Migraine improves after ischemic stroke.

OBJECTIVE: To assess if migraine frequency spontaneously changes after stroke. BACKGROUND: Patent foramen ovale (PFO) closure has been reported to decrease migraine attacks. Because many closures are carried out after an ischemic stroke, it is possible that migraine spontaneously improves after stroke. METHODS: We have prospectively collected all patients with ischemic stroke and active migraine admitted to our stroke unit and have compared their migraine frequency before and 6, 12, and 24 months after stroke. RESULTS: We studied 43 patients. Mean follow-up was 1.3±.5 years. The mean number of migraine attacks per month decreased from 2.9±2.2 before stroke to .7±1.4 six months after stroke (P<.0001), and to .6±.6 one year after stroke (P<.0001). Migraine attacks completely disappeared in 23 of 43 patients at 6 months after stroke (53.5%) and in 22 of 40 at 1 year (55.0%). Improvement of 50% or more or total disappearance of attacks occurred in 34 of 43 patients at 6 months after stroke (79.1%) and in 33 of 40 at 1 year (82.5%). CONCLUSIONS: Ischemic stroke is very often followed by a marked and persistent improvement of prestroke migraine. The causes of improvement are unclear and may involve changes in lifestyle and psychological status, drugs, platelet activation, or modifications of vasoreactivity after stroke. These data suggest that studies reporting the efficacy of PFO closure for migraine in stroke patients are probably biased by the lack of a control group.