BENEFICIAL EFFECT OF RENAL-TRANSPLANTATION ON COGNITIVE BRAIN-FUNCTION

Cognitive brain dysfunction is a common complication of end-stage rena l disease. To investigate the cerebral effect of renal transplantation , we studied P300 event-related potentials-an objective marker of cogn itive brain function-trailmaking test and Mini-mental state in 15 chro nic hemodialysis patients and 45 matched healthy subjects. Before tran splantation, patients showed prolonged P300 latency (364 vs. 337 ms, P < 0.01), smaller amplitude (15.2 vs. 19.1 mu V) and scored lower (P < 0.05) in trailmaking test and Mini-mental state as compared to health y subjects. Following renal transplantation (14 months), P300 latency decreased (337 ms, P < 0.01 vs. before) and amplitude increased (17.4 mu V, P < 0.05 vs. before), indicating improved cognitive brain functi on. The trailmaking test and Mini-mental slate tended to improve. Foll owing transplantation, P300 findings, trailmaking test and Mini-mental state were not different from healthy subjects. Additional studies fo llowing erythropoietin treatment in 6 of the 15 hemodialysis patients revealed decreased (improved) P300 latency (351 vs. 379 ms before, P < 0.05) with further decrease following transplantation (341 ms, P = 0. 06). Our findings indicate that cognitive brain dysfunction in hemodia lysis patients may be fully reversed by successful renal transplantion .