Somatosensory and Brainstem Auditory Evoked Potentials before and After Hemodialysis in Chronic Renal Failure

ABSTRACT

For evaluation of the alterations of the somatosensory evoked potentials(SSEP) and the brainstem auditory evoked potentials(BAEP)before and after hemodialysis, SSEP and BAEP were recorded by using a Medelec ST10 Sensor apparatus before the first dialysis and after subsequent dialyses in 30 urernic patients (19 men and 11 women)and the results were compared with the normal controls. The duration of subsequent hemodialyses varied from 0.5 to 9 months, with a mean of 3.3 months. To evaluate the effect of single hemodialysis on BAEP, BAEP were recorded before and after a single hemodialysis in another 10 uremic patients. According to the results of the median nerve SSEP, the absolute latencies of all responses and all interpeak latencies before hemodialysis and the absolute latencies of all responses and N13-N19 interpeak latency after hemodialysis were significantly delayed compared with normal controls. The absolute latencies of N9 and P23 were significantly delayed in the perdialysis compared with the postdialysis. From the BAEP, the absolute latencies of all responses before and after hemodialysis and the I-V interpeak latency before hernodialysis were significantly delayed compared with the normal controls, but there were no significant changes between predialysis and postdialysis. According to the study of BAEP in another group of 10 uremic patients before and after a single hemodialysis, the absolute latency of wave IV and the I-III interpeak latency were reduced in the postdialysis compared with predialysis but there is no statistical signigicance. The above findings suggest that there are some peripheral or central nervous system dysfunction in chronic renal failure and these dysfunctions might be improved by regular hemodialysis and/or a single hemodialysis. Therefore we suggest that SSEP and BAEP are useful tests for early diagnosis of central and peripheral nervous dysfunction in chronic renal failure and these tests might be useful in evaIuation of the effect of hemodialysis.