Somatosensory Profiling in Primary Headache Disorders: Examining Interictal, Diagnostic and Headache Frequency related Alterations

Migraine and tension-type headache (TTH) are characterized by altered somatosensory processing ictally (during headache). It remains unclear whether such alterations persist interictally (headache-free phase) and whether migraine and TTH share similar or distinct somatosensory profiles. This cross-sectional study examined interictal somatosensory processing using quantitative sensory testing (QST) in primary headache, diagnosis-specific differences between migraine and TTH, and influence of headache frequency. Sixty-five patients with primary headache (32 migraine, 33 TTH) were studied, alongside 51 pain-free controls. Static QST included thermal and pressure detection and pain thresholds at trigeminal (sensitive head area), extra-trigeminal (thenar eminence) and pain-free regions (tibialis anterior muscle), and dynamic QST included tonic temporal summation of pain and conditioned pain modulation. Thermal and pressure detection and pain thresholds did not differ between primary headache and controls, except for higher cold pain thresholds at the head in primary headache (padj=.042). Subdivided by diagnosis, the migraine group was more sensitive to non-noxious and noxious thermal stimuli at trigeminal and extra-trigeminal regions than the TTH or control group, while the TTH group was less sensitive to non-noxious and noxious thermal, but more sensitive to noxious pressure stimuli at the trigeminal region than controls (padj<.036). Dynamic QST did not differ between groups. Primary headaches exhibit distinct interictal somatosensory profiles, independent of headache frequency. Migraine is characterized by thermal hyperesthesia and hyperalgesia, whereas TTH presents with thermal hypoesthesia and mechanical hyperalgesia. These modality-specific profiles suggest mechanistically distinct patterns of peripheral sensitization, while both disorders may share a component of human assumed central sensitization. PERSPECTIVE: Distinct interictal somatosensory profiles in migraine and tension-type headache may inform future studies evaluating mechanism-based, individualized care. These findings provide a rationale for investigating whether centrally directed (top-down) and peripherally targeted, disorder-specific (bottom-up) non-pharmacological strategies can be integrated to optimize treatment effectiveness and address both shared and distinct pain mechanisms.