Abstract text (incl. figure legends and references)

Question: Although aura symptoms usually have been described in association with migraine, their occurrence has been observed with other types of headaches. Studies analyzing the aura in migraine show that visual aura (VA) represents 98% of the symptoms. Nevertheless, no study has reported VA in non-migrainous headache in a population-based setting.

Methods: The present study used the baseline data of the Circannual Change in Headache and Sleep study, which was a nation-wide and population-based survey. We defined migraine and probable migraine as migrainous headache by combining them. Therefore, non-migrainous headache was defined as a headache case other than migrainous headache. VA was assessed using the self-administered visual aura rating scale which is a validated instrument for assessing VA.

Results: Of 3,030 participants, 1,431 (47.2%) and 507 (16.7%) were classified as having non-migrainous and migrainous headaches during the previous year, respectively. VA was reported in 406 (20.9%) participants with headache. The prevalence of VA was significantly lower in non-migrainous headache than that in migrainous headache (26.0% [132/507] vs. 14.5% [207/1431], p<0.001). The prevalence of VA did not significantly differ between women and men (14.6% [110/751] vs. 14.3% [97/680], p=0.837). Headache days/month (median and 25-75% percentiles, 2.0 [0.4-5.0] vs 2.0 [1.0-3.0], p<0.001) and disability (migraine disability assessment, 6.0 [3.0-16.0] vs. 2.0 [0.0-7.0], p<0.001) were significantly higher in non-migrainous headache with VA than those without VA.

Conclusions: VA was prevalent among participants with non-migrainous headache. Some clinical characteristics of non-migrainous headache with VA were more severe than those in non-migrainous headache without VA