Campagna F, Montagnese S, Ridola L, Senzolo M, Schiff S, De Rui M, Pasquale C, Nardelli S, Pentassuglio I, Merkel C, Angeli P, Riggio O, Amodio P.
Screening for hepatic encephalopathy (HE) that does not cause obvious disorientation or asterixis (minimal HE [MHE]/grade 1 HE) is important. We examined if the animal naming test (ANT1 ) (maximum number of animals listed in 1 minute) is useful in this context. In total, 208 healthy controls, 40 controls with inflammatory bowel disease, and 327 consecutive patients with cirrhosis underwent the ANT1 . Patients were tested for MHE by the psychometric HE score, and 146 were assessed by electroencephalography; 202 patients were followed up regarding the occurrence of overt HE and death. In the healthy controls, ANT1 was influenced by limited education (<8 years) and advanced age (>80 years, P < 0.001). Using an age and education adjusting procedure, the simplified ANT1 (S-ANT1 ) was obtained. An S-ANT1 of <10 animals was abnormal. Of the patients, 169 were considered unimpaired, 32 as having HE ≥grade 2, and 126 as having MHE/grade 1 HE. This group had lower S-ANT1 than unimpaired patients (12 ± 0.4 versus 16 ± 0.7, P < 0.001) and higher S-ANT1 than those with HE ≥grade 2 (4 ± 0.9). In grade 1 HE the S-ANT1 was lower than in MHE. Following receiver operating characteristic analysis (Youden’s index), 15 animals produced the best discrimination between unimpaired and MHE/grade 1 HE patients. Thus, a three-level score (0 for S-ANT1 ≥15, 1 for 10 ≤ S-ANT1 < 15, 2 for S-ANT1 <10) was obtained. This score was correlated both to the psychometric HE score (P < 0.0001) and to electroencephalography (P = 0.007). By sample random split validation, both S-ANT1 and its three-level score showed prognostic value regarding the 1-year risk of overt HE and death. No inflammatory bowel disease control had S-ANT <15.
The S-ANT1 is an easily obtainable measure useful for the assessment of HE