Diagnostic Utility of Medial Dorsal Cutaneous Sensory Response and the Medial Dorsal Cutaneous-To-Radial Amplitude Ratio (MDRAR) in Diabetic Polyneuropathy

PURPOSE: This study aimed to assess the diagnostic utility of the medial dorsal cutaneous (MDC) nerve and the medial dorsal cutaneous-to-radial amplitude ratio (MDRAR) in diabetic polyneuropathy (DP). METHODS: Seventy-four patients clinically diagnosed with DP and 40 healthy controls underwent nerve conduction studies (NCS), including sural, radial, medial plantar (MP), and MDC sensory recordings. Most patients had recent-onset, mild-to-moderate DP. Sural-to-radial amplitude ratio (SRAR), medial plantar-to-radial amplitude ratio (MPRAR), and MDRAR were calculated. Minimal tibial F-wave latencies were height-corrected, and sural amplitudes were age-corrected. Diagnostic cut-off values were established by ROC analysis. Values below the cut-off, as well as absent responses, were classified as abnormal, and sensitivity and specificity were calculated. RESULTS: A sural SNAP