Are migraine and cluster headache one spectrum? Implications from cyclical migraine

Abstract

Background and Objectives: Cyclical migraines (C-M) are occasionally met in headache clinics, but not well studied. The aim of the study was to delineate the characteristics of C-M, and compared them with those of cluster headache (CH) and migraine without aura (MO). Methods: We collected patients with C-M from our headache center, and patients with CH and MO from our cross-sectional standardized survey between 2014 and 2020. Data including demographics, headache characteristics, triggers, and relieving factors were recorded. Results: Forty-seven patients with C-M were identified. Most of the characteristics of C-M were found to be intermediate between MO and CH, including gender, attack duration, headache degree, headache side, as well as both migraine-like and CH-like accompanying symptoms. C-M had a significant higher percentage of women, and less severe and lower percentages of most CH-like accompanying features compared to CH. On the other hand, C-M had a significant lower percentage of women, earlier onset, shorter duration of headache attacks, more severe, lower percentages of migraine-like accompanying features and higher percentages of CH-like accompanying features compared to MO. However, triggers and relieving factors in C-M were more similar to CH than MO. Discussion: The largest C-M series defines it as a transition stage between MO and CH. Fewer differences were found between C-M and CH, indicating that C-M may be more similar to CH.