The Usefulness of Sympathetic Skin Response in Patients with Chronic Renal Failure

OBJECTIVE: The sympathetic skin response (SSR) was measured in patients with chronic renal failure (CRF) for diagnosis of uremic polyneuropathy and its correlations with nerve conduction study (NCS) and clinical autonomic symptoms were investigated. METHOD: The SSR was measured in 15 patients with CRF on regular hemodialysis, aged 26 to 67 years. With median nerve stimulation at the wrist using the extremity without arteriovenous fistula, the SSR was recorded from both palm and sole simultaneously. The responses were interpreted as normal (presence) or abnormal (absence). Routine nerve conduction study was also performed in the same extremities and clinical autonomic symptoms were investigated. RESULTS: Nine of fifteen patients (60.0%) had symptoms suggestive of autonomic dysfunction: the most frequent findings were orthostatic dizziness and sweating problem. The SSR was absent in four of fifteen patients (26.7%). There is no significant relationship between SSR and autonomic symptoms (P>0.05). The nerve conduction study was abnormal in eight of fifteen patients (53.3%), and the SSR was absent in two of seven patients with normal NCS. There is no significant relationship between NCS and SSR (P>0.05). CONCLUSION: Although the proportion of abnormal SSR was small, it may be a valuable method in the assessment of uremic polyneuropathy in conjunction with routine nerve conduction study in CRF patients.

Somatosensory Evoked Potential Study in Patients with Polyneuropathy with Chronic Renal Failure

Polyneuropathy is a common complication of chronic renal failure and usually remains stable or improves with hemodialysis. The purpose of this study was to investigate the usefulness of somatosensory evoked potential(SEP) study for the evaluation of polyneuropathy in chronic renal failure(CRF) patients who were on hemodialysis. The clinical findings, conventional nerve conduction study and SEP study were analyzed and compared in 30 patients with chronic renal failure before and after hemodialysis. Abnormal electrophysiological findings were shown in 25 patients(83.3%) of whom 8 patients showed abnormal somatosensory evoked potential(SEP) study only. Therefore it would be useful to perform both the somatosensory evoked potential(SEP) study and conventional nerve conduction study(NCS) for the evaluation of polyneuropathy. Improvement of somatosensory evoked potential(SEP) finding is correlated well with that of clinical symptoms after hemodialysis. Therefore, somatosensory evoked potential(SEP) study can be used to monitor with progression of polyneuropathy in patients with chronic renal failure(CRF) who were on hemodialysis.