Objectives: Dorsal sural nerve conduction studies (NCS) may increase the sensitivity for the diagnosis of polyneuropathy, but clinical use is limited by a lack of reliable normative reference values in all age-groups. The aim of our study was to develop reference values for the dorsal sural nerve, based on a large multicenter cohort of healthy subjects.
Methods: Bilateral antidromic NCS were performed using standard surface electrodes in 229 healthy subjects (aged 21-80 years; median: 54 years). We assessed the normality of data distribution for amplitudes and conduction velocity (CV) and for their logarithmic (ln) transformation. The effects of age and height were determined using linear regression analysis.
Results: Sensory potentials were present in all subjects. Logarithmically transformed data were normally distributed. Age2 and height were most significantly associated with amplitude, and age and height with CV, respectively. There was no significant side-difference. Mean amplitudes (right and left) were 4.8 and 4.9 μV and mean CV 46.7 and 46.9 m/s. Reference limits were e (3.712515 - 0.0000956 * age2 - 0.0115883 * height ± 1.96 * 0.51137) for amplitude and e (4.354374 - 0.0021081 * age - 0.0023354 * height ± 1.96 * 0.11161) for CV.
Conclusions: Dorsal sural nerve NCS are robust and have well defined normative limits.
Significance: The findings provide a basis for more sensitive NCS in clinical practice and future studies of the diagnostic accuracy of NCS in polyneuropathy.