We aimed to investigate whether coexistent self-reported neck pain influences cephalic and extracephalic pain sensitivity in individuals with migraine and tension-type headache (TTH) in relation to diagnosis and headache frequency. A population of 496 individuals completed a headache interview based on ICHD criteria, providing data collected by self-administered questionnaires, assessments of pericranial total tenderness score (TTS) and pressure pain thresholds (PPT). Stimulus-response (SR) functions for pressure vs. pain were recorded. Presence of neck pain in the past year was assessed by the self-administered questionnaire. We categorized participants by primary headache type. We also categorized participants into 3 groups by headache frequency: chronic (≥15) or episodic (<15 headache days/month) headache and controls. TTS, PPTs and the area under the SR curve were compared between subgroups using Generalized Linear Models with pairwise comparisons controlling for age and sex. Individuals with chronic followed by episodic headache had higher TTS than controls (overall p≤0.001). The difference between chronic and episodic headache subgroups was significant in the group with neck pain (p≤0.001) but not in the group without neck pain. In individuals with neck pain, mean TTS was higher in coexistent headache (migraine and TTH), 23.2±10.7, and pure TTH, 17.8±10.3, compared to pure migraine, 15.9±10.9 and no headache 11.0±8.3 (overall p<0.001). Temporal and finger PPTs did not statistically differ among the chronic headache, the episodic headache and controls in individuals with and without neck pain. Temporalis and trapezius SR-functions showed that tenderness was increased in individuals with chronic headache to higher degree than in those with episodic headache, and more so in those with neck pain. Coexistent neck pain is associated with greater pericranial tenderness in individuals with chronic headache and to a lesser degree in those with episodic headache. Sensitization may be a substrate or consequence of neck pain and primary headache, but a longitudinal study would be needed for further clarification.
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