Mechanisms, Diagnosis And Management Of Hepatic Encephalopathy

REviEWS
Mechanisms, diagnosis and management of hepatic encephalopathy
Ravi Prakash and Kevin D. Mullen
abstract | Hepatic encephalopathy (HE) is a serious neuropsychiatric complication of both acute and chronic liver disease. Symptoms of HE can include confusion, disorientation and poor coordination. A general consensus exists that the synergistic effects of excess ammonia and inflammationcause astrocyte swelling and cerebral edema; however, the precise molecular mechanisms that lead to these morphological changes in the brain are unclear. Cerebral edema occurs to some degree in all patients with HE, regardless of its grade, and could underlie the pathogenesis of this disorder. The different grades of HE can be diagnosed by a number of investigations, including neuropsychometrictests (such as the psychometric hepatic encephalopathy score), brain imaging and clinical scales (such as the West Haven criteria). HE is best managed by excluding other possible causes of encephalopathy alongside identifying and the precipitating cause, and confirming the diagnosis by a positive response to empiric treatment. Empiric therapy for HE is largely based on the principle of reducing theproduction and absorption of ammonia in the gut through administration of pharmacological agents such as rifaximin and lactulose, which are approved by the FDA for the treatment of HE.
Prakash, R. & Mullen, K. D. Nat. Rev. Gastroenterol. Hepatol. 7, 515–525 (2010); published online 10 August 2010; doi:10.1038/nrgastro.2010.116

Continuing Medical Education online
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Introduction

learning objectives
Upon completion of this activity, participants should be able to: 1 Describe the types and patterns of hepatic encephalopathy (HE) and risk factors for the development of both minimal and overt HE. 2 Construct an appropriate diagnostic assessment for patients with suspected HE thataddresses a valid differential diagnosis. 3 Develop treatment strategies for HE that incorporate pharmacologic and nonpharmacologic therapies.

Competing interests K. D. Mullen declares an association with the following companies: Ocera Therapeutics and Salix Pharmaceuticals. See the article online for full details of the relationship. R. Prakash and the Chief Editor N. Wood declare no competinginterests. The CME questions author D. Lie has served as a nonproduct speaker for “Topics in Health” for Merck Speaker Services.

Hepatic encephalopathy (He) is a serious neuro­ psychiatric complication of both acute and chronic liver disease.1 this disease encompasses a broad range of neuropsychiatric abnormalities of varying severity: affected patients exhibit alterations in psychomotor,intellectual, cognitive, emotional, behavioral and fine motor functions. He can be classified as either ‘overt’ or ‘minimal’. overt He (oHe) is a syndrome of neuro­ logical and neuropsychiatric abnormalities that can be detected by bedside clinical tests. By contrast, patients with minimal He (mHe) present with normal mental and neurological status upon clinical examination but specific psychometric...