Association of dynamic and widespread mechanical sensitivity in cluster headache

We investigated if dynamic pressure pain sensitivity in the symptomatic area is associated with pressure sensitivity in local and distant pain-free areas in cluster headache (CH). A pressure algometry set consisting of 8 rollers with fixed pressure levels ranging from 500 to 5300 g was used to assess dynamic pressure pain sensitivity in men with episodic CH. Each roller was moved from an anterior-to-posterior direction over the temporalis muscle. The load level of the first painful roller was considered the dynamic pain threshold (DPT). Further, pain elicited during DPT (roller evoked pain) was also assessed. We used a pressure algometer to determine pressure pain thresholds (PPTs) over the temporalis muscle, C5/C6 joint, second metacarpal, and tibialis anterior. Patients were assessed in an asymptomatic (remission) phase, at least 6 months after their last cluster period and without taking pharmacological treatment. Forty men with episodic CH (mean age 42 years) were included. Both outcomes, DPTs (r = 0.781, P < 0.001) and roller-evoked pain (r = 0.586; P < 0.001) were bilaterally correlated. Further, DPT, but not roller-evoked pain, was moderately associated with PPTs measured at the symptomatic (temporalis: r = 0.665, P < 0.001) and distant pain-free (C5-C6 joint: r = 0.389, P = 0.013; second metacarpal: r = 0.551, P < 0.001; and, tibialis anterior: r = 0.308, P = 0.035) points. Dynamic pressure sensitivity in the trigeminal area was correlated to pressure pain sensitivity at both symptomatic and distant pain-free areas in men with CH supporting the use of roller pressure algometry. Dynamic pressure algometry may be a new tool for assessing the status of sensitization in primary headaches.