Sural nerve sensory response in diabetic distal symmetrical polyneuropathy

The sural sensory nerve action potential (SNAP) amplitude is a measure of the number of axons. We tested the hypothesis that sural SNAP amplitude can be used as a marker in screening, severity evaluation, and follow‐up of diabetic distal symmetrical polyneuropathy (DSPN). Methods Patients with type 2 diabetes underwent nerve conduction studies and were followed for 6 years. Composite amplitude scores (CASs) were determined to evaluate DSPN severity. Results Sural SNAP amplitudes were negatively correlated with CAS ( r = −.790, P  < .0001), and changes in sural SNAP amplitudes were negatively correlated with those of CAS after controlling for follow‐up duration ( r = −.531, P = .028). Discussion When a patient's baseline sural SNAP amplitude is above zero, it can be used as one measure of DSPN in screening, severity evaluation, and follow‐up. However, if the patient's sural SNAP value is zero, CAS can be used as a follow‐up measure.