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.

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.

It is a general belief that migraine attacks are prone to occur on days off. Only a few studies, however, have addressed this issue. The objective of this study was to investigate the periodicity of migraine with respect to weekly (circaseptan) variations. Eighty-nine females of fertile age who had participated in a previous questionnaire-based study volunteered to record in detail every migraine attack for 12 consecutive months. Eighty-four patients completed recordings for a mean of 311 days (s.d. = 95.9, range 30-365). A total of 2314 attacks were recorded. Migraine occurrence was almost equally distributed during the week, except on Sundays, when there were significantly fewer attacks (t = -4.42, d.f. = 83, P < 0.001). A Mantel-Haenszel estimate of the relative risk of having an attack on a holiday vs. another day, not Sundays included, was 0.64 (95% CI 0.49-0.85). Our study suggests that days off protect against migraine.

In this case-control study, we analyzed 146 wrists: a) to search for the distribution pattern of the rheumatoid lesions and, b) to correlate the distribution pattern of these lesions with the clinical parameters. Thirty-one patients with rheumatoid arthritis (RA) and 42 controls-all women-were examined by means of a bilateral MR fast field echo (FFE) sequence, in axial plan. The wrist was divided into three regions: metacarpal (level I), carpal (level II) and radioulnar (level III). Erosions were present in thirty (97%) patients and in six (14%) controls. They were asymmetrically distributed at all levels, mainly at level II. Marrow infiltration and bone destruction were seen in 35% of the patients in an asymmetrical pattern at level I and II, respectively. These lesions were absent in the control group. Subchondral cysts were asymmetrically present in both groups-in 48% of the patients at levels II and III, and in 11% of the controls at level II. In the patient group, this asymmetrical pattern of the lesions correlated with the disease duration at levels I and II (p = 0.011 and p = 0.013, respectively). Most lesions were found at the radial force-bearing column of the wrist, more in the right side. Synovial hypertrophy and hyperintense median nerve were evident in 96% and 70% of the patients, respectively. We concluded that contrary to common belief rheumatoid damages to the carpal bones become rather asymmetrical as the disease progresses. The line of force along the radial side of the wrist possibly influences the distribution pattern of the rheumatoid lesions.