Migraine and patent foramen ovale: state of the science

Migraine and Ischemic Stroke: Deciphering the Bidirectional Pathway

Migraine and stroke are common, disabling neurological conditions with several theories being proposed to explain this bidirectional relationship. Migraine is considered as a benign neurological disorder, but research has revealed a connection between migraine and stroke, predominantly those having migraine with aura (MA). Among migraineurs, females with MA are more susceptible to ischemic stroke and may have a migrainous infarction. Migrainous infarction mostly occurs in the posterior circulation of young women. Although there are several theories about the potential relationship between MA and stroke, the precise pathological process of migrainous infarction is not clear. It is assumed that cortical spreading depression (CSD) might be one of the essential factors for migrainous infarction. Other factors that may contribute to migrainous infarction may be genetic, hormonal fluctuation, hypercoagulation, and right to left cardiac shunts. Antimigraine drugs, such as ergot alkaloids and triptans, are widely used in migraine care. Still, they have been found to cause severe vasoconstriction, which may result in the development of ischemia. It is reported that patients with stroke develop migraines during the recovery phase. Both experimental and clinical data suggest that cerebral microembolism can act as a potential trigger for MA. Further studies are warranted for the treatment of migraine, which may lead to a decline in migraine-related stroke. In this present article, we have outlined various potential pathways that link migraine and stroke.

Clinical features of right-to-left shunt in the different subgroups of migraine

OBJECTIVE

Several investigations have documented an association between migraine and right-to-left shunt (RLS). However, whether there are specific clinical features that can distinguish between migraine patients with and without RLS is unclear. This study aims to explore whether there are specific clinical features that can distinguish between migraine patients with and without RLS, and to investigate the relationship between the degree of shunt and clinical parameters of headache.

METHODS

In this study, we enrolled consecutive migraineurs who underwent a structured, standardized questionnaire for family and personal history and for detailed migraine features. RLS was diagnosed based on a contrast enhancement transcranial Doppler (c-TCD) examination.

RESULTS

Overall, 113 migraine with aura (MA) and 192 migraine without aura (MO) patients were included. Patients with MA and RLS (MARLS+) had a higher frequency for sensory aura symptoms than those with MA without RLS (MARLS-) (27.4% vs. 10.0%, p = .03). Patients with MO and RLS (MORLS+) presented with significantly younger initial age of migraine onset and experienced more severe pain intensity than those with MO without RLS (MORLS-) (mean ± SD, 25.6 ± 8.9 vs. 29.8 ± 12.7 years, p = .008 and 5.9 ± 1.4 vs. 5.3 ± 1.3, p = .006, respectively). There was no relationship between the degree of shunt and the clinical parameters of headache.

CONCLUSIONS

Our results indicate that MO patients presented with a younger initial age of migraine onset and that sensory aura symptoms in MA patients may predict the presence of RLS. However, we did not find support for relationship between the degree of shunt and clinical parameters of headache.

Frequency of Patent Foramen Ovale and Migraine in Patients With Cryptogenic Stroke

BACKGROUND AND PURPOSE

Individuals with migraine are at higher risk for stroke, but the mechanism has not been established. On the basis of the association between migraine and intracardiac right-to-left shunt, it has been proposed that stroke in migraineurs could be caused by a paradoxical embolus passing through a patent foramen ovale (PFO) or pulmonary arteriovenous malformation. The aim of this study was to determine the prevalence of PFO with right-to-left shunt in patients who presented with cryptogenic stroke and had a history of migraine.

METHODS

Patients between 18 and 60 years old who presented with an ischemic stroke were characterized based on ASCOD phenotyping (atherosclerosis; small-vessel disease; cardiac pathology; other causes; dissection). A migraine diagnosis was identified by reviewing physician notes, and frequent aura was defined if present in at least 50% of attacks. A PFO with right-to-left shunt diagnosis was identified by the presence of a positive bubble contrast study with either transcranial Doppler, transthoracic, or transesophageal echocardiography.

RESULTS

Of the 712 patients who presented with ischemic stroke, 127 (18%) were diagnosed as cryptogenic; 68 patients had adequate testing for PFO and a documented migraine history. The prevalence of PFO in patients with cryptogenic stroke without migraine was elevated (59%) compared with the general population (18%). Patients with both cryptogenic stroke and migraine had a higher prevalence of PFO (79%). In patients with cryptogenic stroke who had migraine with frequent aura, the prevalence of PFO was 93%. Only 5 patients (4%) had a history compatible with migrainous infarction.

CONCLUSIONS

In patients with cryptogenic stroke who have migraine, there is a high prevalence (79%) of PFO with right-to-left shunt. The timing of the stroke in migraineurs is usually not related to a migraine attack. These observations are consistent with the hypothesis that the mechanism of stroke in migraineurs is most likely because of a paradoxical embolus. Future cryptogenic stroke classification schemes should consider including PFO as a separate etiologic category.

Can neuroimaging differentiate PFO and AF-related cardioembolic stroke from the other embolic sources? Clinical-radiological correlation on a retrospective study

PURPOSE

The aim of this retrospective study was to map the specific ischemic lesion patterns of distribution in patent foramen ovale-related stroke (PFO-stroke) and atrial fibrillation-related stroke (AF-stroke) in patients with idiopatic ischemic stroke.

MATERIALS AND METHODS

750 ischaemic strokes were screened on basis of diagnostic imaging and tests: patients with known causes were excluded. 171 patients with unknown cause were selected and divided in two groups: AF-stroke (43 patients) and PFO-stroke (128 patients). Vascular territories of ischemic involvement were divided into four classes in each group: the anterior cerebral artery, the middle cerebral artery, the vertebro-cerebral artery (including the posterior cerebral artery) and multisite (MS) involvement.

RESULTS

Infarcts in vertebro-basilar territory and multisite represented each one about 32% of infarcts in PFO-stroke group and their involvement are more frequent than AF-stroke group (p = 0.03). Ischemic lesions in PFO-group were predominantly cortical (34.3%), and in AF-group cortical-subcortical (60.4%). Multisite pattern of ischemic lesion was more frequent in patients with severe degree of right to left shunts (37.5%).

CONCLUSION

In clinical practice, PFO may be considered a cause of cortical stroke on the basis of radiological findings, when VB vascular territory or MS brain involvement is present in younger patients (<50 age).

Do interictal microembolic signals play a role in higher cortical dysfunction during migraine aura?

Introduction

The aim of this study was to evaluate the prevalence and clinical impact of interictal microembolic signals (MES) in patients suffering from migraine with higher cortical dysfunction (HCD), such as language and memory impairment, during an aura.

Patients and methods

This study was carried out on 34 migraineurs with language and memory impairment during aura (HCD group), 31 migraineurs with only visual or visual and somatosensory symptoms during aura (Control group I), and 34 healthy controls (Control group II). We used a Doppler instrument to detect microemboli. Demographic data, disease features and the detection of MES between these groups, as well as the predictors of HCD during the aura, were analyzed.

Results

The duration of aura was longer and the frequency of aura was higher among patients with language and memory impairment during aura compared to Control group I. MES was detected in 29.4% patients from the HCD group, which was significantly higher compared to 3.2% in Control group I and 5.9% in Control group II. Regarding the absence or presence of MES, demographic and aura features were not different in the HCD subgroups. A longer duration of aura, the presence of somatosensory symptoms during the aura and the presence of interictal MES were independent predictors of HCD during the aura.

Conclusion

The present findings indicate that HCD and MES are related in patients with migraine with aura. Further research is needed to better understand the exact pathophysiological mechanism.

The brain's heart - therapeutic opportunities for patent foramen ovale (PFO) and neurovascular disease

Patent foramen ovale (PFO), a common congenital cardiac abnormality, is a connection between the right and left atria in the heart. As a "back door to the brain", PFO can serve as a conduit for paradoxical embolism, allowing venous thrombi to enter the arterial circulation, avoiding filtration by the lungs, and causing ischemic stroke. PFO-related strokes affect more than 150,000 people per year in the US, and PFO is present in up to 60% of migraine patients with aura, and in one out of four normal individuals. So, in such a highly prevalent condition, what are the best treatment and prevention strategies? Emerging studies show PFO-related neurovascular disease to be a multi-organ condition with varying individual risk factors that may require individualized therapeutic approaches - opening the field for new pharmacologic and therapeutic targets. The anatomy of PFO suggests that, in addition to thrombi, it can also allow harmful circulatory factors to travel directly from the venous to the arterial circulation, a concept important in finding novel therapeutic targets for PFO-related neurovascular injury. Here, we: 1) review emerging data on PFO-related injuries and clinical trials; 2) discuss potential mechanisms of PFO-related neurovascular disease in the context of multi-organ interaction and heart-brain signaling; and 3) discuss novel therapeutic targets and research frontiers. Clinical studies and molecular mapping of the circulatory landscape of this multi-organ disease will both be necessary in order to better individualize clinical treatment for a condition affecting more than a quarter of the world's population.