Electrodiagnostic reference data for motor nerve conduction studies in Saudi Arabia

OBJECTIVES: To determine nerve conduction studies (NCS) reference data for motor nerves and F-waves in the upper and lower limbs of healthy subjects in Saudi Arabia. METHODS: This is a cross-sectional study conducted between May 2015 and June 2019. Healthy subjects without neurological or systemic diseases were recruited. Motor NCS were performed following a standard protocol. Pearson correlations were employed between NCS parameters and age, gender, height, weight, and body mass index. Reference data were generated using the percentile method. RESULTS: A total of 127 subjects were recruited for the upper limb studies and 137 for the lower limb studies. Quantile regression models were generated to estimate compound muscle action potential amplitude (adjusted for age), as well as F-wave minimal latency (adjusted for height). The estimated reference limits of distal motor latency (ms) and conduction velocity (m/s) for the different nerves were, respectively, 3.7 and 50 for the median nerve, 3.3 and 50 for the ulnar nerve, 5.8 and 40 for the tibial nerve, and 5.0 and 40 for the fibular nerve. CONCLUSION: The reference data for motor NCS parameters and F-wave minimal latency are generally comparable with those of Western countries. However, minimal differences were observed. The underrepresentation of the older age group warrants future studies.