31 research outputs found

    Combined Perfusion and Permeability Imaging Reveals Different Pathophysiologic Tissue Responses After Successful Thrombectomy.

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    Despite successful recanalization of large-vessel occlusions in acute ischemic stroke, individual patients profit to a varying degree. Dynamic susceptibility-weighted perfusion and dynamic T1-weighted contrast-enhanced blood-brain barrier permeability imaging may help to determine secondary stroke injury and predict clinical outcome. We prospectively performed perfusion and permeability imaging in 38 patients within 24 h after successful mechanical thrombectomy of an occlusion of the middle cerebral artery M1 segment. Perfusion alterations were evaluated on cerebral blood flow maps, blood-brain barrier disruption (BBBD) visually and quantitatively on ktrans maps and hemorrhagic transformation on susceptibility-weighted images. Visual BBBD within the DWI lesion corresponded to a median ktrans elevation (IQR) of 0.77 (0.41-1.4) min-1 and was found in all 7 cases of hypoperfusion (100%), in 10 of 16 cases of hyperperfusion (63%), and in only three of 13 cases with unaffected perfusion (23%). BBBD was significantly associated with hemorrhagic transformation (p < 0.001). While BBBD alone was not a predictor of clinical outcome at 3 months (positive predictive value (PPV) = 0.8 [0.56-0.94]), hypoperfusion occurred more often in patients with unfavorable clinical outcome (PPV = 0.43 [0.10-0.82]) compared to hyperperfusion (PPV = 0.93 [0.68-1.0]) or unaffected perfusion (PPV = 1.0 [0.75-1.0]). We show that combined perfusion and permeability imaging reveals distinct infarct signatures after recanalization, indicating the severity of prior ischemic damage. It assists in predicting clinical outcome and may identify patients at risk of stroke progression

    Tumor infiltration in enhancing and non-enhancing parts of glioblastoma: A correlation with histopathology

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    To correlate histopathologic findings from biopsy specimens with their corresponding location within enhancing areas, non-enhancing areas and necrotic areas on contrast enhanced T1-weighted MRI scans (cT1).In 37 patients with newly diagnosed glioblastoma who underwent stereotactic biopsy, we obtained a correlation of 561 1mm3 biopsy specimens with their corresponding position on the intraoperative cT1 image at 1.5 Tesla. Biopsy points were categorized as enhancing (CE), non-enhancing (NE) or necrotic (NEC) on cT1 and tissue samples were categorized as "viable tumor cells", "blood" or "necrotic tissue (with or without cellular component)". Cell counting was done semi-automatically.NE had the highest content of tissue categorized as viable tumor cells (89% vs. 60% in CE and 30% NEC, respectively). Besides, the average cell density for NE (3764 ± 2893 cells/mm2) was comparable to CE (3506 ± 3116 cells/mm2), while NEC had a lower cell density with 2713 ± 3239 cells/mm2. If necrotic parts and bleeds were excluded, cell density in biopsies categorized as "viable tumor tissue" decreased from the center of the tumor (NEC, 5804 ± 3480 cells/mm2) to CE (4495 ± 3209 cells/mm2) and NE (4130 ± 2817 cells/mm2).The appearance of a glioblastoma on a cT1 image (circular enhancement, central necrosis, peritumoral edema) does not correspond to its diffuse histopathological composition. Cell density is elevated in both CE and NE parts. Hence, our study suggests that NE contains considerable amounts of infiltrative tumor with a high cellularity which might be considered in resection planning

    Studying Aggression in Drosophila (fruit flies)

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    Aggression is an innate behavior that evolved in the framework of defending or obtaining resources. This complex social behavior is influenced by genetic, hormonal and environmental factors. In many organisms, aggression is critical to survival but controlling and suppressing aggression in distinct contexts also has become increasingly important. In recent years, invertebrates have become increasingly useful as model systems for investigating the genetic and systems biological basis of complex social behavior. This is in part due to the diverse repertoire of behaviors exhibited by these organisms. In the accompanying video, we outline a method for analyzing aggression in Drosophila whose design encompasses important eco-ethological constraints. Details include steps for: making a fighting chamber; isolating and painting flies; adding flies to the fight chamber; and video taping fights. This approach is currently being used to identify candidate genes important in aggression and in elaborating the neuronal circuitry that underlies the output of aggression and other social behaviors

    Capillary Transit Time Heterogeneity Is Associated with Modified Rankin Scale Score at Discharge in Patients with Bilateral High Grade Internal Carotid Artery Stenosis.

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    BACKGROUND AND PURPOSE:Perfusion weighted imaging (PWI) is inherently unreliable in patients with severe perfusion abnormalities. We compared the diagnostic accuracy of a novel index of microvascular flow-patterns, so-called capillary transit time heterogeneity (CTH) to that of the commonly used delay parameter Tmax in patients with bilateral high grade internal carotid artery stenosis (ICAS). METHODS:Consecutive patients with bilateral ICAS ≄ 70%NASCET who underwent PWI were retrospectively examined. Maps of CTH and Tmax were analyzed with a volumetric approach using several thresholds. Predictors of favorable outcome (modified Rankin scale at discharge 0-2) were identified using univariate and receiver operating characteristic (ROC) curve analysis. RESULTS:Eighteen patients were included. CTH ≄ 30s differentiated best between patients with favorable and unfavorable outcome when both hemispheres were taken into account (sensitivity 83%, specificity 73%, area under the curve [AUC] 0.833 [confidence interval (CI) 0.635; 1.000]; p = 0.027). The best discrimination using Tmax was achieved with a threshold of ≄ 4s (sensitivity 83%, specificity 64%, AUC 0.803 [CI 0.585;1.000]; p = 0.044). The highest AUC was found for left sided volume with CTH ≄ 15s (sensitivity 83%, specificity 91%, AUC 0.924 [CI 0.791;1.000]; p = 0.005). CONCLUSION:The study suggests that CTH is superior to Tmax in discriminating ICAS patients with favorable from non-favorable outcome. This finding may reflect the simultaneous involvement of large vessels and microvessels in ICAS and underscore the need to diagnose and manage both aspects of the disease

    Integrative-interpersonal dynamic therapy for poststroke depression (INID): study protocol of a randomised controlled pilot trial

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    Volz M, Mundiyanapurath S, Schauenburg H, et al. Integrative-interpersonal dynamic therapy for poststroke depression (INID): study protocol of a randomised controlled pilot trial. BMJ Open. 2023;13(8): e077656.IntroductionDepression is the most frequent psychiatric disorder following stroke, affecting about one-third of stroke survivors. Patients experience poorer recovery, lower quality of life and higher mortality compared with stroke survivors without depression. Despite these well-known malign consequences, poststroke depression (PSD) is regarded underdiagnosed and undertreated. Evidence of beneficial effects of psychotherapy to treat PSD remains scarce and inconclusive and is limited by heterogeneity in design, content and timing of the intervention. This pilot study aims to assess the feasibility of a newly developed integrative-interpersonal dynamic PSD intervention in an outpatient setting and provide a first estimation of the potential effect size as basis for the sample size estimation for a subsequent definite trial. Method and analysisPatients will be recruited from two German stroke units. After discharge from inpatient rehabilitation, depressed stroke survivors will be randomised to short-term psychotherapy (12 weeks, & LE;16 sessions) or enhanced treatment as usual. The manualised psychotherapy integrates key features of the Unified Psychodynamic and Cognitive-Behavioural Unified Protocol for emotional disorders and was adapted for PSD. Primary endpoints are recruitment feasibility and treatment acceptability, defined as a recruitment rate of & GE;20% for eligible patients consenting to randomisation and & GE;70% completion-rate of patients participating in the treatment condition. A preliminary estimation of the treatment effect based on the mean difference in Patient Health Questionnaire-9 (PHQ-9) scores between intervention and control group six months poststroke is calculated. Secondary endpoints include changes in depression (PHQ-9/Hamilton Depression Scale) and anxiety (Generalised Anxiety Disorder 7) of all participants across all follow-ups during the first year poststroke. Ethics and disseminationThe INID pilot study received full ethical approval (S-321/2019; 2022-2286_1). Trial results will be published in a peer-reviewed journal in the first half of 2025. One-year follow-ups are planned to be carried out until summer 2025

    Tmax and CTH maps for three patients.

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    <p>Each row shows the most representative images of one patient. The first column depicts Tmax, the second CTH maps. Color-coded bars show Tmax and CTH values in seconds, respectively. The first patient (a, b) had perfusion abnormalities in the same region for Tmax and CTH with differing parts of that region being most severely affected. The second patient (c, d) shows a severe Tmax restriction while only slightly elevated CTH values can be seen. In the third patient (e, f) the profile for both Tmax and CTH seems to be comparable in the anterior and posterior middle cerebral artery border zone, while it is different in the temporoparietal region.</p
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