Visual evoked potentials and long latency event-related potentials in chronic renal failure

We studied auditory event-related potentials elicited in a target detection paradigm (P300) and pattern shift visual evoked potentials (PVEPs) in 22 patients with chronic renal failure and no clinical evidence of cognitive or visual impairment. Thirteen patients were maintained on chronic hemodialysis, and 9 patients were receiving a low-protein diet. Thirty-three percent of patients receiving the low-protein diet and 58% of the dialysis patients had abnormal P300 latencies. Most patients tested had abnormal PVEP. Four hemodialysis patients had elevated serum parathyroid hormone (PTH) levels, and 9 had normal or slightly elevated values. P300 and PVEP latencies were abnormal in both groups. These observations indicate that elevated PTH levels are not solely responsible for the abnormalities in all patients. P300 and PVEP may be valuable in evaluating neuronal dysfunction in the patient with chronic renal failure.