Svein Ivar Bekkelund

Seasonal variation in migraine

Our group has previously shown that migraineurs, as opposed to individuals with other headaches, are more likely to have headache during the bright arctic summer than during the polar night season. We set out to investigate the impact of seasonal light exposure in migraine with and without aura. We performed a questionnaire-based study of 169 female volunteer migraineurs in an arctic area where light conditions during summer and winter seasons are extreme. We included 98 patients with migraine with aura (MA) and 71 with migraine without aura (MoA). One hundred and seven patients (63%) reported seasonal variation in migraine attack frequency. Close to half (47%) of patients with aura, but only 17% of patients without aura, reported more frequent attacks during the light season (P < 0.001). Patients with MA reported interictal light hypersensitivity and light exposure as an attack precipitating factor significantly more often than individuals with MoA. They also reported significantly more frequent use of sunglasses to prevent attacks. We found no significant differences between MA and MoA as regards sleep disturbances, use of oral contraceptives, impact of headache or circadian variations. Seasonal periodicity of migraine in an arctic population with more frequent attacks during the light season is a convincing phenomenon in MA but not in MoA. The amount of light exposure seems to be pivotal to this variation.

Prophylaxis of migraine with melatonin A randomized controlled trial

Background: A previous open-label study of melatonin, a key substance in the circadian system, has shown effects on migraine that warrant a placebo-controlled study. Method: A randomized, double-blind, placebo-controlled crossover study was carried out in 2 centers. Men and women, aged 18–65 years, with migraine but otherwise healthy, experiencing 2–7 attacks per month, were recruited from the general population. After a 4-week run-in phase, 48 subjects were randomized to receive either placebo or extended-release melatonin (Circadin®, Neurim Pharmaceuticals Ltd., Tel Aviv, Israel) at a dose of 2 mg 1 hour before bedtime for 8 weeks. After a 6-week washout treatment was switched. The primary outcome was migraine attack frequency (AF). A secondary endpoint was sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI). Results: Forty-six subjects completed the study (96%). During the run-in phase, the average AF was 4.2 (±1.2) per month and during melatonin treatment the AF was 2.8 (±1.6). However, the reduction in AF during placebo was almost equal (p = 0.497). Absolute risk reduction was 3% (95% confidence interval −15 to 21, number needed to treat = 33). A highly significant time effect was found. The mean global PSQI score did not improve during treatment (p = 0.09). Conclusion: This study provides Class I evidence that prolonged-release melatonin (2 mg 1 hour before bedtime) does not provide any significant effect over placebo as migraine prophylaxis. Classification of evidence: This study provides Class I evidence that 2 mg of prolonged release melatonin given 1 hour before bedtime for a duration of 8 weeks did not result in a reduction in migraine frequency compared with placebo (p = 0.497).

Insomnia and Circadian Variation of Attacks in Episodic Migraine

Objectives.—To assess the influence of insomnia on the 24‐hour temporal pattern of migraine.

Migraine, as compared to other headaches, is worse during midnight-sun summer than during polar night. A questionnaire study in an Arctic population.

Objective.—To investigate potential seasonal variation of migraine and other headaches in an Arctic population where light conditions are extreme during both winter and summer.

Circannual periodicity of migraine

Seasonal rhythm of migraine attacks may support a role of the suprachiasmatic nucleus of the hypothalamus in the pathophysiology of migraine. The objective of this study was to provide evidence for seasonal variation in migraine. Eighty‐nine female migraineurs volunteered to record every migraine attack in detail for 12 consecutive months. Attacks associated with sleep complaints were defined as insomnia‐related. By using Edwards’ model for recognition and estimation of cyclic trends, time‐series analysis was made. Fifty‐eight patients, of which 26 had migraine without aura (MO) and 32 had migraine with aura (MA), completed the study. A total of 1840 attacks were recorded. The mean age ± SD was 36.9 ± 6.0. Patients with a lifetime history of MA showed marked seasonal fluctuation with more attacks in the light season compared to the dark. Time of peak was May 21. Peak/low ratio was 1.30 (95% CI: 1.08–1.55). When insomnia‐related attacks (n = 312) were removed the seasonal variation became insignificant. There is a seasonal trend with more migraine attacks in the light season compared to the dark season in females with MA, but not MO, living in an arctic area. This is caused by the seasonal variation of insomnia‐related attacks in patients with MA.

24-Hour Distribution of Migraine Attacks

Background.— It is a widespread opinion that migraine attacks arise more frequently in the morning and that circadian rhythms may be responsible for the temporal pattern in migraine. However, only one small prospective study has previously been published on this topic.

Creatine kinase activity and blood pressure in a normal population: the Tromso study

Objectives In the vast majority of cases the cause for hypertension is not known. On the basis of observations from black and multiethnic populations, it has been hypothesized that a genetically high tissue creatine kinase activity may be an independent factor responsible for primary hypertension. If the relation between creatine kinase and blood pressure is causal, it is reasonable to believe that it will be independent of ethnicity and present in different populations. In this cross-sectional study, we examined whether creatine kinase was associated with blood pressure in a large Caucasian normal population. Methods and results Data on creatine kinase and blood pressure were analyzed in a random sample of 12 776 men and women (65% of those eligible), aged 30–87 years from a normal population in the municipality of Tromsø, Norway. We used linear regression to model the association between creatine kinase and blood pressure. Creatine kinase was independently associated with blood pressure. A one unit increase in log CK was associated with a 3.3 (95% CI 1.4–5.2) mmHg increase in systolic blood pressure and a 1.3 (95% CI 0.3–2.3) mmHg increase in diastolic blood pressure, after adjustment for age, sex, body mass index, s-glucose, s-creatinine, physical activity and alcohol consumption. The creatine kinase effect on blood pressure was independent of antihypertensive medication, and no difference in creatine kinase level was found between those with controlled and uncontrolled hypertension (geometric mean 101 vs. 104 IU/l, P = 0.1). Conclusion Creatine kinase was associated with blood pressure in this population.

Prevalence of head trauma in patients with difficult headache: the North Norway Headache Study

Objective.—To test whether chronic headache (>3 days/week) is more prevalent than episodic headache (<3 days/week) in patients with a previous history of significant head trauma.

Acceptability, Feasibility, and Cost of Telemedicine for Nonacute Headaches: A Randomized Study Comparing Video and Traditional Consultations

Background The feasibility of telemedicine in diagnosing and treating nonacute headaches, such as primary headaches (migraine and tension-type) and medication-overuse headaches has not been previously investigated. By eliminating the need of travel to specialists, telemedicine may offer significant time and money savings. Objectives Our objective was to estimate the acceptance of telemedicine and investigate the feasibility and cost savings of telemedicine consultations in diagnosing and treating nonacute headaches. Methods From September 2012 to March 2015, nonacute headache patients from Northern Norway who were referred to neurologists through an electronic application system were consecutively screened and randomized to participate in either telemedicine or traditional specialist visits. All patients were consulted by two neurologists at the neurological department in Tromsø University Hospital. Feasibility outcomes were compared between telemedicine and traditional groups. Baseline characteristics and costs were then compared between rural and urban patients. Travel costs were calculated by using the probabilistic method of the Norwegian traveling agency: the cheapest means of public transport for each study participant. Loss of pay was calculated based on the Norwegian full-time employee’s average salary: < 3.5 hours=a half day’s salary, > 3.5 hours spent on travel and consultation=one day’s salary. Distance and time spent on travel were estimated by using Google Maps. Results Of 557 headache patients screened, 479 were found eligible and 402 accepted telemedicine participation (83.9%, 402/479) and were included in the final analyses. Of these, 202 received traditional specialist consultations and 200 received telemedicine. All patients in the telemedicine group were satisfied with the video quality, and 198 (99%, 198/200) were satisfied with the sound quality. The baseline characteristics as well as headache diagnostics and follow-up appointments, and the investigation, advice, and prescription practices were not statistically different between the two randomized groups. In addition, telemedicine consultations were shorter than traditional visits (38.8 vs 43.7 min, P<.001). The travel cost per rural individual (292/402, 73%) was €249, and estimated lost income was €234 per visit. The travel cost in the urban area (110/402, 27%) was €6, and estimated lost income was €117 per visit. The median traveling distance for rural patients was 526 km (range 1892 km), and the median traveling time was 7.8 hours (range 27.3 hours). Rural patients had a longer waiting time than urban patients (64 vs 47 days, P=.001), and fewer women were referred from rural areas (P=.04). Rural women reported higher pain scores than urban women (P=.005). Conclusion Our study shows that telemedicine is an accepted, feasible, time-saving, and cost-saving alternative to traditional specialist consultations for nonacute headaches. Trial Registration Clinicaltrials.gov NCT02270177; http://clinicaltrials.gov/ct2/show/NCT02270177 (Archived by WebCite at http://www.webcitation.org/6hmoHGo9Q)

Insomnia and Periodicity of Headache in an Arctic Cluster Headache Population

To assess the prevalence of chronic insomnia and the periodicity of headache attacks in an Arctic cluster headache population.