A prospective study of migraine with aura attacks in a headache clinic population.

In order to investigate the prevalence of migraine with aura (MA) attacks according to the criteria set by the International Headache Society (IHS) for diagnosis down to the three-digit level of classification, and to determine the recurrence and possible variability of MA attacks over time, we conducted a 6-15-month-long prospective study on 64 MA patients (42 women and 22 men) consecutively referred for the first time to the University of Parma Headache Centre. At the end of the follow-up period, diagnosis was the same as at the first visit for 80.0% of patients, while it was changed for 20.0%. Throughout the duration of the study, the average number of attacks for each patient was 5.3 +/- 6.2 (range 0-30). Attacks of migraine with typical aura were the most frequent (69.1% of patients), but migraine aura without headache (29.1%) and migraine with prolonged aura (20.0%) were also common; by contrast, basilar migraine and migraine with acute onset aura were reported only by one patient in either case. Migraine aura without headache was statistically significantly more frequent in males than in females. Our study results suggest that in most cases the frequency of recurrent MA attacks is relatively low and provide interesting indications about the prevalence of the different MA subtypes listed in the IHS classification, albeit in a headache clinic population.