ABSTRACT
BACKGROUND AND PURPOSE: Haemorrhagic transformation (HT) is one of the main risks of intravenous thrombolysis (IVT) for acute ischaemic stroke. Contraindications serve to exclude patients at high risk of HT after IVT. One of these contraindications is a stroke within the preceding 3 months. It is unclear if this contraindication should include recent clinically silent infarcts (RSIs). The aim of this study was to investigate whether RSIs are associated with a higher risk of HT and a worse clinical outcome after IVT for acute ischaemic stroke. METHODS: In a retrospective monocentric cohort study, all patients who received IVT for acute ischaemic stroke based on magnetic resonance imaging were assessed over 5 years. RSIs were defined as lesions with diffusion restriction and positive signal on fluid attenuated inversion recovery sequences. Patients with RSIs (RSI+) were compared to patients without RSIs (RSI-) regarding HT after IVT and clinical outcome. RESULTS: In all, 981 patients who had received IVT for acute ischaemic stroke demonstrated by magnetic resonance imaging were identified. RSIs were detected in 115 patients (11.5%). HT after IVT was observed in 32 (28.3%) RSI+ and 56 (25.8%) RSI- patients (P = 0.624). Symptomatic intracerebral haemorrhage was noted in two (1.8%) RSI+ and five (2.3%) RSI- patients (P = 1.000). No differences in clinical outcome were observed. CONCLUSIONS: The detection of RSIs in patients treated with IVT for acute ischaemic stroke was not associated with a higher risk of HT or a worse clinical outcome. The results of this study argue against considering RSIs as a contraindication for IVT.
Subject(s)
Brain Ischemia , Fibrinolytic Agents , Stroke , Brain Ischemia/complications , Brain Ischemia/diagnostic imaging , Brain Ischemia/drug therapy , Cohort Studies , Fibrinolytic Agents/adverse effects , Humans , Infarction , Retrospective Studies , Stroke/complications , Stroke/diagnostic imaging , Stroke/drug therapy , Thrombolytic Therapy/adverse effects , Tissue Plasminogen Activator/adverse effects , Treatment OutcomeABSTRACT
BACKGROUND: The German expert recommendations on the management of dysphagia in patients after acute stroke suggest an algorithm for clinical and technical investigations to identify patients at risk for aspiration and thus reduce the rate of aspiration pneumonia. The effectiveness of this algorithm has, however, not yet been prospectively validated . METHODS: In this study 144 consecutive stroke patients were assessed by a full bedside swallowing assessment including the screening procedures of standardized swallowing assessment (SSA) and 2 out of 6. Flexible endoscopic evaluation of swallowing (FEES) was performed in all patients. RESULTS: Aspiration was diagnosed in 25 patients (17.4%) by FEES. The SSA predicted aspiration with a sensitivity of 76% and a specificity of 55.5% and the 2 out of 6 screening with a sensitivity of 68.0% and a specificity of 61.0%. Of the patients 7 with negative screening for 2 out of 6 and 6 patients with negative SSA showed silent aspiration with the penetration aspiration scale (PAS 8) during FEES (28% of all patients with aspiration). Significant predictors for aspiration were dysarthria, dysphonia, abnormal volitional cough and cough after swallowing water; however, in multivariable analysis only dysarthria and cough after swallowing water were identified as independent predictors for aspiration. The rate of aspiration pneumonia was 2.8%. CONCLUSION: Clinical screening alone is not sufficient to identify patients at risk for aspiration pneumonia. The FEES should be used at a low threshold in cases of severe stroke and minor clinical abnormalities, especially concerning isolated dysarthria and cough after swallowing water; therefore, current recommendations should be correspondingly modified.
Subject(s)
Deglutition Disorders/diagnosis , Pneumonia, Aspiration/diagnosis , Pneumonia, Aspiration/etiology , Practice Guidelines as Topic , Stroke Rehabilitation/standards , Stroke/complications , Aged , Deglutition Disorders/etiology , Deglutition Disorders/rehabilitation , Female , Germany , Guideline Adherence , Humans , Male , Neurology/standards , Pneumonia, Aspiration/therapy , Reproducibility of Results , Risk Assessment , Sensitivity and Specificity , Stroke/diagnosis , Treatment OutcomeABSTRACT
Mathematical modeling is required for understanding the complex behavior of large signal transduction networks. Previous attempts to model signal transduction pathways were often limited to small systems or based on qualitative data only. Here, we developed a mathematical modeling framework for understanding the complex signaling behavior of CD95(APO-1/Fas)-mediated apoptosis. Defects in the regulation of apoptosis result in serious diseases such as cancer, autoimmunity, and neurodegeneration. During the last decade many of the molecular mechanisms of apoptosis signaling have been examined and elucidated. A systemic understanding of apoptosis is, however, still missing. To address the complexity of apoptotic signaling we subdivided this system into subsystems of different information qualities. A new approach for sensitivity analysis within the mathematical model was key for the identification of critical system parameters and two essential system properties: modularity and robustness. Our model describes the regulation of apoptosis on a systems level and resolves the important question of a threshold mechanism for the regulation of apoptosis.
