Widespread Pressure Pain Sensitivity over Nerve Trunk Areas in Women with Frequent Episodic Tension-Type Headache as a Sign of Central Sensitization.

OBJECTIVE: Previous studies reported the presence of widespread pressure pain sensitivity in patients with tension-type headache. However, most of the studies assessed pressure pain sensitivity over muscle tissue. Our aim was to investigate the difference in pressure pain sensitivity over musculoskeletal and nerve symptomatic and distant areas between women with frequent episodic tension-type headache (FETTH) and healthy subjects.

METHODS: Thirty-two women with FETTH and 32 matched healthy women participated. Pressure pain threshold (PPT) was bilaterally assessed over several nerve trunks (greater occipital, median, radial, ulnar, common peroneal, tibialis posterior) and musculoskeletal structures (temporalis muscle, C5/C6 joint, tibialis anterior) by an assessor blinded to the subject's condition. A four-week headache diary was used to collect the intensity, frequency, and duration of headache. The Hospital Anxiety and Depression Scale was used to determine anxiety and depressive levels.

RESULTS: Analysis of covariance found lower widespread and bilateral PPTs over all nerve trunks and musculoskeletal structures in women with FETTH pain (P < 0.001). No significant effect of anxiety and depressive levels on PPTs was found (all P > 0.222). PPT over the temporalis muscle was significantly negatively correlated with headache intensity.

CONCLUSIONS: This study found widespread pressure pain hypersensitivity over both nerve trunks and musculoskeletal structures in women with FETTH, suggesting that the presence of central altered nociceptive processing is not just restricted to musculoskeletal areas, for example, muscles, but also pain evoked from directly provoking the nerve trunks by pressure. It is also possible that nerve tissue treatment could lead to a decrease in central sensitization and headache features.