VIENNA (EGMN) – The same brief, Web-based neuropsychologic test used by all U.S. National Football League teams to assess players for the effects of concussion appears to be advantageous for the diagnosis of minimal hepatic encephalopathy.

The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT v4.0) is a well-validated, computer-based neuropsychologic test that takes about 10 minutes. It’s billable as a neuropsychologic test, user friendly, available in 13 languages, can be administered by anybody in the office, and produces immediate results without need of a clinical neuropsychologist to interpret the scores, Dr. Michel H. Mendler explained at the annual International Liver Congress sponsored by the European Association for the Study of the Liver.

“ImPACT could become a new standard for minimal hepatic encephalopathy testing, both in routine clinical practice and to evaluate treatments,” said Dr. Mendler, a gastroenterologist at Loma Linda (California) University.

Minimal hepatic encephalopathy (MHE) is a greatly underdiagnosed neurocognitive disorder present in 60%-80% of patients with cirrhosis. It results in impaired quality of life, increased work disability, and impaired driving made more hazardous by lack of insight. If unchecked, MHE can progress to overt hepatic encephalopathy, a more serious neuropsychiatric syndrome characterized by cognitive and motor deficits that often require hospitalization.

MHE includes deficits in mental processing speed, fine motor skills, memory, complex attention, constructive abilities, and visual-spatial orientation. These deficits, unlike those in overt hepatic encephalopathy, are subtle and require neuropsychologic testing for diagnosis.

Conventional neuropsychologic testing is cumbersome, he said. It’s complex, lengthy, and the results require interpretation by a specialist. A widely used alternative is paper-and-pencil testing using several psychometric tests, such as Digit Symbol and Number Connection tests A and B. But the results of these tests are confounded by the substantial practice effect with repeated testing.

In contrast, ImPACT, which was developed by neuroscientists at the University of Pittsburgh, generates an unlimited number of alternate forms, avoiding the practice effect, Dr. Mendler continued.

He compared ImPACT with paper-and-pencil testing in 90 cirrhotic patients with no history of overt hepatic encephalopathy and 131 matched healthy controls. ImPACT scores identified 25 of 90 cirrhosis patients as having abnormal results consistent with MHE; paper-and-pencil testing identified 16, only 10 of whom were also ImPACT-positive.

In addition, ImPACT identified 12 of 74 paper-and-pencil test-negative patients as having MHE. A total of 7 of 131 healthy controls were ImPACT-positive, a significantly lower false-positive rate than with paper-and-pencil testing, which was positive in 19 controls.

ImPACT-positive cirrhosis patients had a mean total Sickness Impact Profile score of 17.6, compared with 13.5 in ImPACT-negative patients and 2.6 for controls. The Sickness Impact Profile reflects physical and psychosocial functioning.

The ImPACT test (www.impacttest.com) yields four composite scores in the domains of visual memory, verbal memory, reaction time, and visual motor speed.

At present, there are no treatments approved for MHE. Studies are ongoing. It is thought likely, but is as yet unproven, that MHE will respond to the same therapies that are effective in overt hepatic encephalopathy, including lactulose, rifaximin, and dietary manipulations.

In a separate study presented at the congress, Dr. Arun Sanyal reported that the severity of chronic cognitive impairment is cumulative with the number of acute episodes of overt hepatic encephalopathy (OHE), underscoring the importance of early detection, prompt treatment, and preventive therapy.

Fifty cirrhosis patients were followed for a mean of 13 months after their first hospitalization for OHE, during which they experienced a median of 2 but up to 13 further acute episodes and one OHE hospitalization. Their neuropsychologic test scores were highly abnormal, and the severity of the deficits in working memory, attention, psychomotor speed, and response inhibition was highly correlated with the number of OHE episodes.

The implication is that the metabolic derangements that cause OHE might also induce chronic neurologic injuries that aren’t readily reversible, according to Dr. Sanyal, professor of medicine and chairman of the division of gastroenterology, hepatology and nutrition at Virginia Commonwealth University, Richmond.

Dr. Mendler’s study was funded by a research grant from Salix Pharmaceuticals Ltd. He has no other financial relationship with the company nor any financial interest in the ImPACT test. Dr. Sanyal is a consultant to Salix.

Copyright (c) 2009 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

维也纳(EGMN)——所有美国国家橄榄球联盟球队用于评估球员脑震荡影响的同种简单的、基于网络的神经心理测验方法似乎也有助于诊断轻微型肝性脑病。

 

即刻脑震荡后评估与认知测试(ImPACT v4.0)系统是一种经过良好验证的基于计算机的神经心理测验方法。整个测验过程只需花费约10min。Michel H. Mendler博士在欧洲肝病研究学会主办的本年度国际肝病会议上称，这种神经心理测验易于实施、有13种语言版本、可由诊室的任何人进行实施、并即刻生成评分结果，无需临床神经心理医生帮助解读评分。

 

加利福尼亚州洛玛连达大学的胃肠病学家Mendler博士说：“ImPACT有望成为轻微型肝性脑病测验的新标准，不论是在常规临床实践中，还是用于评价治疗。”

 

轻微型肝性脑病(MHE)是一种诊断率很低的神经认知障碍，见于60%~80%的肝硬化患者。 MHE可损害生活质量、降低工作能力并影响驾驶，对其缺乏认识将导致更严重的后果。如果不对MHE进行控制，则其可进展为显性肝性脑病，这是一种更严重的以认知和运动功能缺损为特征的神经精神综合征，通常需要住院治疗。

 

MHE包括心理加工速度、精细运动技能、记忆力、复杂注意力、构建能力和视觉空间定向能力方面的缺损。与显性肝性脑病中所见的缺损不同，这些缺损较为隐匿，需通过神经心理测验才能诊断。

 

他表示，传统的神经心理测验方法不易实施、复杂、耗时长且结果需由专家进行解读。广泛应用的替代方法是纸笔测验方法，包括几种心理测验，如数码-符号测验及数字连接测验A和B。但这些测验的结果受重复测验产生的明显练习效应的干扰。

Mendler博士继续说，相比之下，由匹兹堡大学神经科学家开发的ImPACT测验方法能够生成数量不受限制的复本，避免了练习效应。

他在90例无显性肝性脑病病史的肝硬化患者和131例匹配的健康对照者中对ImPACT与纸笔测验进行了比较。ImPACT测验显示，90例肝硬化患者中25例具有符合MHE诊断的异常评分结果(阳性结果)；纸笔测验显示，16例的结果为阳性，其中仅10例的ImPACT测验结果亦为阳性。

 

此外，对74例纸笔测验阴性的患者进行ImPACT测验发现，12例的结果为阳性。131例健康对照者中共7例的ImPACT测验结果阳性，19例的纸笔测验结果阳性，可以看出，ImPACT测验的假阳性率显著低于纸笔测验。

 

疾病影响问卷(Sickness Impact Profile)平均总体评分在ImPACT测验结果阳性的肝硬化患者中为17.6分，在ImPACT测验结果阴性的患者中为13.5分，在对照者中为2.6分。疾病影响问卷可反映躯体和心理社会功能。

 

ImPACT测验(www.impacttest.com)生成的是视觉记忆、言语记忆、反应时间和视觉运动速度这4个方面的复合评分。

 

目前，针对MHE的治疗方法尚无获得批准。相关研究还在进行中。有观点认为，能够有效治疗显性肝性脑病的疗法(包括乳果糖、利福昔明和饮食调节)同样可有效治疗MHE，但这一观点尚未经证实。

 

Arun Sanyal在会议上报告了另一项研究，其指出，慢性认知功能损害的严重程度随显性肝性脑病(OHE)急性发作次数的增加而加重，强调了早期发现、及时治疗和预防治疗的重要性。

 

50例肝硬化患者在因OHE首次住院后接受平均13个月的随访。随访期间，进一步急性发作的中位次数为2次(最多为13次)，中位OHE住院次数为1次。这些患者的神经心理测验评分非常异常，工作记忆、注意力、精神运动速度和反应抑制方面的缺损与OHE发作次数明显相关。

 

里士满弗吉尼亚州联邦大学胃肠病学、肝病学和营养学系主任兼内科学教授Sanyal博士表示，这表明，导致OHE的代谢紊乱也可诱导不易逆转的慢性神经损伤。

 

Mendler博士的研究获得Salix制药公司的资助。他声明，与该公司不存在其他任何经济关系，在ImPACT测验方面也无任何经济利益冲突。Sanyal博士是Salix公司的顾问。

 

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