Objective: To investigate the value of electromyography (EMG) combined with somatosensory evoked potential (SEP) in evaluation of diabetic neurologic complications. 

Methods: One hundred and thirty-five diabetic patients were grouped according to the course of diabetes (< 1 year, 1-10 years, > 10 years), diabetic perilpheral neuropathy (DPN) (yes or no), ischemic stroke (yes or no), and the locus of cerebral stroke (anterior circulation infarction or posterior circulation infarction). The age, glycosylated hemoglobin level, nerve conduction velocity (NCV), SEP, DPN and ischemic stroke were retrospectively analyzed and compared.

Results: Of the 135 diabetic patients, 50 (37.0%) were diagnosed of DPN, 32 (23.7%) with ischemic stroke, 56 (41.5%) with NCV abnormality, 16 (11.9%) with F wave abnormality, and 27 (20.0%) with SEP abnormality (20%). The rate of NCV abnormality, the proportion of DPN and the proportion of ischemic stroke in diabetes course 1-10-year and >10-year groups were significantly higher than those in the diabetes course < 1 year group (P < 0.05). The rate of NCV abnormality (P < 0.01), the rate of F wave abnormality (P < 0.01) and the rate of SEP abnormality (P < 0.01) in patients with DPN symptoms and signs were significantly higher than those in patients without DPN symptoms and signs. The age of diabetic patients with ischemic stroke was older than those without ischemic stroke (P < 0.01), and the course of diabetes was longer (P = 0.01) with a higher rate of SEP abnormality (P = 0.02). Spearman correlation analysis showed that NCV abnormality (r = 0.26, P < 0.01) and ischemic stroke (r = 0.22, P < 0.01) were positively correlated with the course of diabetes; DPN was positively correlated with the course of diabetes (r = 0.21, P < 0.05), age (r = 0.19, P < 0.05), glycosylated hemoglobin level (r = 0.24, P < 0.01), NCV abnormality (r = 0.75, P < 0.01), and F wave abnormality (r = 0.22, P < 0.01); NCV abnormality (r = 0.28, P < 0.01) and F wave abnormality (r = 0.30, P < 0.01) were both positively correlated with glycosylated hemoglobin level; SEP abnormality was positively correlated with F wave abnormality (r = 0.62, P < 0.01), ischemic stroke (r = 0.20, P < 0.05) and the difference in National Institute of Health stroke scale (NIHSS) score before and after hospitalization (duration: 7-14 d) (r = 0.43, P < 0.05). 

Conclusion: EMG is an important method for screening and diagnosing DPN. EMG combined with SEP can screen early DPN, which helps to improve the detection rate of subclinical DPN, and has a certain value in the assessment of central system damage and prognosis of diabetes.