Sural nerve sensory response in diabetic distal symmetrical polyneuropathy

Introduction: 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.