Evaluation of different diagnostic modalities of minimal hepatic encephalopathy in cirrhotic patients: case-control study.

Abstract

IntroductionMinimal hepatic encephalopathy (MHE) represents one of the most overlooked complications of liver cirrhosis.Aim of the studyTo compare the utility and efficacy of different MHE diagnostic modalities.Material and methodsThis case-control study was conducted on hepatitis C virus (HCV)-related compensated cirrhotic patients. The Psychometric Hepatic Encephalopathy Score (PHES) was used to assign patients to MHE and controls. All patients were subjected to plasma ammonia, serum 3-nitrotyrosine (3-NT), critical flicker frequency (CFF), and the modified inhibitory control test (ICT).ResultsCFF was significantly lower in the control group (38.5, 40 Hz, p = 0.003). The unweighted lures on ICT were 8.7, 4.9 in MHE and controls (p < 0.001). Moreover, ammonia was higher in the MHE group (89, 61.5 µmol/l, p < 0.001). 3-NT was also higher in the MHE group (31.5, 13.7 nmol/l, p < 0.001) respectively. CFF at cutoff < 39 Hz had sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 57.5%, 77.5%, 71.9% and 64.6%, respectively; in modified ICT, at cutoff > 5 unweighted lures the values were 87.5%, 80%, 81.4% and 86.5%, respectively; in ammonia, at cutoff ≥ 76.45 µmol/l the values were 65%, 72.5%, 70.3% and 67.4%, respectively; for 3-NT at cutoff ≥ 14.15 nmol/l the values were 85%, 82.5%, 82.9% and 84.6%, respectively. The accuracy for MHE diagnosis was 67.5%, 83.3%, 68.8%, 83.8% relying on CFF, 3-NT, ammonia, and ICT respectively. On multivariate analysis, CFF < 39 Hz (OR = 10.2, p = 0.04), modified ICT > 5 unweighted lures (OR = 43.2, p = 0.002), and serum 3-NT levels ≥ 14.15 nmol/l (OR = 50.4, p < 0.001) were independent predictors of MHE.Conclusions3-NT and ICT are advantageous to reveal MHE in compensated liver cirrhosis, while CFF can be only used as adjuncts, with humble merits of ammonia.