Neuropsychological and neuroimaging aspects of latent hepatic encephalopathy (LHE).

It has become increasingly clear that many cirrhotic patients who do not display overt clinical encephalopathy, on closer examination, do demonstrate significant cognitive impairment, which often goes unrecognised. This "latent" hepatic encephalopathy (LHE) is usually characterised by memory impairment and psychomotor slowing, and is not simply attributable to the effects of alcohol. Structural neuroimaging studies (CT and MRI) have produced conflicting results. Functional neuroimaging studies (PET and SPECT) which have measured regional cerebral blood flow, however, have found evidence of increased regional cerebral activity in sub-cortical areas in LHE patients, with the degree of sub-cortical activity correlated with the severity of neuropsychological impairment.