Objective: To investigate bilateral widespread pressure pain hyperalgesia in deep tissues over symptomatic (trigemino-cervical) and nonsymptomatic (distant pain-free) regions in patients with cluster headache (CH).
Background: Central sensitization is claimed to play a relevant role in CH. No study has previously searched for widespread pressure hyperalgesia in deep tissues over both symptomatic (trigemino-cervical) and nonsymptomatic (distant pain-free) regions in patients with CH.
Methods: Sixteen men (mean age: 43 ± 11 years) with CH in a remission phase and 16 matched controls were recruited. Pressure pain thresholds (PPTs) were bilaterally measured over the supra-orbital (V1), infra-orbital (V2), mental (V3), median (C5), radial (C6), and ulnar (C7) nerves, C5-C6 zygapophyseal joint, mastoid process, and tibialis anterior muscle by an assessor blinded to the subjects' condition.
Results: The results showed that PPT levels were significantly decreased bilaterally in patients with CH as compared with healthy controls (all sites, P < .001). A greater degree of sensitization over the mastoid process (P < .001) and a lower degree of sensitization over the tibialis anterior muscle (P < .01) was found.
Conclusions: Our findings revealed bilateral widespread pressure pain hypersensitivity in patients with CH confirming the presence of central sensitization mechanisms in this headache condition.
© 2010 American Headache Society.