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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In hepatic encephalopathy, a progressive and diffuse impairment in brain function is associated with gradual alterations that can be detected by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS). In some patients, a variety of movement disorders suggestive of extrapyramidal impairment points toward basal ganglia (BG) alterations. Accordingly, (i) hyperintensities at MRI predominant in the pallidum, an important region of BG involved in the motor control, (ii) redistribution of cerebral blood flow from cortical areas to BG structures observed using positron emission tomography studies, and (iii) the preferential pallidal location of Alzheimer astrocytosis, all support this hypothesis. In most clinical studies, little if any correlations have been found between cerebral hyperintensities and neurological manifestations. The application of a test designed to evaluate patients with Parkinson's disease (where extrapyramidal signs are typical) showed significant clinical correlations both with pallidal hyperintensity and with choline/creatine ratio at 1H MRS in BG structures. Because of complex neuronal connections between BG and many cortical areas, BG dysfunction may influence the neurocognitive manifestations of hepatic encephalopathy. Similarities between chronic Mn intoxication and cirrhosis suggest common pathophysiological mechanisms including altered dopaminergic neurotransmission, although information in chronic liver failure is limited. Clinical observations are presented regarding the evolution of parkinsonian signs in various situations.
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PMID:Clinical significance of basal ganglia alterations at brain MRI and 1H MRS in cirrhosis and role in the pathogenesis of hepatic encephalopathy. 1260 16

Few studies have examined the physiological/biochemical status of hepatocytes in patients with compensated and decompensated cirrhosis in situ. Phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) is a noninvasive technique that permits direct assessments of tissue bioenergetics and phospholipid metabolism. Quantitative (31)P MRS was employed to document differences in the hepatic metabolite concentrations among patients with compensated and decompensated cirrhosis as well as healthy controls. All MRS examinations were performed on a 1.5-T General Electric Signa whole body scanner. The concentration of hepatic phosphorylated metabolites among patients with compensated cirrhosis (n = 7) was similar to that among healthy controls (n = 8). However, patients with decompensated cirrhosis (n = 6) had significantly lower levels of hepatic ATP compared with patients with compensated cirrhosis and healthy controls (P < 0.02 and P < 0.009, respectively) and a higher phosphomonoester/phosphodiester ratio than controls (P < 0.003). The results of this study indicate that metabolic disturbances in hepatic energy and phospholipid metabolism exist in patients with decompensated cirrhosis that are not present in patients with compensated cirrhosis or healthy controls. These findings provide new insights into the pathophysiology of hepatic decompensation.
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PMID:Quantitative hepatic phosphorus-31 magnetic resonance spectroscopy in compensated and decompensated cirrhosis. 1519 82

The term minimal hepatic encephalopathy refers to the subtle changes in cognitive function, electrophysiological parameters, cerebral neurochemical/neurotransmitter homeostasis, cerebral blood flow, metabolism, and fluid homeostasis that can be observed in patients with cirrhosis who have no clinical evidence of hepatic encephalopathy. Use of this term emphasizes the fact that the entity of hepatic encephalopathy is a single syndrome with quantitatively distinct features relating to severity. The absence of clinical evidence of hepatic encephalopathy is key to the diagnosis and can only be determined by a detailed assessment of the patients' history and a comprehensive neurological assessment of consciousness, cognitive, and motor function. The neuropsychological features of minimal hepatic encephalopathy point to a disorder of executive functioning, particularly selective attention and psychomotor speed, but other abnormalities may be observed. Alterations in electrophysiological variables have been described; endogenous evoked potentials are, in principle, more likely to reflect the presence of minimal hepatic encephalopathy, since they reflect cognitive phenomena rather than mere stimulus conduction but the specificity of the changes observed is unclear at present. Changes have also been described in the execution of diadochokinetic movements and in the capacity to discriminate flickering light, both of which may have diagnostic potential. The changes observed in cerebral blood flow and metabolism in SPET, PET, and 1H and 31P MRS studies reflect the pathogenic process that underlies the condition rather than providing diagnostic information. Similarly, the morphological brain abnormalities identified in this population, including mild brain oedema, hyperintensity of the globus pallidus and other subcortical nuclei observed in cerebral MR studies, and the central and cortical atrophy observed in neural imaging studies, are unlikely to have diagnostic utility. The presence of minimal hepatic encephalopathy is not without clinical consequence; it has a detrimental effect on health-related quality of life, the ability to perform complex tasks such as driving, and on outcome.
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PMID:Characteristics of minimal hepatic encephalopathy. 1555 21

We report a possible case of progressive multifocal leukoencephalopathy (PML) that was attempted to evaluate the pathogenesis by a novel brain MRI techniques. A 72-year-old woman had developed subacute visual disturbance, right hemiparesis and sensory disturbance. Laboratory examinations revealed liver dysfunction and pancytopenia due to liver cirrhosis (type C) and preclinical status of multiple myeloma. Thus, this patient had these two underlying diseases, while anti-HIV antibody was negative. She was suspected with PML by detection of JCV-DNA in cerebrospinal fluid using with PCR. MRI showed multifocal T2-high signals in the bilateral parieto-occipital deep white matter, basal ganglia and right cerebellar hemisphere. No gadolinium enhancement was found. On FLAIR and diffusion weighted images (DWI), the lesion showed hyperintensity. The hyperintense areas on DWI showed various pattern on apparent diffusion coefficient (ADC) and fractional anisotropy (FA). In particular white matter changes, the course of FA reflected the clinical course more than ADC. Proton magnetic resonance spectroscopy (1H-MRS) in deep brain white matter showed ratios of reduced N-acetyl aspartate (NAA) and increased choline (Cho) to creatine. 1H-MRS by chemical shift imaging were undergone three times between 4 and 6 months after the onset. The change of these chemical markers correlated with her clinical course. We conclude that the approach of diffusion tensor imaging (DTI) and 1H-MRS are useful for evaluating neuropathologic observations and clinical course.
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PMID:[Neuroradiological study of a possible progressive multifocal leukoencephalopathy using diffusion tensor imaging and proton magnetic resonance spectroscopy]. 1715 35

31P-MRS using DRESS was used to compare absolute liver metabolite concentrations (PME, Pi, PDE, gammaATP, alphaATP, betaATP) in two distinct groups of patients with chronic diffuse liver disorders, one group with steatosis (NAFLD) and none to moderate inflammation (n=13), and one group with severe fibrosis or cirrhosis (n=16). All patients underwent liver biopsy and extensive biochemical evaluation. A control group (n=13) was also included. Absolute concentrations and the anabolic charge, AC=[PME]/([PME]+[PDE]), were calculated. Comparing the control and cirrhosis groups, lower concentrations of PDE (p=0.025) and a higher AC (p<0.001) were found in the cirrhosis group. Also compared to the NAFLD group, the cirrhosis group had lower concentrations of PDE (p=0.01) and a higher AC (p=0.009). No significant differences were found between the control and NAFLD group. When the MRS findings were related to the fibrosis stage obtained at biopsy, there were significant differences in PDE between stage F0-1 and stage F4 and in AC between stage F0-1 and stage F2-3. Using a PDE concentration of 10.5mM as a cut-off value to discriminate between mild, F0-2, and advanced, F3-4, fibrosis the sensitivity and specificity were 81% and 69%, respectively. An AC cut-off value of 0.27 showed a sensitivity of 93% and a specificity of 54%. In conclusion, the results suggest that PDE is a marker of liver fibrosis, and that AC is a potentially clinically useful parameter in discriminating mild fibrosis from advanced.
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PMID:Separation of advanced from mild fibrosis in diffuse liver disease using 31P magnetic resonance spectroscopy. 1764 74

NAFLD (non-alcoholic fatty liver disease) and NASH (non-alcoholic steatohepatitis) are of increasing importance, both in connection with insulin resistance and with the development of liver cirrhosis. Histological samples are still the 'gold standard' for diagnosis; however, because of the risks of a liver biopsy, non-invasive methods are needed. MAS (magic angle spinning) is a special type of NMR which allows characterization of intact excised tissue without need for additional extraction steps. Because clinical MRI (magnetic resonance imaging) and MRS (magnetic resonance spectroscopy) are based on the same physical principle as NMR, translational research is feasible from excised tissue to non-invasive examinations in humans. In the present issue of Clinical Science, Cobbold and co-workers report a study in three animal strains suffering from different degrees of NAFLD showing that MAS results are able to distinguish controls, fatty infiltration and steatohepatitis in cohorts. In vivo MRS methods in humans are not obtainable at the same spectral resolution; however, know-how from MAS studies may help to identify characteristic changes in crowded regions of the magnetic resonance spectrum.
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PMID:Magic angle spinning magnetic resonance: a novel method opening up translational research into NAFLD? 1869 96

Magnetic resonance imaging (MRI) and (1)H magnetic resonance spectroscopy ((1)H-MRS) have been used in clinics for diagnosis of chronic liver diseases. This study was designed to investigate the relationship between MRI/MRS outcomes and the severity of liver damage. Of 50 patients examined, the MRI signal intensity in the globus pallidus as determined by pallidus index (PI) increased as the disease severity (scored by Child Pugh ranking) worsened (r = 0.353, P < 0.05). The changes in PI values were also linearly associated with Mn concentrations in whole blood (MnB) (r = 0.814, P < 0.01). MRS analysis of four major brain metabolites (i.e., Cho, mI, Glx, and NAA) revealed that the ratios of Cho/Cr and mI/Cr in cirrhosis and CHE patients were significantly decreased in comparison to controls (P < 0.05), whereas the ratio of Glx/Cr was significantly increased (P < 0.05). The Child Pugh scores significantly correlated with mI/Cr (-0.484, P < 0.01) and Glx (0.369, P < 0.05), as well as MnB (0.368, P < 0.05), but not with other brain metabolites. Three patients who received a liver transplant experienced normalization of brain metabolites within 3 months of post-transplantation; the MR imaging of Mn in the globus pallidus completely disappeared 5 months after the surgery. Taken together, this clinical study, which combined MRI/MRS analysis, autopsy exam and liver transplant, clearly demonstrates that liver injury-induced brain Mn accumulation can reversibly alter the homeostasis of brain metabolites Cho, mI and Glx. Our data further suggest that liver transplantation can restore normal brain Mn levels.
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PMID:Relationship between changes in brain MRI and (1)H-MRS, severity of chronic liver damage, and recovery after liver transplantation. 1954 51

Hepatocellular carcinoma (HCC) is the commonest primary hepatic malignancy worldwide. Current serum diagnostic biomarkers, such as alpha-fetoprotein, are expensive and insensitive in early tumor diagnosis. Urinary biomarkers differentiating HCC from chronic liver disease would be practical and widely applicable. Using an 11.7T nuclear magnetic resonance system, urine was analyzed from three well-matched subject groups, collected at Jos University Teaching Hospital (JUTH), Nigeria. Multivariate factor analyses were performed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). All patients were of Nigerian descent: 18 hepatitis B surface antigen (HBsAg)-positive patients with HCC, 10 HBsAg positive patients with cirrhosis, and 15 HBsAg negative healthy Nigerian controls. HCC patients were distinguished from healthy controls, and from the cirrhosis cohort, with sensitivity/specificity of 100%/93% and 89.5%/88.9%, respectively. Metabolites that most strongly contributed to the multivariate models were creatinine, carnitine, creatine and acetone. Urinary (1)H MRS with multivariate statistical analysis was able to differentiate patients with HCC from normal subjects and patients with cirrhosis. Creatinine, carnitine, creatine and acetone were identified as the most influential metabolites. These findings have identified candidate urinary HCC biomarkers which have potential to be developed as simple urinary screening tests for the clinic.
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PMID:Characterization of urinary biomarkers of hepatocellular carcinoma using magnetic resonance spectroscopy in a Nigerian population. 1996 28

We compared in vivo hepatic (31) P magnetic resonance spectroscopy ((31) P MRS) and hepatic vein transit times (HVTT) using contrast-enhanced ultrasound with a microbubble agent to assess the severity of hepatitis C virus (HCV)-related liver disease. Forty-six patients with biopsy-proven HCV-related liver disease and nine healthy volunteers had (31) P MRS and HVTT performed on the same day. (31) P MR spectra were obtained at 1.5 T. Peak areas were calculated for metabolites, including phosphomonoesters (PME) and phosphodiesters (PDE). Patients also had the microbubble ultrasound contrast agent, Levovist (2 g), injected into an antecubital vein, and time-intensity Doppler ultrasound signals of the right and middle hepatic veins were measured. The HVTT was calculated as the time from injection to a sustained rise in Doppler signal 10% greater than baseline. The shortest times were used for analysis. Based on Ishak histological scoring, there were 15 patients with mild hepatitis, 20 with moderate/severe hepatitis and 11 with cirrhosis. With increasing severity of disease, the PME/PDE ratio was steadily elevated, while the HVTT showed a monotonic decrease. Both imaging modalities could separate patients with cirrhosis from the mild and moderate/severe hepatitis groups. No statistical difference was observed in the accuracy of each test to denote mild, moderate/severe hepatitis and cirrhosis (Fisher's exact test P =1.00). (31) P MRS and HVTT show much promise as noninvasive imaging tests for assessing the severity of chronic liver disease. Both are equally effective and highly sensitive in detecting cirrhosis.
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PMID:A comparison of 31P magnetic resonance spectroscopy and microbubble-enhanced ultrasound for characterizing hepatitis c-related liver disease. 2191 73

Poor brain reserve in alcoholic cirrhosis could worsen insight regarding disease severity and increase the patients' vulnerability toward further deterioration. The aim of this study was to analyze brain reserve in abstinent alcoholic cirrhotic (Alc) patients compared to nonalcoholic cirrhotic (Nalc) patients in the context of hepatic encephalopathy (HE) and to evaluate relative change in brain reserve between groups over time and before and after elective transjugular intrahepatic portosystemic shunt (TIPS) placement. The cross-sectional study included 46 Alc and 102 Nalc outpatients with or without HE. Cognitive tests were followed by magnetic resonance imaging (MRI), including proton magnetic resonance spectroscopy (1 H-MRS), diffusion tensor imaging, and T1-weighted imaging. The prospective study included 1H-MRS on a subset of 10 patients before and after TIPS placement. Another subset of 26 patients underwent (1) H-MRS at least 1 year apart. For the cross-sectional study, Alc patients were worse on cognitive tests than Nalc patients. MRI results suggest a greater effect of hyperammonemia, brain edema, and significantly higher cortical damage in Alc as compared to Nalc patients. The effect of HE status on cognitive tests and brain reserve was more marked in the Nalc than in the Alc group. For the TIPS study, Nalc patients showed a greater adverse relative change after TIPS compared to the Alc group. At 1-year follow-up, both groups remained stable between the 2 visits. However, Alc patients continued to show poor brain reserve compared to Nalc patients over time. In conclusion, Alc patients, despite abstinence, have a poor brain reserve, whereas Nalc patients have a greater potential for brain reserve deterioration after HE and TIPS. Information regarding the brain reserve in cirrhosis could assist medical teams to refine their communication and monitoring strategies for different etiologies.
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PMID:The etiology of cirrhosis is a strong determinant of brain reserve: A multimodal magnetic resonance imaging study. 2607 90


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