Chronic insomnia and shift work seem to be common among Arctic cluster headache patients. The small number of subjects included in this study implies that conclusions should be drawn with caution, but the findings support the idea of cluster headache as a circadian rhythm disorder.

BackgroundCluster headache (CH) is regarded as a chronobiological disorder. The hypothalamic biological clock may thus be involved in the pathophysiology, but few studies have actually investigated this in CH patients. A variable number tandem repeat (VNTR) polymorphism of the PER3 clock gene has been associated to preferred daily rhythm (chronotype) in several studies. We aimed to study the distribution of PER3 VNTR polymorphisms and chronotypes in a CH population.MethodsWe used blood samples from a biobank of CH patients for genetic tests, and invited all tested patients to complete the Horne-Ostberg Morningness-eveningness Questionnaire (MEQ), the Pittsburgh sleep quality Index (PSQI) and the Shift Work Index. Genotypes were compared to a previously tested population of 432 healthy students.ResultsOne hundred forty nine patients were genotyped, and we found no difference in PER3 VNTR polymorphisms between patients and controls. Seventy-four patients completed the MEQ (54 men, 20 women, mean age 52.3 years ± 13.4), and chronotypes were as follows: 12 % morning-, 37 % intermediate-, and 51 % evening types. Compared with a previous Danish study of CH patients and controls, there were no difference in chronotype distribution. Sixty percent of patients were defined as bad sleepers (PSQI >5), and 51 % of patients currently employed were shift workers.ConclusionsNo association between CH, PER3 VNTR polymorphism and chronotype was found in this study.

Medication overuse headache is a secondary headache—a worsening of a pre-existing headache (usually a primary headache) owing to overuse of one or more attack-aborting or pain-relieving medications.

Background: The effects of caffeine withdrawal on migraineurs are at large unknown. Methods: This was a randomized, double-blind, crossover study (NCT03022838), designed to enroll 80 adults with episodic migraine and a daily consumption of 300-800 mg caffeine. Participants substituted their estimated dietary caffeine with either placebo capsules or capsulated caffeine tablets for 5 weeks before switching the comparators for 5 more weeks. Results: The study was terminated due to low recruitment. Ten subjects with a mean age of 46.3 ± 9.9 years, BMI of 24.9 ± 3.7, and a mean blood pressure of 134/83 ± 17/12 mmHg were enrolled. The average consumption of caffeine per day was 539 ± 196.3 mg. The average monthly headache days and migraine attack frequency at baseline was 11.5 ± 4.9 and 5.2 ± 1.2, respectively. At baseline Pittsburgh Sleep Quality Index was 5.8 ± 2.5 and HIT-6 was 62.8 ± 3.9. There were no differences in these or in parameters from actigraphy during the caffeine period compared with the placebo period. One subject withdrew just after entering the study. In the remaining nine, withdrawal triggered severe migraine attacks in seven, causing one more drop-out, and a typical caffeine withdrawal syndrome in two. Caffeine continuation did not trigger migraines, but one attack occurred in the wake of caffeine reintroduction. Conclusions: The study failed to answer how caffeine withdrawal affects migraineurs over time, but showed that abrupt withdrawal of caffeine is a potent trigger for migraine attacks.

Objective. Cluster headache (CH) may cause excruciating pain and not all patients get satisfactory help. Patient dissatisfaction with general practitioners (GPs) and neurologists, and use of complementary and alternative treatment (CAM) may reflect this. The authors studied patient satisfaction with doctors’ treatment and use of CAM in a Norwegian CH cohort. Subjects. A total of 196 subjects with a cluster headache diagnosis were identified in the registers of two neurological departments in North Norway. Design. Of these, 70 with a confirmed diagnosis according to the second edition of the International Classification of Headache Disorders (ICHD-2) completed a comprehensive questionnaire with questions concerning satisfaction with doctors’ treatment, use of CAM, and effect of both treatment regimes. Results. Satisfaction with doctors’ treatment was reported in 44/70 (63%) (GPs) and 50/70 (71%) (neurologists) while 39/70 (56%) were satisfied with both. Too long a time to diagnosis, median four years, was the most commonly reported claim regarding doctors’ treatment. Use of CAM was reported in 27/70 (39%), and 14/70 (20%) reported experience with ≥ 2 CAM. Ten patients reported benefit from CAM (37% of “CAM users”). The average cluster period was longer in CAM-users than others (p = 0.02), but CAM use was not associated with age, education, use of medication, effect of conventional treatment, duration of cluster attacks, or time to diagnosis. Conclusion. About two-thirds of CH patients were satisfied with treatment from either GPs or neurologists, and about one-third had used CAM. Despite experiencing diagnostic delay and severe pain, cluster patients seem in general to be satisfied with doctors’ conventional treatment.