Evaluation of sural nerve automated nerve conduction study in the diagnosis of peripheral neuropathy in patients with type 2 diabetes mellitus.

INTRODUCTION New tests for improved diagnosis of diabetic peripheral neuropathy (DPN) are useful. MATERIAL AND METHODS We evaluated the utility of automated nerve conduction study (NCS) of the sural nerve with a new portable device for the diagnosis of DPN in patients with type 2 diabetes mellitus (T2DM). This study included 114 T2DM patients (58 men) with mean age 64.60 ±8.61 years. Exclusion criteria were B12 depletion, alcohol abuse and other causes of peripheral neuropathy. The reference method was the Neuropathy Disability Score (NDS) with a threshold NDS ≥ 3. Sural nerve automated NCS was carried out with the portable NC-stat DPNCheck device. Sensory nerve conduction velocity and sensory nerve action potential amplitude were measured bilaterally. Automated NCS was considered abnormal when ≥ 1 of the two aforementioned neurophysiological parameters was abnormal in at least one leg. RESULTS Examination with NC-stat DPNCheck exhibited 90.48% sensitivity, 86.11% specificity, 79.17% positive predictive value (PPV) and 93.94% negative predictive value (NPV). The positive likelihood ratio (LR+) was 6.51 and the negative likelihood ratio (LR-) was 0.11. CONCLUSIONS Sural nerve automated NCS with the NC-stat DPNCheck device exhibits high sensitivity and specificity for the diagnosis of DPN in T2DM.