Effects of Dry Needling of the Obliquus Capitis Inferior in Patients with Cervicogenic Headache and Upper Cervical Dysfunction: An Exploratory Randomized Sham-Controlled Trial.

Background/Objectives: Cervicogenic headache (CeH) is linked to upper cervical dysfunctions. The obliquus capitis inferior (OCI) muscle may contribute to restricted cervical rotation at the C1-C2 level, altered proprioception and pain. Dry needling (DN) of the OCI is hypothesized to target these dysfunctions. The aim of this study was to investigate whether a single intervention combining DN and manual therapy (MT) compared to sham needling (SN) and MT, improves C1-C2 rotation, functional, headache-related and psychological outcomes in a subgroup of CeH patients with a positive cervical flexion-rotation test (CFRT). Methods: Thirty-four participants were randomly assigned to (1) DN or (2) SN. The primary outcome was C1-C2 rotational mobility. Secondary outcomes included headache-related parameters (frequency, intensity, duration and perceived effect), functional parameters (cervical mobility, pain pressure thresholds, motor control and proprioception) and psychological parameters (central sensitization, pain catastrophizing, coping strategies and kinesiophobia). Outcomes were re-evaluated at one-week follow-up. Results: Linear mixed-effects models showed a significant and clinically relevant increase of C1-C2 rotation in the DN group compared to the SN group post-intervention (mean difference [MD]: 4.51°; 95% confidence interval [CI]: 1.74; 7.28), which was maintained at the 1-week follow-up (MD: 5.44°; 95% CI: 2.55; 8.33). No clinically relevant changes were observed in other secondary outcome measures. Conclusions: Targeting the OCI may be of added value in restoring atlanto-axial dysfunction. While short-term mobility gains were observed, a single intervention appears insufficient as a stand-alone treatment to impact functional or psychological outcomes. Future research involving larger samples should examine DN effects as part of a multimodal approach with long-term follow-up.