F‐wave latencies in patients with diabetes mellitus

Abstract

To evaluate the sensitivity of electrophysiologic assessments, we compared F-waves and motor and sensory nerve conduction studies (MNCS and SNCS) in patients with diabetes mellitus (DM). We tested median, ulnar, tibial, and fibular nerves in 132 DM patients divided into those with and without clinical evidence of polyneuropathy. Of 64 asymptomatic patients, 2 (3%) had MNCS or SNCS abnormalities, both of whom had F-wave changes, whereas 21 (33%) had only delayed F-waves, for a combined yield of 23 (36%). The corresponding values for 68 symptomatic patients consisted of 43 (63%), 14 (21%), and 57 (84%). In both groups, F-wave latency had a higher (P<0.05) frequency of abnormality than MNCS in all nerves. F-wave study also surpassed SNCS in lower limb nerves. F-waves of the tibial and fibular nerves are the most sensitive measure to detect subclinical or overt diabetic polyneuropathy. Muscle Nerve 49: 804-808, 2014.