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Longitudinal changes of cortical microstructure in Parkinson's disease assessed with T1 relaxometry
(2016)
Background: Histological evidence suggests that pathology in Parkinson's disease (PD) goes beyond nigrostriatal degeneration and also affects the cerebral cortex. Quantitative MRI (qMRI) techniques allow the assessment of changes in brain tissue composition. However, the development and pattern of disease-related cortical changes have not yet been demonstrated in PD with qMRI methods. The aim of this study was to investigate longitudinal cortical microstructural changes in PD with quantitative T1 relaxometry.
Methods: 13 patients with mild to moderate PD and 20 matched healthy subjects underwent high resolution T1 mapping at two time points with an interval of 6.4 years (healthy subjects: 6.5 years). Data from two healthy subjects had to be excluded due to MRI artifacts. Surface-based analysis of cortical T1 values was performed with the FreeSurfer toolbox.
Results: In PD patients, a widespread decrease of cortical T1 was detected during follow-up which affected large parts of the temporo-parietal and occipital cortices and also frontal areas. In contrast, age-related T1 decrease in the healthy control group was much less pronounced and only found in lateral frontal, parietal and temporal areas. Average cortical T1 values did not differ between the groups at baseline (p = 0.17), but were reduced in patients at follow-up (p = 0.0004). Annualized relative changes of cortical T1 were higher in patients vs. healthy subjects (patients: − 0.72 ± 0.64%/year; healthy subjects: − 0.17 ± 0.41%/year, p = 0.007).
Conclusions: In patients with PD, the development of widespread changes in cortical microstructure was observed as reflected by a reduction of cortical T1. The pattern of T1 decrease in PD patients exceeded the normal T1 decrease as found in physiological aging and showed considerable overlap with the pattern of cortical thinning demonstrated in previous PD studies. Therefore, cortical T1 might be a promising additional imaging marker for future longitudinal PD studies. The biological mechanisms underlying cortical T1 reductions remain to be further elucidated.
Background & Aims: Acute‐on‐chronic liver failure (ACLF) is characterized by high short‐term mortality and systemic inflammation (SI). Recently, different cardiodynamic states were shown to independently predict outcomes in cirrhosis. The relationship between cardiodynamic states, SI, and portal hypertension and their impact on ACLF development remains unclear. The aim of this study was therefore to evaluate the interplay of cardiodynamic state and SI on fatal ACLF development in cirrhosis.
Results: At inclusion, hemodynamic measures including cardiac index (CI) and hepatic venous pressure gradient of 208 patients were measured. Patients were followed prospectively for fatal ACLF development (primary endpoint). SI was assessed by proinflammatory markers such as interleukins (ILs) 6 and 8 and soluble IL‐33 receptor (sIL‐33R). Patients were divided according to CI (<3.2; 3.2‐4.2; >4.2 L/min/m2) in hypo‐ (n = 84), normo‐ (n = 69) and hyperdynamic group (n = 55). After a median follow‐up of 3 years, the highest risk of fatal ACLF was seen in hyperdynamic (35%) and hypodynamic patients (25%) compared with normodynamic (14%) (P = .011). Hyperdynamic patients showed the highest rate of SI. The detectable level of IL‐6 was an independent predictor of fatal ACLF development.
Conclusions: Cirrhotic patients with hyperdynamic and hypodynamic circulation have a higher risk of fatal ACLF. Therefore, the cardiodynamic state is strongly associated with SI, which is an independent predictor of development of fatal ACLF.
Background: Liver cirrhosis is a relevant comorbidity with increasing prevalence. Postoperative decompensation and development of complications in patients with cirrhosis remains a frequent clinical problem. Surgery has been discussed as a precipitating event for decompensation and complications of cirrhosis, but the underlying pathomechanisms are still obscure. The aim of this study was to analyze the role of abdominal extrahepatic surgery in cirrhosis on portal pressure and fibrosis in a preclinical model. Methods: Compensated liver cirrhosis was induced using tetrachlormethane (CCL4) inhalation and bile duct ligation (BDL) models in rats, non-cirrhotic portal hypertension by partial portal vein ligation (PPVL). Intestinal manipulation (IM) as a model of extrahepatic abdominal surgery was performed. 2 and 7 days after IM, portal pressure was measured in-vivo. Hydroxyproline measurements, Sirius Red staining and qPCR measurements of the liver were performed for evaluation of fibrosis development and hepatic inflammation. Laboratory parameters of liver function in serum were analyzed. Results: Portal pressure was significantly elevated 2 and 7 days after IM in both models of cirrhosis. In the non-cirrhotic model the trend was the same, while not statistically significant. In both cirrhotic models, IM shows strong effects of decompensation, with significant weight loss, elevation of liver enzymes and hypoalbuminemia. 7 days after IM in the BDL group, Sirius red staining and hydroxyproline levels showed significant progression of fibrosis and significantly elevated mRNA levels of hepatic inflammation compared to the respective control group. A progression of fibrosis was not observed in the CCL4 model. Conclusion: In animal models of cirrhosis with continuous liver injury (BDL), IM increases portal pressure, and development of fibrosis. Perioperative portal pressure and hence inflammation processes may be therapeutic targets to prevent post-operative decompensation in cirrhosis.
Acute‐on‐chronic liver failure (ACLF) is a syndrome with high short‐term mortality. Precipitating events, including hemorrhage and infections, contribute to ACLF development, but the role of surgery remains unknown. We investigated the development of ACLF in patients with cirrhosis undergoing surgery. In total, 369 patients with cirrhosis were included in the study. The clinical and laboratory data were collected prior to and on days 1‐2, 3‐8, and 9‐28, and at 3 and 12 months after surgery. Surgery type was classified as limited or extensive, as well as liver and nonliver surgery. A total of 39 patients had baseline ACLF. Surgery was performed during acute decompensation in 35% of the rest of the 330 patients, and 81 (24.5%) developed ACLF within 28 days after surgery. Surrogate markers of systemic inflammation were similar in patients who developed ACLF or not. Age, sex, serum sodium, baseline bacterial infection, and abdominal nonliver surgery were independent predictors for the development of ACLF after surgery. Patients who developed ACLF within 28 days after surgery had a higher mortality at 3, 6, and 12 months. Survival did not differ between patients with ACLF at surgery and those developing ACLF after surgery. Development of ACLF within 28 days after surgery and elevated alkaline phosphatase and international normalized ratio were independent predictors of 90‐day mortality. Independent predictors of 1‐year all‐cause mortality were alkaline phosphatase, Model for End‐Stage Liver Disease score, and preoperative hepatic encephalopathy, whereas nonliver surgery was associated with improved survival. ACLF frequently develops in patients with cirrhosis undergoing surgery, especially in those with active bacterial infection, lower serum sodium, and kidney or coagulation dysfunction. Prognoses of ACLF both at and after surgery are similarly poor. Patients with cirrhosis should be carefully managed perioperatively.
Background and purpose: During acute coronavirus disease 2019 (COVID-19) infection, neurological signs, symptoms and complications occur. We aimed to assess their clinical relevance by evaluating real-world data from a multinational registry. Methods: We analyzed COVID-19 patients from 127 centers, diagnosed between January 2020 and February 2021, and registered in the European multinational LEOSS (Lean European Open Survey on SARS-Infected Patients) registry. The effects of prior neurological diseases and the effect of neurological symptoms on outcome were studied using multivariate logistic regression. Results: A total of 6537 COVID-19 patients (97.7% PCR-confirmed) were analyzed, of whom 92.1% were hospitalized and 14.7% died. Commonly, excessive tiredness (28.0%), headache (18.5%), nausea/emesis (16.6%), muscular weakness (17.0%), impaired sense of smell (9.0%) and taste (12.8%), and delirium (6.7%) were reported. In patients with a complicated or critical disease course (53%) the most frequent neurological complications were ischemic stroke (1.0%) and intracerebral bleeding (ICB; 2.2%). ICB peaked in the critical disease phase (5%) and was associated with the administration of anticoagulation and extracorporeal membrane oxygenation (ECMO). Excessive tiredness (odds ratio [OR] 1.42, 95% confidence interval [CI] 1.20–1.68) and prior neurodegenerative diseases (OR 1.32, 95% CI 1.07–1.63) were associated with an increased risk of an unfavorable outcome. Prior cerebrovascular and neuroimmunological diseases were not associated with an unfavorable short-term outcome of COVID-19. Conclusion: Our data on mostly hospitalized COVID-19 patients show that excessive tiredness or prior neurodegenerative disease at first presentation increase the risk of an unfavorable short-term outcome. ICB in critical COVID-19 was associated with therapeutic interventions, such as anticoagulation and ECMO, and thus may be an indirect complication of a life-threatening systemic viral infection.
Oxygenation-sensitive spin relaxation time T2′ and relaxation rate R2′ (1/T2′) are presumed to be markers of the cerebral oxygen extraction fraction (OEF) in acute ischemic stroke. In this study, we investigate the relationship of T2′/R2′ with dynamic susceptibility contrast-based relative cerebral blood flow (rCBF) in acute ischemic stroke to assess their plausibility as surrogate markers of the ischemic penumbra. Twenty-one consecutive patients with internal carotid artery and/or middle cerebral artery occlusion were studied at 3.0 T. A physiological model of the cerebral vasculature (VM) was used to process PWI raw data in addition to a conventional deconvolution technique. T2′, R2′, and rCBF values were extracted from the ischemic core and hypoperfused areas. Within hypoperfused tissue, no correlation was found between deconvolved rCBF and T2′ (r = −0.05, p = 0.788), or R2′ (r = 0.039, p = 0.836). In contrast, we found a strong positive correlation with T2′ (r = 0.444, p = 0.006) and negative correlation with R2′ (r = −0.494, p = 0.0025) for rCBFVM, indicating increasing OEF with decreasing CBF and that rCBF based on the vascular model may be more closely related to metabolic disturbances. Further research to refine and validate these techniques may enable their use as MRI-based surrogate markers of the ischemic penumbra for selecting stroke patients for interventional treatment strategies.
Purpose: In secondary progressive Multiple Sclerosis (SPMS), global neurodegeneration as a driver of disability gains importance in comparison to focal inflammatory processes. However, clinical MRI does not visualize changes of tissue composition outside MS lesions. This quantitative MRI (qMRI) study investigated cortical and deep gray matter (GM) proton density (PD) values and T1 relaxation times to explore their potential to assess neuronal damage and its relationship to clinical disability in SPMS.
Materials and Methods: 11 SPMS patients underwent quantitative T1 and PD mapping. Parameter values across the cerebral cortex and deep GM structures were compared with 11 healthy controls, and correlation with disability was investigated for regions exhibiting significant group differences.
Results: PD was increased in the whole GM, cerebral cortex, thalamus, putamen and pallidum. PD correlated with disability in the whole GM, cerebral cortex, putamen and pallidum. T1 relaxation time was prolonged and correlated with disability in the whole GM and cerebral cortex.
Conclusion: Our study suggests that the qMRI parameters GM PD (which likely indicates replacement of neural tissue with water) and cortical T1 (which reflects cortical damage including and beyond increased water content) are promising qMRI candidates for the assessment of disease status, and are related to disability in SPMS.
Background and Aims: Prothrombin induced by vitamin K absence-II (PIVKA-II) is a serum biomarker linked to hepatocellular carcinoma (HCC), showing superiority to alpha-fetoprotein (AFP) for early disease detection. We aimed to assess the clinical and analytical performance of the Elecsys® PIVKA-II immunoassay in diagnosing HCC and evaluate PIVKA-II's technical performance.
Methods: Serum samples from adult cases (i.e. patients with a first-time HCC diagnosis; n = 168) and disease controls (i.e. patients without HCC with an at-risk condition; n = 208) were assessed. An AFP cut-off of 20 ng/mL was used to differentiate between HCC cases and disease controls. Clinical performance of the Elecsys PIVKA-II assay was compared with that of comparator assays (Lumipulse G PIVKA-II, μTASWako DCP, ARCHITECT PIVKA-II) using receiver operating characteristic curve analysis to determine the area under the curve (AUC) values.
Results: The Elecsys PIVKA-II assay compared favorably with comparator assays. Using a 28.4 ng/mL cut-off, the Elecsys PIVKA-II assay detected HCC with 86.9% sensitivity and 83.7% specificity. Clinical performance of the Elecsys PIVKA-II assay (AUC: 90.8%) was equivalent to that of comparator assays (AUC: 88.3–89.6%). Relatively high PIVKA-II concentrations were observed for cholangiocarcinoma and pancreatic cancer with the Elecsys assay in specificity panel analyses, indicating that high PIVKA-II concentrations should not be used alone in the absence of other clinical data.
Conclusions: The Elecsys PIVKA-II assay showed good analytical performance under routine laboratory conditions, comparing favorably with comparator assays. These findings support the suitability of the Elecsys PIVKA-II assay as an aid in HCC diagnosis.