VISUAL AND AUDITORY-EVOKED RESPONSES IN ACUTE SEVERE HEPATITIS

Evoked responses have not been studied in patients with acute severe h epatitis (ASH) with or without hepatic encephalopathy. This prospectiv e study was undertaken to find our diagnostic as well as prognostic va lue of visual evoked responses (VER), and brain stem auditory evoked r esponses (BAER) in patients with ASH with or without encephalopathy. V isual evoked responses and BAER were studied in 20 patients (14 males and six females) with ASH. The patients were diagnosed as having sever e hepatitis if acute hepatitis was associated with raised serum biliru bin and serum transaminases, and if they had a prothrombin time index of < 50%. After a detailed neuropsychiatric examination of each patien t, the study sample was divided into two groups of 10 patients: ASH wi thout encephalopathy (ASH-WOE), and ASH with encephalopathy (fulminant hepatic failure, FHF). The median P100 latencies of FHF patients were significantly Increased compared with controls and patients in the AS H-WOE group. Abnormal P100 latencies, exceeding 95th percentile values of the controls, were present in one patient in the ASH-WOE group and six patients in the FHF group. The median interpeak latencies I-m, m- V and I-V were significantly prolonged in the FHF group. Interpeak lat encies m-tr were also increased significantly in patients in the ASH-W OE group. While abnormal BAER were seen frequently in both groups, VER abnormalities were largely confined to patients in the FHF group, In the FHF group, six out of 10 patients survived and exhibited clinical improvement in the status of hepatic encephalopathy, Evoked responses were repeated after 2-3 weeks of recovery in these patients and VER ab normalities showed a tendency to normalize, thereby suggesting a progn ostic implication. The incidence of abnormal VER in hepatic encephalop athy complicating ASH far exceeded that of abnormal BAER. Markedly pro longed P100 latencies in FHF patients indicate poor prognosis.