F-wave studies in diabetes mellitus: A comparison between pre-symptomatic and symptomatic patients with distal sensory polyneuropathy

Diabetic patients show a high incidence of subclinical F-wave abnormalities including prolonged F-mean latency and early reduction in F-persistence, with further prolongation in F-mean, minimum and maximum latencies after symptoms appear without significant changes in persistence or chronodispersion. F-wave parameters were significantly correlated with positive sensory symptoms, abnormalities on neurological examination, diabetes duration and glycaemic control.