P: 58 Prediction of Overt Hepatic Encephalopathy by the Continuous Reaction Time Method and the Portosystemic Encephalopathy Syndrome Test in Patients With Cirrhosis

Abstract

BACKGROUND: Predicting overt hepatic encephalopathy (OHE) is of major importance because the condition is unpleasant, requires hospitalization, and partly preventable. The risk is related to pre-existing discrete cognitive defects, and a number of psychometric tests are validated for detection of such defects. For clinical practice it is recommended to apply two different tests. We used the Continuous Reaction Time test (CRT) and the Porto Systemic Encephalopathy Test (PSE), and examined their single and combined value for prediction of OHE in cirrhosis patients. METHODS: We studied 130 mentally unimpaired cirrhosis patients by the two tests and followed them up for on average 38.5 months. The CRT measures velocity and stability in motor reaction times to 150 repeated auditory. The PSE is a paper-and-pencil test measuring the duration of completing 5 tasks. We collected data on episodes of OHE during follow-up. The clinical course was analysed in patient groups according to the outcome of each test and of both tests together. No anti-HE treatment was initiated except for OHE. RESULTS: We observed 74 OHE events. The PHES was abnormal in 47 and predicted 31 OHE episodes among 14 patients (PPV = 29%, NPV of 75%, sens. 40%, spec. 65%). The CRT test was abnormal in 74/130 and predicted 54 OHE episodes among 23 patients (PPV = 31%, NPV = 78%, sens. 65%, spec. 46%). One or both tests were abnormal in 87/130 and predicted 60 OHE episodes among 27 patients (PPV = 31%, NPV = 81%, sens. 77%, spec. 40%). 43/130 had two normal tests but 8 experienced OHE and had 14 OHE-admissions. CONCLUSIONS: The combined use of PSE and CRT test identified 77% of patients who later experienced OHE while ruling out future OHE with an NPV of 81%.