Interictal thermal pain hypersensitivity and central sensitization in migraine patients: a case-control study using quantitative sensory testing.

BACKGROUND

Altered pain processing and central sensitization are key mechanisms underlying migraine. Although quantitative sensory testing (QST) objectively assesses sensory thresholds, its clinical implications in migraine patients are unclear. We hypothesized that migraine patients have lower thermal pain thresholds than controls, reflecting sensory hypersensitivity associated with central sensitization–related features.

METHODS

We conducted a single-center case–control study including 130 patients with migraine and 130 sex-matched healthy controls. Thermal QST was performed during headache-free interictal periods using Intercross-220, assessing the heat detection threshold (HDT), cold detection threshold (CDT), thermal sensory limen (TSL), heat pain threshold (HPT), and cold pain threshold (CPT). Symptoms associated with central sensitization were assessed using the Japanese version of the Central Sensitization Inventory (CSI), a self-report questionnaire.

RESULTS

Compared with healthy controls, migraine patients had a significantly lower HPT and higher CPT, indicating hypersensitivity to thermal pain, as well as altered HDTs and CDTs, while the TSL did not differ between groups. The CSI score was significantly correlated with migraine-related disability, interictal burden, ictal allodynia, sleep disturbance, and depressive symptoms. CSI scores were also significantly associated with QST pain-related parameters, whereas other clinical measures were not significantly correlated with sensory thresholds. QST-defined interictal allodynia was more prevalent in migraine patients than in controls (19.2% vs. 8.5%). A CSI score ≥ 40, indicating a high burden of central sensitivity–related symptoms, was observed in 30.8% of migraine patients and 0.8% of healthy controls. In migraine patients, a CSI score ≥ 40 identified QST-defined allodynia with 100% sensitivity and 85.7% specificity.

CONCLUSIONS

Patients with migraine exhibit interictal hypersensitivity to thermal pain. The CSI may serve as a useful patient-reported tool for identifying symptom burden associated with central sensitization-related sensory hypersensitivity in migraine patients.