Arctic environment triggers migraine attacks.

Patients with difficult headaches referred from general practitioners to a neurology department in North Norway regularly complain of seasonal variation of headache. Svalbard, which comprises a number of islands located in the Arctic Ocean between Norway and the North Pole, is inhabited by approximately 2000 people and is one of the largest populated areas close to the North Pole (Figure 1)1. The seasonal variation in this area is extreme—midnight sun is present from April 20 to August 23, while from November 11 to January 30 (the polar dark season) the sun is completely absent. A previous study in North Norway showed that migraine patients, especially those suffering from migraine with aura (MA), reported more incidences of migraine in the Arctic light season.2,3 We present 3 patients living in Svalbard who illustrate some features of migraine typical in arctic populations.