Characterization of insomnia and sleep quality in a cohort with cluster headache.

objectiveThe objective of this cross-sectional study was to investigate the extent of perceived sleep disturbances in a cluster headache cohort, and to compare how sleep is perceived between participants in an active headache bout to participants in a headache-free remission period.

backgroundCluster headache is a primary headache disorder characterized by extremely painful headache attacks. These attacks commonly occur with a circadian rhythm, with a majority of patients experiencing nocturnal attacks. Sleep is affected in patients with cluster headache, but there are many uncertainties regarding the pathophysiological connection between cluster headache and sleep disturbances and to what extent sleep disturbances persist into remission.

methodsA digital survey was sent out to 701 individuals with cluster headache between January and May 2024. The survey contained questions regarding general health, clinical cluster headache phenotype, and questions from the Karolinska Sleep Questionnaire, the Insomnia Severity Index, and the Dysfunctional Beliefs and Attitudes about Sleep-10. Scores extracted from each questionnaire were compared between study participants in an active bout versus study participants in remission, and study participants in short-term remission (<5 years) versus long-term remission (≥5 years).

resultsOf the 381 individuals who answered the survey, 325 were included in the final analysis. Participants in an active cluster headache bout reported increased sleep disturbances on all measurements compared to participants in remission (insomnia severity: adjusted odds ratio [aOR] = 1.12 [95% confidence interval (CI), 1.07-1.17] p < 0.001; sleep quality: aOR = 0.67 [95% CI, 0.53-0.83] p < 0.001; daytime sleepiness: aOR = 0.59 [95% CI, 0.44-0.78] p < 0.001; and dysfunctional beliefs: aOR = 1.03 [95% CI, 1.01-1.04] p = 0.001). Of the participants in an active bout, 46.5% scored above the Insomnia Severity Index threshold indicating moderate to severe insomnia (≥15) and 43.7% were considered as having poor sleep quality (≤3 on the Sleep Quality Index extracted from the Karolinska Sleep Questionnaire). This is in comparison to 22.0% of participants in remission being above the moderate insomnia threshold and 22.0% considered having poor sleep quality. Participants in long-term remission had better sleep scores overall compared to participants in short-term remission (insomnia severity: aOR = 1.09 [95% CI, 1.03-1.16] p = 0.005; daytime sleepiness: aOR = 0.67 [95% CI, 0.42-1.02] p = 0.072; and dysfunctional beliefs: aOR = 1.03 [95% CI, 1.01-1.05] p = 0.006).

conclusionIndividuals with cluster headache have a large degree of sleep disturbances that are exacerbated during an active bout and not completely alleviated during remission. Future studies are needed to determine if this gradual change in sleep disturbances after an active bout is due to physiological changes, which slowly revert to baseline levels after an active bout or connected to persisting negative behavioral or cognitive associations between sleep and headache.