Psychometric tests, critical flicker frequency, and inflammatory indicators in covert hepatic encephalopathy diagnosis.

Background and aim: Hepatic encephalopathy (HE) is a frequent complication of liver diseases. Systemic inflammation is key for HE pathogenesis. The main goal of the study was to investigate the role of psychometric tests, critical flicker frequency (CFF), and comparative evaluation of inflammatory indicators for the diagnosis of covert HE (CHE).

Materials and methods: The study was a prospective, nonrandomized, case-control study with a total of 76 cirrhotic patients and 30 healthy volunteers. The West Haven criteria were used to determine the occurrence of CHE in cirrhotic patients. Psychometric tests were applied to healthy and cirrhotic groups. CFF, venous ammonia, serum endotoxin, IL-6, IL-18, tumor necrosis factor alpha (TNF-α) levels, and hemogram parameters were evaluated for cirrhotic patients.

Results: CFF values and psychometric tests were found to accurately discriminate CHE positives from CHE negatives (p<0.05). When the control group was excluded, the digit symbol test and the number connection A test failed, unlike CFF and other psychometric tests. Using CFF, a 45 Hz cutoff value had 74% specificity and 75% sensitivity. Basal albumin levels (p=0.063), lymphocyte-to-monocyte ratio (LMR) (p=0.086), and neutrophil-to-lymphocyte ratio (p 0.052) were significant, albeit slightly, among CHE groups. Basal albumin levels had 50% sensitivity and 71% specificity when 2.8 g/dL was used as a cutoff value to determine CHE.

Conclusion: Both psychometric tests and CFF can be useful in diagnosing CHE. Using cytokine and endotoxin levels seems to be inadequate to diagnose CHE. Using LMR and albumin levels instead of psychometric tests for diagnosing CHE can be promising.