Inherited and acquired risk factors and their combined effects in pediatric stroke

Thrombophilia screening in the routine clinical care of children with arterial ischemic stroke

BACKGROUND

Current guidelines recommend thrombophilia evaluation in childhood arterial ischemic stroke, but the impact of screening on management is unknown. The objective of the current study is to report the incidence of thrombophilia identified as part of routine clinical care in the context of available literature reports, and to describe the impact of a diagnosis of thrombophilia on patient management.

METHODS

We conducted a single-institution retrospective chart review for all children with arterial ischemic stroke occurring between January 1, 2009 and January 1, 2021. We collected thrombophilia screening results, stroke etiology, and management. We also reviewed the literature of thrombophilia testing in childhood arterial ischemic stroke published prior to June 30, 2022. Meta-analysis methods were used to assess prevalence rates.

RESULTS

Among children with thrombophilia testing performed, 5% (six of 122 patients) were factor V Leiden heterozygous, 1% (one of 102 patients) were prothrombin gene mutation heterozygous, 1% (one of 122) had protein S deficiency, 20% (23/116 patients) had elevated lipoprotein(a), 3% (three of 110 patients) had elevated homocysteine levels, and 9% (10/112) had elevated antiphospholipid antibodies, only two of whom had persistently elevated levels. There was no change in stroke therapy due to these results. Literature review revealed a wide range of prevalence for most thrombophilia traits, with high cross-study heterogeneity in most cases.

CONCLUSIONS

The rates of thrombophilia in our cohort were consistent with that expected in the general population. The identification of thrombophilia did not alter stroke care. However, some of the results were actionable, prompting evaluation for lipid disorders and patient-specific counseling on cardiovascular risk and risk for venous thrombosis.

The Genetic Basis of Strokes in Pediatric Populations and Insight into New Therapeutic Options

Strokes within pediatric populations are considered to be the 10th leading cause of death in the United States of America, with over half of such events occurring in children younger than one year of life. The multifactorial etiopathology that has an influence on stroke development and occurrence signify the importance of the timely recognition of both modifiable and non-modifiable factors for adequate diagnostic and treatment approaches. The early recognition of a stroke and stroke risk in children has the potential to advance the application of neuroprotective, thrombolytic, and antithrombotic interventions and rehabilitation strategies to the earliest possible timepoints after the onset of a stroke, improving the outcomes and quality of life for affected children and their families. The recent development of molecular genetic methods has greatly facilitated the analysis and diagnosis of single-gene disorders. In this review, the most significant single gene disorders associated with pediatric stroke are presented, along with specific therapeutic options whenever they exist. Besides monogenic disorders that may present with stroke as a first symptom, genetic polymorphisms may contribute to the risk of pediatric and perinatal stroke. The most frequently studied genetic risk factors are several common polymorphisms in genes associated with thrombophilia; these genes code for proteins that are part of the coagulation cascade, fibrolysis, homocystein metabolism, lipid metabolism, or platelets. Single polymorphism frequencies may not be sufficient to completely explain the stroke causality and an analysis of several genotype combinations is a more promising approach. The recent steps forward in our understanding of the disorders underlying strokes has given us a next generation of therapeutics and therapeutic targets by which to improve stroke survival, protect or rebuild neuronal connections in the brain, and enhance neural function. Advances in DNA sequencing and the development of new tools to correct human gene mutations have brought genetic analysis and gene therapy into the focus of investigations for new therapeutic options for stroke patients.

Assessment of Post-Stroke Consequences in Pediatric Ischemic Stroke in the Context of Neuroimaging Results-Experience from a Single Medical Center

Arterial ischemic stroke (AIS) in children is a rare condition; its frequency is estimated at 0.58 to 7.9 new onsets in 100,000 children per year. The knowledge on risk factors, clinical outcomes and consequences of pediatric AIS is increasing. However, there are still many unknowns in the field. The aim of the study was to analyze the clinical presentation of pediatric AIS and its consequences according to the neuroimaging results and location of ischemia. The research was retrospective and observational. The analyzed group consisted of 75 AIS children (32 girls, 43 boys), whereby the age of the patients ranged from 9 months to 18 years at stroke onset. All the patients were diagnosed and treated in one tertiary center. The most frequent stroke subtype was total anterior circulation infarct (TACI) with most common ischemic focus location in temporal lobe and vascular pathology in middle cerebral artery (MCA). The location of ischemic focus in the brain correlated with post-stroke outcomes: intellectual delay and epilepsy, hemiparesis corresponded to the location of vascular pathology. A correlation found between ischemic lesion location and vascular pathology with post-stroke consequences in pediatric AIS may be important information and helpful in choosing proper early therapy. The expected results should lead to lesser severity of late post-stroke outcomes.

Association Between the 20210G>A Prothrombin Gene Polymorphism and Arterial Ischemic Stroke in Children and Young Adults-Two Meta-analyses of 3586 Cases and 6440 Control Subjects in Total

BACKGROUND

Previous data have shown that the 20210G>A polymorphism of the Factor II gene is related to an increased prothrombin level, which may in turn lead to a procoagulant state. The heterogeneous and multifactorial character of arterial ischemic stroke often results in contradictory reports describing the association between the 20210G>A polymorphism and arterial ischemic stroke in different populations. We performed a meta-analysis of available data addressing the relation between the FII 20210G>A polymorphism and arterial ischemic stroke, both in young adults and children.

METHODS

We searched PubMed using appropriate keywords. The inclusion criteria for the study were as follows: case-control study, study population consisting of children, study population consisting of young adults, arterial ischemic stroke confirmed by magnetic resonance imaging or computed tomography, and English language. The exclusion criteria included lack of genotype or allele frequencies, study design other than a case-control study, outcome definition other than arterial ischemic stroke, and previously overlapped patient groups. Finally, 30 case-control studies (14 in children and 16 in young adults) were included. Statistical analyses were conducted using R software. Heterogeneity between the studies was evaluated using the Dersimonian and Laird's Q test. In the case of significant between-studies heterogeneity, the pooled odds ratio was estimated with a random-effects model, otherwise a fixed-effects model was used.

RESULTS

The pooled analysis showed that carriers of 20210A allele (GA+AA genotypes) of the prothrombin gene are more common in arterial ischemic stroke patients, both in children and young adults, than in control subjects (P = 0.006; odds ratio, 1.83; 95% confidence interval, 1.19 to 2.80 and P = 0.001; odds ratio, 1.69; 95% confidence interval, 1.25 to 2.28, respectively).

CONCLUSIONS

The results of the present meta-analysis have proven that the FII 20210G>A polymorphism is associated with arterial ischemic stroke in both pediatric and young adult patients.

Association of Polymorphisms in Coagulation Factor Genes and Enzymes of Homocysteine Metabolism With Arterial Ischemic Stroke in Children

Despite the identification of a wide range of inherited and acquired risk factors for arterial ischemic stroke (AIS) in children, genetic risk factors are incompletely characterized and may vary among different populations. We investigated the role of individual and combined inherited prothrombotic and intermediate-risk factors in 73 children with perinatal (n = 35) and childhood AIS (n = 38) and 100 age- and sex-matched controls. Ten polymorphisms in 8 candidate genes encoding coagulation and fibrinolytic proteins (factor V [FV] Leiden, FV HR2, factor II [FII] G20210A, β-fibrinogen [β-FBG]-455G>A, factor XIII [FXIII]-A p.Val34Leu, plasminogen activator inhibitor 1 4G/5G), homocysteine metabolism (methylenetetrahydrofolate reductase [MTHFR] C677T, MTHFR A1298C), and intermediate-risk factors (angiotensin-converting enzyme I/D, apoE ∊2-4) were detected using a multilocus genotyping assay. Allele-specific polymerase chain reaction was used for the determination of human platelet alloantigens (HPA-1, HPA-2, HPA-3, and HPA-5). Factor V Leiden was associated with an increased risk of AIS (odds ratio [OR]: 4.72, 95% confidence interval [CI]: 1.22-18.27) and perinatal AIS (OR: 8.29, 95% CI: 1.95-35.24). Human platelet antigen-3b allele carriers had a 2-fold lower risk of AIS (OR: 0.51, 95% CI: 0.26-0.98) and perinatal AIS (OR: 0.40, 95% CI: 0.18-0.92). A 2.21-fold increased risk of childhood AIS (95% CI: 1.03-4.73) was identified in FXIII-A Leu34 allele carriers. Combined FV Leiden/FV HR2, FV Leiden/MTHFR A1298C, FV Leiden/MTHFR C677T/MTHFR A1298C, and FV Leiden/FV HR2/MTHFR A1298C heterozygosity was identified in children with AIS but not in controls, which revealed a statistically significant difference. This case-control study shows that besides already documented association between FV Leiden and AIS, other previously unreported polymorphisms (FXIII-A p.Val34Leu, HPA-3) and several genotype combinations that always include heterozygous FV Leiden can be related to AIS in Croatian population.

Association of GSTT1 and GSTM1 gene polymorphisms with coronary artery disease in North Indian Punjabi population: a case-control study

BACKGROUND

Glutathione S-transferases are metabolic enzymes which are responsible for detoxification of endogenous (products of oxidative stress) as well as exogenous (drugs, pesticides, herbicides, environmental pollutants and carcinogens) products. Dysfunctional detoxification enzymes are responsible for the production of oxidative stress; a major contributor to the development of coronary artery disease (CAD).

OBJECTIVES

The present case-control study aimed to investigate the association of GSTT1 and GSTM1 gene polymorphisms with CAD.

METHODS

In the present study, 200 patients diagnosed with CAD and 200 age, sex and population subgroup matched healthy controls were enrolled. The GSTT1 and GSTM1 gene polymorphisms were examined using multiplex PCR.

RESULTS

The frequency of GSTT1 null genotype was significantly (p=0.038) lower in patients with CAD (6.00%) than in controls (12.50%). The GSTT1 null genotype showed protection against CAD (OR=0.45, 95% CI 0.22 to 0.92, p=0.028). The frequency of GSTM1 null genotype was significantly (p=0.004) higher in patients (31%) compared with controls (18%). The GSTM1 null genotype conferred twofold increased risk of developing CAD (OR=2.05, 95% CI 1.28 to 3.27, p=0.003).

CONCLUSIONS

The results concluded that the GSTT1 null genotype showed protection against CAD while the GSTM1 null genotype might be involved in the pathogenesis and development of CAD.

Systematic review: hereditary thrombophilia associated to pediatric strokes and cerebral palsy

OBJECTIVES

This review aimed to organize and consolidate the latest knowledge about mutations and genetic polymorphisms related to hereditary thrombophilia and their potential association with pediatric stroke and cerebral palsy (CP).

SOURCES

Scientific articles published from 1993 to 2013, written in Portuguese, English, French, and Spanish, were selected and reviewed. The publications were searched in electronic databases, and also in the collections of local libraries. The terms "hereditary thrombophilia", "polymorphisms", "mutation", "pediatric strokes", and "cerebral palsy" were used for the research.

SUMMARY OF THE FINDINGS

The search in databases and in the bibliographic references retrieved 75 articles for inclusion in this review. Studies that investigated hereditary thrombophilias and their associations to CP and arterial and venous pediatric stroke presented contradictory results. The meta-analysis and case-control studies that showed positive results for this association described only slightly increased relative risks and sometimes had questionable conclusions. The association of two or more hereditary thrombophilias, or the association between thrombophilia and other specific clinical risk factors, suggest a higher risk of CP and pediatric stroke than isolated hereditary thrombophilia.

CONCLUSIONS

Larger, multicenter studies should be developed in order to elucidate the role of mutations leading to hereditary thrombophilia and the development of CP and pediatric stroke. The complex and multifactorial etiology of CP and stroke makes this an arduous and difficult task; however, the benefits generated by these studies are immeasurable.

Quantitative assessment of association between rs1801133 polymorphism and susceptibility to stroke

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to stroke. To assess the association between this polymorphism and stroke risk, we conducted a comprehensive meta-analysis based on 73 eligible studies. A total of 73 studies, including 10,225 cases and 13,800 controls identified between 1999 and 2012, were selected through researching the PubMed, MEDLINE, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Chinese National Knowledge Infrastructure and Literature database databases. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of stroke risk was associated with the rs1801133 polymorphism in all genetic models (homozygote model: OR 1.296, 95% CI 1.109-1.514; dominant model: OR 1.179, 95% CI 1.058-1.315; recessive model: OR 1.209, 95% CI 1.063-1.375; allele comparison model: OR 1.154, 95% CI 1.061-1.256). In the stratified analyses, significantly increased stroke risks were indicated among Asians in all genetic models (homozygote model: OR 1.726, 95% CI 1.314-2.267; dominant model: OR 1.535, 95% CI 1.282-1.838; recessive model: OR 1.452, 95% CI 1.160-1.818; allele comparison model: OR 1.403, 95% CI 1.211-1.626).The present meta-analysis suggests that rs1801133 polymorphism contributes to the risk of stroke, of note, in Asian populations.

Functional electrical stimulation therapy for recovery of reaching and grasping in severe chronic pediatric stroke patients

Stroke affects 2.7 children per 100,000 annually, leaving many of them with lifelong residual impairments despite intensive rehabilitation. In the present study the authors evaluated the effectiveness of 48 hours of transcutaneous functional electrical stimulation therapy for retraining voluntary reaching and grasping in 4 severe chronic pediatric stroke participants. Participants were assessed using the Rehabilitation Engineering Laboratory Hand Function Test, Quality of Upper Extremity Skills Test, Pediatric Evaluation of Disability Inventory, and Assisting Hand Assessment. All participants improved on all measures. The average change scores on selected Rehabilitation Engineering Laboratory Hand Function Test components were 14.5 for object manipulation (P = .042), 0.78 Nm for instrumented cylinder (P = .068), and 14 for wooden blocks (P = .068) and on the grasp component of Quality of Upper Extremity Skills Test was 25.93 (P = .068). These results provide preliminary evidence that functional electrical stimulation therapy has the potential to improve upper limb function in severe chronic pediatric stroke patients.

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.

Review of lipid and lipoprotein(a) abnormalities in childhood arterial ischemic stroke

National organizations recommend cholesterol screening in children to prevent vascular disease in adulthood. There are currently no recommendations for cholesterol and lipoprotein (a) testing in children who experience an arterial ischemic stroke. While dyslipidemia and elevated lipoprotein (a) are associated with ischemic stroke in adults, the role of atherosclerotic risk factors in childhood arterial ischemic stroke is not known. A review of the literature was performed from 1966 to April 2012 to evaluate the association between childhood arterial ischemic stroke and dyslipidemia or elevated lipoprotein (a). Of 239 citations, there were 16 original observational studies in children (with or without neonates) with imaging-confirmed arterial ischemic stroke and data on cholesterol or lipoprotein (a) values. Three pairs of studies reported overlapping subjects, and two were eliminated. Among 14 studies, there were data on cholesterol in 7 and lipoprotein (a) in 10. After stroke, testing was performed at >three-months in nine studies, at ≤three-months in four studies, and not specified in one study. There were five case-control studies: four compared elevated lipoprotein (a) and one compared abnormal cholesterol in children with arterial ischemic stroke to controls. A consistent positive association between elevated lipoprotein (a) and stroke was found [Mantel-Haenszel OR 4·24 (2·94-6·11)]. There was no association in one study on total cholesterol, and a positive association in one study on triglycerides. The literature suggests that elevated lipoprotein (a) may be more likely in children with arterial ischemic stroke than in control children. The absence of confirmatory study on dyslipidemia should be addressed with future research.

GSTM1, GSTT1, GSTP1, and GSTA1 genetic variants are not associated with coronary artery disease in Taiwan

BACKGROUND AND OBJECTIVE

The genetic variants of xenobiotic-metabolizing enzymes, such as those encoded by glutathione-S-transferase (GST) genes, may be associated with the risk of coronary artery disease (CAD). To investigate the genetic factors for CAD, we examined the GSTM1, GSTT1, GSTP1, and GSTA1 genotypes in a CAD cohort in Taiwan.

METHODS

Our study included 458 CAD participants and 209 control participants who received coronary angiography to assess CAD. The severity of CAD was defined as the number of coronary vessels with 50% or greater stenosis. Sequence variation of the GSTM1 and GSTT1 genes was determined using a polymerase chain reaction (PCR). The GSTP1 (Ile105Val), and GSTA1 (-69C>T) genetic variants were identified using a combination of PCR and restriction fragment length polymorphism analysis. Logistic regression analysis was used to calculate the odds ratios (ORs) and 95% confidence intervals.

RESULTS

Among the GST genetic variants examined, the GSTT1 null genotype was more prevalent in CAD participants with 3 stenosed vessels than in control participants (OR=1.64, P=.02). This association was no longer observed after adjusting for age, sex, smoking, alcohol use, diabetes mellitus, and serum levels of total cholesterol and high-density lipoprotein cholesterol (OR=1.28, P=.40). Both univariate and multivariate logistic regression analyses found no significant associations between CAD and the other genetic variants, either separately or in combination. In addition, no effects of interactions between the genotypes and environmental factors, such as cigarette smoking, were significantly associated with the risk of CAD.

CONCLUSION

The GST genetic variants examined were not associated with susceptibility to CAD in our Taiwanese cohort. This null association requires further confirmation with larger samples.

Clinical profile, common thrombophilia markers and risk factors in 85 young Indian patients with arterial thrombosis

CONTEXT AND OBJECTIVE

Arterial thrombosis may occur consequent to hereditary thrombophilia and increased lipoprotein(a) [Lp(a)] and fibrinogen. Our aim was to study the prevalence of common thrombophilia markers in 85 consecutive cases of arterial thrombosis.

DESIGN AND SETTING

A retrospective study was conducted from 85 consecutive young patients treated as outpatients or admitted due to stroke or myocardial infarction at a tertiary care hospital.

METHODS

Eighty-five Indian patients (age < 45 years) presenting ischemic stroke (n = 48) or myocardial infarction (n = 37) and 50 controls were studied for seven thrombophilia markers including antithrombin (AT), factor V, protein C, protein S, activated protein C resistance (APC-R), fibrinogen and Lp(a). Functional assays for protein C, protein S, factor V and APC-R were performed using clotting-based methods. Semi-quantitative estimation of fibrinogen was done using Clauss's method and Lp(a) using immunoturbidimetry. Statistical analysis was done using the Epi Info 6 software.

RESULTS

Thirty-three samples (38.8%) tested positive for one or more thrombophilia markers. The three commonest abnormalities were elevated Lp(a) (20%), fibrinogen (17.6%) and low APC-R (14.2%). Low levels of protein C, protein S and AT were present in 4.7, 9.4 and 7% of the patients, respectively. Overall, the risk factor profile was: smoking (33%), positive family history (15.3%), hyperlipidemia (7%), hypertension, diabetes mellitus and obesity (2.3% each).

CONCLUSIONS

An association was found between low levels of protein C, protein S and AT and arterial thrombosis, but only elevated fibrinogen levels, smoking, positive family history and hyperlipidemia showed statistical significance.

Inherited prothrombotic risk factors in children with first ischemic stroke

Stroke in children is a heterogeneous disorder. Over 100 risk factors for stroke have been reported and genetic predisposition to stroke has been established. The most frequently reported risk factors are congenital heart malformations, hemolytic anemias, collagen vascular diseases, some rare inborn metabolic disorders, trauma, infection and thrombophilia. The aim of this article is to provide an overview of investigated inherited prothrombotic risk factors in children with first ischemic stroke. Various prothrombotic risk factors have been investigated in pediatric stroke including elevated homocysteine and lipoprotein (a), antithrombin, protein C and protein S deficiency, Factor V Leiden, Factor II G20210A and plasminogen activator inhibitor-1 4G/5G polymorphism. Despite similar criteria for inclusion of different studies in meta-analyses investigating first ischemic stroke in children, the obtained results were not consistent for all prothrombotic risk factors. The discrepancies found could be explained by methodological issues like different sample sizes, patient populations included and lack of controls. In order to provide the necessary power for randomized control trials, multi-center, multi-national approaches like International Pediatric Stroke Study have been initiated with the aim to describe risk factors for childhood stroke and explore their relationship with presentation, age, geography, and infarct characteristics. Although it is evident from numerous studies that the frequency of inherited prothrombotic factors is increased in pediatric stroke, single thrombophilia does not fully explain stroke in a child as it represents only a mild risk factor. Further studies are needed, as improved understanding of underlying mechanisms will improve primary and secondary prevention of childhood stroke.

Inherited thrombophilia in pediatric ischemic stroke: an Egyptian study

Pediatric stroke is relatively uncommon, with often subtle clinical presentations. Numerous predisposing risk factors can be both inherited and acquired, including cardiac disease, vascular abnormalities, infectious diseases, collagen tissue diseases, inborn errors of metabolism, anticardiolipin antibody, lupus anticoagulant, deficiencies of protein C, protein S, antithrombin, or plasminogen, and prothrombotic mutations. We explored risk factors, clinical features, and neuroimaging among Egyptian children with ischemic stroke, and estimated the prevalence of inherited thrombophilia. We included 20 children with ischemic stroke, recruited from the Pediatric Neurology Outpatient Clinic (Ain Shams University). Basic clinical evaluations for stroke and genotyping for factor V 1691 G-A (factor V Leiden), prothrombin 20210 G-A mutations, and methylenetetrahydrofolate reductase 677 C-T polymorphisms were performed using real-time polymerase chain reaction, with fluorescent melting curve detection analysis. Ten patients (50%) manifested methylenetetrahydrofolate reductase polymorphisms (six homozygotes and four heterozygotes). Heterozygous factor V Leiden was present in five (25%), whereas prothrombin mutation was present in only one (5%). Five patients (25%) manifested combined prothrombotic abnormalities. Thirteen demonstrated evidence of inherited thrombophilic disorder; 25% manifested more than one mutation. For appropriate risk assessment, even in the presence of overt acquired thrombotic risk factors, physicians should request complete thrombophilia screening for patients with stroke.

The TT genotype of methylenetetrahydrofolate reductase 677C>T polymorphism increases the susceptibility to pediatric ischemic stroke: meta-analysis of the 822 cases and 1,552 controls

The 677C>T polymorphism within methylenetetrahydrofolate reductase (MTHFR) gene is related to an elevated level of homocysteine. Thus it may be considered as a genetic risk factor in ischemic stroke. Apparently studies of this type of polymorphism in childhood stroke have shown conflicting results. We performed meta-analysis of all the data that are available in relation with MTHFR polymorphism and the risk of ischemic stroke in children. We searched PubMed (last search dated December 2010) using "MTHFR polymorphism", "ischemic stroke" "child", "children", "pediatric stroke" as keywords and reference lists of studies and reviews on the topic. Finally, 15 case-control studies corresponded to the inclusion criteria for meta-analysis. These studies involved the total number of 822 children and adolescents after ischemic stroke and 1,552 control subjects. Fixed or random effects models were used depending on the heterogeneity between the studies. The association between ischemic stroke and 677C>T polymorphism within MTHFR gene was observed in three of the studies. The pooled analysis showed that TT genotype of MTHFR gene is more common in stroke patients than in controls (p = 0.0402, odds ratio = 1.57, 95 % confidence interval 1.02-2.41). The Egger's test did not reveal presence of a publication bias. The results based on a sizeable group of cases and controls have proved that the 677C>T polymorphism in MTHFR gene is associated with the development of ischemic stroke in children.

Risk factors and clinical outcomes of childhood ischemic stroke in a single Korean tertiary care center

A 10-year, retrospective review of the risk factors and clinical outcome of childhood ischemic stroke treated in a single tertiary care center was conducted. Sixty-two children were identified (33 boys and 29 girls), ages 1 month to 17 years. Risk factors included vasculopathy (35.5%), cardiac disease (17.4%), metabolic disorder (14.5%), infection (14.5%), and coagulopathy (1.6%). Nine patients (14.5%) had no identifiable cause of stroke and 1 patient had 2 risk factors. Hemiplegia (69.3%) and seizures (32.3%) were the most common presenting features, and seizures were significantly more frequent in children <12 months of age than in older children (71.4% vs 20.8%, P = .001). Recurrence of stroke occurred in 55.6% of patients with metabolic disorder, 33.3% of those with cardiac disease, and 19.0% of those with vasculopathy. Vasculopathy including moyamoya disease was the most important risk factor for ischemic stroke in Korea, and their prognosis were varied with the etiology of stroke.

Etiological analysis of presumed perinatal stroke

This study aimed to investigate the maternal, pre- and perinatal, and prothrombotic factors with congenital hemiparesis due to presumed perinatal stroke (PPS). Prothrombotic risk factors including protein C and S, antithrombin III, lipoprotein (a), homocystein, factor VIII levels; anticardiolipin antibodies and lupus anticoagulant; methylenetetrahydrofolate reductase mutations, factor V Leiden, prothrombin G20210A mutations were investigated. Arterial ischemic stroke was detected in 60% and periventricular venous infarction in 40%. At least one prothrombotic risk factor was present in 69%, two in 17%, and three or more in 8.5% of cases. The most common combination was methylenetetrahydrofolate reductase C677T and factor V Leiden heterozygosity. The etiology and pathogenesis of PPS is still unclear. According to this study, most of the patients with PPS might have one or more prothrombotic risk factors and certain prenatal risk factors including intrauterine growth retardation, twin gestation and preeclampsia might be related to PPS.

Perfil cognitivo, déficits motores e influência dos facilitadores para reabilitação de crianças com disfunções neurológicas

OBJETIVO: Investigar se crianças e adolescentes saudáveis e com doenças neurológicas podem ser reunidas em grupos distintos e homogêneos, usando como critérios o desempenho cognitivo, o funcionamento motor e as percepções dos pais quanto aos facilitadores para a reabilitação. MÉTODOS: Participaram deste estudo 15 crianças saudáveis (C) e 43 pacientes (28 com paralisia cerebral e 15 com acidente vascular cerebral), entre cinco e 18 anos. Foi aplicado aos pais o instrumento denominado Avaliação dos Fatores Ambientais relacionados à Reabilitação Neurológica Infantil (AFARNI). O comprometimento cognitivo foi avaliado por meio do Mini-Exame do Estado Mental, adaptado para essa faixa etária, e o comprometimento motor foi investigado por avaliação clínica. Para comparar os resultados, foi realizada uma análise de conglomerados e ANOVA. RESULTADOS: A análise de conglomerados identificou quatro grupos de pacientes com características clínicas e sociodemográficas distintas, confirmados pela ANOVA (p<0,001). Houve dissociação entre os grupos com relação ao comprometimento cognitivo e motor. Os pais de crianças com maior comprometimento avaliaram de forma mais positiva os facilitadores para a reabilitação. CONCLUSÕES: A qualificação dos facilitadores para a reabilitação por meio da AFARNI e a avaliação cognitiva com auxílio do Mini-Exame do Estado Mental podem contribuir para identificar as necessidades de suporte para crianças com deficiências neurológicas que apresentam comprometimento cognitivo e motor.

Inherited thrombophilia in childhood arterial stroke: data from Lebanon

Pediatric ischemic stroke still represents a burden, and more than half of the survivors will experience cognitive or motor disabilities. The objective of this study was to investigate the role of thrombophilia in a cohort of children with arterial ischemic stroke. The records of infants and children with clinically and radiologically confirmed stroke were reviewed. Patients with venous or perinatal stroke were not included. Thirty-three patients were diagnosed with arterial ischemic stroke. The male/female ratio was 1.75:1. The median age was 4 years. The most frequent clinical manifestations were hemiparesis (54.5%) and seizures (33.3%). Genetic thrombophilia testing was available on 24 patients. Nine of the 24 patients (37.5%) were heterozygous for factor V Leiden. None of the patients carried the factor II G20210A variant. Ten patients (41.7%) were heterozygous and 3 (12.5%) were homozygous for methylenetetrahydrofolate reductase (MTHFR) C677T variant. Fifteen patients (62.5%) had one or more genetic polymorphism. Factor V Leiden was significantly associated with arterial ischemic stroke (P < 0.001). Stroke recurred in 2 children with multiple risk factors and MTHFR C677T mutation. Factor V Leiden is one of the major genetic risk factors for pediatric arterial ischemic stroke in Lebanon. MTHFR C677T was prevalent among patients with recurrent stroke.

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.

Pharmacology in childhood arterial ischemic stroke

In recent years, there has been increasing recognition of the impact of childhood stroke and interest in the role of drugs in the acute, chronic, and prophylactic management of this condition. Most treatment strategies are based on studies in adults with stroke, and the relative infrequency of stroke and the heterogeneity of etiologies in childhood compared with adults present significant challenges in study design for childhood stroke studies. The presence of thrombophilia has been associated with stroke in children, strengthening the concept that antithrombotic, antiplatelet, and even thrombolytic agents have a role in stroke treatment and prevention. There are several potential roles for drugs in the treatment of childhood stroke including hyperacute therapy, antithrombotic medication, antiplatelet medication, and disease-specific medications. Herein, we review the use and rationale of these medications in childhood arterial ischemic stroke.

Diagnosis and management of pediatric arterial ischemic stroke

Pediatric stroke is among the top 10 causes of death in children and an important cause of chronic morbidity, with an incidence of 3.3/100,000 children/year. Risk factors associated with stroke in children include cardiac diseases, hematologic and vascular disorders, and infection. Clinical presentation varies depending on age, underlying cause, and stroke location. Antithrombotics and anticoagulants are used in the treatment of pediatric stroke; however, there are no established guidelines for the use of these agents in children. In this article we review the cause, pathophysiology, clinical presentation, diagnosis, acute management, secondary prevention, and outcome of children with stroke. The approach to patients with sickle cell disease and Moyamoya disease is also discussed. Up to date studies to determine the optimal acute treatment of childhood stroke and secondary prevention and risk factor modification are critically needed.

Childhood and teenage stroke

OBJECTIVE

The purpose of this manuscript is to review the various etiologies and to discuss the therapeutic issues in childhood stroke.

METHODS

A PubMed search of literature pertaining to childhood stroke was conducted from 1983 to 2008 using specific key search words pertinent to cerebrovascular disorders in childhood.

RESULTS

The analysis of the multiple causes of childhood stroke including arterial ischemic strokes and cerebral venous thrombosis was presented. Current therapy and outcome data in childhood stroke are also discussed throughout the length of the article.

CONCLUSIONS

With increasing vigilance among physicians and improved neuroimaging modalities, the diagnosis of childhood stroke is now made earlier, with increasing frequency and greater accuracy. However, larger and well-controlled studies regarding the optimal management of childhood stroke in terms of the use of both antithrombotic drugs and anticoagulation are still needed in addition to longitudinal follow-up studies of children with stroke.

Stroke in children: inherited and acquired factors and age-related variations in the presentation of 48 paediatric patients

AIM

Stroke is relatively rare in children and the clinical presentation of paediatric stroke is often subtle. Numerous predisposing risk factors are known, and these can be both inherited and acquired. They include cardiac disease, vascular abnormalities, endothelial damage, infectious diseases, collagen tissue diseases, certain inborn errors of metabolism and anticardiolipin antibody, lupus anticoagulant and deficiencies of protein C, protein S, antithrombin or plasminogen. In addition, abnormal activated protein C resistance (or Factor V Leiden), Factor II G20219A variant, and the thermolabile variant of methylenetetrahydrofolate reductase (MTHFR C677T) need to be considered.

METHODS

To explore the prevalence of different predisposing conditions in paediatric stroke patients, we evaluated 48 patients, including subjects with ischaemic and haemorrhagic stroke subtypes.

RESULTS

Only 7 out of 48 (14.5%) had no recognizable risk factors: the majority of paediatric stroke patients had pre-existing risk factors that predisposed to the condition. The major genetic risk factor in our series of patients was homozygosity for the MTHFR C677T mutation (7 out of 48 patients); three more patients were found to be heterozygous for the Factor V Leiden mutation. Acquired predisposing conditions were present in 23 out of 48 patients and included pulmunar stenosis, head trauma, hyperlipidaemia and varicella infection. A total of 17 patients had both genetic and acquired predisposing factors.

CONCLUSION

Our results emphasize that multiple predisposing risk factors commonly predispose to paediatric stroke. In addition, the primary clinical presentation appeared to differ between the older and younger children: hemiparesis was the typical presentation in children <1 year of age while seizure predominated in older children.

Genetic risk factors for arterial ischemic stroke in children: a possible MTHFR and eNOS gene-gene interplay?

In order to investigate the influence of genetic factors in childhood stroke, we compared the distributions of mutations/ polymorphisms affecting hemostasis and/or endothelial function (factor V [FV] Leiden, factor II [FII] G20210A, methylenetetrahydrofolate reductase [MTHFR] C677T, angiotensin-converting enzyme [ACE] insertion/deletion [ID], and endothelial nitric oxide synthase [eNOS] G894T) among children with stroke and controls. A total number of 26 children with arterial ischemic stroke and a control group of 50 healthy children were included in the study. No statistically significant differences in allelic and genotypic distribution were detected in comparisons between groups. However, when combined genotypes were analyzed, statistical significance was observed for the association of MTHFR CT and eNOS TT gene variants. The results of our study suggest that this genotype combination represents a risk factor of 7.2 (P = .017) for arterial ischemic stroke in children.

Inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine

OBJECTIVE

The aim of this study was to investigate the prevalence and possible association of inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine.

METHODS

We performed genotypic analysis for factor V G1691A, factor II G20210A, methylenetetrahydrofolate reductase C677T, and 4 common platelet glycoprotein polymorphisms (human platelet alloantigen-1, -2, -3, and -5) in 150 children <18 years of age with established diagnoses of stroke, transient ischemic attack, or migraine. Children were classified into 5 groups, namely, childhood arterial ischemic stroke (N = 33), perinatal arterial ischemic stroke (N = 26), hemorrhagic stroke (N = 20), transient ischemic attack (N = 36), and migraine (N = 35). The control group consisted of 112 children < or =18 years of age from the same geographical region who had no history of neurologic or thromboembolic diseases.

RESULTS

Heterozygosity for factor V G1691A was associated with approximately sevenfold increased risk for arterial ischemic stroke, perinatal arterial ischemic stroke, and transient ischemic attack. Increased risk for transient ischemic attack was found in carriers of the human platelet alloantigen-2b allele, human platelet alloantigen-5a/b genotype, and combined human platelet alloantigen-2b and human platelet alloantigen-5b genotype. The presence of the human platelet alloantigen-2b allele was associated with a 2.23-fold increased risk for migraine, whereas carriers of the human platelet alloantigen-3b allele had a lower risk for arterial ischemic stroke than did carriers of the human platelet alloantigen-3a allele.

CONCLUSIONS

Factor V G1691A has an important role in susceptibility to arterial ischemic stroke, both in the perinatal/neonatal period and in childhood, as well as transient ischemic attacks. A minor impact of human platelet alloantigen polymorphisms suggests that platelet glycoprotein polymorphisms may increase the risk of transient ischemic attacks and migraine, but this should be confirmed in larger studies.

MTHFR homozygous mutation and additional risk factors for cerebral infarction in a large Italian family

Several cases with cerebral infarctions associated with the C677T mutation in the methylenetetrahydrofolate reductase gene (MTHFR) have been reported. Given the large number of asymptomatic individuals with the MTHFR mutation, additional risk factors for cerebral infarction should be considered. This study describes a large family with the MTHFR mutation and a combination of heterozygous factor V Leiden mutations and different additional exogenous and endogenous thrombogenic risk factors. Psychomotor retardation and a left fronto-insular infarct associated with the MTHFR mutation together with diminished factor VII and low level of protein C was documented in the first patient. In the second patient, generalized epilepsy and a malacic area in the right nucleus lenticularis was associated with the MTHFR mutation and a low level of protein C. In the third patient, right hemiparesis and a left fronto-temporal porencephalic cyst were documented, together with the MTHFR mutation and hyperhomocysteinemia. An extensive search of additional circumstantial and genetic thrombogenic risk factors should be useful for prophylaxis and prognosis of infants with cerebral infarctions associated with the MTHFR mutation and of their related family members.

Prothrombotic polymorphisms, mutations, and their association with pediatric non-cardioembolic stroke in Asian-Indian patients

Genes involved in the hemostatic mechanism are logical candidate genes for association studies in prothrombotic conditions such as stroke. Since the underlying etiology in pediatric strokes is different than adults, looking for genetic causes would be the logical thing to do in the pediatric stroke population. Fifty-eight Asian-Indian stroke patients below 15 years of age and equal number of age- and sex-matched healthy controls were the subjects for the study. The subjects were screened for 13 polymorphisms and three mutations spread across seven different candidate genes involved in the hemostatic system. Of the 13 polymorphisms and three mutations studied, four polymorphisms, HPA-I, TAFI 147Ala>Thr, methylene tetrahydrofolate reductase (MTHFR) 677 C>T, and MTHFR 1298 A>C, showed significant association with the disease phenotype. MTHFR 677 C>T showed the strongest association and therefore may have a strong predisposing role for pediatric strokes. Gene-gene interaction studies showed a strong interaction between HPA-I and MTHFR 677 C>T polymorphism. The wild type of both these polymorphisms synergistically showed a strong protective effect [p < 0.0001, O.R: 10.06(4.26-23.71)]. Polymorphisms in HPA-I and MTHFR may have important predisposing roles in the development of pediatric stroke.

Risk factors for perinatal arterial stroke: a study of 60 mother-child pairs

The objective of the present study was to examine demographic, historical, and prothrombotic risk factors in infants with perinatal arterial stroke and their mothers. Risk factors were evaluated in 60 mother-child pairs with perinatal arterial stroke. Prothrombotic factors analyzed included the DNA mutations factor V Leiden, prothrombin 20210, MTHFR C677T and A1298C; serum activity levels for protein C, protein S, and antithrombin III; serum levels of lipoprotein(a); and, in the mothers, antiphospholipid antibodies. Boys predominated, 36:24. There were four twin sets. Sixty percent were term and 22% were post-date. Ten were large for gestational age. Five mothers had abdominal trauma. Nine mothers (15%) had preeclampsia. Emergency caesarean section was performed in 17 cases (28%). Eight placental exams revealed seven with abnormalities. Seizures were the presenting sign in 70%, and 30% presented with early handedness or cerebral palsy. Prothrombotic risk factors were found in 28 of 51 mothers (55%) and 30 of 60 children (50%). Forty-one pairs (68%) had at least one abnormality in mother, child, or both. Long-term sequelae included cerebral palsy (40 of 51; 78%), cognitive impairment (35 of 51; 68%), seizures (23 of 51; 45%), and microcephaly (26 of 51; 51%). Perinatal arterial stroke is the result of multifactorial, synergistic fetal and maternal factors among which the prothrombotic factors, both fetal and maternal, appear significant.

Risk factors for pediatric stroke: consequences for therapy and quality of life

A retrospective population-based study was conducted to calculate incidence of pediatric stroke, detect risk factors, determine long term outcome and to optimize therapy. Patients (age: >1 month and <19 years) with stroke in Vorarlberg, Austria, from 1984-2005 were investigated. Outcome was evaluated in terms of neurological deficits, neuropsychological measures, and quality of life. Consequences on therapy were established according to current guidelines. Twenty-two children, median age 6 years (range, 0.9-14) years, 16 ischemic and 6 hemorrhagic stroke, correspond to an incidence of 1.96 and 0.74/100.000 child-years, respectively. No child died; one had a recurrent stroke. Twenty children (12 boys) were included after a median time of 3.7 years (range, 0.4-18). Risk factors were vasculopathy (17/20; 85%), lipometabolic disorders (17/20; 85%), and prothrombotic abnormality (10/20; 50%). Three children had no risk factor; four children had a reduced quality of life. The study led to therapeutic consequences in 13 of 20 children (65%): aspirin (5/20; 25%), folic acid in (3/20; 15%), and rehabilitative therapy (9/20; 45%). Most children with pediatric stroke have more than one risk factor, mainly vasculopathies or elevation of lipoprotein(a). Overall outcome is determined solely by neurological deficits and is positively influenced by good quality of life.

Hypercoagulation Testing in Ischemic Stroke

Context.—The utility of laboratory testing for hypercoagulability in the setting of stroke is uncertain.

Objective.—To review the current literature and to make recommendations with regard to laboratory testing for various hypercoagulability risk factors for ischemic stroke.

Data Sources.—Published articles studying the utility of various hypercoagulation tests in predicting initial and/or recurrent stroke or transient ischemic attack as well as cerebral vein thrombosis were collected and reviewed, with an emphasis on prospective studies.

Conclusions.—Certain tests, such as C-reactive protein, homocysteine, antiphospholipid antibodies, and lipoprotein(a), may be useful in patients with a history of stroke or at high risk for stroke, as evidenced by prospective data. Factor V Leiden, prothrombin G20210A, protein C, protein S, and antithrombin are not recommended for routine testing but may be useful in certain populations, such as in pediatric patients or in patients with cerebral vein thrombosis.

Schlaganfälle im Kindes- und Jugendalter

Zusammenfassung. Schlaganfälle im Kindes- und Jugendalter gehören zu den seltenen Erkrankungen des Kindesalters. Die neurologischen Beeinträchtigungen verursachen sehr unterschiedliche neuropsychologische Defizite. Art und das Ausmaß der kognitiven Beeinträchtigungen hängen wesentlich vom Alter der Kinder zum Zeitpunkt des Schlaganfalls und von der Lokalisation der Schädigung ab. Eine neuropsychologisch orientierte Diagnostik kann wertvolle Ansatzpunkte zur Therapie der kognitiven Defizite sowie der schulbezogenen Lernstörungen liefern. Dabei spielen Aufmerksamkeits- und Gedächtnisstörungen auch bei der Beurteilung der allgemeinen Intelligenz von Kindern mit einem Schlaganfall eine zentrale Rolle. Therapeutische Bemühungen erfordern aufgrund der Vielschichtigkeit von Beeinträchtigungen nach einem Schlaganfall im Kindes- und Jugendalter einen multidisziplinären Ansatz.

Different additional risk factors for cerebral infarctions associated with the factor V Leiden mutation in a family

Several cases with cerebral infarctions associated with the factor V Leiden mutation have been reported. However, bearing in mind the large number of asymptomatic individuals with the factor V Leiden mutation, additional risk factors for cerebral infarctions should be considered. In this report, two siblings with cerebral infarctions associated with a combination of heterozygous factor V Leiden mutation and different additional exogenous and endogenous thrombogenic risk factors are described. Respiratory problems in the perinatal period and increased lipoprotein (a) concentrations in the first patient and an episode of gastroenteritis from Shigella infection and persistent high titers of serum anticardiolipin and beta(2)-glycoprotein I antibodies in the second patient were recorded as additional thrombogenic risk factors. Furthermore, both patients were found to be heterozygous for the methylenetetrahydrofolate reductase gene C677T mutation. These findings suggest that even in the same family, different additional thrombogenic risk factors can be present in infants with cerebral infarctions associated with the factor V Leiden mutation. An extensive search of additional circumstantial and genetic thrombogenic risk factors should be useful for prophylaxis and prognosis of these infants with cerebral infarctions associated with the factor V Leiden mutation and of their related family members. To our knowledge, the second patient in this study is the first patient reported to have cerebral infarctions associated with the combination of the factor V Leiden mutation and persistent high titers of serum beta(2)-glycoprotein I antibodies.

Homozygous MTHFR C677T gene mutation and recurrent stroke in an infant

The role of homozygosity for the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene as an independent risk factor for primary and recurrent stroke has been questioned, although recent data appear to be supportive. However, the association of homozygous C677T MTHFR mutation with silent brain infarctions in infancy has not been reported. The authors describe an 11-month-old male who had suffered a silent brain infarction followed by a symptomatic arterial stroke. The evaluation revealed mildly elevated homocysteine levels secondary to homozygous C677T alleles for MTHFR and iron deficiency anemia. An extensive evaluation for other causes of infarction was negative. We suggest that the mother's homozygous MTHFR status played a role in the early onset of stroke and that iron deficiency anemia may have contributed to the recurrence. The patient was treated with anticoagulation therapy, folic acid, and iron supplementation and has not had a recurrent event during 3 years of follow-up. This case provides further evidence that homozygous MTHFR mutation is a predisposing factor for early and recurrent pediatric stroke, including silent infarcts, especially in the presence of other risk factors.

Prothrombotic risk factors in ischemic stroke and migraine in children

OBJECTIVE

To evaluate the contribution of antiphospholipid antibodies (aPL) and thrombomodulin (Thm) in the pathogenesis of stroke and migraine in children.

MATERIALS AND METHODS

Ninety children were included in the study: 30 children (4-15 years) after an ischemic stroke of an unknown etiology; 30 migrainous patients (8-15 years), who were hospitalized in the Department of Developmental Neurology, Medical University of Gdansk, Poland, and 30 healthy children of the same age.

RESULTS

The statistical analysis showed an increase in the values of anticardiolipin antibodies (aCL), anti beta2-glycoprotein 1 (beta2-GP1) and Thm in children with stroke and migraine than in the control group. The resultant values were higher, but stayed at standard.

CONCLUSION

The possible role of prothrombotic factors in individual cases of pediatric stroke and migraine cannot be excluded.

Cerebrovascular disorders in childhood: etiology, clinical presentation, and neuroimaging findings in a case series study

OBJECTIVE: To describe the main etiologies, neurological manifestations and neuro-imaging findings among children with sequelae of cerebrovascular disorders. METHOD: Case series study of children whose diagnosis was stroke sequelae. Variables studied were age at the time of first episode, number of episodes, etiology, motor deficits, epilepsy, and effected vascular territory. RESULTS: Twenty three patients were studied. Average age at first episode was 6.91 (±2.08) years. Fourteen patients were female. The number of stroke events per patient ranged from one to five. The most frequent etiologies were heart disease and sickle cell anemia. The most frequent neurological deficit was right hemiparesis. Nine patients experienced seizures. The left middle cerebral artery was the most affected vascular area. CONCLUSION: Our findings are similar to those described in the literature. Despite a careful investigation, some causes of stroke remain unidentified.

Prothrombotic factors in children with stroke or porencephaly

OBJECTIVE

This study compared the frequencies of genetic and functional coagulation abnormalities in children with arterial ischemic stroke or porencephaly with frequencies in previously published studies.

METHODS

A series of 59 children (age 0-18 years) with arterial ischemic stroke or porencephaly were referred to the National Institutes of Health. A blood sample, buccal smear sample, questionnaire, and pedigree were requested for each child. Blood samples were analyzed for protein C (PC); protein S; antithrombin (AT); activated PC resistance (APCR); lipoprotein (a) [Lp(a)]; lupus anticoagulant; anticardiolipin antibodies; and the methylenetetrahydrofolate reductase C677T (MTHFR), factor V G1619A, factor II G20210A (PT), plasminogen activator inhibitor-1 4G6755G, and tissue factor pathway inhibitor C536T mutations. The frequency of each coagulation abnormality was compared with published international pediatric stroke case and control rates.

RESULTS

At least 1 prothrombotic abnormality was identified in 63% (36 of 57) of children studied, including plasminogen activator inhibitor-1 4G6755G (15 of 56), MTHFR (12 of 56), elevated Lp(a) (12 of 59), APCR (11 of 58), factor V G1619A (5 of 57), PT (3 of 57), PC deficiency (1 of 59), and AT deficiency (1 of 59). The MTHFR mutation, elevated Lp(a), the PT mutation, and AT deficiency rates were similar to rates in cases and more common than control subjects in previously published studies. The rate of children with APCR or multiple abnormalities was higher than in previous pediatric stroke studies. A family history of early thrombosis was identified in one third of the children with a prothrombotic abnormality.

CONCLUSIONS

Two thirds of children in this study had at least 1 of the prothrombotic risk factors tested, and several children had multiple risk factors. These results provide additional evidence that prothrombotic abnormalities are common among children with AIS or porencephaly.

Prothrombotic abnormalities in childhood ischaemic stroke

Childhood ischaemic stroke, incorporating arterial ischaemic stroke and cerebral sinus venous thrombosis, is associated with significant morbidity and mortality in children. The majority of cases in children present with well-recognised risk factors. The appreciation of the role prothrombotic abnormalities have in disease states is developing rapidly. Prothrombotic abnormalities are abnormalities of the coagulation system, fibrinolytic system, endothelial cells or platelets that lead to a reduced threshold for pathological thrombus formation. Our understanding of the role of prothrombotic abnormalities in childhood ischaemic stroke is increasing and has a direct bearing on the development of effective management and prevention strategies. We provide a brief background of prothrombotic abnormalities and review the available literature on prothrombotic markers in childhood ischaemic stroke. Overall, prothrombotic abnormalities have been identified in 20-50% of children presenting with AIS and 33-99% of children with cerebral sinus venous thrombosis. There appear to be a number of associations emerging including an increased frequency of factor V Leiden mutation, elevated lipoprotein (a), protein C deficiency and antiphospholipid antibodies in children presenting with arterial ischaemic stroke. The pathogenic role of prothrombotic abnormalities as predisposing to initial and recurrent childhood ischaemic stroke is becoming increasingly evident. The impact on treatment, however, will only be clarified with carefully designed, multi-institutional prospective studies.

Cerebral venous thrombosis in a patient with Evans syndrome: a rare association

In this report we describe a case of extensive cerebral venous thrombosis in a patient with Evans syndrome. A 19-year-old male patient with Evans syndrome was admitted to the hospital with the complaints of headache, convulsive seizure, and vomiting. The cerebral venous thrombosis including left lateral, left sigmoid, straight sinus, and vena jugularis interna was diagnosed by cerebral magnetic resonance angiography. When the thrombosis developed, he was in hematological remission and he was not receiving any medications except lamivudine for chronic hepatitis B infection. As a genetic prothrombotic risk factor, he had heterozygous prothrombin G20210A gene mutation. His clinical and radiologic findings improved after unfractionated heparin and subsequently with coumadin therapy. On follow-up, cerebral venous thrombosis reoccurred in different localizations, but complete recanalization could be obtained with antithrombotic therapy. We present the case since the association of cerebral venous thrombosis and Evans syndrome is very rare.

Is there a genetic basis for pediatric stroke?

PURPOSE OF REVIEW Childhood: stroke is more common than brain tumor, but because there is a wide spectrum in terms of etiology and most centers see only a few cases every year, there have been few large studies of genetic and environmental risk factors until recently. This review focuses on the clinical and radiologic methodology required to distinguish phenotypes in patients, and it focuses on the available data on genetic predisposition.

RECENT FINDINGS

A number of conditions with Mendelian inheritance (eg, sickle cell disease) predispose to childhood stroke, but the search for epistatic polymorphisms that explain why some but not all of these patients are affected has been hampered by our poor understanding of the pathophysiology. Emergency vascular imaging, including arteriography and venography, will almost certainly assist with the description of stroke subtypes with different genetic predisposition in these patients and in the important group of children who were completely healthy before their stroke. Environmental exposure (eg, to infection, hypoxemia, and vitamins) may play a crucial role in modifying genetic expression and must be described carefully in prospective studies.

SUMMARY

Now that much of the work on classifying stroke subtypes in children has been undertaken, international collaboration is likely to lead to identification of the genetic and environmental risk factors, and thus to primary and secondary prevention.