Prolongation of F-wave minimal latency: a sensitive predictor of polyneuropathy

Int J Neurosci. 2016 Jun;126(6):520-525. doi: 10.3109/00207454.2015.1040492. Epub 2015 Aug 5.

Abstract

Introduction: To evaluate the sensitivity of F-wave minimal latencies, we compared F-waves with motor and sensory nerve conduction studies (MNCS and SNCS) in patients with peripheral neuropathy.

Methods: A retrospective chart review conducted in 484 patients confirmed the clinical evidence of a polyneuropathy, and studies of F-wave minimal latencies as well as MNCS and SNCS in each patient.

Results: Overall rate of abnormality reached 469/484 (96.9%) for F-wave minimal latencies as compared to 374/484 (77%) for nerve conduction studies ( p < 0.0001). Nerve-specific abnormalities of F-waves showed 290/354 (82%), 140/171 (82%), 367/398 (92%) and 357/376 (95%) for median, ulnar, peroneal and tibial nerves, respectively. Corresponding values for MNCS consisted of 108/354 (31%), 29/171 (17%), 258/398 (65%) and 189/376 (50%) (all p < 0.0001). In contrast, SNCS revealed abnormalities in 120/333 (36%), 60/159 (38%) and 266/474 (56%) of median, ulnar and sural nerves.

Conclusion: F-wave minimal latencies serve as the best predictor of polyneuropathy followed by SNCS and then MNCS.

Keywords: F-wave minimal latency; height-latency nomogram; nerve conduction studies; peripheral neuropathy; polyneuropathy.