Neurophysiological abnormalities in uraemic encephalopathy.

Sophisticated electrophysiological assessments have been employed to display cortical alterations in uraemia and to follow the influence of haemodialysis treatment (RDT). Flash-Visual Evoked Responses (VERs); Pattern Reversal Visual Evoked Potentials (VEPs); Brain-stem Auditory Evoked Responses (BAERs); Electroencephalogram (EEG) with Berg's analysis of frequencies were recorded in 15 uraemic patients, 10 of whom subsequently started RDT. VER latency was delayed compared with controls and unmodified after RDT. VEP latency was similarly delayed returning to normal range with RDT. BAER, preliminarily recorded only in 10 patients, showed increased latency of waves I, III, V. EEG showed 7 to 10 and 10 to 13 Hz to be reduced, and after eight months of haemodialysis the 13 to 20 Hz band increased.