Diagnostic Criteria and Outcome Measures for Cervicogenic Headache in Randomised Controlled Trials: An Updated Systematised Review With Age-Based Subgroup Analysis.

Abstract

The overlap in signs and symptoms of CGH with other forms of headaches greatly complicates the process of an appropriate diagnosis, resulting in inaccurate diagnoses in approximately 50% of CGH cases. To identify and categorise the diagnostic criteria employed for CGH in randomised controlled trials published from 1997 to 2023 and to descriptively examine the outcome measures and physical examination methods employed, with reference to different age group applications. The literature search for this systematised review was conducted from six different electronic databases using a specific search strategy and citation tracking. In total, 498 articles were screened by two reviewers based on preset inclusion and exclusion criteria using the PICO format, and disagreements were resolved by consensus; 59 RCTs were included in the review. Data were extracted on study characteristics, diagnostic criteria, outcome measures, and assessment methods. Due to methodological and clinical heterogeneity, a narrative qualitative synthesis was performed. Fifty-nine RCTs involving 3454 participants were included. The mean age of participants ranged from 11.6 ± 2.3 years in paediatric samples to 54.5 ± 7.9 years in older adults. Cervicogenic Headache International Study Group (CHISG/Sjaastad) criteria were most commonly used (49%), followed by International Headache Society (IHS) criteria (39%) and International Classification of Headache Disorders, 2nd edition (ICHD-2) criteria (3%). The commonly employed outcome measures included pain intensity (VAS/NPRS), headache frequency and duration, cervical range of motion, and disability indices (e.g., NDI). Subgroup analysis revealed a lack of standardised diagnostic criteria in paediatric and adolescent studies. The included studies identified inconsistency in diagnostic criteria and outcome measures, particularly in younger populations. Despite the availability of established frameworks, their variable applications in the studies limit their comparability and clinical translation. This review highlights the urgent need for standardised diagnostic criteria for specific age and outcome coresets to strengthen future CGH research and clinical practice.