Measurement of cross-sectional area of cervical roots and brachial plexus trunks.

INTRODUCTION: The aim of this study was to determine normal reference values for cross-sectional area (CSA) and the correlation between demographic factors and CSA in the cervical roots and brachial plexus trunks using ultrasonography.

METHODS: Ninety-five age-matched healthy individuals were studied. Ultrasonographic tests were performed via nerve tracing from the cervical root to the brachial plexus trunk. The CSA of each nerve was measured in the C5-8 ventral roots and brachial plexus (trunk level).

RESULTS: Normal values of each cervical root were: C5, 5.66 ± 1.02 mm(2); C6, 8.98 ± 1.65 mm(2); C7, 10.43 ± 1.86 mm(2); and C8, 10.76 ± 2.02 mm(2). Values for the brachial plexus were: upper trunk, 16.70 ± 2.88 mm(2); middle trunk, 14.01 ± 2.70 mm(2); and lower trunk, 13.75 ± 2.57 mm(2). The side-to-side discrepancy was 11.91 ± 11.11%. Body mass index (BMI) and height correlated frequently with nerve CSA.

CONCLUSIONS: These reference values may be helpful in investigating pathologies involving the cervical area.