Effects of haemodialysis and continuous ambulatory peritoneal dialysis on P300 cognitive potentials in uraemic patients.

The aim of this study was to determine the effects of haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) on P300 cognitive potentials in patients with chronic renal failure (CRF) and to find out if P300 potential is a valuable marker for following subclinical cognitive disorder. This study was performed in 42 patients with chronic uraemia, of whom 25 were on HD and 17 on CAPD, and in 25 healthy subjects. All the subjects were investigated in terms of P300 cognitive potential obtained from auditory stimuli with the oddball paradigm and the Mini-Mental State (MMS) examination. Patients undergoing HD were evaluated before (pre-dialysis) and after (post-dialysis) standard HD treatment. P300 latency was longer in HD patients than in the control group and CAPD patients. The MMS score was greater and P300 latency was shorter after a standard HD session when compared to pre-dialysis values in HD patients (p < 0.001 for both values). There was a negative correlation between P300 latency and MMS scores, and a positive correlation between P300 amplitude and MMS scores. In conclusion, P300 is useful for evaluating cognitive function in uraemia, even in asymptomatic patients, and CAPD is superior to HD in the management of cognitive impairment.