EVOKED-POTENTIALS (VEPS AND BAEPS) IN A LARGE COHORT OF SHORT-TERM AND LONG-TERM HEMODIALYZED PATIENTS

To evaluate the presence and the severity of uraemic encephalopathy (U E) in regular dialysis treatment patients in relation to dialytic age, pattern reversal visual evoked potentials (PRVEPs) and brainstem audi tory evoked potentials (BAEPs) were respectively performed in 86 and 9 8 patients on haemodialysis for 1-194 months, divided into three subgr oups according to dialytic age (group 1, < 5 years of regular dialysis ; group 2, 5-10 years; group 3, > 10 years). VEPs in the whole group o f 86 patients and in each subgroup with different dialytic age differe d significantly from controls for both eyes, 41.7% of whom had patholo gical P100; no differences were observed between the three subgroups.B AEPs were pathological in 9.7% of the ears and 18.4% of patients. On t he right ear the three subgroups were significantly different from con trols in the latencies of peaks III and V; subgroup 2 and 3 differed f rom controls in the I-V interpeak, while the interpeak I-III was diffe rent from controls only in subgroup 3. On the left ear the three subgr oups differed significantly from controls in the latencies of peak V; subgroup 2 and 3 were significantly different from controls in the lat ency of peak 1; subgroup 3 was different in the peak III latency; subg roup 1 and 3 were different from controls in the interpeak I-V; no dif ferences were observed in BAEPs between the three subgroups with incre asing dialytic age. No significant correlations were found between the neurophysiological parameters and some biochemical parameters (urea, creatinine, PTH). In summary, regular dialysis does not prevent the pe rsistence of mild signs of uraemic encephalopathy, but these signs do not appear to worsen with increasing dialytic age.