F-wave minimal latency, mean latency, persistence, chronodispersion and tacheodispersion were studied to evaluate the diagnostic sensitivity of various F-wave parameters in the ulnar and peroneal nerves in subjects with diabetic polyneuropathy. The minimal & mean latencies were corrected by height and age, 35 diabetic patients were divided into two groups according to the conventional electrophysiologic study: no evidence of polyneuropathy (group 1) and polyneuropathy (group 2).

F mean latency of ulnar nerve and F minimal latency, mean latency of peroneal nerve showed the highest sensitivity. The F conduction velocity and tacheodispersion showed gradual decline from control to group 2 in ulnar & peroneal nerves.

Therefore height and age corrected F mean and minimal latency or F tacheodispersion are sensitive methods in early diagnosis of diabetic neuropathy.