Inhibitory Control Test for the Detection of Minimal Hepatic Encephalopathy in Patients with Cirrhosis of Liver

Background & aims: Minimal hepatic encephalopathy (MHE) has significant impact on future clinical outcomes, such as occurrence of overt HE (OHE) and survival in patients of cirrhosis. In the absence of a 'gold standard', psychometric hepatic encephalopathy score (PHES) is widely used for the diagnosis of MHE. This cross-sectional and prospective study was carried out to determine the usefulness of inhibitory control test (ICT) for the diagnosis of MHE. Methods: One hundred and two patients with cirrhosis and without a history of OHE were enrolled in to the study and were subjected to PHES and ICT. MHE was diagnosed when the PHES was <= -5. ICT was considered abnormal when the numbers of ICT lures were more than 14. Results: Forty-one (40.2%) patients had MHE. There were 40 patients with normal PHES and ICT, 32 with abnormal PHES and ICT, 9 with abnormal PHES and normal ICT, and 21 with abnormal ICT and normal PHES score. ICT had 78% sensitivity and 65.6% specificity and an are a under-the-curve value of 0.735 (95% CI = 0.632-0.830) for the diagnosis of MHE. In patients with cirrhosis, ICT did not correlate with severity of liver disease as measured by CTP score (r = 0.044, P = 0.658) and MELD score (r = 0.176, P = 0.077). ICT did not predict survival as well as PHES; while 6 (11.3%) patients died among those who had altered ICT compared to 4 (8.2%) patients who did not have altered ICT (P = 0.74), 8 (19.5%) patients died among those who had altered PHES compared to 2 (3.3%) patients who did not have altered PHES (P = 0.013). Conclusion: ICT is not as useful as PHES in diagnosing MHE in patients with cirrhosis of the liver. It does not correlate with disease severity and predict survival as well as PHES.