWI was performed in referred patients with a clinical diagnosis of hyperacute (<6h from onset) cerebral infarction using conventional MR sequences as well as DW sequences. Examinations included the usual DW sequence (b=1000 s/mm²) and two high-b-value DW sequences (b=3000 s/mm² and b=5000 s/mm²). Patients with hyperacute stroke in the posterior circulation were included if MR imaging, including the usual DW sequence, was normal or if the diagnosis was uncertain. RESULTS In all six studied patients, ischemic lesions were better visualized with high-b-value DWI compared with the usual DWI. On increasing the b value, DW images appeared to be noisier while white-matter tracts became progressively hyperintense. CONCLUSION At 3T, high-b-value DW sequences may be helpful for diagnosing hyperacute infarctions in the vertebrobasilar territory, but further studies are needed to confirm this hypothesis.

Repeated Intra-Arterial Thrombectomy within 72 Hours in a Patient with a Clear Contraindication for Intravenous Thrombolysis

Introduction. Treating patients with acute ischemic stroke, proximal arterial vessel occlusion, and absolute contraindication for administering intravenous recombinant tissue plasminogen activator (rtPA) poses a therapeutic challenge. Intra-arterial thrombectomy constitutes an alternative treatment option. Materials and Methods. We report a case of a 57-year-old patient with concomitant gastric adenocarcinoma, who received three intra-arterial thrombectomies in 72 hours due to repeated occlusion of the left medial cerebral artery (MCA). Findings. Intra-arterial recanalization of the left medial cerebral artery was performed three times with initially good success. However, two days later, the right medial cerebral artery became occluded. Owing to the overall poor prognosis at that time and knowing the wishes of the patient, we decided not to perform another intra-arterial recanalization procedure. Conclusion. To our knowledge, this is the first case illustrating the use of repeated intra-arterial recanalization in early reocclusion of intracranial vessels.

Preexisting cognitive impairment in intracerebral hemorrhage

Preexisting cognitive impairment is a predictor of cognitive decline after ischemic stroke, but evidence in intracerebral hemorrhage (ICH) is limited. We aimed to determine the prevalence of premorbid cognitive impairment in patients with ICH.

Repeated Intravenous Treatment with Recombinant Tissue-Type Plasminogen Activator in Patients with Acute Ischemic Stroke

Objective: Increased use of systemic thrombolysis, demographic changes, and higher chances of surviving first-ever strokes all lead to an increasing number of patients with recurrent stroke. However, data on repeated thrombolysis are limited. Here, we report on the safety and clinical effects of repeated intravenous recombinant tissue-type plasminogen activator (rt-PA) treatment in a large consecutive cohort of stroke patients. Methods: We identified all stroke patients who received repeated thrombolysis. We determined safety and 3-month clinical outcome after the first and second thrombolysis. All patients received follow-up brain imaging. Good clinical outcome was defined as a modified Rankin Scale of 0-2 or recovery to the prestroke status. Results: In total, 24 patients were included (i.e. 1.5% of all stroke patients treated with rt-PA at our center who survived the first treatment; male 45.8%; median age at first event: 74.5 years). No allergic or anaphylactic reactions were recorded after the first time of treatment, but oral angioedema developed once during the second treatment. No symptomatic intracerebral hemorrhage was observed. Clinical outcome was good in 75.0% after the first, but in only 41.7% after the second treatment (p = 0.021). Conclusions: Repeated thrombolysis was not associated with a higher rate of complications. However, the clinical outcome appears to be less satisfactory than after the first treatment.

3-T contrast-enhanced MR angiography with parallel imaging in cerebral venous and sinus thrombosis

BACKGROUND AND PURPOSE Contrast-enhanced (CE) 3D magnetic resonance venography (MRV) and CE 3D magnetization prepared rapid acquisition of gradient echo (MP-RAGE) sequences are increasingly commonly used methods for evaluation of the intracranial venous system. Our aim was to compare CE MRV, 2D time-of-flight (TOF) MRV and MP-RAGE sequences at 3 T for visualization of cerebral venous and sinus thrombosis. MATERIAL AND METHODS Patients with suspected or known cerebral venous thrombosis were examined prospectively by TOF MRV, CE MRV and MP-RAGE sequences. In 11 consecutive patients (all women; mean age, 42.5 years; age range, 25-70 years) with venous thrombosis, scores according to overall image quality, and presence or absence (score P) and differentiation (score D) of venous thrombosis were evaluated. RESULTS By all measurements, overall image quality ranged from good to excellent. In 20 of 52 venous structures (38.5%), score P was the same on TOF MRV, CE MRV and MP-RAGE sequences. Venous thrombosis was definitely or almost definitely present or absent with TOF MRV in 20 of 52 (38.5%), with CE MRV in 97 of 99 (97.9%) and with MP-RAGE sequences in 86 of 99 (86.9%) venous structures. In all venous structures with uncertain diagnosis on TOF MRV, thrombosis was definitely or almost definitely present or absent on CE MRV and MP-RAGE sequences. Differentiation of thrombosis was better on CE MRV (score D: 3.33) than on MP-RAGE sequences (score D: 2.78), followed by TOF MRV (score D: 1.32). CONCLUSION CE MRV was superior to TOF MRV and MP-RAGE sequences in visualizing cerebral venous and sinus thrombosis.

Influence of Renal Function on Treatment Results after Stroke Thrombectomy

Background: Renal dysfunction (RD) may be associated with poor outcome in ischemic stroke patients treated with mechanical thrombectomy (MT), but data concerning this important and emerging comorbidity do not exist so far. Here, we investigated the influence of RD on postprocedural intracerebral hemorrhage (ICH), clinical outcome, and mortality in a large prospectively collected cohort of acute ischemic stroke patients treated with MT. Methods: Consecutive patients with anterior-circulation stroke treated with MT between October 2010 and January 2016 were included. RD was defined as glomerular filtration rate (GFR) <60 mL/min/1.73 m2. In a prospective database, clinical characteristics were recorded and brain images were analyzed for the presence of ICH after treatment in all patients. Clinical outcome was assessed by the modified Rankin Scale (mRS) after 3 months. To evaluate associations between clinical factors and outcomes uni- and multivariate regression analyses were conducted. Results: In total, 505 patients fulfilled all inclusion criteria (female: 49.7%, mean age: 71.0 years). RD at admission was present in 20.2%. RD patients were older and had cardiovascular risk factors more often. Multivariate regression analysis after adjustment for age, stroke severity, diabetes, hypertension, GFR, previous stroke, MT alone, or additional thrombolysis and recanalization results revealed that lower GFR was not independently associated with poor outcome (mRS 3-6; OR 1.13, 95% CI 0.99-1.28; p = 0.072) or ICH. However, lower GFR at admission was associated with a higher risk of mortality (OR 1.15, 95% CI 1.01-1.31; p = 0.038). Compared to admission, GFR values were higher at discharge (mean: 77.9 vs. 80.8 mL/min/1.73 m2; p = 0.046). Conclusions: We did not find evidence for an association of lower GFR with an increased risk of poor outcome and ICH, but lower GFR was a determinant of 90-day mortality after endovascular stroke treatment. Our findings encourage also performing MT in this relevant subgroup of acute ischemic stroke patients.

Changes in Cognitive Function after Left Atrial Appendage Occlusion

Background: Cognitive dysfunction is a frequent phenomenon after surgical and cardiovascular interventions. No data on cognitive function after left atrial appendage occlusion (LAAO) are available so far. The aim of the present study was to evaluate the cognitive function after LAAO compared to before LAAO. Methods and findings: Patients who underwent LAAO for treatment of atrial fibrillation at the Heidelberg Department of Internal Medicine III were eligible for this observational, explorative, single-center, non-randomized cohort study, between July 2013 and January 2016. Neurological examination and neuropsychological assessments were conducted one day before LAAO and one month after LAAO, using a comprehensive neuropsychological test battery that included several cognitive domains including executive function, verbal fluency, verbal and non-verbal memory. Paired t-tests and correlation analyses were applied to compare test results pre- and post-intervention. In addition, we descriptively analyzed the number of relevant changes (± 1 standard deviation) over all cognitive domains for each patient. 20 patients completed the study. Mean age was 72.6 ± 6.8 years and 15 (75%) were male. There were no significant changes in any of the tested cognitive domains in group statistics. Descriptive single case analysis showed more deteriorations than improvements by one standard deviation over all cognitive domains in three patients, while in 11 patients the number of positive changes exceeded the number of negative changes. Conclusion: LAAO does not adversely affect cognitive function in the majority of cases.