The role of blink reflex R1 latency as an electrophysiological marker in diabetic distal symmetrical polyneuropathy

Abstract Objective Studies showed a relatively prolonged blink R1 latency in patients with diabetic distal symmetrical polyneuropathy (DSPN) compared to that without DSPN. We tested the hypothesis that blink R1 latency would provide a diagnostic alternative to nerve conduction studies (NCS) in DSPN and act as a marker of the severity of NCS abnormalities in DSPN. Method A total of 109 patients with type 2 diabetes underwent blink reflex studies and NCS. We used the composite amplitude scores of nerve conductions (CAS), which consisted of motor (tibial, peroneal and ulnar) and sensory (sural and ulnar) amplitudes for estimating the severity of NCS. Results Patients with DSPN had longer blink R1, R2, and contralateral R2 latencies (P  Conclusion Blink R1 latency may be valuable in auxiliary diagnosis and in determining the severity of NCS abnormalities in DSPN. Significance Blink R1 latency can be added as a supplemental marker of severity of NCS in DSPN, especially if the patient’s sural amplitudes has a floor effect.