Event-related potentials in evaluation of metabolic encephalopathies.

Auditory event-related potentials (ERPs) were studied in 28 patients with chronic liver cirrhosis and in 34 patients on regular hemodialysis treatment for chronic renal failure. Prolongation of P3 wave latency was the earliest and most evident sign of brain cognitive dysfunction in both groups. The changes of ERPs well corresponded to the stage of metabolic affliction when, in addition, N1 and N2 wave latencies were delayed in patients with more advanced liver cirrhosis. In the group of hemodialyzed patients, ERPs reflected the effects of an individual treatment procedure as well.