Patients with vs without episodic or chronic cluster headache may have reduced sleep quality, possibly due to the occurrence of nocturnal headache attacks, according to a study published in Headache.
Cluster headache patterns often align with circadian rhythms and researchers believe attacks may be related to sleep disturbances and differences in chronotype. However, the impact and directionality of such relationships in terms of pathophysiology remains uncertain.
In this cross-sectional study, adults with episodic (n=487; mean age, 50.4; 74.7% men) or chronic (n=147; mean age, 48.5; 74.1% men) cluster headaches, as well as healthy controls (n=367; mean age, 43.9; 43.9% men) were recruited from the Dutch Leiden University Cluster headache neuro-Analysis. Participants were asked to complete web-based surveys that included the Pittsburgh Sleep Quality Index, Circadian Type Inventory, Munich Chronotype Questionnaire, and Hospital Anxiety and Depression Scale.
The study outcomes were sleep onset, sleep duration, mid-sleep phase, chronotype distribution, the Flexibility Circadian Type Inventory Score, and the Languid Circadian Type Inventory score. For each of these outcomes, linear regression analyses were performed and adjusted for potential confounders, with headache diagnosis as the primary predictor.
Study participants with cluster headaches were found to have earlier chronotypes more often compared with healthy controls, as indicated by a mid-sleep phase occurring earlier (adjusted B, −15.85 minutes; 95% CI, −29.30 to −2.40; P =.021). Participants with episodic cluster headaches had more trouble coping with reduced sleep compared with healthy controls (adjusted B, 0.75; 95% CI, 0.09-1.40; P =.025), and patients with chronic cluster headaches had greater difficulty altering their sleep rhythms (adjusted B, −1.65; 95% CI, −2.55 to 0.74; P <.001).
Participants with chronic or episodic cluster headaches reported reduced sleep quality compared with the control group. There were 235 patients with episodic cluster headaches (48.3%; adjusted B, −1.71; 95% CI, 0.10-0.32; P <.001) who rated themselves as “poor sleepers” and 105 patients with chronic cluster headaches (71.4%; adjusted B, −0.93; 95% CI, 0.24-0.65; P <.001) who described themselves in the same way vs 94 (25.6%) participants in the control group. A total of 130 (26.7%) and 63 (42.9%) patients with episodic and chronic cluster headaches, respectively, reported a relationship between sleep pattern and the probability of having a headache attack. There were no significant differences detected for any of the other outcomes.
Study strengths include a large sample size, a well-defined cohort, and a high response rate that indicated participants were highly motivated. Study limitations include a lack of information regarding sleep patterns prior to cluster headache onset.
“Although the exact causality remains unclear, association between cluster headache and sleep seems robust and remains intriguing,” noted the authors. “[Patients with] cluster headache will likely benefit from a structured, regular daily schedule.”
Coo IFD, Oosterhout WPJV, Wilbrink LA, Zwet EWV, Ferrari MD, Fronczek R. Chronobiology and sleep in cluster headache [published online May 31, 2019]. Headache. doi:10.1111/head.13567