ABSTRACT
Objective To investigate the value of nerve conduction studies (NCSs),F wave analysis,somatosensory evoked potential (SEP) and skin sympathetic response (SSR) in the early diagnosis of diabetic peripheral neuropathy (DPN).Methods A total of 110 patients with diabetes mellitus were recruited as the diabetic group and another 50 well-matched healthy volunteers as the normal controls.Sensory and motor NCSs of the median,ulnar,posterior tibial and common peroneal nerves were performed.F waves were recorded from the median and posterior tibial nerves.SEPs elicited by stimulation to nerves of both the upper and lower limbs as well as SSRs were measured,all in both the diabetic group and the normal controls.Results The total rate of nerve conduction abnormality was 74.5％ in the diabetic group,with sensory nerve conduction abnormalities more frequent and more severe among motor nerves in the extremities.The total rate of F wave abnormalities was 57.3％ in the diabetic group.The rate in patients with normal distal motor conduction in their median and posterior tibial nerves was 50.7％.The total SEP abnormality rate was 70.0％ with regard to the proximal peripheral nerve potentials in the diabetic group,but there was no obvious abnormality of the supraclavicular electrical potential in the upper limbs for those with normal sensory nerve conduction in the median nerve.The rate of occurrence of abnormality in the gluteus point potential in the lower limbs of those with normal posterior tibial sensory conduction was 62.5％.The total rate of SSR abnormalities was 80.0％ in the diabetic group but 72％ among those with normal nerve conduction in their extremities.Combining the NCS,SSR,SEP and F wave results,the total abnormality rate was 90.9％ in the diabetic group,which was much higher than with any single test used alone.Conclusion NCS is essential for diagnosing DPN.Early diagnosis of subclinical diabetic neuropathy will be significantly enhanced when nerve conduction,SSRs,SEPs and F waves are tested together.
