Temporal changes of circadian rhythmicity in cluster headache

Abstract

Objective To investigate the temporal changes of circadian rhythmicity in relation to the disease course in patients with cluster headache. Methods In this multicenter study, patients with cluster headache were recruited between September 2016 and July 2018. We evaluated the patients for circadian rhythmicity and time of cluster headache attacks in the current bout and any experience of bout-to-bout change in circadian rhythmicity. We analyzed the patterns of circadian rhythmicity in relation to the disease progression (the number of total lifetime bouts, grouped into deciles). Results Of the 175 patients in their active, within-bout period, 86 (49.1%) had circadian rhythmicity in the current bout. The prevalence of circadian rhythmicity in the active period was overall similar regardless of disease progression. Sixty-three (46.3%) out of 136 patients with ≥2 bouts reported bout-to-bout changes in circadian rhythmicity. The most frequent time of cluster headache attacks was distributed evenly throughout the day earlier in the disease course and dichotomized into hypnic and midday as the number of lifetime bouts increased ( p = 0.037 for the homogeneity of variance). When grouped into nighttime and daytime, nighttime attacks were predominant early in the disease course, while daytime attacks increased with disease progression (up to 7th deciles of total lifetime bouts, p = 0.001) and decreased in patients with the most advanced disease course ( p = 0.013 for the non-linear association). Conclusions Circadian rhythmicity is not a fixed factor, and changes according to the disease course. Our findings will be valuable in providing a new insight into the stability of functional involvement of the suprachiasmatic nucleus in the pathophysiology of cluster headache.

Cluster headache in Asian populations: Similarities, disparities, and a narrative review of the mechanisms of the chronic subtype

“…Patients with CH are known to experience their headache attacks during a specific time of the day defining the circadian rhythm of CH. In a recent large-scale Korean study recruiting 193 patients, only 86 (49.1%) of 175 patients reported circadian rhythmicity in their active period whereas, in past bouts, up to 70.9% experienced circadian rhythmicity, suggesting that the circadian rhythmicity is not stable but changes over time ( 26 ). Other Asian studies reported circadian rhythmicity in 65.0–67.5% of the patients ( 9 , 13 ).…”

“…More than half (54.7–59%) of the patients in European and American studies reported circannual rhythmicity ( 25 , 27 ). In Korea, 51.7% of the patients reported a seasonal rhythmicity; however, those who reported a seasonal rhythmicity (vs. those without) were nearly twice as likely to report circadian rhythmicity as well (66.2% vs. 37.1%, p < 0.001), suggesting a close relationship between circadian and circannual rhythmicity ( 26 ).…”

“…In Taiwan, only 11.5% reported ≥1 bout per year, and in Japan, most commonly (40%) patients have less than 1 bout per year ( 14 ). In Korea, patients enrolled during their within-bout period presented approximately 1 bout per year ( 26 ), whereas the average inter-bout duration ranged from 16–20 months ( 23 ), and the estimated bout frequency was <1 per year when patients of within- and inter-bout periods were taken together ( 15 ). In China, most patients with CH had a bout frequency of <1 per year (38.3%), followed by 1–2 per year (35.8%).…”

“…In Taiwan, the majority of patients (56.0%) reported only one attack per day, followed by every other day (13.5%) (9). In Korea, the median attack frequency was 2 per day, and the majority of patients had an attack frequency of 1–3 in the active period (26). In Japan, the majority of patients had an attack frequency of 1–2 per day (44.0%) (14), followed by >2 attacks per day (18.0%).…”

“…higher frequency or longer duration, are more likely to develop a chronic form (50). Generally, eCH patients in Asian countries, compared to those in European and North American countries, have a lower disease load as shown by a lower attack frequency, lower bout frequency, and shorter bout duration (9,13,14,26). Therefore, Asian populations may be less likely to transform from eCH to cCH.…”