The diagnostic sensitivity of different F wave parameters.

OBJECTIVE To examine the relative diagnostic sensitivity of various F wave parameters. METHODS Normal values for minimum, mean, and maximum F wave latency, chronodispersion, and persistence in the four major motor nerves were established and systematically applied to at least four separate categories of patients (radiculopathies, polyneuropathies, mononeuropathies, and others). F Waves were studied both isolated and in comparison with other motor nerve conduction parameters. RESULTS F Chronodispersion was the most often abnormal parameter, particularly in lumbosacral radiculopathies. Minimum F wave latency was more useful in polyneuropathies. Compared with minimum F wave latency, F chronodispersion was able to identify most additional cases. CONCLUSIONS F Wave studies should include minimum F wave latency and chronodispersion.