Different effects of air microembolism through patent foramen ovale in patients with migraine: A quantitative
Raffaele Ornello1, Matteo Spezialetti2, Valeria Caponnetto1
1Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
Background:
Literature suggests an association between patent foramen ovale (PFO) and migraine, mostly migraine with aura (MA). Previous data suggest that air microembolism through PFO can lead to bioelectrical abnormalities detectable at electroencephalogram (EEG) in patients with MA, thus suggesting a pathophysiological mechanism for the MA-PFO association. However, those data lack replication.
Methods:
Patients with MA or migraine without aura (MO) and large PFO underwent a 19-channel EEG recording before and after injection of air microbubbles. We compared EEG power before and after microbubble injection for each electrode location, for each frequency band (theta: 5-7 Hz; alpha: 8-12 Hz; beta: 13-30 Hz; lower gamma: 31-45 Hz), and for total global power (the average of EEG power at each location and frequency band).
Results:
We included 10 patients, four with MA and six with MO; six patients had medium-to-high migraine frequency (four or more monthly migraine days), while four had low frequency (one monthly migraine day). EEG power changes after air microembolism varied across patients. Considering the overall group, total global EEG power did not change; however, EEG power in the higher frequency ranges (beta and lower gamma) increased in patients with MA.
Conclusions:
We did not replicate the effects of air microembolism previously reported in patients with migraine. Aura status, migraine frequency, and medications might influence patients' response to microembolism. More refined EEG measurements are needed to clarify the dynamic role of PFO on migraine occurrence.
Insights
This study did not replicate previous findings on patent foramen ovale (PFO) and migraine. Air microbubbles did not significantly alter EEG power in most patients, suggesting PFO
Area of Science:
- Neurology
- Cardiology
- Neurophysiology
Background:
- A patent foramen ovale (PFO) is linked to migraines, particularly migraine with aura (MA).
- Previous research suggested air microembolism via PFO could cause EEG abnormalities in MA patients, proposing a mechanism for the MA-PFO link.
- These prior findings require replication.
Purpose of the Study:
- To investigate the effect of air microembolism on electroencephalogram (EEG) power in patients with PFO and migraine.
- To attempt replication of previously reported bioelectrical abnormalities in MA patients with PFO.
Main Methods:
- 19-channel EEG recordings were performed before and after air microbubble injection in patients with PFO and either MA or migraine without aura (MO).
- EEG power was compared across electrode locations and frequency bands (theta, alpha, beta, lower gamma) pre- and post-injection.
- Total global EEG power was also analyzed.
Main Results:
- EEG power changes post-microembolism varied individually.
- Overall, total global EEG power showed no significant change in the group.
- Patients with MA experienced an increase in EEG power within the beta and lower gamma frequency bands.
Conclusions:
- The study did not replicate the previously reported effects of air microembolism on EEG in migraine patients.
- Factors such as aura status, migraine frequency, and medication may influence individual responses to microembolism.
- Further research with advanced EEG techniques is necessary to elucidate the role of PFO in migraine pathophysiology.
