Role of minimal F-wave latency in the electrodiagnosis of polyneuropathy

Background and objective: Polyneuropathy is a debilitating condition that causes damage to more than two peripheral nerves in the body. The objective of this research was to detect the role of minimal F-wave latency as compared with other nerve conduction parameters for the electro-diagnosis of polyneuropathies. Methods: In this descriptive, prospective cross-sectional study, 80 consecutive patients with clinical diagnosis of polyneuropathy (both acute and chronic) between July and December 2023, presenting to the Neurology Department at King Edward Medical University were enrolled. Patients with clinical diagnosis of cervical/lumbar radiculopathies, plexopathies, compressive myelopathy , neuromuscular junction diseases, motor neuron disorders, or localized neuropathies were excluded from this research. NCS and EMG were carried out using conventional procedure. The results were recorded in the predesigned pro forma along with the history and demographic information. Statistical software SPSS 25.0 was used for the analysis of the recorded data. Results: F-wave abnormality was detected in 57 (71.3%) for median nerve, 57 (71.3%) for ulnar nerve, 79 (98.7%) for tibial nerve and in 79 (98.7%) patients for peroneal nerve. Nerve-specific motor nerve conduction study (MNCS) abnormality was found in 47 (58.8%) for median nerve, 43/80 (53.8%) for ulnar nerve, 59 (73.7%) for tibial nerve and in 57(71.3%) patients for peroneal nerve. Nerve-specific sensory nerve conduction study (SNCS) abnormality was present in 43 (53.3%) for median nerve, 43 (53.3%) for ulnar nerve, 50 (62.5%) for sural nerve, and in 49 (61.3%) patients for superficial peroneal nerve. Overall rate of abnormality was 85% for F-wave minimal latencies in comparison with 64% for MNCS and 56% for SNCS. Conclusion: Minimal F-wave latency can be an effective diagnostic parameter for detection of polyneuropathy. This can facilitate in early detection and management of polyneuropathy.