Predictors of Minimal Hepatic Encephalopathy in Patients with Cirrhosis

BACKGROUND/AIM: Minimal hepatic encephalopathy (MHE) impairs patient’s daily functioning of life. Predictors of MHE in cirrhotic patients have not been evaluated. PATIENTS AND METHODS: A total of 200 cirrhotic patients (Child A, 74 [37%]; Child B, 72 [36%]; Child C, 54 [27%]) were evaluated by psychometry, P300 auditory event-related potential (P300ERP) and critical flicker frequency (CFF). MHE was diagnosed by abnormal psychometry (>2 S.D.) and P300ERP (>2.5 S.D.). Univariate and multivariate logistic regression analyses were performed to determine the predictors of MHE. RESULTS: Eighty-two (41%) patients were diagnosed to have MHE – 26/74 (35%) in Child A, 26/72 (36%) in Child B and 30/54 (56%) in Child C. Ninety-seven (48.5%) patients had abnormal psychometric tests, and 96 (48%) had prolonged P300ERP (>358 ms). Sixteen (16.5%) patients with abnormal psychometry had P300ERP < 358 ms, and 15 (14.5%) patients with normal psychometry results had P300ERP > 358 ms. One hundred and three patients had CFF value < 39 Hz with specificity of 86.6% and sensitivity of 72.9% for MHE. Model for end-stage liver disease (MELD) (17.9 ± 5.7 vs. 13.4 ± 4.2, P = 0.005), Child-Turcotte-Pugh (CTP) score (8.4 ± 2.5 vs. 7.7 ± 2.2, P = 0.02), ammonia (104.8 ± 37.9 vs. 72.5 ± 45.2 µmol/L, P = 0.001) and CFF (37.0 ± 2.8 vs. 41.0 ± 3.4 Hz, P = 0.001) were significantly higher in MHE as compared to non-MHE patients. Ninety-one (45.5%) patients had MELD > 15.5, 115 (57.5%) had CTP score > 7.5, while 93 (46.5%) had venous ammonia > 84.5 µmol/L. On univariate analysis, MELD (8.52 [95% CI, 4.46-16.26; P = 0.001]), CFF (17.34 [95% CI, 8.16-36.85; P = 0.001]) and venous ammonia (7.80 [95% CI, 4.11-14.81; P = 0.003]) were associated with MHE; while CTP score (1.51 [95% CI, 0.85-2.69; P = 0.30]) was not significant. On multivariate analysis, MELD, CFF and venous ammonia were predictive of MHE. CONCLUSION: Prevalence of MHE in this study was 41%; and MELD > 15.5, CFF < 39 Hz and venous ammonia > 84.5 µmol/L were predictive of MHE.