Reference values of upper extremity nerve conduction studies in a Colombian population

Objective: To establish appropriate reference values of upper extremity nerve conduction studies (NCS) at the Del Valle University Hospital, from Colombia. Methods: Two hundred and twenty-two (N = 222) healthy volunteers were recruited. Latencies, amplitudes and conduction velocities from the Median, Ulnar, and Radial nerves were performed following recommendations from Buschbacher and Prahlow. Then, according to the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) task force for reference value establishment, analyses of variance were run where each electrophysiological parameter from every nerve tested was used as dependent variable, to define which characteristics have to be kept for the model. Percentiles 3 and 97 from each of the parameters were derived. Finally, a multivariate quantile regression analysis model was tested. Results: Sensory percentiles were 2.8–3.5 ms, 18.9–120.8 μV, and 40.0–50.0 m/s for the Median, 2.1–2.9 ms, 10.4–106.9 μV, and 41.0–58.0 m/s for the Ulnar, while 2.6–3.5 ms, 11.3–69.9 μV, and 39.0–54.0 m/s for the Radial nerve. The same parameters for motor function were 2.8–3.9 ms, 4.6–15.0 mV, and 49.0–68.0 m/s for the Median, while 2.3–3.5 ms, 3.9–11.5 mV and 51.0–70 m/s for the Ulnar nerve. Conclusions: Values of latency, amplitude, and conduction velocity of sensory and motor functions from upper extremity nerves among Colombians are similar to equal parameters, obtained by comparable studies of populations alike. Significance: This is the first study to establish reference values for upper extremity NCS carried out following the AANEM recommendations in a South American population.