Prevalence of cardiac right left shunts in migraine: a population-based case-control study.

We aimed to investigate the prevalence of cardiac right left shunts (RLS) in population-based samples of subjects with migraine with aura (n = 42), migraine without aura (n = 44) and controls without headache (n = 41). Cardiac RLS was assessed with transcranial Doppler sonography with intravenous injection of saline. Prevalence of RLS was highest in migraineurs with aura (45.2%) compared to migraineurs without aura (34.1%) and controls (41.5%). Permanent as opposed to latent RLS was more common among patients with migraine with aura (40.5%) than in patients with migraine without aura (23.3%) or controls (24.4%). Differences did not reach statistical significance between the three groups (p = 0.564 for RLS prevalence, p = 0.349 for prevalence of permanent shunts). Our data implicate a trend towards higher prevalence of RLS with larger shunts in subjects with migraine with aura.