Evoked Potentials for the Evaluation of Latent Hepatic Encephalopathy in Pediatric Liver Transplant Candidates

BACKGROUND: Visual evoked potentials (VEPs) and brain stem auditory evoked potentials (BAEPs) have been proposed as tools in the diagnosis of subclinical hepatic encephalopathy (HE). However, little information exists to determine their usefulness in pediatric patients. This study was undertaken to evaluate both methods in the detection of subclinical HE in pediatric liver transplant candidates. METHODS: VEPs and BAEPs were recorded in 15 pediatric liver transplant candidates with no clinical signs of HE. The wave latencies found in these examinations were then compared with those in 16 healthy controls of similar age. Laboratory data on liver function and electroencephalographic data from the patients were also recorded to examine their correlation with the evoked potentials results. RESULTS: No differences were found in the BAEP results between patients and controls. However, in the VEPs, the liver transplant candidates had significantly prolonged N1 (N75) latencies when compared with controls; no significant delay was found in the other waves. In contrast, among the children with liver disease, higher BAEP peak latencies correlated positively with electroencephalographic abnormalities, but this correlation was not observed in VEPs. CONCLUSIONS: Evoked potentials might be of use in detecting alterations related to HE in children. However, further studies are necessary to determine their sensitivity and specificity in this situation.