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

Abstract

Objective: To derive a normative database for nerve conduction values of the lateral antebrachial cutaneous nerve (LACN) using a large and varied subject population.

Design: Descriptive study.

Setting: Private office or university-based clinic.

Participants: Volunteers (n = 213), recruited through advertisements, who met inclusion criteria.

Main outcome measures: Onset latency, peak latency, baseline-to-peak amplitude, peak-to-peak amplitude, area, rise time, duration, side-to-side differences, 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+/-0.2 ms. The 95th and 97th percentile values for onset latency were 2 and 2.1 ms, respectively. Mean peak latency was 2.2+/-0.2 ms. Both the 95th and 97th percentile values for peak latency were 2.5 ms. Mean onset to peak amplitude was 18+/-10 microV. The 5th and 3rd percentile values for onset to peak amplitude were 6 and 5 microV, respectively. Mean peak-to-peak amplitude was 22+/-15 microV. The 5th and 3rd percentile values for peak-to-peak amplitude were 7 and 6 microV, respectively. Mean area was 11+/-7nV-s, mean rise time was 0.5+/-0.1 ms, and mean duration was 1.1+/-0.2 ms. Mean side-to-side difference was 0.1+/-0.2 ms for onset latency, 0.1+/-0.2 ms for peak latency, 1+/-12 microV for onset to peak amplitude, and 0+/-17 microV for peak-to-peak amplitude. Increasing age and BMI were associated with lower mean amplitudes, but did not affect the lower limits of normal.

Conclusion: These normative values will be useful in electrodiagnostic study of the LACN.