Oral Contraceptives Are a Risk Factor for Cerebral Vein Thrombosis

Hormonal contraceptives and cerebral venous thrombosis risk: a systematic review and meta-analysis

Objectives: Use of oral contraceptive pills (OCP) increases the risk of cerebral venous sinus thrombosis (CVST). Whether this risk varies by type, duration, and other forms of hormonal contraceptives is largely unknown. This systematic review and meta-analysis update the current state of knowledge.

Methods: We performed a search to identify all published studies on the association between hormonal contraceptive use and risk of CVST in women aged 15–50 years.

Results: Of 861 studies reviewed, 11 were included. The pooled odds of developing CVST in women aged 15–50 years taking OCPs was 7.59 times higher compared to women not taking OCPs (OR = 7.59, 95% CI 3.82–15.09). Data are insufficient to make conclusions about duration of use and other forms of hormonal contraceptives.

Conclusion: Oral contraceptive pills use increases the risk of developing CVST in women of reproductive age. Future studies are required to determine if duration and type of hormonal contraceptives modify this risk.

Venous thromboembolism in women

Abstract

The risk of venous thromboembolism (VTE) varies throughout a woman’s life and is associated primarily with underlying hormonal exposure. Alteration in hemostatic mechanisms, including resistance to activated protein C, may explain this altered risk. Initially, development of VTE with the use of contraception in young adulthood may reveal inherited thrombophilia. Pregnancy, and particularly the post-partum period, likely confer the greatest risk of VTE, but the absolute risk is small. Guidelines for prevention of VTE during pregnancy are based on personal or family history of VTE, and known inherited thrombophilia. Use of hormone replacement therapy later in life is associated with increased risk of VTE, and may be safest if given as an estrogen-only preparation to young postmenopausal women for less than 5 years. Universal screening for thrombophilia prior to pregnancy or initiating hormonal therapy is not recommended; however, selected testing in high-risk groups may be warranted. The lack of firm recommendations for the prevention of VTE in women highlights the need for future investigation aimed at identifying high-risk groups and evaluating the efficacy of prophylactic measures.

Two consecutive dural arteriovenous fistulae in a child: a case report of successful treatment with gamma knife radiosurgery

INTRODUCTION

The occurrence of dural arteriovenous fistulae in children is quite rare. Endovascular embolization is typically the first line treatment. In general, Gamma Knife radiosurgery is used as adjuvant treatment and seldom performed as the first line treatment in children.

DISCUSSION

We report a case of a 27-month-old girl who presented with an initial dural arteriovenous fistula (AVF) located at anterior base of the left middle cranial fossa. She subsequently developed another dural AVF over the left transverse-sigmoid sinus region 2 years later.

CONCLUSION

Both fistulae were successfully obliterated with Gamma Knife radiosurgery.

Thromboses veineuses cérébrales

Venous thromboses in the cerebrum are rare, within the context of both cerebrovascular disease and all of the venous thrombotic diseases. Its clinical aspects are polymorphic in their onset and in their acute phase, making diagnosis difficult. MRI with angiographic sequences can show the presence of a thrombus within a venous vessel and its consequences on the cerebral parenchyma. Hemostatic disorders are the leading causes of cerebral venous thrombosis, in particular, constitutional thrombophilia often associated with one or several promoting factors such as use of oral contraception. This explains the incidence peak among young women. The cause of approximately 20% of cerebral venous thromboses is never identified. Antithrombotic treatment must be prescribed on an emergency basis when the diagnosis is made, even if potentially hemorrhagic lesions are also present. The risk of permanent neurologic damage is approximately 13%.

Thrombophilic abnormalities, oral contraceptives, and risk of cerebral vein thrombosis: a meta-analysis

Recent studies suggest that thrombophilic abnormalities and the use of oral contraceptives (OCs) are the leading causes of cerebral vein thrombosis (CVT). The purpose of this study was to assess the association between CVT and thrombophilic states, OCs, and their interaction. For data sources, we used the MEDLINE, EMBASE, and Cochrane Library databases (January 1994 to March 2005), reference lists of retrieved articles, and contact with content experts. We selected studies comparing the prevalence of OC use and the prevalence of prothrombitic abnormalities in patients with CVT compared with healthy controls. Two reviewers independently selected studies and extracted study characteristics, quality, and outcomes. Odds ratios (ORs) were calculated for each trial and pooled using the Mantel-Haenszel method. Seventeen studies were included. There was an increased risk of CVT in patients using OCs (OR 5.59; 95% confidence interval [CI] 3.95 to 7.91; P < .001), and in patients with factor V Leiden (OR 3.38; 95% CI 2.27 to 5.05; P < .001), with mutation G20 210A of prothrombin (OR 9.27; 95% CI 5.85 to 14.67; P < .001) and with hyperhomocysteinemia (OR 4.07; 95% CI 2.54 to 6.52; P < .001). We concluded that OC users, and patients with factor V Leiden, the prothrombin G20 120A mutation, and hyperhomocysteinemia are at a significantly increased risk of CVT.

Association of the protein C promoter CG haplotype and the factor II G20210A mutation is a risk factor for cerebral venous thrombosis

The factor II G20210A mutation and estrogen treatment are described as risk factors for cerebral venous thrombosis (CVT). We evaluated these known risk factors in a population of CVT patients and investigated the role of a combination of two polymorphisms in the promoter of the protein C gene (PC promoter CG haplotype), newly described as risk factors for deep venous thrombosis. A retrospective population of 26 CVT patients was compared with a control group of 84 healthy volunteers. After a multivariate analysis, we confirmed that the factor II G20210A mutation is an independent risk factor for CVT with odds ratio 4.7 (95% confidence interval, 2.83--75.3). We demonstrated that the CVT risk is increased when this mutation is associated either with the PC promoter CG haplotype (odds ratio=19.8; 95% confidence interval, 2.1--186.5) or, in females, with an estrogen treatment (odds ratio=24; 95% confidence interval, 2.26--127.3). In this work, the association of the factor II G20210A mutation and the PC promoter CG haplotype or estrogen treatment seems to be a particular risk for CVT.

Prothrombin 20210A and Oral Contraceptive Use as Risk Factors for Cerebral Venous Thrombosis

BACKGROUND

This study investigates the association between cerebral vein thrombosis (CVT) and the mutations FV 1691A (factor V Leiden), PT 20210A and MTHFR 677TT and acquired factors including oral contraceptive (OC) use.

METHODS

26 patients (21 females) and 217 healthy controls (134 females) were studied. Multiple regression analysis was performed.

RESULTS

The frequency of the three mutations in cases and controls were: PT 20210A, 23 versus 1%, odds ratio (OR) 21.40 (95% CI 4.29-118.75), p < 0.001; FV 1691A, 8 versus 1%, OR 5.94 (95% CI 0.66-46.9); MTHFR 677TT, 4 versus 7%, OR 0.54 (95% CI 0.03-4.08). OC use was more frequent in female patients over 14 years old than in controls (84 vs. 40%, OR 8.15, 95% CI 2.09-37.13, p < 0.001). The model that best explained the thrombotic risk included PT 20210A and OC use.

CONCLUSIONS

PT 20210A and OC use are the main thrombophilic risk factors predisposing to CVT and should be routinely investigated in patients with this disease.

Dural arteriovenous fistula associated with prothrombin gene mutation

An association between dural arteriovenous fistula and cerebral sinus thrombosis is reported. It is clear in several cases that thrombosis precedes the development of the fistula while it is unclear that it occurs in every case. The authors report a case of a woman with sinus thrombosis and presence of prothrombin gene mutation who subsequently developed a large dural arteriovenous fistula. Various possible factors involved in the pathogenesis of a dural fistula are discussed, with emphasis on underlying thrombophilia and oral contraceptive use in this patient.

Combined heterozygosity of factor V leiden and the G20210A prothrombin gene mutation in a patient with cerebral cortical vein thrombosis

Cerebral venous thrombosis (CVT) is a rare type of stroke with a variety of causes. Several reports have suggested that either factor V Leiden or G20210A prothrombin gene mutation is associated with an increased risk of CVT. The genetic thrombophilias are typically associated with other predisposing factors. We report a unique case of CVT in a patient with both the factor V Leiden and the G20210A prothrombin gene mutations without other identifiable precipitating factors in a 28-year-old white male in good health. MRI and cerebral arterial angiography showed cerebral cortical venous thrombosis. This case suggests that combined heterozygous individuals may be particularly prone to spontaneous thrombosis, like CVT.

Screening for activated protein C resistance before oral contraceptive treatment: a pilot study

The feasibility and cost-effectiveness of screening women for congenital thrombophilic alterations before oral contraceptive (OC) treatment was investigated. A total of 525 women (mean age 21.9 years, 73% aged < 25 years) were examined before their first OC course. At first screening, completely normal results were recorded in 485 (92.4%) women, the remaining showing single (n = 34) or multiple (n = 6) alterations. At second examination (possible in 37 of 40), activated protein C resistance (APCR) was confirmed in 21 cases (4.0%, 18 with factor V Leiden), protein C, or protein S reduction in 8 (1.5%) and 2 (0.4%) cases, respectively. No cases with antithrombin III deficiency were detected. The global estimated cost ($US) to detect one altered case was: $7795 for protein S, $2696 for antithrombin III (no case found), $1374 for protein C and $433 for APCR. The present study confirms that extensive thrombophilic screening before OC treatment is not currently advisable. APCR assessment, however, seems to have a favorable cost-effectiveness ratio: the alteration is frequent and has a synergistic effect with OC; sensibility and specificity of some methods are good; family history is unreliable to single out possible carriers; finally, carriers can be fully informed of their increased thrombotic risk if treated with OC and can receive thromboprophylaxis during life situations associated with high thrombotic risk (e.g., pregnancy and puerperium).

Prothrombin gene G20210-->A transition is a risk factor for cerebral venous thrombosis

BACKGROUND AND PURPOSE

It has been recently reported that a G-->A transition at nucleotide position 20210 in the 3'-untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increased risk of deep venous thrombosis. To date, it is unknown whether this polymorphism also represents a risk factor for cerebral venous thrombosis (CVT).

METHODS

Venous blood samples were collected from 45 patients with CVT and from 354 healthy blood donors as controls. A second control group consisted of 131 subjects with acute ischemic stroke or transient ischemic attack (TIA). Genomic DNA was isolated from peripheral blood leukocytes. Amplification of DNA was performed by polymerase chain reaction (PCR). The G-->A transition at nucleotide position 20210 of the prothrombin gene was detected by allele-specific restriction digestion.

RESULTS

The G20210-->A transition in the prothrombin gene was found in a heterozygous form in 4 of 45 patients with CVT (8.9%) and in 8 of 354 healthy control subjects (2.3%). This difference was statistically significant (P=0.010). The G20210-->A transition increased the relative risk for CVT approximately 5-fold (age-adjusted odds ratio 5.7; 95% CI 1.5 to 21.5). In contrast, in the group of patients with acute cerebral ischemia, only 3 of 131 subjects (2.3%) were heterozygous for the G20210-->A transition, which corresponded to the prevalence in the group of healthy blood donors.

CONCLUSIONS

The recently described G20210-->A transition in the 3'-untranslated region of the prothrombin gene is an inherited risk factor for CVT but obviously not for acute ischemic stroke or TIA.

High risk of cerebral-vein thrombosis in carriers of a prothrombin-gene mutation and in users of oral contraceptives

BACKGROUND

Idiopathic cerebral-vein thrombosis can cause serious neurologic disability. We evaluated risk factors for this disorder, including genetic risk factors (mutations in the genes encoding factor V and prothrombin) and nongenetic risk factors (such as the use of oral contraceptive agents). We compared the prevalence of these risk factors in 40 patients with cerebral-vein thrombosis, 80 patients with deep-vein thrombosis of the lower extremities, and 120 healthy controls. The G1691A mutation in the factor V gene and the G20210A prothrombin-gene mutation, which are established genetic risk factors for venous thrombosis, were studied. We also assessed the use of oral contraceptives and other risk factors for thrombosis.

RESULTS

The prevalence of the prothrombin-gene mutation was higher in patients with cerebral-vein thrombosis (20 percent) than in healthy controls (3 percent; odds ratio, 10.2; 95 percent confidence interval, 2.3 to 31.0) and was similar to that in patients with deep-vein thrombosis (18 percent). Similar results were obtained for the mutation in the factor V gene. The use of oral contraceptives was more frequent among women with cerebral-vein thrombosis (96 percent) than among controls (32 percent; odds ratio, 22.1; 95 percent confidence interval, 5.9 to 84.2) and among those with deep-vein thrombosis (61 percent; odds ratio, 4.4; 95 percent confidence interval, 1.1 to 17.8). For women who were taking oral contraceptives and who also had the prothrombin-gene mutation (seven patients with cerebral-vein thrombosis but only one control), the odds ratio for cerebral-vein thrombosis rose to 149.3 (95 percent confidence interval, 31.0 to 711.0).

CONCLUSIONS

Mutations in the prothrombin gene and the factor V gene are associated with cerebral-vein thrombosis. The use of oral contraceptives is also strongly and independently associated with the disorder. The presence of both the prothrombin-gene mutation and oral-contraceptive use raises the risk of cerebral-vein thrombosis further.