VALIDATION OF THE ANIMAL NAMING TEST IN THE SCREENING OF MINIMAL HEPATIC ENCEPHALOPATHY

Abstract

Background: Burden of minimal hepatic encephalopathy (MHE) is significant, but easy and valid tools for screening is an unmet need. We aimed to validate the animal naming test for MHE screening in Korea. Methods: Liver cirrhosis (LC) patients without history of overt HE were recruited prospectively from 13 centers. All participants completed Korean paper‐pencil test (KPPT) and the animal naming test (ANT). ANT consists of listing as many names of animals as possible in a minute. The number of animals listed in one minute (ANT1) was collected. MHE was diagnosed when KPPT scores ≥ 2. Results: A total of 629 healthy controls and 124 LC patients were enrolled. The most common etiology of LC was alcohol (64.0%). Mean MELD score of LC patients was 11. Prevalence of MHE was 39.2% by KPPT. ANT1 was negatively correlated with age (ρ=‐0.233, p<0.001) and positively correlated with education‐years (ρ=0.298, p<0.001) in the healthy controls. ANT1 was significantly correlated with KPPT scores (ρ=‐0.387, p<0.001) in LC patients. ANT1s were significantly different between healthy controls and LC patients (p<0.001). ANT1s for healthy controls, LC patients without MHE, and LC patients with MHE were 17.4±4.6, 16.9±5.1, and 13.1±3.7, respectively. They were different when compared between LC patients without MHE and LC patients with MHE (p<0.001). ANT1 (OR 0.713, p<0.001) was the only significant factor independent of model for end‐stage liver disease (MELD) score in multivariate analysis for MHE diagnosis. The cut‐off point for the highest Youden's index value was 15.5 for ANT1 with 77.6% of sensitivity and 57.3% of specificity. Conclusion: The animal naming test is an easy, simple and valid method for screening of MHE.