Potential source of cerebral embolism in migraine with aura: a transcranial Doppler study

History of Migraine and the Risk of Spontaneous Cervical Artery Dissection

The pathophysiology of spontaneous cervical artery dissection (sCAD) is largely unknown. An association with migraine has been suggested, but not definitively proven. In the setting of a hospital-based prospective case-control study we assessed personal and family history of migraine in 72 patients with sCAD, 72 patients with cerebral infarct unrelated to a CAD (non-CAD) and 72 control subjects. Personal history of migraine was significantly associated to sCAD compared to non-CAD (59.7% vs. 30.6%; OR 3.14; 95% CI 1.41-7.01) and controls (18.1%; OR 7.41; 95% CI 3.11-17.64). As opposed to migraine with aura, migraine without aura was significantly more frequent among sCAD than among non-CAD (56.9% vs. 25.0%; OR 3.91; 95% CI 1.71-8.90) and controls (12.5%; OR 9.84; 95% CI 3.85-25.16). Similar results were observed when the frequencies of family history of migraine were compared. These findings are consistent with the hypothesis that migraine may represent a predisposing condition for sCAD.

Is the search for right-to-left shunt still worthwhile?

OBJECTIVES

Patent foramen ovale (PFO) is a common disembryogenic defect with well-attested prevalence but dubious etiopathogenetic linkage with cryptogenic stroke and different clinical conditions. Transcranial color-coded Doppler (TCCD) assures high accuracy in diagnosing right-to-left shunt (RLS) and its functional aspects. Aim of the study was to evaluate RLS prevalence and degree in subjects submitted to TCCD for conditions theoretically associated or caused by paradoxical embolism to the brain.

METHODS

PFO assessment, performed in 10 major diagnostic categories and a control group, followed a standardized protocol with a 10 or 20 microbubbles (MB) cutoff to identify any or only large RLS, respectively.

RESULTS

Among 2113 patients, a significant larger RLS prevalence was found in stroke (53.3%), TIA (45.7%) and migraine with aura (39.7%) when compared with non-migraineurs controls (25.5%). RLS degree was significantly higher in stroke and TIA patients: The ROC curve from MB load data helped to identify new cutoff values for both normal breathing (42 MB) and Valsalva (139 MB) tests. From logistic regression, a family history for PFO, ASA, and male gender appeared independent predictors of a RLS. By contrast, RLS seemed independent of white matter abnormalities presence on brain neuroimaging or stroke mimics.

CONCLUSIONS

In addition to recently defined criteria, genetically determined inheritable traits and epidemiologic characteristics (male gender) should be taken into account when assessing PFO and related cerebrovascular risk profile. A newly defined threshold in TCCD MB count is suggested to discriminate shunts related to stroke and TIA from innocent ones.

Systemic right-to-left shunts, ischemic brain lesions, and persistent migraine activity

OBJECTIVE

To assess whether migraine in the general population is associated with increased risk of systemic right-to-left shunts (RLS) and whether RLS are associated with increased prevalence of brain infarcts and persistent recurrence of migraine attacks at older age.

METHODS

Brain MRI and transcranial Doppler with air contrast in 166 unselected migraineurs (mean age ± SD 56 ± 7.7 years; 70% women; n = 96 migraine with aura) and 69 controls (mean age ± SD 55 ± 7.6 years; 65% women) from the general population.

RESULTS

Participants with migraine with aura more frequently had Valsalva-induced RLS (60%), in particular large-sized, compared to controls (42%; odds ratio [OR] 2.1; 95% confidence interval [CI] 1.1-3.9; p = 0.02) and participants with migraine without aura (40%; OR 2.3; 95% CI 1.2-4.3; p = 0.01). They also more frequently had spontaneous RLS (35%) than participants with migraine without aura (17%; OR 2.6; 95% CI 1.3-5.6; p = 0.01) but not compared to controls (26%; OR 1.6; 95% CI 0.8-3.1; p = 0.2). Participants with migraine with aura and spontaneous RLS more frequently had persistent migraine activity (85%) than participants with migraine without spontaneous RLS (63%; OR 3.4; 95% CI 1.2-10.1; p = 0.03). Nine percent of participants with RLS had silent posterior circulation infarcts compared to 3% of participants without RLS (OR 2.8; 95% CI 0.9-9.3; p = 0.08), independent of migraine status. RLS were not associated with white matter lesions.

CONCLUSIONS

RLS are more prevalent in migraineurs with aura but do not explain the increased prevalence of silent posterior circulation infarcts or white matter lesions in migraineurs. Spontaneous RLS are associated with persistent migraine.

Patent Foramen Ovale and Migraine: Closing the Debate--A Review

BACKGROUND

A link between patent foramen ovale (PFO) and migraine as well as the utility of closure of PFO and its effect on migraine have been subjects of debate. The present review is an effort to gather the available evidence on this topic and formulate recommendations.

METHODS

A systematic search of electronic databases (Medline, Embase, Cochrane Library) was performed. A separate search in associated reference lists of identified studies was done. Observational studies and clinical trials published in English using the International Headache Society criteria for diagnosis of migraine were included in the analysis. The search was performed in 3 categories: prevalence of migraine in patients with PFO, prevalence of PFO in migraine patients, and effect of PFO closure and its effect on migraine. The quality of evidence and strength of recommendations during review of these studies was analyzed.

RESULTS

About 14 observational studies with 2602 subjects who had PFO were identified. Migraine prevalence ranged from 16% to 64%. Another 20 studies reported 2444 patients with migraine; the prevalence of PFO ranged from 15% to 90%. About 20 observational studies (1194 patients) that examined the effect of PFO closure on migraine were identified. Resolution of migraine was reported in 10% to 83% of patients, improvement in 14% to 83%, no change in 1% to 54%, and worsening in 4% to 8%. The overall quality of these observational studies was poor. Finally, 3 randomized clinical trials included a total of 238 patients who underwent PFO closure compared with 234 patients in the control groups. All 3 trials failed to meet their primary end points defined as migraine resolution and greater than 50% reduction in migraine days at 1 year. In 2 of the clinical trials, there was some benefit noted in a small subset of migraine patients with aura, but the numbers were too small to extrapolate the findings to the general migraine population.

CONCLUSIONS

There is no good quality evidence to support a link between migraine and PFO. Closure of PFO for migraine prevention does not significantly reduce the intensity and severity of migraine. We do not recommend the routine use of this procedure in current practice.

Coincidental Impact of Transcatheter Patent Foramen Ovale Closure on Migraine with and without Aura - A Comprehensive Meta-Analysis

BACKGROUND

We analyzed the literature to assess the coincidental impact on migraines of transcatheter patent foramen ovale (PFO) closure performed for secondary stroke prevention.

METHODS

We searched Medline, EMBASE, and the Cochrane database for studies published up until August 2013. We included English-language studies that provided information on complete resolution or improvement in migraine headaches following PFO closure. Two study authors identified 375 original articles and both independently reviewed 32 relevant manuscripts. Data including study methodology, inclusion criteria, PFO closure and migraine outcomes were extracted manually from all eligible studies. Pooled odds (and probability) of resolution or improvement of migraine headaches were calculated using random-effects models.

RESULTS

Twenty studies were analyzed. Most were uncontrolled studies that included a small number of patients with cryptogenic stroke who had undergone PFO closure and had variable time of followup. The probability of complete resolution of migraine with PFO closure (18 studies, 917 patients) was 0.46 (95% confidence interval 0.39, 0.53) and of any improvement in migraine (17 studies, 881 patients) was 0.78 (0.74, 0.82). There was evidence for publication bias in studies reporting on improvement in migraines (Begg's p=0.002), but not for studies on complete resolution of migraine (p=0.3). In patients with aura, the probability of complete resolution of migraine post-PFO closure was 0.54 (0.43, 0.65), and in those without aura, complete resolution occurred in 0.39 (0.29, 0.51).

CONCLUSIONS

Among patients with unexplained stroke and migraine undergoing transcatheter PFO closure, resolution of headaches occurred in a majority of patients with aura and for a smaller proportion of patients without aura.

The Role of Patent Foramen Ovale in Cryptogenic Stroke

INTRODUCTION

Almost one-third of ischemic strokes has an unknown etiology and are classified as cryptogenic stroke. Paradoxical embolism because of a patent foramen ovale (PFO) is detected in 40%-50% of these patients. Recently, PFO has been reported as a risk factor for patients of all age groups.

METHODS

In this study, 1080 ischemic stroke patients admitted to our clinic (2011-2013) were retrospectively evaluated. Age, sex, risk factors, complete blood count, vasculitis, biochemical and hypercoagulability tests, magnetic resonance imaging, magnetic resonance angiography, transthoracic echocardiography, transeosophageal echocardiography (TEE) findings, and therapeutic approaches were evaluated.

RESULTS

The age range of the participants (seven male and four female patients) was 20-60 years (mean=43.09±11.13 years). Hemiparesis (n=10), diplopia (n=2), hemianopsia (n=2), and dysarthria (n=2) were the main findings of the neurological examinations. Patient medical history revealed hypertension (n=3), asthma (n=1), deep venous thrombosis (n=1), and smoking (n=4). Diffusion-weighted imaging showed middle cerebral artery (n=8) and posterior cerebral artery (n=3) infarctions. In one case, symptomatic severe carotid stenosis was detected. In eight cases, TEE showed PFO without any other abnormalities, but PFO was associated with atrial septal aneurysm in two cases, and in one case it was associated with ventricular hypokinesia and pulmonary arterial hypertension. Antiplatelet therapy was applied to nine patients and percutaneous PFO closure operation to two patients. In a 2-year follow-up, no recurrent ischemic stroke was recorded.

CONCLUSION

PFO, especially in terms of the etiology of cryptogenic stroke in young patients, should not be underestimated. We want to emphasize the importance of TEE in identifying potential cardioembolic sources not only in young but also in all ischemic stroke patients with unknown etiology; we also discuss the controversial management options of PFO.

Migraine with aura and patent foramen ovale: myth or reality?

Several observational studies report that subjects with migraine with aura have a higher prevalence of right-to left shunt, commonly due to patent foramen ovale, and that patent foramen ovale is more prevalent in subjects with migraine with aura. Although migraine without aura has been less extensively studied, it does not seem to be associated with an increased prevalence of right-to left shunt. The mechanism that underlies the possible relationship between patent foramen ovale and migraine with aura remains speculative. The proposed mechanisms are migraine-triggering vasoactive chemicals bypassing the pulmonary filter and reaching the cerebral circulation and paradoxical microembolization. However, it is unclear, at this time, if there is a causal or comorbid association between the two conditions. In some families atrial shunts show a dominant inheritance that seems to be linked to inheritance of migraine with aura. Migraine with aura is an independent risk factor for ischemic stroke, and patent foramen ovale is present more frequently in patients with cryptogenic stroke than in controls. At this moment, there is no convincing evidence that excess stroke risk of migraine is simply mediated by patent foramen ovale through paradoxical embolism. Several non-controlled studies suggest that closure of the foramen ovale significantly reduces attack frequency in migraine patient, but the only prospective placebo-controlled trial does not support these results. Patent foramen ovale closure, at present, is not indicated as a treatment for migraine in clinical practice.

Patent foramen ovale

Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately ∼25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. With the advent of transoesophageal and transthoracic echocardiography, as well as transcranial Doppler, a PFO can be routinely detected in clinical practice. Medical treatment with either antiplatelet or anticoagulation therapy is recommended. At the current time, closure of the PFO by percutaneous interventional techniques does not appear to reduce the risk of stroke compared to conventional medical treatment, as shown by three large clinical trials. Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO. This Primer discusses the epidemiology, mechanisms, pathophysiology, diagnosis, screening, management and effects on quality of life of PFO.

Evaluation of migraine in patients with ischaemic stroke

An association between migraine and ischaemic stroke has been observed for many years, but the exact mechanisms by which migraine can lead to stroke are still unknown. The purpose of this study was to determine the prevalence of migraine headaches in patients with ischaemic stroke. In this prospective cohort study, we assessed 323 patients with ischaemic stroke; these diagnoses were assigned based on the International Headache Society criteria for migraine with or without aura. Patients were recruited without major risk factors such as stroke, hypertension, hyperlipidaemia, diabetes, taking oral contraceptive pills, history of drug abuse and trauma in issue of their Stroke. Data were collected via a written questionnaire upon admission and were analysed with SPSS version 16 software. Comparisons were performed using Mann-Whitney's U test and chi-square and t-test. Migraine headache was present in 11.2% (36 of 323) of patients, 8.1% of women and 3.1% of men. Migraine prevalence was highest in the age over 60  years. There was a history of migraine without aura for over 2  years in 6.2% of patients with ischaemic stroke. Also, we found no significant correlation between migraine headache and location of the lesion in patients with ischaemic stroke.

Patent foramen ovale: Unanswered questions

The foramen ovale is a remnant of the fetal circulation that remains patent in 20-25% of the adult population. Although long overlooked as a potential pathway that could produce pathologic conditions, the presence of a patent foramen ovale (PFO) has been associated with a higher than expected frequency in a variety of clinical syndromes including cryptogenic stroke, migraines, sleep apnea, platypnea-orthodeoxia, deep sea diving associated decompression illness, and high altitude pulmonary edema. A unifying hypothesis is that a chemical or particulate matter from the venous circulation crosses the PFO conduit between the right and left atria to produce a variety of clinical syndromes. Although observational studies suggest a therapeutic benefit of PFO closure compared to medical therapy alone in patients with cryptogenic stroke, 3 randomized controlled trials (RCTs) did not confirm the superiority of PFO closure for the secondary prevention of stroke. However, meta-analyses of these RCTs demonstrate a significant benefit of PFO closure over medical therapy alone. Similarly, observational studies provide support for PFO closure for symptomatic relief of migraines. But one controversial randomized study failed to replicate the results of the observational studies while another two demonstrated a partial benefit. The goal of this review is to discuss the clinical conditions associated with PFO and provide internists and primary care physicians with current data on PFO trials, and clinical insight to help guide their patients who are found to have a PFO on echocardiographic testing.

Sleep Apnea in Patients with and without a Right-to-Left Shunt

OBJECTIVES

To assess the presence of right-to-left shunting (RLS) in patients with obstructive sleep apnea (OSA), and compare clinical characteristics and parameters of the sleep studies of patients with and without RLS.

BACKGROUND

The most common cause of RLS is due to intermittent flow through a patent foramen ovale (PFO). PFO occurs more frequently in patients with OSA and may be involved in the exacerbation of OSA.

METHODS

Patients with an abnormal polysomnogram seen at UCLA-Santa Monica Sleep Medicine Clinic were enrolled. A diagnosis of RLS was made using a transcranial Doppler (TCD) bubble study. Gender and age-matched controls were drawn from patients referred for cardiac catheterization who underwent a TCD. The frequency of RLS in OSA patients and the controls was evaluated. Clinical characteristics and polysomnogram parameters were compared between OSA patients with and without a RLS.

RESULTS

A total of 100 OSA patients and 200 controls participated in the study. The prevalence of RLS was higher in patients with OSA compared to the control group (42% versus 19%; p < 0.0001). Patients with OSA and a RLS had a lower apnea-hypopnea index (AHI), less obstructive apnea, and fewer hypopnea episodes than patients with OSA without a RLS. The baseline and nadir SpO2 were similar in both groups and did not correlate with the level of RLS assessed by TCD. The degree of desaturation for a given respiratory disturbance, as measured by oxygen desaturation index (ODI)/AHI ratio, was higher in OSA patients with RLS versus OSA patients without RLS (0.85 ± 0.07 versus 0.68 ± 0.04; p < 0.0001).

CONCLUSION

RLS, most commonly due to a PFO, occurs 2.2 times more frequently in OSA patients compared to a control population that was matched for age and gender. The severity of sleep apnea is not greater in OSA patients who have a PFO. However, patients with OSA and a PFO are more likely to become symptomatic at a younger age with an equivalent decrease in nocturnal SpO2, and have greater arterial desaturation in proportion to the frequency of respiratory disturbances.

A meta-analysis of case-control studies of the association of migraine and patent foramen ovale

OBJECTIVES

To establish quantitative evidence, we performed the first meta-analysis of case-control studies assessing the relationship between migraine and patent foramen ovale (PFO).

METHODS

MEDLINE and EMBASE were searched through April 2015 using PubMed and OVID. Eligible studies were case-control studies reporting PFO (or migraine) prevalence in migraine patients versus no-migraine subjects (or PFO patients versus no-PFO subjects).

RESULTS

Of 395 potentially relevant articles screened initially, 21 eligible studies enrolling a total of 5572 participants were identified and included. Pooled analyses demonstrated statistically significant 3.36-fold migraine-with-aura [odds ratio (OR), 3.36; 95% confidence interval (CI), 2.04-5.55; p<0.00001] and 2.46-fold migraine-with/without-aura prevalence (OR, 2.46; 95% CI, 1.55-3.91; p=0.0001) but statistically non-significant 1.30-fold migraine-without-aura prevalence (OR, 1.30; 95% CI, 0.85-1.99; p=0.22) in PFO patients relative to no-PFO subjects.

CONCLUSIONS

PFO is associated with 3.4-fold migraine-with-aura and 2.5-fold migraine-with/without-aura prevalence but unassociated with migraine-without-aura prevalence.

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.

Right-to-Left Shunt Does Not Increase the Incidence of Silent Lacunar Infarcts in Patients with Migraine

Right-to-left shunt (RLS) is associated with cryptogenic stroke and migraine. Herein we investigated the relationship between RLS and silent lacunar infarcts in patients with migraine. A total of 263 patients with migraine who met eligibility criteria were enrolled from January 2010 to December 2011, among which 127 subjects fell into RLS group. Baseline demographics were comparable between RLS and non-RLS groups (P > 0.05). The incidence of silent lacunar infarcts in RLS group was not significantly different from that of the non-RLS group (25.2% versus 21.3%, P > 0.05). Furthermore, we found that the incidence of silent lacunar infarcts in permanent and latent RLS subgroups was comparable with non-shunt RLS subgroup (28.6% versus 24% versus 21.3%, P > 0.05). Similarly, the incidence of silent lacunar infarcts in the non-RLS group, mild-shunt group, and large-shunt group was also comparable (21.3% versus 23.8% versus 29.3%, P > 0.05). In addition, RLS did not increase the incidence of silent lacunar infarcts in migraine patients with elder age (<50 years age group: 15.8% versus 17.9%; ≥50 years age group: 53.1% versus 37.5%, both P > 0.05). In conclusion, RLS does not increase the incidence of silent lacunar infarcts in patients with migraine. Further prospective studies are warranted to validate this finding.

Current status of percutaneous PFO closure

The clinical significance of persistent patent foramen ovale (PFO) is not well defined. Empirically, PFO has been associated with many clinical conditions. In cryptogenic stroke, migraine, and orthodeoxia/platypnea, a plausible biologic mechanism exists to support PFO closure as a possible treatment. Although transcatheter closure of PFO has been available for over 2 decades, it has remained controversial due to a paucity of evidence to guide patient and device selection. Contemporary studies investigating PFO closure as treatment for patients with these conditions have been published recently and longitudinal data regarding the safety and efficacy of the devices is now available. In this review, we aim to describe the potential clinical significance of a patent foramen in the adult, appraise the newest additions to the body of evidence, and discuss the safety, benefit, patient selection, and future of transcatheter treatment of PFO.

Contrast Echocardiography and Migraine in Divers with Patent Foramen Ovale

Background:

It has been proposed that the patent foramen ovale (PFO) may be associated with migraine, in particular migraine with aura. However, it is not clear whether paradoxical embolism triggers crises of headache. Cerebral embolization is provoked in subjects with PFO through contrast echocardiography, a safe method to diagnose the presence of foramen ovale pervium.

Methods:

Twenty-four men practicing diving, an activity characterized by increased prevalence of PFO and migraine, underwent trans-thoracic echocardiography with contrast solution, composed of saline and air mixture and checked for the occurrence of migraine in the following 24 hours.

Results:

A PFO (five of minimal size, i.e. visible only during Valsalva, one of small and two of medium size) was detected in 8/24 divers (33%). No one reported headache over the 24 hours after the procedure.

Discussion:

Our preliminary data suggest that cerebral micro-embolism, provoked by contrast echocardiography, does not systematically trigger migraine crises when a minimal-to-medium sized patent foramen ovale is present.

Progress in Clinical Neurosciences: Migraine-Stroke: A Causal Relationship, but Which Direction?

A significant association between migraine and ischemic stroke has been demonstrated in population and case-control studies. The risk of ischemic stroke appears to be higher in migraine with aura (MWA) than migraine without aura (MwoA). Migraine-stroke comprises a number of distinct entities, including migrainous infarction, in which ischemic stroke occurs during an attack of MWA and migraine-related stroke, in which the causal link is less clear. Migrainous infarction accounts for only one-third of migraine-stroke, strokes may occur during attacks of MwoA, and a number of cerebrovascular disorders may present as MWA or MwoA. Migraine may occur as a consequence of conditions that are known to cause stroke; therefore it remains to be determined whether migraine predisposes to stroke in the absence of any known disease associations, if it is an epiphenomenon of an underlying stroke diathesis, or if it requires the presence of another stroke risk factor to produce cerebral ischemia. Furthermore, it is unclear if ischemia results in migraine more often than migraine results in ischemia. Careful clinical studies that evaluate this bidirectional relationship are needed to determine why migraine patients are subject to a higher risk of ischemic stroke.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Patent foramen ovale and migraine attacks: a systematic review

BACKGROUND

Migraine headache and the presence of a patent foramen ovale have been associated with each other, although the precise pathophysiological mechanism(s) are uncertain. The purpose of this systematic review was to identify the extent of patent foramen ovale prevalence in migraineurs and to determine whether closure of a patent foramen ovale would improve migraine headache.

METHODS

An electronic literature search was performed to select studies between January 1980 and February 2013 that were relevant to the prevalence of patent foramen ovale and migraine, and the effects of intervention(s) on migraine attacks. Of the initial 368 articles presented by the initial search, 20 satisfied the inclusion criteria assessing patent foramen ovale prevalence in migraineurs and 21 presented data on patent foramen ovale closure.

RESULTS

In case series and cohort studies, patent foramen ovale prevalence in migraineurs ranged from 14.6% to 66.5%. Case-control studies reported a prevalence ranging from 16.0% to 25.7% in controls, compared with 26.8% to 96.0% for migraine with aura. The extent of improvement or resolution of migraine headache attack symptoms was variable. In case series, intervention ameliorated migraine headache attack in 13.6% to 92.3% of cases. One single randomized trial did not show any benefit from patent foramen ovale closure. The data overall do not exclude the possibility of a placebo effect for resolving migraine following patent foramen ovale closure.

CONCLUSION

This systematic review demonstrates firstly that migraine headache attack is associated with a higher prevalence of patent foramen ovale than among the general population. Observational data suggest that some improvement of migraine would be observed if the patent foramen ovale were to be closed. A proper assessment of any interventions for patent foramen ovale closure would require further large randomized trials to be conducted given uncertainties from existing trial data.

Two-dimensional echocardiography using second harmonic imaging for the diagnosis of intracardiac right-to-left shunt: a meta-analysis of prospective studies

Right-to-left shunting (RLS), usually through a patent foramen ovale (PFO), has been associated with migraine, cryptogenic stroke and hypoxemia. With emerging observational studies and clinical trials on the subject of PFO, there is a need for accurate diagnosis of PFO in patients being considered for transcatheter closure. While transesophageal echo (TEE) bubble study is the current standard reference for diagnosing PFO, transthoracic echo with second harmonic imaging (TTE-HI) may be a preferable screening test for RLS due to its high accuracy and non-invasiveness. The aim of this meta-analysis was to determine the accuracy of TTE-HI compared to TEE as the reference. A systematic review of Medline, Cochrane and Embase was done for all the prospective studies assessing for intracardiac RLS using TTE-HI compared to TEE as the reference; both TTE-HI and TEE were performed with a contrast agent and a maneuver to provoke RLS in all studies. A total of 15 studies with 1995 patients fulfilled the inclusion criteria. The weighted mean sensitivity and specificity for TTE-HI were 91 and 93 % respectively. Likewise, the positive and negative likelihood ratios were 13.52 and 0.13 respectively. TTE-HI is a reliable, non-invasive test with proficient diagnostic accuracies. The high sensitivity and specificity of TTE-HI make it a useful initial screening test for RLS. If the precise anatomy is required, then TEE can be obtained before scheduling a patient for transcatheter PFO closure.

Impact of transcatheter closure of patent foramen ovale in the evolution of migraine and role of residual shunt

OBJECTIVES

To retrospectively evaluate the impact on daily activities of transcatheter closure of patent foramen ovale (PFO) versus medical therapy in patients with migraine and to analyze the role of the residual shunt after PFO closure.

BACKGROUND

While non-controlled observational studies reported an improvement of migraine after PFO closure, a randomized trial has shown no benefit of such an intervention. The role of residual shunt after PFO closure is also poorly known.

METHODS

Out of 217 patients with migraine and echocardiographic evidence of PFO, 89 were managed with percutaneous PFO closure (Group A) while 128 were medically treated (Group B). All MIDAS questionnaires were obtained at the first evaluation and repeated at least 6 months after the index evaluation or after the PFO closure. All the patients were also asked to give a subjective estimate of their migraine status. A postprocedural transcranial Doppler study was available in 70 patients in Group A.

RESULTS

The mean basal MIDAS score did not differ between the two groups (p = 0.859). After a mean follow-up (FU) of 1399 ± 982 days the MIDAS score decreased significantly in both groups (Group A baseline vs FU, p < 0.001; Group B baseline vs FU, p < 0.001), but no differences were observed between groups (p = 0.204). However a significantly higher number of Group A patients reported a perceived clinical benefit or the disappearance of migraine compared to Group B (p < 0.001). Patients with moderate or severe residual right to left shunt were no more likely to have an higher MIDAS score or to complain of migraine than those with mild or no shunt.

CONCLUSIONS

Although the overall evolution of migraine is not significantly different, the abolition of migraine occurs in a larger proportion after PFO closure.

Review of Data and Discussion - Who Should Undergo Patent Foramen Ovale Closure in 2014?

A patent foramen ovale is a relatively common finding in the general population and is associated with a number of conditions, including cryptogenic stroke. In 2014, percutaneous patent foramen ovale (PFO) closure is a frequently performed procedure; the bulk of these procedures being carried out for secondary prevention of cryptogenic stroke, along with other indications, such as prevention of decompression illness, platypnoea-orthodeoxia syndrome and migraine. Of these conditions the largest body of evidence available is for cryptogenic stroke and there is ongoing debate of the benefit of PFO closure over medical therapy. This article will review the available evidence of PFO closure in each of these contexts, with a particular focus on randomised controlled trials, and endeavour to outline in whom the evidence suggests closure should be considered.

Accuracy of transcranial Doppler for the diagnosis of intracardiac right-to-left shunt: a bivariate meta-analysis of prospective studies

OBJECTIVES

The aim of this meta-analysis was to determine the accuracy of transcranial Doppler (TCD) compared with transesophageal echocardiography (TEE) as the reference.

BACKGROUND

Right-to-left shunting (RLS), usually through a patent foramen ovale (PFO), has been associated with migraine, cryptogenic stroke, and hypoxemia. With emerging observational studies and clinical trials on the subject of PFO, there is a need for accurate diagnosis of PFO in patients with these conditions, and those being considered for transcatheter closure. Although a TEE bubble study is the current standard reference for diagnosing PFO, the TCD bubble study may be a preferable alternative test for RLS because of its high sensitivity and specificity, noninvasive nature, and low cost.

METHODS

A systematic review of Medline, the Cochrane Library, and Embase was done to look for all the prospective studies assessing intracardiac RLS using TCD compared with TEE as the reference; both tests were performed with a contrast agent and a maneuver to provoke RLS in all studies.

RESULTS

A total of 27 studies (29 comparisons) with 1,968 patients (mean age 47.8 ± 5.7 years; 51% male) fulfilled the inclusion criteria. The weighted mean sensitivity and specificity for TCD were 97% and 93%, respectively. Likewise, the positive and negative likelihood ratios were 13.51 and 0.04, respectively. When 10 microbubbles was used as the embolic cutoff for a positive TCD study, TCD produced a higher specificity compared with when 1 microbubble was used as the cutoff (p = 0.04); there was, however, no significant change in sensitivity (p = 0.29).

CONCLUSIONS

TCD is a reliable, noninvasive test with excellent diagnostic accuracies, making it a proficient test for detecting RLS. TCD can be used as a part of the stroke workup and for patients being considered for PFO closure. If knowledge of the precise anatomy is required, then TEE can be obtained before scheduling a patient for transcatheter PFO closure.

Brain magnetic resonance imaging findings in cryptogenic stroke patients under 60 years with patent foramen ovale

PURPOSE

To compare magnetic resonance imaging (MRI) brain feature in cryptogenic stroke patients with patent foramen ovale (PFO), cryptogenic stroke patients without PFO and patients with cardioembolic stroke.

MATERIALS AND METHODS

The ethics committee required neither institutional review board approval nor informed patient consent for retrospective analyses of the patients' medical records and imaging data. The patients' medical files were retrospectively reviewed in accordance with human subject research protocols. Ninety-two patients under 60 years of age were included: 15 with cardioembolic stroke, 32 with cryptogenic stroke with PFO and 45 with cryptogenic stroke without PFO. Diffusion-weighted imaging of brain MRI was performed by a radiologist blinded to clinical data. Univariate, Fischer's exact test for qualitative data and non-parametric Wilcoxon test for quantitative data were used.

RESULTS

There was no statistically significant difference found between MRI features of patients with PFO and those with cardioembolic stroke (p<.05). Patients without PFO present more corticosubcortical single lesions (p<.05) than patients with PFO. Patients with PFO have more often subcortical single lesions larger than 15mm, involvement of posterior cerebral arterial territory and intracranial occlusion (p<.05) than patients with cryptogenic stroke without PFO.

CONCLUSION

Our study suggests a cardioembolic mechanism in ischemic stroke with PFO.

Headaches caused by vascular disorders

The clinical association between stroke and headache is complex, ranging from the largely irrelevant to the highly specific. The incidence and clinical relevance of acute headache are highly dependent on stroke subtype and etiology. In this article the issue of headache accompanying acute stroke is addressed in some detail.

White matter lesions in children and adolescents with migraine

BACKGROUND

The etiology and clinical importance of white matter lesions in migraine remain poorly understood. To understand these issues more fully, we reviewed the brain magnetic resonance imaging scans of pediatric patients and assessed the relationships between white matter lesions, migraine type, patent foramen ovale, and right-to-left shunting.

METHODS

The magnetic resonance imaging scans of a cohort of children (n = 89) and adolescents, ages 6 to 18 years, who participated in a study of migraine and patent foramen ovale were reviewed. All children in the cohort had undergone saline contrast transthoracic echocardiography and transcranial Doppler studies.

RESULTS

White matter lesions were detected in 15 of the 89 patients (17%). White matter lesions were small (<5 mm) in the majority (10/15; 66%). We observed no relationship between the presence of white matter lesions and (1) migraine type (six patients with white matter lesions among 35 with migraine with aura [17%] vs. nine with white matter lesions among 54 without aura [17%]; P = 1.0); (2) patent foramen ovale (five with white matter lesions among 35 with patent foramen ovale [14%] vs. 10 with white matter lesions among 54 without patent foramen ovale [19%]; P = 0.77); or (3) shunt size (two large shunts in 15 with white matter lesions [13%] vs. nine large shunts among 72 without white matter lesions [13%]; P = 1.0).

CONCLUSIONS

These results indicate that small white matter lesions are not infrequent in children and adolescents with migraine. However, no relationships between white matter lesions and migraine type, patent foramen ovale, or degree of right-to-left shunting were observed.

Long-term outcomes after percutaneous patent foramen ovale closure

Percutaneous patent foramen ovale (PFO) closure is a treatment for cryptogenic stroke and migraine headache. The goal of this study was to assess long-term outcomes of patients treated with percutaneous PFO closure. Records of patients with percutaneous PFO closure at Emory University Hospital from February 2002 to July 2009 were reviewed. Follow-up telephone questionnaire and chart review assessed recurrent stroke, migraine, and complications. Data was reviewed on 414 consecutive patients. Long-term follow-up was obtained in 207 of patients, and mean follow up was 4.6 ± 2.0 years. Cryptogenic stroke was the primary indication for intervention in 193 (93%) patients. Thirteen (7%) patients had a recurrent neurologic event post closure. In patients with multiple neurological events at baseline, 17% (n = 11) had a recurrent event, compared with 2% (n = 2) of patients with a single neurological event prior to PFO-closure (P < 0.002). Post closure, migraine frequency and severity declined from 4.5 to 1.1 migraine/month (P < 0.01) and 7.2 to 3.6 out of 10 (P < 0.01) in patients with history of migraine (n = 60). Thirty-day mortality was 1% (n = 2). One patient had device erosion 5 years post-procedure requiring emergent surgery. Atrial fibrillation was newly diagnosed in 8 (4%) patients within 6 months. In conclusion, the long-term rate of recurrent stroke after PFO closure is low in patients with a single neurological event at baseline. Serious long-term complications after PFO closure are rare. PFO closure may decrease the frequency and severity of migraine.

Diagnostic value of transthoracic echocardiography for patent foramen ovale: a meta-analysis

As a non-invasive and convenient modality, transthoracic echocardiography (TTE) has been widely recommended for the diagnosis of patent foramen ovale (PFO). In this study our aim was to systematically review the diagnostic accuracy of TTE in detection of PFO. We conducted comprehensive searches in PubMed, Embase and the Cochrane Library to the end of September 1, 2012. Sixteen studies comprising 1831 patients were included in the meta-analysis. The quality of reported studies was modest. The summary sensitivity and specificity of TTE in diagnosis of PFO were 88% (95% confidence interval [CI], 79-94) and 97% (95% CI, 92-99), respectively. The positive likelihood ratio was 27.1 (95% CI, 11.2-65.1), and the negative likelihood ratio was 0.12 (95% CI, 0.07-0.22). The summary diagnostic odds ratio was 221 (95% CI, 95-518). Subgroup analyses suggested that age and initial disease may affect the accuracy of TTE in detection of PFO. The meta-analysis suggested that TTE is a test with high sensitivity and specificity in detection of PFO, but it may not be appropriate for screening for PFO in all patients, especially patients with a small right-left shunt.

[A case of migraine with aura attenuated by transcatheter closure of atrial septal defect]

A 38-year old man with an 8-year history of migraine with subclinical abnormal brain lesions on MRI was admitted to our hospital. His migraine attacks followed visual disturbance or dysarthria. Brain MRI revealed old infarctions restricted to the posterior circular region. On transesophageal cardiography, an atrial septal defect (ASD) was detected, and a bubble study showed an immediate appearance of many bubbles in the left atrium via ASD without Valsalva maneuver. The bubble study on transcranial-color-flow imaging also detected micro-embolic signals at the left vertebral artery and the left middle cerebral artery without Valsalva maneuver. Since paradoxical embolism via ASD was highly suspected and Qp/Qs was more than 1.5, transcatheter closure of ASD using AMPLATZER(®) Septal Occluder was performed. At a 2-year follow up, no recurrence of either migraine or infarction was found. This case indicates the relevance of right-to-left shunt to migraine with aura, as well as the usefulness of transcatheter closure of ASD using AMPLATZER(®) Septal Occluder for treatment of migraine with aura.

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.

Migraine prevalence in patients with atrial septal defect

Background

Patients with a patent foramen ovale have a high prevalence of migraine with aura (MA). However, whether patients with an atrial septal defect (ASD) have a high prevalence of migraine remains unclear. The present study aimed to determine the prevalence of migraine and its clinical characteristics in patients with ASD.

Findings

Ninety-five patients (age ≥ 20 years) who had undergone percutaneous ASD closure responded to a questionnaire used by neurologists to diagnose migraine either with or without aura. We diagnosed migraine before ASD closure according to the criteria of the International Headache Society. The overall prevalence of migraine seemed to be higher in the present study than in the Japanese general population (24.2% vs. 9.4%, respectively). All patients with MA were female and significantly younger than those without migraine (p < 0.01).

Conclusions

Our findings suggested that the susceptibility to the development of MA differs according to sex and age in patients with cardiac shunt.

Paradoxical embolization: a potential cause of cerebral damage in Alzheimer's disease?

BACKGROUND

There are considerable overlaps between vascular dementia and Alzheimer's disease (AD), with a suggestion that cerebrovascular disease (CVD) contributes to the neurodegenerative pathology of AD. Paradoxical embolization of venous emboli into the systemic circulation through a venous to arterial circulation shunt (v-aCS), the most commonly a patent foramen ovale (PFO), is known to cause cryptogenic stroke in younger people. We reviewed the potential role of paradoxical embolization in AD.

METHODS

A review of the literature on paradoxical embolization in neurological disorders and techniques to detect v-aCS and PFO, supplemented by data from our own studies.

RESULTS

Before our research, the role of paradoxical embolism in dementia had not been studied. The potential role of embolization in cerebral damage was highlighted by studies in patients undergoing coronary artery bypass or carotid surgery. Paradoxical embolization was found to occur in patients with cryptogenic stroke, migraine, decompression sickles and during hip surgery. The methods for detecting v-aCS or PFO had not been standardized. We found 'significant' v-aCS (equivalent to PFO) in 32% of AD patients compared with 22% of controls, but the study was not sufficiently powered to test the statistic significance of this difference. In AD, there was evidence of an association between 'significant' v-aCS and the severity of white matter hyperintensities on magnetic resonance imaging (MRI).

CONCLUSION

Paradoxical embolization through a v-aCS may be a potentially preventable or treatable cause of CVD in AD.

Prevalence of right-to-left shunts on transcranial Doppler in chronic migraine and medication-overuse headache

BACKGROUND

It was suggested that right-to-left shunt (RLS) may be highly prevalent in chronic migraine (CM) patients, indicating that patent foramen ovale (PFO) might be an aggravating and chronifying factor of migraine. Since a high proportion of chronic migraineurs also have medication-overuse headache (MOH), one may wonder if they have a more severe form of the disorder and more frequently a PFO.

OBJECTIVE

The objective of this study is to determine the prevalence and grade of RLS in patients suffering from CM and MOH.

METHODS

A cross-sectional multicenter study of air-contrast transcranial Doppler was conducted in 159 patients with CM ( N  = 57) or MOH ( N  = 102) attending a tertiary headache clinic.

RESULTS

The prevalence of RLS in CM was 37% (11% large shunts) and in MOH patients 31% (13% large shunts). There was no difference between the two groups ( P  = 0.49).

CONCLUSION

RLS prevalence in CM is within the upper range of those reported in episodic migraine without aura or in the general population, and not higher in MOH. PFO is thus unlikely to have a significant causal role in these chronic headaches.

The effect of patent foramen ovale closure on visual aura without headache or typical aura with migraine headache

OBJECTIVES

The aim of this study was to assess the prevalence of right-to-left (R to L) shunt in patients with visual aura and evaluate the effect of shunt closure on resolution of aura.

BACKGROUND

Right-to-left shunting is associated with migraine headache (MH) with aura. Some patients present with visual aura without headaches. It is unclear whether visual aura without headache is a form of migraine or a transient neurologic dysfunction.

METHODS

Of patients referred to the University of California, Los Angeles for suspected patent foramen ovale (PFO), 225 had visual aura with or without MH. Patients were assessed for a shunt and evaluated for MH and/or visual aura. They were divided into 3 groups: 1) visual aura associated with MH; 2) visual aura unrelated in time to MH; and 3) visual aura without MH. The frequency of R to L shunt was compared with a control group of 200 patients. Eighty patients underwent PFO closure. Residual shunts, MH, and visual aura were reassessed after 3 and 12 months.

RESULTS

The prevalence of R to L shunt in Groups A, B, and C was 96%, 72%, and 67%, respectively, versus 18% in the control group (p < 0.0001). The frequency of shunting was similar in Group B versus Group C, but much higher in all 3 groups compared with control subjects. Twelve months after PFO closure, symptoms of aura were resolved in 52%, 75%, and 80% of patients in Groups A, B, and C, respectively (p = NS).

CONCLUSIONS

The similar distribution of R to L shunting in all 3 patient groups and the correlation between PFO closure and improvement of aura suggests a similar pathophysiology between the presence of PFO and the visual aura phenomenon, whether or not headache is present in the symptom complex.

Migraine and cardiocerebrovascular risk in women

The interest of the medical community has recently focused on the relationship between gender and cardiocerebrovascular risk. In this paper, we will first review gender differences in cardiocerebrovascular disorders, then we will discuss the existing evidence on the links between migraine and stroke and cardiovascular disease in women, and speculate on the possible physiopathological interpretations of this emerging epidemiological link. In the third part of this work, we will address the issue of the effect of sex hormones on vascular risk, and consider the evidence concerning the safety of oral contraceptives and hormone-replacement therapy. Finally, we will outline the main trends of future research and its possible clinical and therapeutic implications.

Right-to-left atrial shunting associated with aortic root aneurysm: a case report of a rare cause of platypnea-orthodeoxia syndrome

Platypnea-orthodeoxia is a rare syndrome characterised by dyspnoea and hypoxaemia worsened on upright posture. We report the case of a 76 year-old man treated for lung adenocarcinoma who had developed severe hypoxaemia due to right-to-left shunt through a patent foramen ovale (PFO). Diagnosis was suspected by systemic uptake of isotope during lung scintigraphy performed to exclude pulmonary embolism. Arterial blood gas analysis in supine and upright positions demonstrated orthodeoxia. Contrast-enhanced transoesophageal echocardiography revealed a slightly redundant atrial septum and large right-to-left shunt through a PFO despite normal pulmonary pressure. Chest computed tomography and echocardiography showed a 59-mm aneurysm of the thoracic aorta. The opening of the PFO seemed to be the result of mechanical deformation of the atrial septum by aortic root dilatation. Transcatheter closure of the atrial defect has provided excellent results, including a rapid increase in systemic saturation and improvement of symptoms without any complications.