Electrophysiological study in patients with chronic hepatic insufficiency.
Twenty patients affected by chronic hepatic insufficiency were studied by means of combined EEG, VEP and BAEP recordings. Subjects were classified, according to Parsons-Smith criteria, in grade 0 (without any clinical sign) and grade I (with minimal mental disturbances). In group 0 patients an elevated incidence of VEP alterations (40%) was observed, while EEG and BAEP recordings were less frequently (10%) abnormal. In group I patients a high degree of EEG (60%), VEP (70%) and BAEP (70%) abnormalities was found. Mean latency and interpeak interval values in group I patients were significantly prolonged if compared with the grade 0 and control groups. No correlations were found between electrophysiological data and blood biochemical parameters examined (ammoniemia, aminoacidemic pattern).