A Multidimensional Clinical-Functional Model of Cervicogenic Headache: Neck Disability, Pain Topography, and Treatment Response in a Multicentre Cohort

Technical Summary: A Multidimensional Clinical-Functional Model of Cervicogenic Headache

Problem Statement
Cervicogenic headache (CGH) presents a significant diagnostic challenge due to the clinical overlap between cervical symptoms, imaging abnormalities, and migraine-like features. Current diagnostic frameworks often rely heavily on cervical imaging or single clinical markers, yet these approaches frequently fail to distinguish CGH from primary headache disorders like migraine. The clinical phenotype of CGH remains incompletely defined, creating a "grey zone" where pain topography, neck-related disability, cervical provocation, and treatment response must be interpreted collectively. There is a need to determine whether functional measures (such as neck disability) and multidimensional clinical profiles offer superior diagnostic and prognostic value compared to structural imaging findings alone.

Methodology
This study employed a multicentre, observational, cross-sectional design involving 660 patients diagnosed with ICHD-3-based cervicogenic headache across 15 neurology and headache clinics in Turkey between 2023 and 2025.

• Data Collection: Researchers collected demographic data, headache burden metrics (attack severity, frequency, duration), cervical clinical features (Neck Disability Index [NDI], pain radiation, provocation signs), cervical imaging findings (straightening, radiculopathy, clinically relevant abnormalities), migrainous symptom burden (a 0–7 score based on nausea, photophobia, etc.), lifestyle factors, and treatment responses.
• Phenotyping: Patients were classified into pain topography phenotypes: "cervicogenic-dominant" (occipital/craniocervical pain), "migraine-like anterior" (frontal/periorbital pain), and "mixed."
• Statistical Analysis: The study utilized Spearman's rank correlation, multivariable regression models to identify independent predictors of headache attack severity, and exploratory mediation analyses to test if NDI mediated the relationship between cervical structural pathology and headache severity. Block-response analyses were restricted to the subset of patients (n=247) who underwent cervical structure or nerve blocks to avoid misclassifying untreated patients as non-responders.

Key Contributions

1. Shift from Imaging-Centric to Functional-Centric Models: The study provides empirical evidence that cervical imaging abnormalities (straightening, radiculopathy) do not independently predict headache severity when functional and clinical variables are accounted for.
2. Identification of NDI as the Primary Predictor: The Neck Disability Index (NDI) was identified as the strongest independent predictor of headache attack severity, monthly frequency, and attack duration.
3. Mediation of Structural Pathology: The study demonstrates that the association between cervical structural pathologies (radiculopathy, straightening) and headache severity is largely mediated by neck-related functional impairment (NDI), suggesting that structural findings become clinically meaningful primarily when they translate into disability.
4. Phenotypic Differentiation: The research delineates distinct clinical profiles based on pain topography. Occipital/craniocervical pain clusters with higher disability and better response to cervical blocks, whereas frontal/periorbital pain clusters with migrainous accompaniments.
5. Treatment Response Predictors: The study distinguishes between markers of disease burden (NDI) and markers of treatment response. While NDI predicts severity, the dominant pain phenotype (specifically cervicogenic-dominant) is a stronger predictor of positive response to cervical nerve or structure blocks.

Results

• Cohort Characteristics: The median age was 44 years (72.9% female). Median monthly headache frequency was 8 days, and median attack severity was 7/10. 94.8% reported neck-to-head radiating pain, and 70.6% had clinically relevant cervical imaging abnormalities.
• Imaging vs. Function: In unadjusted analyses, cervical straightening, radiculopathy, and imaging abnormalities correlated with higher headache burden. However, in multivariable regression models, these structural variables lost significance. Conversely, NDI remained a robust independent predictor (B=0.682, p<0.001).
• Mediation Analysis: Exploratory mediation models indicated that NDI mediated approximately 80% of the effect of cervical radiculopathy on attack severity and 61% of the effect of cervical straightening. The direct effects of these structural findings on severity were not statistically significant.
• Phenotype and Treatment:
  • Cervicogenic-dominant phenotype: Associated with higher NDI, greater attack severity, and a 93% response rate to cervical blocks.
  • Migraine-like anterior phenotype: Associated with lower NDI and a 53% response rate to blocks.
  • Migrainous Symptoms: Migrainous symptom burden independently contributed to attack severity but did not exclude a cervical origin.
• Lifestyle Factors: Daily screen exposure showed an inverse association with some burden markers, potentially reflecting behavioral restriction due to pain rather than a protective effect. Regular walking was associated with lower NDI and better post-treatment outcomes.

Significance and Claims
The paper claims to move the understanding of cervicogenic headache beyond an imaging-based construct toward a multidimensional clinical-functional model. It asserts that:

• Diagnostic Value: Diagnosis should rely on the convergence of neck disability, pain radiation, posterior pain topography, cervical provocation findings, and treatment response rather than imaging alone.
• Clinical Utility: NDI serves as a critical marker for headache burden, while pain topography (posterior vs. anterior) is more predictive of response to interventional procedures like nerve blocks.
• Differentiation: The presence of migrainous symptoms does not preclude a cervical diagnosis; rather, the study supports a model where posterior pain and provocation signs define a cervicogenic-dominant pattern, while anterior pain and migrainous features define an overlap phenotype.
• Limitations: The authors explicitly note that the cross-sectional design precludes causal inference, and mediation findings should be viewed as statistical indirect-pathway models. They also acknowledge that diagnostic practices and imaging interpretations varied across the 15 centres and that the study lacked a matched migraine control group, limiting definitive differential diagnostic claims outside the CGH cohort.

In conclusion, the study proposes that integrating functional impairment (NDI), pain topography, and provocation signs offers a more clinically applicable framework for differential diagnosis and treatment selection in cervicogenic headache than structural imaging alone.