Microembolic air load during contrast-transcranial Doppler: a trigger for migraine with aura?

BACKGROUND: There is a well-known association between migraine with aura (MA) and right-to-left shunt (RILES) because of patent foramen ovale (PFO). The occurrence of MA attacks after microbubble (MB) injection during contrast-enhanced transcranial Doppler (ce-TCD) has been recently described. OBJECTIVES: The aim of this study was to analyze the prevalence of RILES in a consecutive cohort of MA patients and to characterize the occurrence of MA attacks after diagnostic ce-TCD. METHODS: A total of 159 consecutive MA patients underwent ce-TCD with air-mixed saline to disclose RILES. RILES was characterized in terms of MB amount (small-moderate or large) and occurrence at rest and/or during Valsalva maneuver (permanent or latent). RESULTS: RILES was revealed in 79/159 patients (∼ 50%). Permanent RILES were detected in 56/79 (71%) and latent RILES in 23/79 (29%) MA patients. The occurrence of a typical MA attack was overall observed in 12/159 patients (7.5%; 95% CI: 4-12.8%), but arose only in RILES-positive ones, immediately after ce-TCD (12/79; 15.2%; P< .001). All 12 patients had permanent RILES (12/56; 21.4%; P= .015) and MA attack was mostly observed in large RILES-positive patients, even without statistical significance (P= .118). CONCLUSIONS: Microembolic air load could act as a trigger of MA attack. According to recent studies and to the clinical characteristics observed in our patients, microembolization because of MB injection might provoke a decrease in cerebral oxygen saturation, thus triggering cortical spreading depression and, thereafter, MA attack. Larger and prospective studies will be necessary to confirm our data and observe a wider correlation.

Shunt-associated migraine responds favorably to atrial septal repair: a case-control study.

BACKGROUND AND PURPOSE: Transcatheter closure of patent foramen ovale (PFO) has been reported to improve migraine in patients with cerebrovascular disorders in noncontrolled studies. The aim of the study was to compare the course of migraine assessed prospectively over a 12-month period in symptomatic (for cerebrovascular disease) and asymptomatic patients undergoing PFO closure and in patients with PFO treated medically. METHODS: Twenty-three stroke symptomatic (SS; 39+/-10 years of age; males/females [M/F] 5/18) and 27 stroke asymptomatic (SA; 40+/-12 years of age; M/F 5/22) patients with migraine underwent PFO closure. Twenty-seven patients with migraine and PFO (controls [CTRLS]; 36+/-11 years of age; M/F 4/23) were followed up medically. Migraine severity was assessed at baseline with a scale that takes into account the frequency, duration, and intensity of the attacks and the occurrence of aura (score range 0 to 10). Six months later, the patients were given a structured diary to annotate monthly with the same scale the characteristics of the attacks for the next 6 months. By the end of 1 year, the migraine score was averaged for the last 6 months. RESULTS: Baseline severity of migraine did not differ between groups (6.3 to 6.1 and 6.7 in SS, SA, and CTRLS groups, respectively). At the 1-year assessment, the overall migraine score had significantly improved by 3.7 and 2.8 points in SS and SA, respectively (P<0.001 on repeated-measure ANOVA), whereas it had nonsignificantly worsened by 0.1 points in CTRLS. Multiple linear regression analysis showed that the improvement in SS and SA was independent of migraine type, age, and cerebrovascular risk factors. Twenty-one of 21 patients with migraine with aura in the CTRLS group still had aura at the end of follow-up, whereas only 3 of 14 among SA and 4 of 19 among SS continued to have migraine preceded by aura (P<0.0001 on Fisher exact test). CONCLUSIONS: Compared with medical treatment, closure of PFO brings about a significant overall improvement in migraine. This seems to occur irrespective of migraine type and of previous cerebrovascular disease. In addition to the overall improvement, in migraine with aura, the occurrence of aura is dramatically reduced.