Phase Specific Pain Localization in Cluster Headache Patients.

Abstract Background and Objective:Applying local treatments like neuromodulation or injections for cluster headache, requires exact knowledge of the anatomical structures and pain topography. However studies with emphasis on exact pain localization are rare although local treatments are increasingly used for patients in whom systemic pharmacotherapy is ineffective or contraindicated. Here, survey results with emphasis on exact pain location in cluster headache attacks for onset of pain, peak pain and radiation of pain, are presented. Methods: Data from 631 respondents were collected for 23 months using an online survey composed of 117 questions on pain location, epidemiology, and clinical features. 5260 datapoints on 44 pain locations were analyzed.Results: There is a periorbital concentration of pain during onset and peak phases of attacks. Pain locations outside the periorbital region were reported more frequently during radiation when compared to the onset and peak of attacks. Dorsal (occipital/nuchal) pain is more frequent during onset and radiation compared to peak: onset pain (13%) vs. peak pain (6%), p < 0,001. Pain radiation (22%) vs. peak pain (6%), p < 0,001. There is no significant difference in dorsal pain frequencies for pain radiation (22%) vs. onset (13%), p = 0,552. Furthermore, single pain spots differ significantly in frequency during the three attack phases.Conclusions: Analysis of the pain location data shows phase specific frequencies and distributions of pain location during the three stages of a cluster headache attack. Single pain spots differ significantly in frequency during the three attack phases. Dorsal pain is more frequent during onset and radiation, compared to peak. Extra-orbital pain locations are more frequent during pain radiation. These findings will help to better understand cluster headache and might help to identify further target structures for local treatments.