Clinical characteristics of migraine in a population-based twin sample: similarities and differences between migraine with and without aura

Objective: To look into clinical differences between migraine with and with out aura in a population-based sample of migraineurs. Background: Migraine presents in two major forms, migraine with and migraine without aura. With the exception of the aura phase, the clinical characteristics of these enti ties are very similar. Despite this, however, the recent epidemiological da ta underline differences between migraine with and without aura. We tried t o examine whether other features besides the aura differ between these two major forms of migraine. Methods: We studied 321 twins suffering from migra ine with aura and 166 twins with migraine without aura from the population- based Finnish Twin Cohort. Migraine was diagnosed according to the criteria of the international Headache Society (MS). Analysis was based on the comb ination of a mailed questionnaire and a telephone interview by a neurologis t. Special attention was paid to differences between migraine with and with out aura. results: Some qualities of headaches differed between MS defined migraine with and without aura. Unilateral headache (Chi-squared p=0.039) a nd photophobia (Chi-squared p=0.010) were more typical for migraine with au ra, while nausea was more typical for migraine without aura (Chi-squared p = 0.002). Duration of headache in migraine without aura was also longer tha n in migraine with aura (Mann-Whitney U-test 0.007). Conclusions: There are clinical differences between MS defined migraine with and without aura; ev en the headache phase between the two entities differs. It is worthwhile di stinguishing between them when looking for the elusive genes for these more common forms of migraine.