Feasibility of Ultrasound Measurements of Peripheral Sensory Nerves in Head and Neck Area in Healthy Subjects

BACKGROUND: Current diagnostic methods for nerve compression headaches consist of diagnostic nerve blocks. A less-invasive method that can possibly aid in the diagnosis is ultrasound, by measuring the cross-sectional area (CSA) of the affected nerve. However, this technique has not been validated, and articles evaluating CSA measurements in the asymptomatic population are missing in the current literature. Therefore, the aim of this study was to determine the feasibility of ultrasound measurements of peripheral extracranial nerves in the head and neck area in asymptomatic individuals. METHODS: The sensory nerves of the head and neck in healthy individuals were imaged by ultrasound. The CSA was measured at anatomical determined measurement sites for each nerve. To determine the feasibility of ultrasound measurements, the interrater reliability and the intrarater reliability were determined. RESULTS: In total, 60 healthy volunteers were included. We were able to image the nerves at nine of 11 measurement sites. The mean CSA of the frontal nerves ranged between 0.80 ± 0.42 mm(2) and 1.20 ± 0.43 mm(2), the mean CSA of the occipital nerves ranged between 2.90 ± 2.73 mm(2) and 3.40 ± 1.91 mm(2), and the mean CSA of the temporal nerves ranged between 0.92 ± 0.26 mm(2) and 1.40 ± 1.11 mm(2). The intrarater and interrater reliability of the CSA measurements was good (ICC: 0.75–0.78). CONCLUSIONS: Ultrasound is a feasible method to evaluate CSA measurements of peripheral extracranial nerves in the head and neck area. Further research should be done to evaluate the use of ultrasound as a diagnostic tool for nerve compression headache.