Liver and brain metabolism alterations in patients with minimal hepatic encephalopathy

Introduction: Minimal hepatic encephalopathy (MHE) is a neuropsychiatric complication of chronic liver disease, predominantly liver cirrhosis. Due to the lack of clear clinical symptoms, early diagnosis of MHE is difficult and relies mainly on neuropsychological tests.

Aim: We studied the correlations between cognitive impairment as measured by a Polish adaptation of the Wechsler Adult Intelligence Scale (WAIS-R (PL)) and selected biochemical parameters such as prothrombin time (PT), ammonia concentration and brain metabolites detected by proton magnetic resonance spectroscopy (H¹MRS) in patients with liver cirrhosis and controls.

Material and methods: Material and methods: Localized proton magnetic resonance spectroscopy was performed in 36 patients with chronic liver disease and 34 healthy volunteers matched for age, gender and level of education. In each participant laboratory and neuropsychological tests was performed.

Results: The examined blood parameters of liver function were similar in patients with and without MHE and were significantly abnormal compared to the control group. Only in patients with MHE did PT and ammonia concentration correlate with total WAIS-R (PL), verbal subscore of WAIS-R (PL) and non-verbal subscore of WAIS-R (PL). Cirrhotic patients showed a significant reduction of myo-inositol/creatine (Mi/Cr) and myo-inositol/choline (Mi/Cho) ratios in the three studied brain regions as compared to controls. Patients with MHE “+” had significantly decreased ratio of NAA/Cr as compared to the MHE “–” group in gray matter in the posterior occipital cortex.

Conclusions: Our study shows some brain metabolic disturbances typical only for MHE. The H¹MRS can be helpful in the diagnosis of this disease.