Cryptogenic Ischemic Stroke Research Articles

Patent Foramen Ovale and Stroke: Should PFOs Be Closed in Otherwise Cryptogenic Stroke?

Since initial reports of its association with ischemic stroke appeared in 1988, there has been continued controversy regarding the existence and strength of the association between patent foramen ovale (PFO) and ischemic stroke. Many case-control studies have reported an association between incident cryptogenic ischemic stroke and PFO, yet population-based studies have failed to confirm this association. Studies of the risk of recurrent stroke in patients with cryptogenic stroke with or without PFO have not shown an increased risk of recurrent stroke in patients with PFO. Meanwhile, use of devices to close PFOs and atrial septal defects percutaneously has increased dramatically since their introduction. Completion of the randomized clinical trials of PFO closure currently in progress is vital to determine if the benefits of PFO closure in cryptogenic stroke outweigh its risks.

Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective study

PurposeIschemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality. There are several causes of stroke, affecting prognosis, outcomes, and management, but in many cases, the etiology remains undetermined. We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by standard methods. The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months. The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation.Methods and resultsWe prospectively enrolled 24 patients under 75 years of age, 15 men and 9 women of mean age 49 years, who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism. All causes of stroke were excluded by normal 12-lead ECG, 24-h Holter monitoring, echocardiography, cervical Doppler, hematological, and inflammatory tests. All patients underwent electrophysiological study. Of the patients, 37.5% had latent atrial vulnerability, and 33.3% had inducible sustained arrhythmia. Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months. No sustained arrhythmia was found. Only one patient had non-significant episodes of atrial fibrillation.ConclusionIn this study, symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder in patients under 75 years with unexplained cerebral ischemia. The use of this device should not be generalized in the systematic evaluation of these patients. In addition, this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients.

230 Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective continuous monitoring study

Ischemic stroke (IS) is a frequent pathology, burdened by high rate of recurrence and significant morbidity and mortality. There are several causes of IS, affecting prognosis, outcomes and management, but in many cases the etiology remains undetermined despite comprehensive research. We hypothezised that atrial fibrillation (AF) was largely involved in this pathology but was underdiagnosed by standard methods. The aim of this study was to determine the incidence of AF in cryptogenic IS, by using continuous monitoring of the heart rate over several months. The secondary objective was to test the predictive value of atrial vulnerability study towards spontaneous AF. We prospectively enrolled 24 patients under 75 years: 15 men and 9 women of mean age 48.8± 13.6 years who experienced cryptogenic IS presumed of cardioembolic mechanism within the last 4 months. Any cause of IS was excluded by normal 12-lead ECG, 24-hour Holter monitoring, echocardiography, cervical Doppler, haematological and inflammatory tests. All patients underwent electrophysiological study. 7 patients (29.2%) had inducible arrhythmia during programmed atrial stimulation and 9 (37.5%) had a latent vulnerability index (LVI) <2.5. Patients were secondarily implanted with an implantable loop recorder (ILR) (Medtronic™ Reveal Plus 9526) to look for spontaneous AF over a mean follow-up interval of 14.5 months. No sustained arrhythmia was found. Only one patient had non significant AF access (<30 s). In this patient, it was not triggered sustained arrhythmia but the LVI was low. This study shows that contrary to what was expected, AF does not appear to be a common pathology in patients under 75 years with unexplained IS. The use of ILR should not be generalized in the systematic assessment of these patients because of its unprofitability. Finally this study attests the poor value of atrial vulnerability study for predicting spontaneous AF in such patients.

Prognosis after Cryptogenic Cerebral Ischemia in Patients with Coagulopathies

Background/Aim: Prognosis and optimal secondary prevention in ischemic stroke patients with coagulopathies remain unclear. The goal of this prospective observational multicenter study was to determine the risk of recurrence in cryptogenic stroke patients with either no or defined coagulopathies under various prevention regimens. Methods: A total of 429 patients from 14 German stroke centers with an acute cryptogenic ischemic stroke or transient ischemic attack in whom specialized coagulation testing for inherited and acquired coagulopathies (factor V Leiden mutation/resistance to activated protein C, prothrombin mutation, deficiencies of protein C, protein S, antithrombin III, anticardiolipin IgG antibodies, lupus anticoagulant) had been performed were included. Biannual follow-up in 339 (79%) of these patients assessed recurrent cerebrovascular events and secondary prevention therapy during a mean period of 2.5 years. Results: A defined coagulopathy was detected in 89 patients with follow-up, whereas no coagulopathy could be found in 250 patients with follow-up (control group). The Kaplan-Meier estimate for recurrent ischemic stroke or transient ischemic attack after 3 years was 13.6% (95% CI: 5.9–21.2%) in patients with a coagulopathy compared to 9.3% (95% CI: 5.4–13.2%) in controls, which was not significant after adjustment for potential risk factors by Cox regression analysis. Only a previous cerebrovascular ischemic event was an independent predictor for risk of recurrence in coagulopathy and control patients. Conclusions: Our observational data do not indicate a significantly increased risk for recurrent cerebrovascular events in cryptogenic stroke patients with a coagulopathy or any significant influence of the type of antithrombotic treatment.

Influence of transoesophageal echocardiography on therapy and prognosis in young patients with TIA or ischaemic stroke

Objective. To determine the influence of transoesophageal echocardiography (TEE) on therapy and prognosis in patients with cryptogenic transient ischaemic attack (TIA) or ischaemic stroke under the age of 50 years.Methods and results. We evaluated all patients aged 50 and under who were referred to our university hospital for cryptogenic TIA or ischaemic stroke during the period 1 January 1996 to 31 December 2004. All patients underwent both transthoracic echocardiography (TTE) and TEE. Patients with known pre-existent heart disease, such as atrial fibrillation, were excluded. Eighty-three patients with TIA (22) and ischaemic stroke (61) were enrolled. Mean age was 39+/-8 years (range 18 to 50). In 30% of the patients TEE detected one or more potential cardioembolic source, compared with 10% for TTE (p=0.003). Standard treatment (aspirin 38 mg daily) was changed in 7% of the patients due to the TEE findings. Complete followup was obtained in 93% with an average of 5+/-3 years. Twelve recurrences occurred; two out of six patients (33%) with therapy change and ten out of 71 (14%) of the patients without therapy change had a recurrent TIA or ischaemic Stroke.Conclusion. In patients with cryptogenic TIA or ischaemic stroke, TEE is superior to TTE in the detection of a potential cardiac source of embolism. However, findings obtained by TEE only influence the already initiated treatment in a small percentage of patients. The recurrence rate both in the group with and without therapy change is high. (Neth Heart J 2009;17:373-7.).

Transcranial Doppler and Transesophageal Echocardiography: Comparison of Both Techniques and Prospective Clinical Relevance of Transcranial Doppler in Patent Foramen Ovale Detection

Patent foramen ovale (PFO) has been investigated in several conditions apart from cryptogenic ischemic stroke. Contrast transesophageal echocardiography (cTEE) is the gold standard for the diagnosis, although it has some known limitations. Contrast transcranial Doppler (cTCD) allows a semiquantitative estimation of right-to-left shunt (RLS) volume. The aims of our study were to confirm the diagnostic accuracy of cTCD in PFO diagnosis and to compare the abilities of cTCD and cTEE to detect a RLS and PFO, respectively, under normal breathing. The latter could represent an important feature for its clinical significance. A total of 100 consecutive patients (59 women and 41 men, age 46 +/- 12 years) were evaluated after stabilized ischemic stroke/transient ischemic attack, migraine, and lacunae, and before neurosurgery in sitting position. All patients undertook cTEE and cTCD, at rest and under Valsalva maneuver (VM). cTEE under VM was the reference standard. A categorization of patients and a semiquantitative cTCD classification were proposed. In all, 63 of 100 patients had PFO diagnosed by cTEE. A general concordance of up to 90% between both techniques was found. cTCD sensitivity and specificity were 96.8% and 78.4%, respectively. In 17 of 100 patients with cTEE-proven PFO under VM, cTCD and cTEE detected RLS at rest in 75% (95% confidence interval [CI] 62%-85%) and 48% (95% CI 35%-61%) of cases, respectively (P < .001). cTEE disclosed RLS at rest in about 71% (95% CI 9%-42%) of cTCDs showing a "shower-curtain" pattern and only in about 22% (95% CI 52%-85%) of those cTCDs without that pattern. In diagnosing PFO, cTCD has a good accuracy compared with cTEE. To detect a RLS at rest, cTCD appears to be more sensitive than cTEE. The latter resulted positive under normal breathing, mostly in cases of significant RLS at cTCD. Our results point out the impact of cTCD in the evaluation of RLS volume, thus aiding, in association with the anatomic details by cTEE, in the prevention of the occurrence or recurrence of paradoxical embolism in individuals with and without cerebrovascular diseases. The combination of cTEE and cTCD could be considered the real gold standard for PFO in the near future.

0205: Comparison of Patent Foramen Ovale and Aortic Atherosclerosis in Patients with Cryptogenic Ischemic Stroke or Transient Ischemic Attack

0205: Comparison of Patent Foramen Ovale and Aortic Atherosclerosis in Patients with Cryptogenic Ischemic Stroke or Transient Ischemic Attack

Patent Foramen Ovale, Cardiac Valve Thickening, and Antiphospholipid Antibodies as Risk Factors for Subsequent Vascular Events

We sought to estimate risk of recurrent stroke/TIA/death in the subgroup of the Patent Foramen Ovale in the Cryptogenic Stroke Study (PICSS) cohort with patent foramen ovale (PFO) and antiphospholipid antibodies (aPL) and to estimate risk of recurrent stroke/TIA/death in aPL-positive patients who have thickened left-side heart valves (VaT). PFO is associated with cryptogenic ischemic stroke. Also, the presence of aPL is associated with ischemic cerebrovascular disease. Combined data from 2 major substudies of the Warfarin Aspirin Recurrent Stroke Trial (WARSS) were evaluated. PICSS subjects were included if they were enrolled in the Antiphospholipid Antibodies and Stroke Study (APASS) and underwent a baseline aPL test (lupus anticoagulant, anticardiolipin antibodies, or both) within 1 month of the stroke. All patients in PICSS underwent transesophageal echocardiography for PFO as well as VaT, which was performed blinded to aPL status and treatment arm (325 mg/day aspirin or adjusted dose warfarin; target international normalized ratio, 1.4-2.8). The primary outcome event was the 2-year risk of recurrent stroke/TIA/death and was evaluated using Cox proportional hazards model. Because there was no treatment effect, warfarin and aspirin groups were combined to increase power. For the combined end point, power to detect HR of 2 was 47.8% for the PFO and aPL-positive group, and 75.3% for the valve thickening and aPL-positive group, assuming 2-sided type I error of 0.05. Five hundred twenty-five subjects were tested for the combined presence of PFO and aPL and were available for evaluation. The primary outcome event rate was 23.9% (HR, 1.39; 95% CI, 0.75-2.59) in the PFO-positive/aPL-positive group, compared to 13.9% (HR, 0.83; 95% CI, 0.44-1.56) in the PFO-positive/aPL-negative group, and 19.9% (HR, 1.16; 95% CI, 0.68-1.90) in the PFO-negative/aPL-positive group. Five hundred forty-five subjects tested for combined presence of aPL and left-side cardiac VaT were available for evaluation. The primary event rate was 22.6% (HR, 1.65; 95% CI, 0.88-3.09) in the VaT-positive/aPL-positive group, compared to 19.4% (HR, 1.50; 95% CI, 0.82-2.75) in the VaT-positive/aPL-negative group, and 20.2% (HR, 1.63; 95% CI, 0.81-3.25) in the VaT-negative/aPL-positive group. The combined presence of aPL either with a PFO or with left-side cardiac VaT did not significantly increase risk of subsequent cerebrovascular events in this PICCS/APASS cohort of patients.

Cerebral Ischemic Events Associated With ‘Bubble Study’ for Identification of Right to Left Shunts

Detection of an intracardiac shunt is frequently sought during the evaluation of patients with cryptogenic ischemic stroke and agitated saline intravenous injection, or "bubble study" (BS), is performed in most cases. We present the first attempt to identify the clinical features in patients who had cerebral ischemic events with BS. Using a list serve established by the American Academy of Neurology, a member posted a question regarding the safety of BS in patients with patent foramen ovale. A standardized questionnaire was used to gather data about patients with cerebral ischemic events, details of each case were reviewed, and the findings pooled. Five patients with ischemic complications of BS (all female, aged 42 to 90 years) were identified from 4 institutions, 3 ischemic strokes and 2 transient ischemic attacks. Events occurred either during or within 5 minutes of BS. Early brain MRIs confirmed acute infarction in 3, including one who had transient symptoms. MRI infarct volumes were small, and deficits were mild in those who developed stroke. Diagnostic evaluation revealed a patent foramen ovale alone in one case, a pulmonary arteriovenous malformation in one case, and a patent foramen ovale and/or pulmonary shunt in 3 cases. Ischemic cerebrovascular complications can occur in patients who undergo BS and are associated with the presence of cardiac or pulmonary shunts. The true incidence and degree of disability remains unknown, and further study is indicated to assess the impact of technical differences in BS methodology. Novel methods to promote physician communication such as the use of electronic list serves may reduce barriers to reporting of drug, technique, or device complications and should be explored to identify rare complications that otherwise will likely go unappreciated.

Patent foramen ovale and ischemic stroke recurrence

During the last two decades, evidence has shown an association between patent foramen ovale (PFO) and cryptogenic stroke, predominantly in younger patients. In a meta-analysis of case-control studies, approximately 35%–50% of patients with cryptogenic ischemic stroke had a PFO, vs only 4%–10% of age-matched patients. That is a fivefold increase risk of cryptogenic stroke in younger patients with PFO.1 However, causality and its recurrence seem to be more complex, considering that 27% of the general population has this vestige of fetal circulation.2 The risk of stroke recurrence due to the failure of the primum and secundum septa to fuse postnatally is low. In the PFO-ASA trial, the recurrence in aspirin-treated patients was 2.3% in 4 years vs 4.2% observed in those without an interatrial septal abnormality. This risk strikingly increased to 15.2% if coexisting atrial septal aneurysm (ASA) was present.3 The ASA-PFO embolic mechanism is unclear but it is possibly related to motion dynamics influencing flow through the PFO leading to paradoxical emboli or possibly being a nidus for thrombus formation. In other …

Recurrent cerebral ischemia in medically treated patent foramen ovale

Among patients with a patent foramen ovale (PFO) and a prior cryptogenic ischemic stroke or TIA, the absolute and relative risk of recurrent events is unclear. We conducted a systematic review and meta-analysis of clinical studies in any language published up to February 2008. We included studies reporting original data on recurrent cerebrovascular events in patients with prior cryptogenic stroke or TIA and PFO. Two authors independently extracted data and evaluated study quality. We identified 15 eligible studies, four with a non-PFO comparison group. In these four studies, the pooled relative risk (RR) for recurrent ischemic stroke or TIA in patients with vs without a PFO was 1.1 (95% confidence interval [CI] 0.8 to 1.5). For ischemic stroke, the pooled RR was 0.8 (95% CI 0.5 to 1.3). We tabulated the absolute rate of recurrent events in all 15 studies. The pooled absolute rate of recurrent ischemic stroke or TIA in patients with PFO was 4.0 events per 100 person-years (95% CI 3.0 to 5.1) while the rate of recurrent ischemic stroke was 1.6 events per 100 person-years (95% CI 1.1 to 2.1). In medically treated patients with prior cryptogenic stroke, while the absolute rate of recurrent events is variable, available evidence does not support an increased relative risk of recurrent ischemic events in those with vs without a patent foramen ovale. Patent foramen ovale closure in these patients cannot be recommended until the results of ongoing clinical trials are reported.

Altered Fibrin Clot Structure/Function in Patients With Cryptogenic Ischemic Stroke

We tested the hypothesis that fibrin structure/function is unfavorably altered in patients with cryptogenic ischemic stroke. Ex vivo plasma fibrin clot permeability, turbidimetry, and efficiency of fibrinolysis were determined in 89 patients with patent foramen ovale (PFO) and a history of first-ever stroke, 58 patients with first-ever stroke and no PFO, and 120 healthy controls. Stroke patients, evaluated 3 to 19 months after the event, and controls did not differ with regard to age, sex, smoking, and fibrinogen. Stroke patients with or without PFO had lower clot permeability (P<0.0001), faster fibrin polymerization (P<0.0001), prolonged clot lysis time (P<0.0001), higher maximum D-dimer levels released from clots (P<0.0001), and maximum rate of D-dimer release (P=0.02) than controls. Time from stroke occurrence showed no association with any clot variables. Scanning electron microscopy of fibrin clots showed increased fiber diameter and density in stroke patients. Clots from stroke patients with PFO were more permeable and showed shorter lysis time compared to those without PFO, and this was related to lower proportion of smokers in the former group. Altered fibrin clot structure and resistance to fibrinolysis are associated with cryptogenic stroke.

A suture not always the ideal solution: Problems encountered in developing a suture‐based PFO closure technique

To summarize our experiences with the first-in-man suture-based patent foramen ovale (PFO) closure technique. PFO is often present with the occurrence of cryptogenic stroke and migraine with aura. Successful PFO closure can be performed percutaneously using catheter techniques with many different closure devices. The described novel closure system is intended to deliver, via endovascular access, a suture into the atrial septal wall tissue for closure of PFO. Eleven patients, between 22 and 58 years of age (mean 46.6 +/- 9.6), who had a cryptogenic ischemic stroke, TIA, or a peripheral embolism and a PFO were considered for percutaneous closure with this technique. The mean stretched diameter of the defect evaluated during balloon sizing was 8.8 +/- 0.4 mm (range 7-12.5). Delivery of the suture was successful in all patients. No intraprocedural complications occurred. During the follow up, complete closure could be achieved in one patient. Six patients with significant residual shunting during follow-up had successful closure using a conventional device. One patient was lost for follow-up after the 3-month visit. The residual shunt in the remaining three patients was very small and they declined to be treated with a conventional device. No complications occurred during the follow up. Transcatheter application of a suture for closure of PFO is technically feasible and safe. However, despite successful suturing of the septum primum to the septum secundum, the PFO did not close in most of the patients.

Rôle du tabagisme dans la pathologie vasculaire cérébrale

Up to one quarter of all strokes are directly attributable to cigarette smoking, that percentage can get up to 50% for young adults admitted for an cryptogenic ischemic stroke. Cigarette smoking increases the relative risk of ischemic stroke about two-fold, three-fold for subarachnoid haemorrhage. Current smoking is not clearly identified as a risk factor for intra-cerebral haemorrhage. The risk is consistent for all subtypes of stroke according aetiology and is strongest for ischemic stroke caused by arterial atherothromboembolism. The risk is dependent upon the amount of cigarettes smoked and passive smoking is a substantial risk of stroke. The relative risk is maximal in middle age, declining with advancing years. The toxicity is higher among female smokers, especially when they have several risk factors such as oral contraceptiveS and migraine with aura. Whereas it is well known that the effectiveness of cigarette withdrawal reduces the risk of new vascular event, two thirds of young patients continue to smoke.

Prevalence of prothrombotic polymorphisms in a selected cohort of cryptogenic and noncryptogenic ischemic stroke patients

Ischemic stroke is a complex multifactorial disease and approximately 30%, especially in the young, are cryptogenic. In some of the patients with cryptogenic ischemic stroke the underlying risk factor may be a prothrombotic state. We studied 101 patients with ischemic stroke under 55 years of age. All the patients underwent an extensive diagnostic evaluation to determine the cause of stroke. Common variations in the genes encoding factor V, prothrombin, 5,10-methylenetetrahydrofolate reductase, plasminogen activator inhibitor-1, and human platelet alloantigens-1 were evaluated. Of the 101 patients with ischemic stroke, 28 patients had cryptogenic ischemic stroke. At least one of the different genetic polymorphisms investigated was present in 44% patients in the total group and in 48% of patients with cryptogenic ischemic stroke. In this study population under 55 years of age there was no significant difference in the prevalence of various genetic polymorphisms, factor V, prothrombin, 5,10-methylenetetrahydrofolate reductase, plasminogen activator inhibitor-1, and human platelet alloantigens) in patients with cryptogenic ischemic stroke and in patients with ischemic stroke of determined cause.

Tissue factor +5466A&gt;G polymorphism predicts plasma TF levels in subjects with cryptogenic ischaemic stroke

Tissue factor +5466A>G polymorphism predicts plasma TF levels in subjects with cryptogenic ischaemic stroke -

Diagnostic and therapeutic impact of cardiac MRI in patients with cryptogenic ischemic stroke

Diagnostic and therapeutic impact of cardiac MRI in patients with cryptogenic ischemic stroke

Abstract 1173: Risk of Recurrent Cerebrovascular Events in Patients with Cryptogenic Cerebral Ischemia and Patent Foramen Ovale: A Meta-Analysis of Observational Studies

In patients with a patent foramen ovale (PFO) and a prior cryptogenic ischemic stroke or transient ischemic attack (TIA), the risk of recurrent events is unclear. To conduct a systematic review and meta-analysis of studies assessing the risk of recurrent cerebrovascular events in patients with cryptogenic cerebral ischemia and PFO. MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) databases were searched to identify studies in any language. Searches were supplemented by scanning bibliographies of key articles. Studies reporting original data on recurrent cerebrovascular events in patients with prior cryptogenic stroke or TIA and PFO, with or without a non-PFO comparison group, were included. Uncontrolled case series evaluating device or surgical closure of PFO were excluded. Two authors independently extracted the data from included studies and evaluated study quality. For studies with a non-PFO comparison group, relative risks were pooled using a fixed effects model after confirming homogeneity of results. For all studies, the pooled absolute rate of recurrent events was calculated using a random effects model due to heterogeneity of results. Fifteen studies published between 1994 and 2007, following 2377 patients over a mean of 37 months were included. In the four studies with a non-PFO comparison group, the pooled relative risk of recurrent stroke or TIA associated with the presence of a PFO was 1.1 (95% CI 0.8 to 1.5), while for recurrent ischemic stroke the pooled relative risk associated with the presence of a PFO was 0.8 (95% CI 0.5 to 1.3). The pooled absolute rate of recurrent ischemic stroke or TIA in patients with PFO was 4.0 events per 100 person-years (95% CI 3.0 to 5.1) while the rate of recurrent ischemic stroke was 1.6 events per 100 person years (95% CI 1.1 to 2.1). No clinical or imaging features are reliably associated with increased risk of recurrent events. In medically treated patients with prior cryptogenic stroke, available evidence does not support an increased risk of recurrent ischemic events in those with vs. without a PFO. Routine PFO closure in these patients may not be warranted, outside of ongoing clinical trials.

Cryptogenic stroke and patent foramen ovale: Clinical clues to paradoxical embolism

BackgroundPatent foramen ovale (PFO) is an independent risk factor for cerebral infarction. Since ~25% of the population have a PFO, the simple association of PFO with stroke is not enough to establish the diagnosis of paradoxical embolism. We evaluated possible clinical clues to the diagnosis of paradoxical embolism. MethodsAmong patients with cryptogenic ischemic stroke (CS) who were investigated for a right-to-left shunt (RLS), we compared clinical, coagulation and biochemical parameters in patients with PFO versus without PFO. ResultsAmong 1689 new patients referred for TIA/non-disabling stroke between 2001 and 2007, 175 with cryptogenic stroke (CS) were investigated for RLS by transcranial Doppler (TCD) bubble studies; 89 (5.5%) with positive TCD had a PFO confirmed by TEE. In multivariate logistic regression, a history of DVT or pulmonary embolism (OR, 4.39; 95% CI, 1.23–15.69; p=0.023), prolonged travel (OR, 8.77; 95% CI, 1.775–43.3; p=0.008) , migraine (OR, 2.30: 95% CI, 1.07–4.92; p=0.031), a Valsalva maneuver preceding the onset of focal neurological symptoms (OR, 3.33; 95% CI, 1.15–9.64; p=0.026) and waking up with stroke/TIA (OR, 4.53, 95% CI, 1.26–16.2; p=0.018) were independently associated with PFO-associated cerebrovascular events. Patients with PFO had higher plasma total homocysteine levels than patients without PFO (8.9±3 versus 7.9±2.6 µmol/L respectively; p=0.021). ConclusionsA history of DVT or pulmonary embolism, migraine, recent prolonged travel, sleep apnea, waking up with TIA or stroke or a Valsalva maneuver preceding the event are clinical clues to the diagnosis of paradoxical embolism among patients with CS.

Extracerebral paradoxical embolisms in patients with intracardiac shunts

Abstract Background Intracardiac shunts are considered to play a role in cryptogenic ischemic stroke. However, data on paradoxical embolization into the peripheral arteries remains scarce. Since passage of the emboli through an intracardiac shunt is considered to be the possible etiological mechanism, identification of the presence of a venous thrombus and its migration via the cardiac shunt are essential to confirm this pathogenic mechanism. However, both of these essential components are often difficult to establish due to various methodological and temporal issues. Methods Various factors limiting the diagnostic methods of intracardiac shunts are discussed. Results The diagnostic criteria for intracardiac shunt should be aimed at looking into both cerebral as well as peripheral arterial beds. Utilizing the quantitative grading scales may help in a better assessment of the intracardiac shunts. Conclusions Quantification of the intracardiac shunt and its “functional potential” should be considered an individuals' preferential predisposition for the involvement of various arterial beds. This would help in a better understanding of the complex relationship between intracardiac shunts and various systemic embolic phenomena and planning for a definitive treatment.