Inherited thrombophilia in ischemic stroke and its pathogenic subtypes

Radiological pattern in cryptogenic stroke/TIA patients with and without thrombophilia

BACKGROUND

The radiological pattern of stroke patients with thrombophilia is unknown. Our aim is to compare the MRI radiological pattern of silent and acute lesions in cryptogenic stroke/TIA patients under 60 years of age with and without thrombophilia.

METHODS

Cryptogenic stroke/TIA patients under 60 years of age hospitalized at our Stroke Unit during four years were consecutively included. Thrombophilia screening was performed at 3 months after stroke and verified 12 weeks later. The follow-up was performed at 3, 12 and 24 months. Radiological pattern was assessed with the Fazekas and van Swieten scales.

RESULTS

During four years, 185 cryptogenic stroke/TIA patients under 60 years of age were included; mean age was 51 years, 61% were female, with a follow-up of 22±3.2 months. Thrombophilia was detected in 20% of patients. We detected a significant increase of previous vascular events (29.7% vs 7.5%, p=.01) as well as lower hypercholesterolemia (27% vs 62.5% p=.003) in the thrombophilia group, without significant differences in other vascular risk factors or vascular recurrence during follow-up. Regarding the acute lesion, we did not detect significant differences between groups. The radiological pattern of silent lesions showed that the thrombophilia group presented more large confluent lesions (39.1% vs 19.2%, p=.02) with greater sparing of the anterior territory (0% vs 30%, p=.01).

CONCLUSIONS

Our data suggest a characteristic radiological pattern of silent lesions in cryptogenic stroke/TIA patients with thrombophilia, with more confluent lesions and less involvement of the anterior territory.

The Etiology of the Thrombotic Phenomena Involved in the Process of Coronary Artery Disease-What Is the Role of Thrombophilic Genes in the Development of This Pathology?

Cardiovascular diseases, among which includes coronary artery disease, represent one of the most important causes of mortality and morbidity worldwide. Research aimed at determining the risk factors involved recognizes a group of "traditional" risk factors, but also more recent studies identified over 100 "novel" ones which may have a role in the disease. Among the latter is the thrombophilia profile of a patient, a pathology well-established for its involvement in venous thromboembolism, but with less studied implications in arterial thrombosis. This paper reviews the literature, explaining the pathophysiology of the thrombophilia causes associated most with coronary thrombosis events. Results of several studies on the subject, including a meta-analysis with over 60,000 subjects, determined the significant involvement of factor V Leiden, prothrombin G20210A mutation, plasminogen activator inhibitor-1 and antiphospholipid syndrome in the development of coronary artery disease. The mechanisms involved are currently at different stages of research, with some already established and used as therapeutic targets.

Thrombophilia Testing in Stroke: A Case Report and Review of Evidence

Thrombophilia is commonly associated with venous thromboembolism, but its relationship with arterial thrombosis, specifically stroke, is not as clearly established. Several large studies have failed to establish a significant connection between inherited thrombophilia and stroke. While tests for Factor V Leiden mutation, prothrombin mutation, protein C deficiency, protein S deficiency, antithrombin deficiency, and antiphospholipid antibodies are typically done for thrombophilia diagnosis, there appears to be little or no correlation between these markers and stroke. In this article, we discuss a case of a 26-year-old male admitted with right neck pain that developed after playing basketball; he was found to have a right cerebellar infarction. He underwent extensive tests for hypercoagulable disorders, which were negative. We also review current evidence and reassess the value of thrombophilia testing in stroke patients.

Low value of inherited thrombophilia testing among patients with stroke or transient ischemic attack: A three-year retrospective study

BACKGROUND/PURPOSE

Inherited thrombophilia testing in the acute inpatient setting is controversial and expensive, and rarely changes clinical management. We evaluated ordering patterns and results of inpatient inherited thrombophilia testing for patients who presented with an isolated acute ischemic stroke or transient ischemic attack (TIA) without concurrent venous thromboembolism.

METHODS

We retrospectively analyzed patients admitted for acute ischemic stroke or TIA between January 1st, 2019 and December 31st, 2021 at Thomas Jefferson University Hospitals in Philadelphia, PA and who underwent inherited thrombophilia testing during the hospital admission. Charts were reviewed to determine stroke risk factors, test results, and clinical management.

RESULTS

Among 2108 patients admitted for acute ischemic stroke or TIA (including branch and central retinal artery occlusions) during the study period, the study included 249 patients (median age 49.0 years, 50.2% female) who underwent inpatient testing for factor V Leiden, prothrombin G20210A variant, hyperhomocysteinemia, PAI-1 elevation, and deficiencies of protein C and S and antithrombin. 42.2% of patients had at least one abnormal test, and among the 1035 tests ordered, 14.3% resulted abnormal. However, 28% of abnormal tests were borderline positive antigen or activity assays that likely represented false positives. There was no significant difference in the likelihood of a positive test among patients without stroke risk factors vs those with risk factors (47.1% vs 40.9%, P = .428), nor any significant difference between those under vs over age 50 years (45.7% vs 38.3%, P = .237). No patients with an abnormal result had their clinical management changed as a result. Charges for the tests totaled $468,588 USD.

CONCLUSIONS

Inherited thrombophilia testing in the hospital immediately following isolated acute arterial ischemic stroke or TIA was associated with high rates of likely false positive results and was expensive. Positive results did not change clinical management in a single case.

Dilemmas in hematology: consults in patients with arterial thrombosis

Arterial thrombotic events, particularly ischemic stroke and myocardial infarction, are common, and mostly occur due to atherosclerotic disease or arrhythmias. The diagnosis and management of the majority of such events occurs without the involvement of a hematologist, following established guidelines or pathways. In this review, we discuss 3 scenarios in which optimal management is less certain. These scenarios concern patients with a left ventricular thrombus, in whom the duration and choice of anticoagulant has been debated, patients with ischemic stroke and a patent foramen ovale, in whom the role of patent foramen ovale closure requires careful consideration, and the role of thrombophilia testing in young patients after a stroke or myocardial infarction, which remains an area of contention. We consider the available evidence and published guidelines in order to provide a practical, evidence-based approach to these 3 clinical scenarios.

Pediatric Stroke: A Review of Common Etiologies and Management Strategies

Pediatric stroke is an important cause of mortality and morbidity in children. There is a paucity of clinical trials pertaining to pediatric stroke management, and solidified universal guidelines are not established for children the way they are for the adult population. Diagnosis of pediatric stroke can be challenging, and it is often delayed or mischaracterized, which can result in worse outcomes. Understanding risks and appropriate therapy is paramount to improving care.

Hereditary Thrombophilia Testing Among Hospitalized Patients: Is It Warranted?

Background

Hereditary thrombophilias (HTs) are a group of inherited disorders that predispose the carrier to venous thromboembolism (VTE). It is estimated that 7% of the population has some form of HT. Although testing for HT has become routine for many hospitalized patients, knowing when to order the tests and how to interpret the results remains challenging. In the United States, there are no clear guidelines regarding testing for HT. We conducted a study to evaluate the utilization of HT testing among hospitalized patients to examine its impact on immediate management decisions and overall cost burden. In addition, we discuss the common reasons for healthcare providers to order these tests and review the data behind these reasons in the literature.

Methodology

A retrospective analysis of 2,402 patients who underwent HT testing between February 1, 2016, and January 31, 2018, was conducted. Eligible patients had at least one HT test ordered during hospitalization. The primary outcome was to determine the incidence of positive actionable tests. A positive actionable test was defined as a positive result that changed the anticoagulation intensity, type, or duration. Patients with a history of previous VTE, ongoing medical conditions requiring life-long anticoagulation, or unprovoked VTE were considered non-actionable.

Results

Among the 2,402 patients, 954 patients met the inclusion criteria with a mean age of 54 years. A total of 397 (41.6%) tests were ordered for acute VTE, while the rest were for non-VTE conditions, such as stroke, pregnancy complications, peripheral artery diseases, and others. Only 89 positive tests were actionable (14% of the positive tests, and 9.3% of the total ordered tests). There was a statistically significant association between increasing age and having both a positive test result (p = 0.006) and an actionable test (p = 0.046). The total cost of ordering these tests was estimated to be $566,585.

Conclusions

HT testing in the inpatient setting did not alter management in many cases and was associated with increased healthcare costs. The decision to order these tests should be individualized based on the clinical scenario.

Hypoxic-ischemic injury causes functional and structural neurovascular degeneration in the juvenile mouse retina

Ischemic stroke is a major cause of long-term disabilities, including vision loss. Neuronal and blood vessel maturation can affect the susceptibility of and outcome after ischemic stroke. Although we recently reported that exposure of neonatal mice to hypoxia–ischemia (HI) severely compromises the integrity of the retinal neurovasculature, it is not known whether juvenile mice are similarly impacted. Here we examined the effect of HI injury in juvenile mice on retinal structure and function, in particular the susceptibility of retinal neurons and blood vessels to HI damage. Our studies demonstrated that the retina suffered from functional and structural injuries, including reduced b-wave, thinning of the inner retinal layers, macroglial remodeling, and deterioration of the vasculature. The degeneration of the retinal vasculature associated with HI resulted in a significant decrease in the numbers of pericytes and endothelial cells as well as an increase in capillary loss. Taken together, these findings suggest a need for juveniles suffering from ischemic stroke to be monitored for changes in retinal functional and structural integrity. Thus, there is an emergent need for developing therapeutic approaches to prevent and reverse retinal neurovascular dysfunction with exposure to ischemic stroke.

Prothrombotic Factors Have Significant Association with Arterial and Venous Strokes in Indian Tamilians

BACKGROUND

Prothrombotic factors have been correlated with vascular events in young patients, with recurrent strokes, and with venous thromboembolisms. However, their prevalence in adult strokes, in healthy populations, and in specific ethnic groups is not well defined. We investigated the association of prothrombotic factors with strokes in a South Indian Tamil population.

METHODS

In this hospital-based cross-sectional study, plasma homocysteine (Hcys), protein C and protein S activity levels, activated protein C resistance (APCR) as a surrogate for factor V Leiden (FVL), fibrinogen, and antithrombin III (ATIII) were determined from 75 consecutive patients with ischemic stroke (IS), 25 with cortical venous thrombosis (CVT), and 75 healthy control participants. The Student t test or Mann-Whitney U test was used for comparing prothrombotic factor levels between the stroke and control groups. The χ2 or Fisher exact test was used for comparisons of proportions of thrombophilia and estimation of odds ratios. Mid-P correction was done for multiple estimations.

RESULTS

Hcys levels in patients with IS were significantly higher compared with those in healthy control participants (P = 0.02). Proportions of ATIII deficiency and hyperfibrinogenemia were significantly higher in the IS group, and no healthy control participants had hyperfibrinogenemia. Protein C deficiency was more frequent in those with IS (17%; P < 8 × 10-5) and CVT (P < 10-7) compared with healthy control participants, and protein C activity levels (P = 0.016) were also significantly lower in patients with CVT. Other parameters had no significant associations with IS and CVT. The frequency of protein S deficiency was high in healthy control participants (60%) and in both patients with IS (45%; P = 0.1) and patients with CVT (48%; P = 0.4). No patients or control participants had abnormal APCR.

CONCLUSIONS

In Tamilian participants, several prothrombotic factors were associated with IS. Protein C deficiency alone was associated with CVT. Replication of the pattern in genetically linked populations around the world may affect management of stroke in those populations.

Cerebral Venous Sinus Thrombosis in Women: Subgroup Analysis of the VENOST Study

Background

Early diagnosis of cerebral venous sinus thrombosis (CVST) associated with reproductive health-related risk factors (RHRF) including pregnancy, puerperium, and oral contraceptive (OC) use can prevent severe neurological sequelae; thus, the symptoms must be documented in detail for each group.

Methods

Out of 1144 patients with CVST, a total of 777 women were enrolled from a multicenter for the study of cerebral venous sinus thrombosis (VENOST). Demographic, biochemical, clinical, and radiological aspects were compared for 324 cases with RHRF and 453 cases without RHRF.

Results

The mean age of the RHRF (-) group (43.2 ± 13 years) was significantly higher than of the RHRF (+) group (34 ± 9 years). A previous history of deep venous thrombosis (3%), isolated cavernous sinus involvement (1%), cranial neuropathy (13%), comorbid malignancy (7%), and its disability scores after 12 months (9%) were significantly higher in the RHRF (-) group. The RHRF (+) group consisted of 44% cases of puerperium, 33% cases of OC users and 23% of pregnant women. The mean age was found to be higher in OC users (38 ± 9 years). A previous history of deep venous thrombosis was slightly higher in the pregnancy subgroup (4%). Epileptic seizures were more common in the puerperium group (44%).

Conclusion

The results of our study indicate that the risk of CSVT increases parallel to age, OC use, and puerperium period. In addition, when considering the frequency of findings and symptoms, epileptic seizures in the puerperium subgroup of the RHRF (+) group and malignancies in the RHRF (-) group may accompany the CSVT. In daily practice, predicting these risks for the CSVT and early recognition of the symptoms will provide significant benefits to patients.

Protein C Deficiency as a Risk Factor for Stroke in Young Adults: A Review

Protein C (PC) is a 62-kD vitamin K dependent glycoprotein produced by the liver as a zymogen and is activated by binding to the thrombin-thrombomodulin complex, with protein S (PS) acting as a cofactor. Among its various functions, PC acts as a naturally occurring anticoagulant and its deficiency, either homozygous or heterozygous, predisposes the individual to a state of thrombosis, particularly venous thromboembolism, and mainfests as myocardial infarction (MI), deep venous thrombosis, pulmonary embolism, or stroke. This review discusses the pathophysiology of the anticoagulatory effect of PC, mode of inheritance of its deficiency, the arterial and venous involvement in patients with stroke, and its risk factors. A detailed analysis of published case reports on PC deficiency as a causative agent of stroke in young adults has also been included along with the management of such patients.

Hypercoagulable states in arterial and venous thrombosis: When, how, and who to test?

Evaluation for underlying hypercoagulable states in patients with thrombosis is a frequent clinical conundrum. Testing for thrombophilias is often reflexively performed without strategic approach nor clear appreciation of the clinical implications of such results. Guidelines vary in the appropriate utilization of thrombophilia testing. In this review, we discuss the more commonly encountered inherited and acquired thrombophilias, their association with initial and recurrent venous thromboembolism, arterial thromboembolism, and role in women's health. We suggest an approach to thrombophilia testing guided by the clinical presentation, suspected pathophysiology, and an understanding of how such results may affect patient care.

Alpha-2-antiplasmin Arg407Lys polymorphism and cryptogenic ischemic cerebrovascular events: Association with neurological deficit

OBJECTIVE

Genetic background of cryptogenic ischemic stroke (IS) and transient ischemic attack (TIA) remains uncertain. Alpha-2-antiplasmin (α2AP) Arg407Lys polymorphism has been shown to be less common in patients with abdominal aortic aneurysm (AAA) compared with healthy controls. We investigated associations of α2AP Arg407Lys polymorphism with cryptogenic IS and TIA.

METHODS

We studied 165 consecutive Caucasian patients who experienced cryptogenic IS (n=123) or TIA (n=42). Neurological outcomes were assessed using the modified Rankin Scale (mRS) in the acute phase of cerebral ischemia and 8 (6-12) months after the index episode. Patients were genotyped for α2AP Arg407Lys polymorphism (rs1057335) using real time PCR technique.

RESULTS

The allele frequency of Arg407Lys polymorphism was: 0.82/0.18. The 407Lys allele was more frequent in TIA patients compared to the IS group (0.29 vs. 0.14, p=0.003). In the whole group, as well as in IS and TIA patients analyzed separately, possession of the 407Lys allele was associated with excellent outcome (mRS 0-1) during follow-up (p<0.05) but not in the acute phase of ischemic events both in thrombolyzed and nonthrombolyzed IS patients. The multivariate logistic regression model showed that the excellent outcome (mRS 0-1) assessed after 8 (6-12) months since the index cerebral ischemia was predicted by the occurrence of Lys407 allele (OR 6.18, 95% CI, 2.01-18.98, p=0.001).

CONCLUSION

The presence of 407Lys allele is associated with better prognosis in cryptogenic cerebrovascular events. Our findings suggest that the α2AP Arg407Lys polymorphism could be involved in the pathogenesis of cerebral ischemia and its outcomes.

Pediatric arterial ischemic stroke: Epidemiology, risk factors, and management

Pediatric arterial ischemic stroke (AIS) is an uncommon but important cause of neurologic morbidity in neonates and children, with consequences including hemiparesis, intellectual disabilities, and epilepsy. The causes of pediatric AIS are unique to those typically associated with stroke in adults. Familiarity with the risk factors for AIS in children will help with efficient diagnosis, which is unfortunately frequently delayed. Here we review the epidemiology and risk factors for AIS in neonates and children. We also outline consensus-based practices in the evaluation and management of pediatric AIS. Finally we discuss the outcomes observed in this population. While much has been learned in recent decades, many uncertainties sill persist in regard to pediatric AIS. The ongoing development of specialized centers and investigators dedicated to pediatric stroke will continue to answer such questions and improve our ability to effectively care for these patients.

Activated Protein C Resistance Does Not Increase Risk for Recurrent Stroke or Death in Stroke Patients

Background

Activated protein C (APC) resistance is the most common inherited prothrombotic disorder. The role of APC resistance in ischemic stroke is controversially discussed.

Objectives

The aim of this single center follow up study was to investigate the effect of APC resistance on stroke recurrence and survival in stroke patients.

Patients/Methods

We retrospectively identified 966 patients who had had an ischemic stroke or transitory ischemic attack (TIA) and in whom laboratory tests for APC resistance had been conducted. These patients were contacted to determine the primary outcomes of recurrent ischemic stroke or death.

Results

A total of 858 patients with an average follow up time of 8.48 years were included. APC resistance did not influence cumulative incidence functions for stroke free and total survival. In multivariate analyses, crude and adjusted hazard ratios for recurrent stroke as well as for death where not significantly increased in patients with APC resistance. This also applies to the subgroups of young patients, patients with cryptogenic stroke and patients with atrial fibrillation.

Conclusion

APC-resistance is not a risk factor for subsequent stroke or death in patients with a first ischemic stroke or TIA. Testing for APC-resistance in stroke patients therefore cannot be routinely recommended.

Anticardiolipin antibodies in various diseases in Taiwan: a retrospective analysis

The goals of this study are to determine the frequency of anticardiolipinantibodies (ACA) in patients with various diseases and to evaluate the clinical significance of ACA in Taiwan. We collected 690 patients from ACA laboratory records. They were divided into eight groups in order to compare ACA percentages. Positive rates of ACA in different disease groups were below 20%, except for 38.2% in autoimmune diseases with vascular thrombosis. Compared with old stroke, the ACA positivity in young stroke was not significantly different (P 0.482). The positive percentage of lupus anticoagulant (LA) (2.86%) was lower than that of ACA (15.66%) in young stroke (P 0.015). Among patients with pregnancy loss or prematurity, the ACA positivity in lupus patients (44.44%) was higher than without lupus (9.76%; P 0.01). The prevalence of ACA is higher in patients with vascular thrombosis complicated by autoimmune diseases than with thrombosis alone in Taiwan. Young and old stroke do not differ in ACA positivity. Moreover, ACA is more prevalent than LA for young stroke related coagulation.The ACA positivity for pregnancy loss or prematurity is very low in Taiwan. In summary, this is the first report on the frequency of ACA and other coagulation factors in various diseases in Taiwan.

Hereditary protein S deficiency leads to ischemic stroke

Hereditary protein S (PS) deficiency is an independent risk factor for venous thromboembolism. However, the correlation between PS and arterial thrombotic disease, such as cerebral thrombosis, is not clear. The present study focused on the molecular mechanisms underlying ischemic stroke caused by a PS gene mutation in one family. The activity of antithrombin, protein C and PS in the plasma of the proband was measured, and the genes encoding PS were amplified and sequenced. The cellular localization and expression of PS were analyzed in HEK‑293 cells. The proband was a 50‑year‑old male. Plasma PS activity of the proband was 38.9%, which was significantly decreased compared with normal levels. Sequencing analysis revealed a PROS1 c.1486_1490delGATTA mutation on exon 12. This frameshift mutation converts Asp496 in the precursor PS into the termination codon. In addition, the PROS1 mutation was correlated with low PS activity in the family. Functional tests revealed that the mutant protein aggregated in the cytoplasm and its secretion and expression decreased. In conclusion, protein S mutation appeared to be the primary cause of thrombosis in the family of the present study. However, the correlation between PS deficiency and ischemic stroke requires further investigation.

Unusual co-existence of dural sinus thrombosis and aneurysmal subarachnoid hemorrhage in a patient with lupus

Subarachnoid hemorrhage and dural sinus thrombosis are important manifestations of neuropsychiatric lupus erythematosus. We report the case of a woman with relapsed lupus nephritis, in partial remission, who presented with the unusual combination of dural sinus thrombosis (due to protein S functional deficiency) and aneurysmal subarachnoid hemorrhage. She had a fatal outcome, as has often been reported with subarachnoid hemorrhage in the context of active lupus. To our knowledge, this is the first report of such an unusual association in lupus, and highlights unique challenges in the management of intracranial hemorrhage in the context of dural sinus thrombosis.

[Update on the genetics of stroke]

Stroke is a disease with significant morbidity, mortality, and economic and social impacts. It is a complex entity whose pathogenesis involves multiple environmental and genetic factors, with the latter having a role in up to 50% of strokes. The objective of the review is to analyze the available methods for the genetic diagnosis including linkage studies of variation in copy number, gene - candidate approximations, or whole genome (GWAS) and polymorphisms associated with its pathogenesis. We describe several single nucleotide polymorphisms (SNPs) associated with stroke in association studies and GWAS such as SNPs of angiotensin, the aldosterone system, paraoxonases, nitric oxide, coagulation, and fibrinolysis system, among others. We also analyze the role of certain polymorphisms in the phenotype of the carotid plaque, intracranial aneurysms and lobar hemorrhages. Pharmacogenomic aspects in which SNPs affect the response and safety regarding the use of different drugs are also described. Several SNPs that significantly contribute to the risk of stroke are also described. The advent of techniques like GWAS has contributed to the understanding of genetics and pharmacogenomics of stroke.

Anticoagulation for noncardiac indications in neurologic patients: comparative use of non-vitamin k oral anticoagulants, low-molecular-weight heparins, and warfarin

OPINION STATEMENT

Patients with neurologic disorders may develop a wide variety of thromboembolic events, both as a primary manifestation and as a consequence of their underlying neurologic condition. There are many available options for anticoagulation, ranging from warfarin to the parenteral subcutaneously administered anticoagulants to the non-vitamin K oral anticoagulants (NOACs). Warfarin is orally available, well-studied, and easily reversible in the setting of bleeding, but has a prolonged onset of action, measured in days, and equally slow offset; requires frequent monitoring for dose titration; and has multiple drug-drug and food-drug interactions. Parenteral heparin-based anticoagulants are well-studied and have more predictable pharmacokinetics but are often more expensive, only partially reversible, and require daily injections, which can be difficult for patients to tolerate over long periods of time. The NOACs are easy to administer and have predictable pharmacokinetics but are expensive, not easily reversible, and are not as extensively studied. Specific agents are preferable in some defined neurologic conditions. For acute ischemic stroke, we do not recommend immediate anticoagulation with any agent. For patients with intracranial malignancy (either primary or metastatic), we recommend a low-molecular-weight heparin (LMWH) rather than warfarin or a NOAC. For thromboembolic disease in the setting of spinal cord injury, warfarin, LMWH, or the NOACs are reasonable options. In the setting of VTE or stroke related to antiphospholipid antibody syndrome (APS), we recommend long-term warfarin anticoagulation with an INR goal of 2-3, pending the results of ongoing research involving the NOACs. For cerebral venous sinus thrombosis not related to malignancy or APS, we recommend the use of LMWH in the acute setting, followed by at least three months of warfarin. In this article, we discuss the pharmacology, pathophysiology, and comparative research that served as a basis for our recommendations.

Evaluation and management of stroke in young adults

PURPOSE OF REVIEW

This article provides an overview of the evaluation and management of ischemic stroke in young adults, with an emphasis on cervical artery dissection, patent foramen ovale, and hypercoagulable states.

RECENT FINDINGS

The incidence of ischemic stroke in young patients is increasing, although the reasons remain unclear. Patients with ischemic stroke at a young age are more likely to die at an early age than their peers. Well-established vascular risk factors are prevalent in young stroke patients. Recent studies have informed the treatment of dissection and patent foramen ovale among others. The utility of testing for hypercoagulable states in ischemic stroke is unclear.

SUMMARY

Ischemic stroke in young adults is a major public health problem. A wide range of etiologies of ischemic stroke is found in this age group. A careful history, thorough examination, and methodical workup are essential. Specific management is predicated on identification of the underlying etiology.

The role of genetic risk factors in arterial ischemic stroke in pediatric and adult patients: a critical review

The incidence of arterial ischemic stroke (AIS) in childhood (about 2-13 per 100,000 children a year) is much lower than the incidence in the adult population. Still, adverse outcomes of acute brain ischemia in childhood include death (10% of AIS children), neurological sequel, epileptic seizures (over 50%) and recurrence (over 20%). The knowledge of childhood stroke etiopathogenesis is still insufficient and the diagnostic and therapeutic procedures--controversial. Risk factors for childhood stroke differ from those observed in adults due to differing exposure to external risk factors. The most frequently reported risk factors for pediatric ischemic stroke are cerebral arteriopathies and vascular malformations, cardiac diseases, infections, traumas and metabolic diseases. Because of its multifactorial etiology pediatric AIS probably has a multigenic inheritance pattern. The genetic susceptibility to AIS may be determined by specific polymorphic variants encoding markers of hemostasis regulation and they are some of the most important targets in searching for genetic determinants in pediatric AIS. The authors have reviewed the recent literature on risk factors of childhood ischemic stroke with the focus on genetic factors like polymorphisms of genes encoding coagulation factors II, V, VII and XIII, MTHFR, fibrinogen beta, and compared them with the results performed in adult patients.

Recurrent ischemic cerebrovascular events in a patient with type I antithrombin deficiency caused by 9788 G>A splice site mutation: a case report

Type I antithrombin deficiency is an autosomal dominant disorder associated with high risk for venous thromboembolism. Data on the association between antithrombin deficiency and arterial thromboembolism are inconsistent. We report here the case of AT deficiency in a 43-year-old man free of cardiovascular risk factors who experienced venous thromboembolism and ischemic stroke followed by two transient ischemic attacks after interruption of oral anticoagulation due to colonoscopy. DNA sequencing of the antithrombin gene revealed heterozygosity for the previously reported substitution G to A at nucleotide position 9788 in intervening sequence four. To our knowledge, this report is the first to show that this genetic abnormality can be associated with recurrent cerebrovascular ischemic events.

Recent advances in the management of transient ischaemic attack: a clinical review

Transient ischaemic attack (TIA) if untreated carries a high risk of early stroke and is associated with poorer long-term survival. There have been recent advances in the understanding of TIA, its investigations, management and organisation of services for patient care. Clinically, patients are diagnosed TIA if they have transient sudden-onset focal neurological symptoms which usually completely and rapidly resolve by presentation. Patients with residual symptoms should be evaluated as potentially having stroke, if they present within 4.5 h of onset, should be urgently evaluated for their potential eligibility for thrombolysis. TIA patients should receive rapid attention with essential investigations, including brain imaging, electrocardiograph and carotid ultrasound. Immediate administration of an antiplatelet agent is recommended after brain imaging, with subsequent attention to preventing or treating other mechanistic factors. There is emerging evidence that TIA patients can be managed safely in the outpatient setting after initial rapid management in emergency departments as part of a structured clinical pathway supervised by stroke specialists. Clinical systems of management may require approaches individualised to the healthcare setting, while adopting the central aspects of rapid management.

Large-scale meta-analysis of genetic studies in ischemic stroke: Five genes involving 152,797 individuals

BACKGROUND:

Ischemic stroke descent has a genetic basis. Stroke represents a complex trait, which is assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies.

MATERIALS AND METHODS:

We performed a literature-based systematic review of genetic association studies in stroke abound several populations. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for each gene-disease association. Following a review of 300 manuscripts, five candidate gene variants were analyzed among 152,797 individuals (45,433 cases and 107,364 controls).

RESULTS:

For these five candidate genes studied, the prothrombin OR is 1,57 (1,23-2,89), the factor V Leiden OR is 1,43 (0,67-6,24), the mean OR of angiotensin I converting enzyme (ACE) insertion/deletion (I/D) polymorphism is 1,11 (1,02-1,25), the summary OR for the C677T variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) is 1,23 (0,61-1,47) and the pooled OR for the apolipoprotein E (APOE) gene is 0,95 (0,77-1,14) .

CONCLUSION:

These data suggest the genetic associations of some genes with ischemic stroke and it is necessary to compete with other genes. Our findings could represent an epidemiological base and a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

Epidemiology and risk factors of cerebral ischemia and ischemic heart diseases: similarities and differences

Cerebral ischemia and ischemic heart diseases, common entities nowadays, are the main manifestation of circulatory diseases. Cardiovascular diseases, followed by stroke, represent the leading cause of mortality worldwide. Both entities share risk factors, pathophisiology and etiologic aspects by means of a main common mechanism, atherosclerosis. However, each entity has its own particularities. Ischemic stroke shows a variety of pathogenic mechanisms not present in ischemic heart disease. An ischemic stroke increases the risk of suffering a coronary heart disease, and viceversa. The aim of this chapter is to review data on epidemiology, pathophisiology and risk factors for both entities, considering the differences and similarities that could be found in between them. We discuss traditional risk factors, obtained from epidemiological data, and also some novel ones, such as hyperhomocisteinemia or sleep apnea. We separate risk factors, as clasically, in two groups: nonmodifiables, which includes age, sex, or ethnicity, and modifiables, including hypertension, dyslipidemia or diabetis, in order to discuss the role of each factor in both ischemic events, ischemic stroke and coronary heart disease.

Prothrombin G20210A and factor V Leiden polymorphisms in stroke

The molecular epidemiology of stroke is critically lacking in the developing world. We explored the relationships between genetics polymorphism and risk for ischemic stroke among the residents of Casablanca, Morocco. Ninety-one stroke patients matched 1:2 for their age, gender, and ethnic background to 182 healthy controls who were genotyped for the prothrombin G20210A mutation and factor V (FV) Leiden and were assessed for conventional risk factors for stroke. No significant association was found between prothrombin gene mutation with stroke (p = .054). Regarding stroke subtypes, significant relationships between patients with a large artery disease subtype of stroke and this mutation was found compared to controls (p = .046). As a genetic risk factor to develop this event, a strong association was observed when adjusted for conventional vascular risk factors (adjusted OR, 4.3; p = .029). No FV Leiden was found. We suggest that prothrombin mutation but not FV Leiden should be considered as a modest genetic risk factor for large artery disease stroke subtype in the Moroccan population.

Role of investigating thrombophilic disorders in young stroke

Our knowledge about various inherited and acquired causes of thrombophilic disorders has increased significantly during the past decade. Technology for various diagnostic tests for these rare disorders has matched the rapid advances in our understanding about the thrombophilic disorders. Inherited thrombophilic disorders predispose young patients for various venous or arterial thrombotic and thromboembolic episodes. Our understanding has also improved about various gene-gene and gene-environment interactions and their impact on the resultant heterogenous clinical manifestations. We describe various thrombophilic disorders, their diagnostic tests, pathogenic potential in isolation or with other concurrent inherited/acquired defects and possible therapeutic and prophylactic strategies. Better understanding, optimal diagnostic and screening protocols are expected to improve the diagnostic yield and help to reduce morbidity, disability, and mortality in relatively younger patients harbouring these inherited and acquired thrombophilic disorders.

Churg-strauss syndrome as an unusual aetiology of stroke with haemorrhagic transformation in a patient with no cardiovascular risk factors

Background

We present here a case of haemorrhagic brain infarction in a middle-aged and physically active male, who had never smoked. This case report aims to remind the internist and neurologist to bear in mind unusual aetiologies of brain infarcts in patients without classical cardiovascular risk factors.

Case Description

A 49-year-old male with pulmonary asthma and a prior history of nasal polyps had a wake-up stroke with left-sided symptoms and speech disturbance. A head MRI and MR angiography revealed a recent haemorrhagic infarct in the right putamen and corona radiata. The left hemiparesis progressed to sensory-motor hemiplegia on the 4th day. In the head CT, it was shown that the haemorrhagic infarct had progressed to a large haematoma. A pansinusitis was also diagnosed. The aetiological investigations revealed a minor atrial septal defect (ASD) with shunting and a heterozygotic clotting factor V R506Q mutation. A remarkable blood eosinophilia of 9.80 E9/l (42%) together with fever, sinusitis, wide-spread bilateral nodular pulmonary infiltrates that did not respond to wide-spectrum antimicrobial treatment, positive anti-neutrophilic cytoplasmic antibodies, a high myeloperoxidase antibody level and slightly positive anti-proteinase 3 antibodies suggested the diagnosis of Churg-Strauss syndrome. These inflammatory symptoms and findings promptly responded to treatment with corticosteroids and cyclophosphamide.

Conclusions

Even after the concomitant findings of the low risk factors, i.e. small ASD and heterozygotic clotting factor mutation, continued search for the final aetiology of stroke revealed Churg-Strauss syndrome, which was the key to the treatment.

A review of hereditary and acquired coagulation disorders in the aetiology of ischaemic stroke

The diagnostic workup in patients with ischaemic stroke often includes testing for prothrombotic conditions. However, the clinical relevance of coagulation abnormalities in ischaemic stroke is uncertain. Therefore, we reviewed what is presently known about the association between inherited and acquired coagulation disorders and ischaemic stroke, with a special emphasis on the methodological aspects. Good-quality data in this field are scarce, and most studies fall short on epidemiological criteria for causal inference. While inherited coagulation disorders are recognised risk factors for venous thrombosis, there is no substantial evidence for an association with arterial ischaemic stroke. Possible exceptions are the prothrombin G20210A mutation in adults and protein C deficiency in children. There is proof of an association between the antiphospholipid syndrome and ischaemic stroke, but the clinical significance of isolated mildly elevated antiphospholipid antibody titres is unclear. Evidence also suggests significant associations of increased homocysteine and fibrinogen concentrations with ischaemic stroke, but whether these associations are causal is still debated. Data on other acquired coagulation abnormalities are insufficient to allow conclusions regarding causality. For most coagulation disorders, a causal relation with ischaemic stroke has not been definitely established. Hence, at present, there is no valid indication for testing all patients with ischaemic stroke for these conditions. Large prospective population-based studies allowing the evaluation of interactive and subgroup effects are required to appreciate the role of coagulation disorders in the pathophysiology of arterial ischaemic stroke and to guide the management of individual patients.

Risk factors for ischemic stroke and transient ischemic attack in patients under age 50

To analyze risk factors for ischemic stroke and transient ischemic attack (TIA) in young adults under the age of 50. To make recommendations for additional research and practical consequences. From 97 patients with ischemic stroke or TIA under the age of 50, classical cardiovascular risk factors, coagulation disorders, history of migraine, use of oral contraceptives, cardiac abnormalities on ECG and echocardiography, and the results of duplex ultrasound were retrospectively analyzed. Literature was reviewed and compared to the results. 56.4% of the patients had hypertension, 12.1% increased total cholesterol, 20% hypertriglyceridemia, 31.5% an increased LDL-level, 32.6% a decreased HDL-level and 7.2% a disturbed glucose tolerance. Thrombophilia investigation was abnormal in 21 patients and auto-immune serology was abnormal in 15 patients. Ten of these patients were already known with a systemic disease associated with an increased risk for ischemic stroke (i.e. systemic lupus erythematosus). The ECG was abnormal in 16.7% of the cases, the echocardiography in 12.1% and duplex ultrasound of the carotid arteries was in 31.8% of the cases abnormal. Conventional cardiovascular risk factors are not only important in patients over the age of 50 with ischemic stroke or TIA, but also in this younger population under the age of 50. Thrombophilia investigation and/ or autoimmune serology should be restricted to patients without conventional cardiovascular risk factors and a history or other clinical symptoms associated with hypercoagulability and/ or autoimmune diseases.

Screening for coagulation disorders in patients with ischemic stroke

The role of coagulation disorders in the pathogenesis of (recurrent) ischemic stroke is uncertain. Therefore, the clinical utility of screening patients with ischemic stroke for these conditions and the therapeutic implications of a detected coagulation disorder in a patient who experienced ischemic stroke are uncertain. We reviewed the currently available data on the relationship between various inherited and acquired coagulation abnormalities (factor V Leiden and prothrombin G20210A mutations, deficiencies of protein C, protein S and anti-thrombin, hyperhomocysteinemia, the antiphospholipid syndrome and increased levels of fibrinogen) and ischemic stroke. Based on the existing evidence we discuss the usefulness of screening stroke patients for prothrombotic conditions and current recommendations regarding the optimal management of ischemic stroke patients in whom a coagulation disorder is found.

[Cryptogenic cerebral infarction: from classification to concept]

Since the foundations laid by Sacco and Mohr in 1989, from the Stroke data bank, cryptogenic infarctions have had a predominant place among the causes of ischemic strokes. In that study, they accounted for approximately 40% of the stroke causes. Cryptogenic infarctions are infarctions without a defined cause, despite a complete work-up; they differ from infarctions of undetermined causes, which may involve overlapping causes or an incomplete investigation. The size of this group will probably shrink as knowledge advances. Patent foramen ovale (PFO), with or without a septal aneurysm, is more frequent in patients with a cryptogenic infarction. Transesophageal echocardiography is the reference examination for screening for these abnormalities. A meta-analysis of several case-control studies showed a significant association between PFO and stroke in subjects younger than 55 years. For now, these septal abnormalities constitute a risk factor but not a cause. Complex aortic atheroma affecting area upstream of the left subclavian artery may be a source of cerebral embolisms in some conditions. The prevalence of this disease increases with age. It is identified most frequently in patients older than 60 years with a cryptogenic infarction. The thickness of the atheromatous plaque determines whether it is a risk factor or a cause. Recent stroke classifications do not consider carotid atheromatous lesions less than 50% to be a source of ischemic stroke. Nonetheless some studies identify moderate stenosis of the carotid artery more frequently in infarctions of unknown causes than in other categories. The increased risk of cerebral infarction when parents and homozygous twins have a history of stroke suggests that there may be genetic causes that have not yet been detected. An unknown genetic cause would thus be included in the infarctions of unknown causes. A recent study tested for Fabry disease in young patients with a cryptogenic infarction: 4.9% of the men and 2.4% of the women had a functional mutation of the alpha-galactosidase gene. These findings must be confirmed. Some studies suggest an association between cryptogenic infarction and hereditary thrombophilias. Nonetheless the risk attributable to these thrombophilic disorders is slight and the discovery may be only a coincidence. The work described above shows the importance of stratification in the identification of stroke causes: age older or younger than 55/60 years, type of interatrial abnormality (PFO and aneurysms of the interatrial septum), type of atheroma of the aortic arch (more or less than 4mm). They also show the difficulty involved in attributing cause to an identified abnormality: is carotid stenosis of less than 50% a marker of atherosclerosis or also a cause of stroke? To continue improving our understanding of the mechanisms of strokes, new investigational techniques are under evaluation. They include magnetic resonance imaging (MRI), computed tomographic angiography (CT), positron emission tomography (PET) of carotid plaque and of the aortic arch, transcranial Doppler, cardiac recording by telemetry, and even new biological assays.

Epidemiology of ischemic and hemorrhagic stroke: incidence, prevalence, mortality, and risk factors

The epidemiology of ischemic and hemorrhagic stroke is an ongoing exploration to identify risk factors that continue to expand with the advent of technological advancements and preventative medical practices. Identification of risk factors that can or cannot be modified is a crucial step in determining stroke risk. Many of the modifiable risk factors are well established, and specific interventions to reduce stroke risk have been established. Some risk factors are less established, and intervention to reduce risk is yet to be determined by evidence-based medicine. Data from ongoing randomized clinical trials continue to enhance our ability to prevent a first stroke.

Hereditary thrombophilic factors in stroke due to cerebral infarct

BACKGROUND

The stroke is the third most common cause of all deaths. In new studies, the importance of hereditary thrombophilic factors on stroke is emphasized. The aim of this study is to determine the role of hereditary thrombophilic factors including factor V Leiden A1691G (FVL), prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T gene mutations in patients with stroke because of cerebral infarct.

METHODS

Twenty-four patients with stroke and 53 controls with risk factor for stroke were enrolled. Polymerase chain reaction was used to detect these mutations.

RESULTS

Heterozygote FVL mutation in 2 (8.3%) patients and MTHFR mutation in 10 (41.7%) patients were detected. In the control group, there were 2 (3.8%) patients with heterozygote FVL mutation and 15 (28.3%) patients with MTHR mutation. Both FVL and MTHFR gene mutations were detected in 1 patient and 2 controls, respectively. Prothrombin gene mutation was not found in 2 groups. There were not statistically significant differences for all 3 mutations in-between 2 groups (P > 0.05). Odds ratios were 0.431 (0.074-2.504, 95% CI) for FVL mutation and 0.553 (0.221-1.381, 95% CI) for MTHFR mutation, respectively.

CONCLUSION

Although our study group was small, hereditary thrombophilic factors might not be risk factors for stroke because of cerebral infarct.