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 without 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 entities are very similar. Despite this, however, the recent epidemiological data underline differences between migraine with and without aura. We tried to examine whether other features besides the aura differ between these two major forms of migraine. METHODS: We studied 321 twins suffering from migraine 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 (IHS). Analysis was based on the combination of a mailed questionnaire and a telephone interview by a neurologist. Special attention was paid to differences between migraine with and without aura. RESULTS: Some qualities of headaches differed between IHS defined migraine with and without aura. Unilateral headache (Chi-squared p = 0.039) and photophobia (Chi-squared p = 0.010) were more typical for migraine with aura, while nausea was more typical for migraine without aura (Chi-squared p = 0.002). Duration of headache in migraine without aura was also longer than in migraine with aura (Mann-Whitney U-test 0.007). CONCLUSIONS: There are clinical differences between IHS defined migraine with and without aura; even the headache phase between the two entities differs. It is worthwhile distinguishing between them when looking for the elusive genes for these more common forms of migraine.