Reliability of Longus Colli Muscle Size Measurement in Healthy Subjects and Patients with Cervicogenic Headache Using Ultrasonography

The deep cervical flexor muscles have a major role in neck stabilization and evidence suggests that these muscles especially longus colli muscle (LCM) becomes dysfunctional in patients suffering from cervicogenic headache. Therefore, measurement of these muscles in healthy subjects and patients may be of great value to understand the stabilization function of the muscles and also to follow the effect of interventions. The aim of this study was to compare the reliability of longus colli muscle size measurement in healthy subjects and patients with cervicogenic headache using ultrasonography. This methodological research was performed on 34 subjects including 13 patients with cervicogenic headache (20-35 years old) with headache over 3 month period and 21 healthy subjects (18-25 years old). Neck LCM size was measured in supine position in two sides at the level of thyroid cartilage ultrasonography. Two images of LCM cross section area (CSA) were taken on the same day with an hour interval to assess the within-day reliability and the third image was taken two days later to determine between-days reliability. Then data were compared using statistical analysis. The mean of the cross section area of the muscle in subjects with cervicogenic headache was 0.77 cm2 in two sides and in healthy subjects were 0.74 cm2 in left side and 0.75 cm2 in right side. Within day and between days reliability in healthy subjects was varied ranging from 0.83 to 0.92. In patient group it was ranged between 0.90-0.98. The results indicated that ultrasonography could be a reliable tool to measure the cross section area of LCM in healthy subjects and patients with cervicogenic headache. Therefore, this non invasive method can be used to follow up the effect of exercise therapy interventions.