临界视觉闪烁频率对轻微肝性脑病的诊断价值

轻微肝性脑病(MHE)的早期发现和治疗对肝病患者有重要意义。临界视觉闪烁频率(CFF)以其客观性、简易性、可重复性高等特点在MHE的诊断中受到越来越多的关注。通过CFF对肝硬化、肝炎患者和门体循环异常者MHE的诊断价值的一系列研究,CFF在MHE诊断中的价值已初步建立,同时研究也发现还存在很多问题有待进一步探索。     

Predictors of nonresponse to lactulose for minimal hepatic encephalopathy in patients with cirrhosis

Background/Aims: Minimal hepatic encephalopathy (MHE) impairs health‐related quality of life and predicts overt hepatic encephalopathy (HE) in cirrhotic patients. Lactulose is effective in the treatment of MHE. However, not all patients respond to lactulose. We evaluated predictors of nonresponse to lactulose. Patients and methods: Consecutive 110 cirrhotic patients without HE were evaluated for MHE by psychometry, P300 auditory event‐related potential (P300ERP), venous ammonia and critical flicker frequency (CFF). MHE was diagnosed by abnormal psychometry and P300ERP (>2 SD). MHE patients were treated with lactulose for 1 month. Response was defined by normalization of the abnormal test parameters (both psychometric tests and P300ERP). Results: Sixty patients (54.5%) were diagnosed as having MHE: 17/39 (44%) in Child's A, 21/42 (50%) Child's B and 22/29 (76%) in Child's C. There was a significant difference between Child's C's vs Child's A's and B's (P<0.05). Abnormal psychometric tests and abnormal P300ERP were seen in 74 (67%) and 74 (67%) patients respectively. Of 60 patients with MHE, after treatment, psychometry remained abnormal in 22 (36.6%) and P300ERP in 21 (35%) patients. CFF was<38 Hz in 34 (57%) and 11 (18%) patients, respectively, before and after treatment in MHE patients. There was a significant difference between the baseline serum sodium level (134.7±2.6 vs 131.1±2.2 mmol/L, P=0.001) and the venous ammonia level (76.6±20.7 vs 113.4±22.8 μmol/L, P=0.001) between responders vs nonresponders. Receiver operating characteristic analysis was performed to identify the cutoff for venous ammonia [cutoff 93.5 mmol/L, area under the curve (AUC) 0.892 (0.814–0.970)] and for the serum sodium level [cutoff 132.5 mmol/L, AUC 0.874 (0.779–0.998)]. Taking a cutoff of 93.5 mmol/L for ammonia patient had a sensitivity of 88.5% and a specificity of 79.4%, respectively, and a cutoff of 132.5 mmol/L for serum sodium patient had a sensitivity of 76.5% and a specificity of 88.5% for nonresponse to lactulose. On univariate analysis and multivariate analysis, serum sodium and venous ammonia were the only two parameters associated with nonresponse to lactulose. Conclusion: The prevalence of MHE was 55% and MHE improved in 57% patients with lactulose. Baseline low serum sodium and high venous ammonia were highly predictive of nonresponse to lactulose therapy.     

临界闪烁频率诊断轻微肝性脑病的价值

轻微肝性脑病(MHE)是指临床上无明显肝性脑病相关症状和生物化学指标异常,但用精细的智力试验或神经电生理检查可见智力、神经、精神的异常而诊断的肝性脑病,过去被称为亚临床型肝性脑病[1].据报道,1991至2003年肝硬化患者MHE发病率国外为30％ ～ 84％[2-3];在国内为27.6％ ～ 71.8％[4-5].近期Sharma[6]对200例肝硬化患者的研究表明MHE的发病率为41％;Mittal等[7]报道322例肝硬化患者的MHE发病率为49.69％.MHE发病率差异较大可能与病例选择(病因和病情严重程度)、样本数量、诊断手段、是否年龄校正等因素有关,其中诊断方法和诊断标准差异为主要原因.目前国际上对MHE诊断的金标准尚未完全获得统一认识,故无统一标准.     

Management options for minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is a neurocognitive dysfunction that is present in the majority of patients with cirrhosis. MHE has a characteristic cognitive profile that cannot be diagnosed clinically. This cognitive dysfunction is independent of sleep dysfunction or problems with overall intelligence. MHE has a significant impact on quality of life, the ability to function in daily life and progression to overt hepatic encephalopathy. Driving ability can be impaired in MHE and this may be a significant factor behind motor vehicle accidents. A crucial aspect of the clinical care of MHE patients is their driving history, which is often ignored during routine care and can add a vital dimension to the overall disease assessment. Driving history should be an integral part of the care of patients with MHE. The preserved communication skills and lack of specific signs and insight make MHE difficult to diagnose. The predominant strategies for MHE diagnosis are psychometric or neurophysiological testing. These are usually limited by financial, normative or time constraints. Studies into inhibitory control, cognitive drug research and critical flicker frequency tests are encouraging. These tests do not require a psychologist for administration and interpretation. Lactulose and probiotics have been studied for their potential use as therapies for MHE, but these are not standard-of-care practices at this time. Therapy can improve the quality of life in MHE patients but the natural history, specific diagnostic strategies and treatment options are still being investigated.     

肝硬化患者轻微肝性脑病临床相关危险因素分析

目的评估肝硬化人群中轻微型肝性脑病（MHE）发生的相关因素.方法在121例肝硬化患者,分别进行心理肝性脑病得分（PHES）和临界闪烁频率（CFF）测定,并评估肝功能分级状态.结果在121例肝硬化患者中,检出MHE者70例（57.9%）.性别、受教育程度、肝病病因、肝功能Child-Pugh分级、血浆氨浓度等因素对肝硬化患者发生MHE无统计学意义（P〉0.05）;经Logistic多因素回归分析,仅发现年龄为MHE发生的危险因素（P=0.041, OR=1.035）,而MHE发生与性别、教育程度、肝病病因、肝功能Child-Pugh分级和血浆氨浓度无关（P〉0.05）.结论在肝硬化患者中MHE发生率较高,年龄增长是肝硬化患者发生MHE的危险因素.     

Relationship between interleukin-6 and ammonia in patients with minimal hepatic encephalopathy due to liver cirrhosis

Aim: Previous studies have shown significantly elevated levels of interleukin (IL)-6 in cirrhotic patients with minimal hepatic encephalopathy (MHE), but the relationship between circulating levels of IL-6 and ammonia is unclear. The aim of this study is to investigate the relationship between both variables in cirrhotic patients with MHE. Methods: Psychometric tests including number connection test part A (NCT-A) and digit symbol test (DST) were performed to diagnose MHE in 85 cirrhotic patients. Simultaneously, circulating levels of IL-6 and ammonia were measured. Results: Thirty-two (37.6%) cirrhotic patients were diagnosed with MHE. IL-6 and ammonia were the independent predictors of the presence of MHE (P < 0.05 for both variables). Circulating levels of IL-6 and ammonia correlated with the severity of MHE represented by results of NCT-A (r = 0.56, P < 0.05 and r = 0.39, P < 0.05, respectively) and DST (r = −0.48, P < 0.05 and r = −0.47, P < 0.05, respectively). Moreover, there was a significant correlation between circulating levels of IL-6 and those of ammonia in patients with MHE (r = 0.61, P < 0.05), and a positive additive interaction was found between IL-6 and ammonia on the presence of MHE, with a significant synergy index of 1.51 (95% confidence interval = 1.12–3.46). Conclusion: The present study demonstrates a significant correlation and a positive additive interaction between IL-6 and ammonia in cirrhotic patients with MHE, suggesting that IL-6 may have a potential synergistic relationship with ammonia in the induction of MHE.     

Development of a three‐factor neuropsychological approach for detecting minimal hepatic encephalopathy

Background: Minimal hepatic encephalopathy (HE) has profoundly negative effects on daily functioning ad quality of life. However, standard psychometric procedures have not been widely incorporated into efforts to develop a neuropsychological battery for this condition. Aims: To establish the construct and diagnostic validity of a neuropsychological approach for the recognition of minimal HE in patients with cirrhosis. Methods: A comprehensive battery of neuropsychological tests was administered to cirrhotic patients with at most grade 1 HE, recruited from the liver transplant and advanced liver disease clinics. An inflammatory bowel disease comparison group was similarly evaluated, thus controlling for the secondary effects of chronic illness on cognition. Testing results for the cirrhosis group were subjected to principal component analysis to establish the relevant cognitive constructs and associated measures. Factor analysis was applied to the neuropsychological battery of 20 tests to determine the cognitive factors to be used. Age‐adjusted standardized neuropsychological factor scores were then compared for the two groups. Results: Factor analysis revealed that our battery of 20 tests was measuring three cognitive factors. Based on the pattern of factor loadings, we labeled these important cognitive factors: global cognitive function; psychomotor speed; and learning and memory. Logistic regression revealed that only impaired psychomotor speed distinguished cirrhotics with no more than grade 1 HE from medically ill controls. Conclusions: The cirrhosis group was characterized by a pattern of preserved global cognitive functioning, mild memory impairment, and moderate psychomotor speed impairment. Discussion: This distinctive pattern of focal psychomotor speed deficits is suggestive of subcortical pathway involvement in minimal HE.     

临界视觉闪烁频率在肝硬化失代偿期患者轻型肝性脑病诊断中的价值

目的 探讨临界视觉闪烁频率（CFF）对肝硬化失代偿期患者轻型肝性脑病诊断上的应用价值。方法 对160例肝硬化失代偿期患者进行CFF检测,并与对照组进行比较。结果 肝硬化失代偿期患者CFF值＜ 39.0 Hz以下者占多数（76.25%）,而对照组CFF值均＞ 40.0 Hz,两组间比较差异有统计学意义（t = 7.35,P ＜ 0.01）。CFF值＜ 39.0 Hz以下的患者平均血氨异常率为78.96%,分别与CFF值＞ 39.0 Hz各组比较,差异有统计学意义（t = 5.65,P ＜ 0.01）。结论 检测CFF值是肝硬化失代偿期患者及早发现轻型肝性脑病的一项客观而敏感的诊断方法。     

Minimal hepatic encephalopathy: Consensus statement of a working party of the Indian National Association for Study of the Liver

Hepatic encephalopathy (HE) is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Overt HE occurs in approximately 30–45% of cirrhotic patients. Minimal HE (MHE), the mildest form of HE, is characterized by subtle motor and cognitive deficits and impairs health‐related quality of life. The Indian National Association for Study of the Liver (INASL) set up a Working Party on MHE in 2008 with a mandate to develop consensus guidelines on various aspects of MHE relevant to clinical practice. Questions related to the definition of MHE, its prevalence, diagnosis, clinical characteristics, pathogenesis, natural history and treatment were addressed by the members of the Working Party.     

Psychometric hepatic encephalopathy score for diagnosis of minimal hepatic encephalopathy in China

AIM:To construct normal values for the tests of the psychometric hepatic encephalopathy score(PHES)and to evaluate its usefulness in the diagnosis of minimal hepatic encephalopathy(MHE)among Chinese individuals with cirrhosis.METHODS:The five tests of PHES,number connection test-A(NCT-A),number connection test-B,serial dotting test,line tracing test and digit symbol test(DST),were administered to all enrolled subjects in a quiet room with sufficient light.Cirrhotic subjects with overt HE were excluded by the West-Haven criteria and a detailed neurological examination.Based on the nomograms of healthy volunteers,the patients were classified as having MHE when their PHES was less than-4.RESULTS:In total,146 healthy volunteers completed all the PHES tests.Age and education years were confirmed to be predictors of all five tests.In total,53patients with liver cirrhosis completed the PHES.Of the patients with liver cirrhosis,24(45.3%),22(41.5%)and 7(13.2%)had Child-Pugh grades A,B and C,respectively.MHE was diagnosed in 26 patients(49.1%).Compared with compensated cirrhotic patients(Child A),decompensated cirrhotic patients(Child B and C)had a higher proportion of MHE(65.5%vs 29.2%).No differences in age and education years were found between the MHE and non-MHE groups.NCT-A and DST were able to diagnose MHE with a sensitivity of 76.9%and a specificity of 96.3%(AUC=0.866,K=0.735).CONCLUSION:The proportion of MHE is associated with liver function.NCT-A and DST are simple tools that can be used for the diagnosis of MHE in China.     

Recent developments in the diagnosis and treatment of covert/minimal hepatic encephalopathy

The terms minimal hepatic encephalopathy and covert hepatic encephalopathy are defined. Clinical assessment is unreliable and both require the use of diagnostic tools. Of these, psychometric tests are the most widely used. They require proper standardization and may be biased by patient cooperation or lack thereof. The measure of the critical flicker frequency and of the electroencephalogram, possibly quantified, are also useful. The alteration of any of them is not strictly parallel in size and may vary from patient to patient. When possible, the use of multiple measures might increase diagnostic reliability. These functional measures should be interpreted within the clinical/biochemical profile of the patient to exclude other disorders. A flow chart for treatment is proposed on the basis of current knowledge.