Electrodiagnostic reference values for the lateral antebrachial cutaneous nerve: Standardization of a 10-cm distance

Objective: To derive a normative database for nerve conduction values of th e lateral antebrachial cutaneous nerve (LACN) using a large and varied subj ect population. Design: Descriptive study. Setting: Private office or university-based clinic. Participants: Volunteers (n = 213), recruited through advertisements, who m et inclusion criteria. Main Outcome Measures: Onset latency, peak latency, baseline-to-peak amplit ude, peak to-peak amplitude, area, rise time, duration, side-to-side differ ences, and the effects of age, race, sex, height, and body mass index (BMI) were investigated on 213 healthy volunteers between the ages of 19 and 79 years. Results: The mean +/- SD onset latency was 1.7 +/- 0.2ms. The 95th and 97th percentile values for onset latency were 2 and 2.1ms, respectively. Mean p eak latency was 2.2 +/- 0.2ms. Both the 95th and 97th percentile values for peak latency were 2.5ms. Mean onset to peak amplitude was 18 +/- 10 muV. T he 5th and 3rd percentile values for onset to peak amplitude were 6 and 5 m uV, respectively. Mean peak-to-peak amplitude was 22 +/- 15 muV. The 5th an d 3rd percentile values for peak-to-peak amplitude were 7 and 6 muV, respec tively. Mean area was 11 +/- 7nV-s, mean rise time was 0.5 +/- 0.1ms, and m ean duration was 1.1 +/- 0.2ms. Mean side-to-side difference was 0.1 +/- 0. 2ms for onset latency, 0.1 +/- 0.2ms for peak latency, 1 +/- 12 muV for ons et to peak amplitude, and 0 +/- 17 muV for peak-to-peak amplitude. Increasi ng age and BMI were associated with lower mean amplitudes, but did not affe ct the lower limits of normal. Conclusion: These normative values will be useful in electrodiagnostic stud y of the LACN.