Validation of the animal naming test for diagnosing minimal hepatic encephalopathy

Abstract

Introduction and aim

The diagnosis of minimal hepatic encephalopathy (MHE) is complex in clinical practice, given that its adequate evaluation is time-consuming. The animal naming test (ANT1) has proven to be a useful tool for rapid MHE identification. Our aim was to validate the ANT1 in a cohort of Mexican patients with cirrhosis of the liver.

Material and methods

An observational, cross-sectional, and analytic study was conducted within the time frame of June 2022 and May 2023. MHE diagnosis was made using the psychometric hepatic encephalopathy score (PHES). Patients with overt HE evaluated through the West Haven criteria were excluded. The ANT1 was performed on all participants.

Results

A total of 199 patients with cirrhosis and 31 non-cirrhotic control subjects were analyzed. Women predominated (61.8% and 71%) and mean patient age was 55 ± 10 and 53.6 ± 12 (range 19–84 years), respectively. Ninety patients (45.2%) met the MHE criteria determined by the PHES. Using an ANT1 cutoff point of ≤15, MHE was identified in 65 (32.7%) patients, along with 75% sensitivity, 72% specificity, 53% positive predictive value, 87% negative predictive value, and 73% diagnostic accuracy. The area under the curve for diagnosing MHE was 0.763 (standard error, 0.081; 95% confidence interval, 0.604−0.923; p ≤ 0.0001).

Conclusions

The ANT1 was shown to be a useful tool for identifying MHE in daily clinical practice. In our population, a cutoff point ≤15 animals named could be utilized for rapid screening of patients at high risk for progressing to overt HE, who would then require extensive testing.