Minimal hepatic encephalopathy (MHE) is the mildest form of the spectrum of neurocognitive impairment in cirrhosis. It is a frequent occurrence in patients of cirrhosis and is detectable only by specialized neurocognitive testing. MHE is a clinically significant disorder which impairs daily functioning, driving performance, work capability and learning ability. It also predisposes to the development of overt hepatic encephalopathy, increased falls and increased mortality. This results in impaired quality of life for the patient as well as significant social and economic burden for health providers and care givers. Early detection and treatment of MHE with ammonia lowering therapy can reverse MHE and improve quality of life. ( J CLIN EXP HEPATOL 2015;5:S42-S48) H epatic encephalopathy (HE) is a neurocognitive disorder in which brain function is impaired and is associated with both acute and chronic liver dysfunction. 1 It is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Minimal HE (MHE) is the mildest form of spectrum of HE which is characterized by subtle cognitive and psychomotor deficits in the absence of recognizable clinical symptoms of HE. 2 It occurs in patients with liver dysfunction and/or portosystemic shunts. In MHE, neurocognitive abnormalities primarily affect attention, speed of information processing, executive control, motor ability and coordination in an individual. 3 In 1970, Zeegen et al 4 first described this condition when they discovered that 38% of patients who had undergone portal decompression surgery scored abnormal in Reitan trail making test (number connection test). Eight years later, the term subclinical HE 5 was introduced to describe these patients. Since then, this condition was described under various names like early HE, latent HE, subclinical HE and finally minimal HE. The latest classification combines MHE and grade 1 HE into covert HE while higher grades are classified as overt HE, thus simplifying the clinical schema so that HE can be uniformly diagnosed. 6 Covert HE means that the mental defect is not detectable by the clinician using conventional testing and is not noticeable to the patient. However, it is significant because these patients usually have neuropsychiatric and neurophysiological abnormalities on advanced testing which are not enough to cause disorientation or asterixis. MHE is regarded as a preclinical stage of HE and ammonia and systemic inflammation plays an important role in its pathogenesis similar to HE. Ammonia lowering therapies were used in the treatment of MHE and found to be effective.MHE is clinically significant as it impairs daily functioning, health related quality of life (HRQOL) and driving skills, predicts the development of overt HE and is associated with poor survival. 7-11 Overt HE develops in >50% of MHE patients within three years. 10 These patients pose a significant burden to their care givers depending on the severity of cognitive dysfunction. 2,12 Considering all ...