Homocysteine, folate and vitamin B12 in puerperal cerebral venous thrombosis

The risk profiles of pregnancy-related cerebral venous thrombosis: a retrospective study in a comprehensive hospital

OBJECTIVES

To investigate the risk factors and underlying causes of pregnancy-related cerebral venous thrombosis (PCVT).

METHODS

A retrospective cohort of 16 patients diagnosed with CVT during pregnancy and postpartum (within six weeks after delivery) in a comprehensive hospital in China between 2009 and 2022 were carefully reviewed, focusing on demographic, clinical, and etiological characteristics, especially underlying causes. We matched 16 PCVT patients with 64 pregnant and puerperal women without PCVT to explore risk factors and clinical susceptibility to PCVT.

RESULTS

PCVT occurred commonly during the first trimester (43.75%) and the puerperium (37.5%). The frequency of anemia, thrombocytosis and thrombocytopenia during pregnancy, dehydration, and pre-pregnancy anemia was significantly higher in women with PCVT than in those without PCVT (P < 0.05). Among the 16 patients, five were diagnosed with antiphospholipid syndrome and one was diagnosed with systemic lupus erythematosus. Three patients had distinct protein S deficiency and one had protein C deficiency. Whole Exome Sequencing (WES) was performed for five patients and revealed likely pathogenic mutations associated with CVT, including heterozygous PROC c.1218G > A (p. Met406Ile), heterozygous PROS1 c.301C > T (p. Arg101Cys), composite heterozygous mutation in the F8 gene (c.144-1259C > T; c.6724G > A (p. Val2242Met)) and homozygous MTHFR c.677C > T (p. Ala222Val).

CONCLUSIONS

The occurrence of anemia, thrombocytopenia and thrombocytosis during pregnancy, dehydration and pre-pregnancy anemia suggested a greater susceptibility to PCVT. For confirmed PCVT patients, autoimmune diseases, hereditary thrombophilia, and hematological disorders were common causes. Screening for potential etiologies should be paid more attention, as it has implications for treatment and long-term management.

Swedish obstetric thromboprophylaxis guideline: background and update

Risk estimation concerning venous thromboembolism (VTE) and thromboprophylaxis for those at risk is routine in pregnancy. For 20 years, Swedish obstetricians have followed a weighted-risk algorithm guideline for risk estimation, based on which patient selection, timing, duration and dosage of thromboprophylaxis are determined. This article presents the latest update, the basis for the algorithm and its application for assessing moderate- to high obstetric VTE risk, defined as equal or greater absolute risk per time unit than the antepartum risk of women with one prior VTE. The risk score is based on risk factors conferring approximately fivefold increased risk of VTE or a multiple thereof. This article also presents algorithm efficacy data and describes lifestyle advice provided to patients. In our experience, the Swedish guideline for obstetric VTE risk estimation is easy to follow. It helps identify women at high risk. The risk of under- or overtreatment is thus minimised.

Does gender difference matter in cerebral venous thrombosis?

Female specific risk factors (FSRFs) in cerebral venous thrombosis (CVT) may have difference in clinical, imaging and outcome parameters compared to those females with additional risk factors and males. We compare the clinical, MRI and outcome between male and female patients with CVT. We also compare female patients with and without female specific risk factors. 172 patients were included from a prospectively maintained CVT registry. The diagnosis was confirmed on magnetic resonance venography (MRV). Clinical details, risk factors, MRI and MRV findings were noted. The risk factors in the females were categorized as 1) Isolated FSRF (oral contraceptive, pregnancy, puerperium), 2) FSRF in addition to other risk factor, 3) non FSRF only, and 4) no risk factor groups. Outcome at 6 months was assessed using modified Rankin Scale (mRS) as death, poor (mRS 3-5) and good (mRS ≤ 2). There were 80 (46.5%) females; 24 (30%) had FSRFs and 18 (75%) of whom also had other risk factors leaving only 6(25%) females with isolated FSRF. The frequency of other prothrombotic risk factors, and clinical and imaging findings were similar in males and females except more frequent hyperhomocysteinemia in males (59% vs 41%; P = 0.036) and altered sensorium in females (66% vs 40%; P = 0.001). 17(9.9%) patients died, 12(7%) had poor and 143(83.1%) had good outcome, which were similar in both the gender, and in the females with and without FSRF. Isolated FSRF is rare in CVT, and there is no gender difference in terms of non FSRFs, clinico-radiological severity and outcome.

First report of cerebral venous thrombosis following inactivated-virus covid vaccination (Sinopharm and Sinovac)

Cerebral venous thrombosis (CVT) is an uncommon cerebrovascular disease, which has been reported with covid infection as well as covid vaccines, particularly AstraZeneca and Janssen vaccines. We present four consecutive cases of CVT after receiving either Sinopharm or Sinovac vaccine, both of which are composed of an inactivated-virus. All the patients recovered well with anticoagulation and discharged with a good functional outcome. This is the first case series reporting CVT following the administration of these vaccines.

A study of hyperhomocysteinemia in cerebral venous sinus thrombosis

Background & objectives:

Vegetarianism may result in low vitamin B12 and acquired hyperhomocysteinemia leading to thrombotic conditions such as cerebral venous sinus thrombosis (CVST). The clinico-radiological presentation and outcome of patients with hyperhomocysteinemia may be different from those without, but there is a paucity of information. This study was undertaken to find out the relationship of homocysteine (Hcy) with vitamin B12, folic acid and methyltetrahydrofolate reductase (MTHFR) mutation in the patients with CVST, and compare clinico-radiological severity and outcome of patients with and without hyperhomocysteinemia.

Methods:

Ninety-six CVST patients in whom Hcy level was measured, were included, and their risk factors and neurological, magnetic resonance (MR) imaging and MR venography findings were noted. They were evaluated for prothrombotic conditions including Hcy, vitamin B12, folic acid and MTHFR 677C→T mutation. Three month outcome was categorized as death, poor and good.

Results:

Seventy three per cent patients had risk factors; hyperhomocysteinemia in 52.1 per cent, protein S deficiency in 47.8 per cent, protein C deficiency in 19.4 per cent, MTHFR 677C→T mutation in 30.7 per cent, antinuclear antibody 11 per cent, and Factor V Leiden mutation in two per cent each. Thirty two per cent patients with hyperhomocysteinemia had no other thrombotic cause, and 22 per cent of them had either vitamin B12 and or folic acid deficiency only. The patients with hyperhomocysteinemia more frequently had vitamin B12 deficiency (70 vs. 13%), MTHFR 677C→T mutation (47.5 vs. 9.1%) and superior sagittal sinus thrombosis (78 vs. 56.5%) than normal Hcy group. The clinico-radiological severity and outcome were similar.

Interpretation & conclusions:

Hyperhomocysteinemia was an important correctable risk factor of CVST in patients from northern India, and majority of them had either low vitamin B12 level or MTHFR mutation.

Hyperhomocysteinemia as a Risk Factor and Potential Nutraceutical Target for Certain Pathologies

Hyperhomocysteinemia is recognized as a risk factor for several diseases, including cardiovascular and neurological conditions. Homocysteine (HCys) is a key metabolite involved in the biosynthesis and metabolism of methionine (Met), which plays a pivotal role in the physiological cell's life cycle. The biochemistry of Met is finely regulated by several enzymes that control HCys concentration. Indeed, balanced activity among the enzymes is essential for the cell's well-being, while its malfunction could raise HCys concentration which can lead to the onset of several pathological conditions. The HCys concentration increase seems to be caused mainly by the widely diffused polymorphisms of several enzymes. Nowadays, a blood test can easily detect elevated concentrations of HCys, referred to as Hyperhomocysteinemia (HHCys). Prolonged exposure to this condition can lead to the onset of cardiovascular disease and can lead to the development of atherosclerosis, stroke, inflammatory syndromes like osteoporosis and rheumatism, as well as neuronal pathologies including Alzheimer's and Parkinson's diseases. In this review, we analyzed the literature of several pathological conditions in which the molecular pathways of HHCys are involved. Interestingly, several observations indicate that the calibrated assumption of correct doses of vitamins such as folic acid, vitamin B6, vitamin B12, and betaine may control HHCys-related conditions.

The effects of L-cysteine and N-acetyl-L-cysteine on homocysteine metabolism and haemostatic markers, and on cardiac and aortic histology in subchronically methionine-treated Wistar male rats

Methionine is the precursor of homocysteine, a sulfur amino acid intermediate in the methylation and transsulfuration pathways; methionine-rich diets were used to induce hyperhomocysteinemia, and cardiovascular pathology was often observed. Other sulfur amino acids interfere with this metabolism, i.e., L-cysteine (Cys) and N-aceyl-L-cysteine (NAC), and probably also affect cardiovascular system. Their effects are controversial due to their ability to act both as anti- or pro-oxidant. Thus, this study aimed to elucidate their influence on levels of homocysteine, folate and vitamin B12, levels of different haemostatic parameters (fibrinogen, D-dimer, vWF Ag, vWF Ac) in rat serum or plasma as well as their effects on cardiac and aortic tissue histology in subchronically methionine-treated rats. Wistar albino rats were divided into 4 experimental groups: (a) control group (0.9% sodium chloride 0.1-0.2 mL/day) (n = 10) (K); (b) DL-methionine (0.8 mmol/kg/bw/day) (n = 10) (M); (c) DL-methionine (0.8 mmol/kg/bw/day) + L-cysteine (7 mg/kg/bw/day) (n = 8) (C); (d) DL-methionine (0.8 mmol/ kg/bw/day) + N-acetyl-L-cysteine (50 mg/kg/bw/day) (n = 8) (N). All substances were applied i.p., treatment duration 3 weeks. Lower levels of vitamin B12 in all the groups were found. Folate was reduced only in N group. Decreased fibrinogen was noted in C and N groups and increased D-dimer only in C. VWF activity was reduced in M and C groups. Deleterious effects in heart were observed, especially after Cys and NAC application. Aortic tissue remained unchanged. In conclusion, it could be said that sulfur amino acids have the significant impact on cardiovascular system in subchronically methionine-treated rats. This study points out the relevance of their complex interactions and deleterious effects mediated by either direct influence or procoagulant properties.

Profile of 26 HIV Seropositive individuals with Cerebral Venous Thrombosis

BACKGROUND

HIV infection has been found to be prothrombotic condition. However, venous thromboembolism associated with HIV is restricted to peripheral vasculature with few reports of cerebral venous thrombosis (CVT).

OBJECTIVE

To examine the clinical manifestations of CVT among HIV seropositive individuals and explore the possible etiological factors.

METHODS AND RESULTS

It is a prospective study of 26 (M:F-18:8) patients of CVT associated with HIV seropositive status. Their age and duration of illness was 33.8±6.8years and 11.3±8.5days respectively. Headache and vomiting was the most common symptom followed by seizures. Drowsiness with GCS (Glasgow coma score) ranging from 9-14 was present in two-thirds of the patients. Serum homocysteine was elevated in 70% of patients. Vitamin B12 was low in 12.5% and insufficient levels in 25%. 88.5% of the patients recovered completely to GCS 15/15 in 2-7days during follow up; 11.5% patients expired during the acute state.

CONCLUSION

This study represents the largest series of CVT in HIV seropositive individuals. There is increased risk of thrombosis due to elevated homocysteine and low Vitamin B12. They have better sensorium inspite of extensive radiological involvement.

Cerebral venous sinus thrombosis in pregnancy and puerperium: A pooled, systematic review

Pregnancy and puerperium are risk factors for cerebral venous sinus thrombosis (CVST); however studies describing diagnosis and management in this population are limited. The objective of this study was to amalgamate published case reports and series regarding diagnosis and management of CVST in pregnancy and puerperium. Searches of PubMed and the Cochrane library were performed using search terms "pregnancy"/"puerperium" and "sinus occlusion"/"sinus thrombosis". Studies were included in our pooled analysis if they included individual patient symptoms, management approach and follow-up condition. Multivariate regression was utilized to assess the effect of non-modifiable factors on excellent outcome (mRS 0). Sixty-six patients were included. Mean duration of symptom onset to diagnosis was 5.9days (95% CI 4.2-7.6). Clot involvement of the superior sagittal sinus was seen in 67% of cases, the transverse/sigmoid in 64% and of the deep venous system in 15% of cases. Management approaches included anticoagulation (91% of patients), IA (intra-arterial) thrombolysis alone (26%), and IA thrombectomy with IA thrombolysis (8%). Fifty-nine percent of patients were mRS 0 at follow-up; 94% were mRS 0-2. Presentation with headache alone was associated with excellent outcome on multivariate analysis (p=0.04); coma/obtundation predicted against excellent outcome (p=0.03). As compared to IA thrombolysis alone, patients undergoing IA thrombolysis with IA thrombectomy demonstrated a trend toward better outcome (p=0.10).

Cerebral Venous Sinus Thrombosis From a Tertiary Care Teaching Hospital in India

OBJECTIVE

The prognosis of cerebral venous sinus thrombosis (CVST) may be dependent on underlying causes and magnetic resonance imaging findings. We report the clinical, laboratory, and radiologic spectrum, and outcome of consecutive patients with CVST.

METHODS

Consecutive patients with CVST over the last 15 years were subjected to detailed history, clinical examination, and laboratory tests as per fixed protocol. The diagnosis of CVST was based on MR venography. The magnetic resonance imaging findings and the sinuses involved were noted. The patients were treated with low-molecular-weight heparin or unfractionated heparin for 14 days, followed by oral anticoagulation. Hospital mortality and 3-month outcome (good or poor) were recorded and correlated with various clinical and laboratory parameters.

RESULTS

There were 86 patients whose median age was 30 (6 to 76) years; 47 of them were females. Headache was present in 91.9%, vomiting in 68.6%, focal weakness in 53.5%, seizure in 51.2%, and altered sensorium in 53.5%. Female-specific etiology was present in 34%, prothrombotic condition in 62.8%, infections in 19.8%, and malignancy in 2.8%; no cause could be established in 25.6% of patients. Hyperhomocystinemia was present in 45.9% of patients. Five patients died in the unfractionated heparin group. At 3 months, 77 patients were followed up, of whom 68 had complete, 3 had partial, and 6 had poor recovery. The 3-month outcome was related to Glasgow Coma Scale score and type of heparin used.

CONCLUSIONS

In our study multiple prothrombotic conditions were common, and low-molecular-weight heparin reduces mortality and results in good outcome.

Hyperhomocysteinemia, low vitamin B12, and low folic acid: Are risk factors of cerebral vascular thrombosis in northwest Iran?

BACKGROUND

Cerebral vascular thrombosis (CVT) is the thrombosis of intracranial and sinuses. The aim of this is to estimate of risk of low folic acid, low vitamin B12, and hyperhomocysteinemia (hyper-Hcys) for CVT.

MATERIALS AND METHODS

A total of 24 patients with CVT and 36 healthy controls participated in a cross-sectional case-control study. The deficient levels of folic acid and vitamin B12 defined as <10^th percentile of folic acid and vitamin B12 level and hyper-Hcys was defined as >90^th percentile of homocysteine of control group.

RESULTS

Patients had higher levels of total homocysteine (tHcys) than controls (14.7 ± 6.5 vs. 6.4 ± 2.7 μmol/L, P = 0.001). Also, vitamin B12 level in case group was lower compared to control subjects (185.4 ± 58 vs. 299 ± 75 ng/mL, P = 0.001). Hyper-Hcys and low vitamin B12 were significantly more prevalent in CVT patients than controls. Although, significant independent association with risk of CVT was found for hyper-Hcys [adjusted odds ratio (OR) 14.3, 95% confidence interval (CI): 2.6-77.1, P = 0.002] and low vitamin B12 (adjusted OR 24.6, 95% CI: 2.3-262.9, P = 0.008). Association between low folic acid and risk of CVT was not significant. A significant negative correlation was found between the levels of tHcys and vitamin B12 (r = -0.32, P = 0.01).

CONCLUSION

Hyper-Hcys and low vitamin B12 were related with the high risk for CVT.

Hyperhomocysteinemia in Greyhounds and its Association with Hypofolatemia and Other Clinicopathologic Variables

Background

Folate and cobalamin are essential cofactors for homocysteine (HCY) metabolism. Hyperhomocysteinemia, a multifactorial condition, may reflect B vitamin deficiency and is associated with increased risk of cardiovascular disease, thrombosis, and neurodegenerative and chronic gastrointestinal diseases in humans. Hyperhomocysteinemia has been reported in Greyhounds with suspected chronic enteropathy.

Objectives

To evaluate the frequencies of and the association between hypofolatemia and hyperhomocysteinemia in Greyhounds.

Animals

Data and serum samples from 559 Greyhounds.

Methods

Nested case‐control study. The frequency of hypofolatemia in Greyhounds was determined by a laboratory database search. The relationship between hyperhomocysteinemia (measured by gas chromatography‐mass spectrometry) and hypocobalaminemia and hypofolatemia was evaluated, and its frequency compared between healthy Greyhounds and Greyhounds with thrombosis or chronic diarrhea.

Results

Hypofolatemia was identified in 172 of 423 (41%) Greyhounds and was more common in hypo‐ than in normocobalaminemic dogs (49% vs. 35%; P = .0064). Hyperhomocysteinemia was detected in 53 of 78 (68%) of Greyhounds, being more common in hypo‐ than in normofolatemic dogs (88% vs. 59%; P = .0175). All healthy Greyhounds, 21 of 30 (70%) of dogs with chronic diarrhea and 6 of 8 (75%) of those with thrombosis, were hyperhomocysteinemic. Serum HCY concentrations were inversely correlated with serum folate concentration (ρ = −0.28; P = .0386) and were positively associated with serum albumin concentration (ρ = 0.66; P = .0022).

Conclusions and Clinical Relevance

Hyperhomocysteinemia occurs frequently in the Greyhound population. Its association with hypofolatemia suggests decreased intracellular availability of B vitamins, but the functional implications warrant further investigation. Hyperhomocysteinemia in Greyhounds potentially may serve as a spontaneous canine model to further investigate hyperhomocysteinemia in humans.

The Effects of Homocysteine Level in the Critically Ill Patient. A Review

Increased levels of homocysteine (HCYS) represent a risk factor for a series of physiopathological conditions: mental retardation, cardiovascular and neurodegenerative diseases, Parkinson's and Alzheimer's disease, depression, osteoporosis, endothelial dysfunction and inhibition of cell proliferation. This paper aims to present the pathophysiological implications of HCYS and the correlation of hyperhomocysteinemia (H-HCYS) with critical condition in the intensive care unit (ICU). Hypovitaminosis B and folate deficiency is directly involved in the inhibition of HCYS metabolism and the accumulation of HCYS in the plasma and tissues. Critically ill patients are more prone to H-HCYS due to hypermetabolism and accelerated synthesis produced by reactive oxygen species (ROS). In conclusion it can be affirmed that the determination and monitoring of HCYS plasma levels may be of interest in optimizing the therapy for critically ill patients. Moreover, by controlling HCYS levels, and implicitly the essential cofactors that intervene in the specific biochemical pathways, such as vitamin B6, vitamin B12 and folic acid can provide a diversified and personalized treatment for each patient.

Cerebral Venous Thrombosis: Current and Newer Anticoagulant Treatment Options

BACKGROUND

Cerebral venous thrombosis (CVT) is rare and involves thrombosis of the veins and sinuses of the brain, most commonly the superior sagittal sinus. Approximately 5 CVT cases occur per 1 million persons in western countries. CVT causes 0.5% of strokes. Early diagnosis is crucial to prevent such outcomes as hydrocephalus, intracranial hypertension, and further seizures. Standard medical treatment of CVT consists of low-molecular-weight heparin and endovascular thrombolysis. Small case reports have found that the newer oral anticoagulants can be used for CVT treatment; however, they are associated with increased risk of bleeding and other adverse effects.

REVIEW SUMMARY

CVT can be triggered by an imbalance of the body's homeostasis or reduced action of the intrinsic antithrombotic mechanism. Factors influencing this change include infection, brain tumor, inflammatory conditions, genetic thrombophilias, head trauma that causes intracranial bleeding, and certain medications. CVT may cause brain infarction and increased intracranial pressure. Sometimes, idiopathic intracranial hypertension presents as the only clinical manifestation. Confirmation of the diagnosis typically is through neuroimaging. Current CVT treatment depends on disease extent and severity.

CONCLUSIONS

CVT is a rare neurological disease with potentially serious implications and high neurological morbidity and mortality rates. Understanding the role of risk factors-such as genetic or acquired thrombophilia, pregnancy, use of oral contraceptives, and hyperhomocysteinemia-in CVT development is important. Although heparin and warfarin have been used for more than 50 years, newer oral anticoagulants (eg, dabigatran, rivaroxaban, apixaban) might offer an alternative to traditional therapy.

Association study of methylenetetrahydrofolate reductase C677T mutation with cerebral venous thrombosis in an Iranian population

There are limited data on the role of methylenetetrahydrofolate reductase C677T polymorphism and hyperhomocysteinemia as risk factors for cerebral venous thrombosis in Iranian population. We examined a possible association between fasting plasma homocysteine levels, methylenetetrahydrofolate reductase C677T polymorphism, and cerebral venous thrombosis in 50 patients with a diagnosis of cerebral venous thrombosis (20-63 years old) and 75 healthy controls (18-65 years old). Genotyping of the methylenetetrahydrofolate reductase C677T gene polymorphism was performed by PCR-restriction fragment length polymorphism analysis, and homocysteine levels were measured by enzyme immunoassay. Fasting plasma homocysteine levels were significantly higher in cerebral venous thrombosis patients than in controls (P = 0.015). Moreover, plasma homocysteine levels were significantly higher in methylenetetrahydrofolate reductase 677TT genotype compared to 677CT and 677CC genotypes in both cerebral venous thrombosis patients (P = 0.01) and controls (P = 0.03). Neither 677CT heterozygote genotype [odds ratio (OR) 1.35, 95% confidence interval (CI) 0.64-2.84, P = 0.556] nor 677TT homozygote genotype (OR 1.73, 95% CI 0.32-9.21, P = 0.833) was significantly associated with cerebral venous thrombosis. Additionally, no significant differences in the frequency of 677T allele between cerebral venous thrombosis patients and controls were identified (OR 1.31, 95% CI 0.69-2.50, P = 0.512). In conclusion, our study demonstrated that elevated plasma homocysteine levels are significant risk factors for cerebral venous thrombosis. Also, methylenetetrahydrofolate reductase 677TT genotype is not linked with cerebral venous thrombosis, but is a determinant of elevated plasma homocysteine levels.

Plasma S-adenosylhomocysteine: A potential risk marker for cerebral venous thrombosis

BACKGROUND

Despite a plethora of studies suggesting that hyperhomocysteinemia is associated with an increased risk for arterial and venous thrombosis, there is paucity of data on the role of the S-adenosylhomocysteine (SAH), the metabolic precursor of homocysteine (Hcy) as a risk predictor for cerebral venous thrombosis (CVT).

METHOD

We estimated fasting plasma concentrations of total homocysteine (tHcy), SAH and S-adenosylmethionine (SAM), in 185 CVT patients and 248 healthy controls, by reverse-phase high performance liquid chromatography coupled with coulometric electrochemical detection.

RESULTS

Fasting tHcy, SAH and SAM were significantly higher in patients compared with controls. Increased tHcy and SAH concentrations were associated with 4.54-fold (95% CI, 2.74-7.53) and 35.77-fold (95% CI, 19.45-65.79) increase in risk for CVT, respectively. Receiver operating characteristic (ROC) curve analysis showed that the area under curve, sensitivity and specificity was higher for SAH compared to tHcy. Further, discriminant analysis to distinguish between tHcy and SAH showed that SAH had a significantly higher percentage classification, with lower Wilk's lambda and higher χ(2), compared to tHcy.

CONCLUSION

Increased plasma SAH may be a more sensitive risk marker for CVT than plasma tHcy.

Prevalence and Geographical Variation of Prothrombin G20210A Mutation in Patients with Cerebral Vein Thrombosis: A Systematic Review and Meta-Analysis

Objectives

To compare the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis against healthy controls, and evaluate geographical variations.

Design

Systematic review and meta-analysis of case control studies.

Methods

We conducted a systematic review of electronic databases including MEDLINE and EMBASE. The main outcome was the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis; we also analyzed individual country variations in the prevalence. The random-effects model OR was used as the primary outcome measure.

Results

In total 19 studies evaluated 868 cases of cerebral venous thrombosis and 3981 controls. Prothrombin G20210A was found in 103/868 of the patients with cerebral venous thrombosis and 105/3999 of the healthy controls [random effects pooled OR 5.838, 95% CI 3.96 to 8.58; I²17.9%]. The prevalence of prothrombin G20210A was significantly elevated in Italian studies (OR 9.69), in Brazilian studies (OR 7.02), and in German studies (OR 3.77), but not in Iranian studies (OR 0.98).

Conclusion

Prothrombin G20210A is significantly associated with cerebral venous thrombosis when compared to healthy controls, although this association is highly dependent on the country of origin.

[Cerebral venous sinus thrombosis associated with hyperhomocysteinemia due to combined deficiencies of folate and vitamin B12]

A 63-year-old man was admitted to our hospital because of convulsive seizures. Radiological examinations revealed cerebral venous sinus thrombosis in the anterior part of the superior sagittal sinus. He had marked hyperhomocysteinemia (93.5 nmol/ml) due to combined deficiencies of folate and vitamin B12. He was T/T homozygous for methylene tetrahydrofolate reductase C677T polymorphism. He received a supplement therapy of vitamins. First, he was administered folate orally. After 3 months, the serum level of homocysteine decreased to 22.6 nmol/ml (an 86% reduction), but was still above the normal level. Next, an additional supplement therapy of vitamin B12 lowered the homocysteine level to normal (12.3 nmol/ml) after 4 months. These results showed that the increase of homocysteine levels in this patient was mainly caused by the deficiency of folate. Additionally, acquired risk factors like vitamin deficiencies increased the level of serum homocysteine to almost 100 nmol/ml.

Cerebral venous thrombosis-a primer for the haematologist

Cerebral venous thrombosis (CVT) is a condition that can affect all age groups and can often be difficult to diagnose and treat. The difficulties in diagnosis are mainly due to the non-specific presenting features of CVT, which can range from isolated headache and visual or auditory problems, to serious symptoms such as hemiparesis and coma. Therefore, it can present to various specialists including general physicians, obstetricians and neurologists. In recent years, more widespread use of cerebral imaging has led to the diagnosis being made more often. Since thrombosis is the key component, haematologists are consulted in the management of these patients including for identification of a causative factor for CVT. In this regard, the pivotal International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) has shed more light on its epidemiology and management options. This review aims to provide guidance to haematologists when faced with a patient with CVT, based on the currently available evidence.

Cerebral venous thrombosis, pregnancy and oral contraceptives

Cerebral venous thrombosis (CVT) is a rare variety of cerebro-vascular disease accounting for 0.5% of all stroke. It can occur at any age. It has a 3/1 female preponderance with a peak in young women due to gender specific risk factors, especially oral contraceptives and to lesser extent pregnancy, post-partum, and in vitro fertilization. Despite a wide variety of clinical presentations, early diagnosis, mostly based on MRI/MRA, is crucial but often difficult particularly during post-partum because of the numerous causes of headache that may occur after delivery. Antithrombotic treatment based on low molecular weight heparin and symptomatic treatment should be started as rapidly as possible. The overall prognosis of CVT is much better than that of arterial stroke and it is even better in women with gender specific risk factors, with a complete recovery in 80% of patients. Future pregnancy is not contra-indicated, but contraception with oestro-progestogens is definitely contra-indicated.

Association between B-group vitamins and venous thrombosis: systematic review and meta-analysis of epidemiological studies

A homocysteine-independent role for B-group vitamins on venous thrombosis (VT) development has been reported. However, related research findings remain inconsistent. PUBMED, EMBASE, and COCHRANE databases were searched to collect information on all eligible studies to make a meta-analysis about the relationship between B-group vitamins and VT. Literature search results did not suggest a correlation between thiamin, pantothenic acid, niacin, or riboflavin with VT. Based on their correlations in the literature, folic acid, vitamin B12, B6 were considered in the meta-analysis and systematic review. Significant standardized mean differences were obtained for plasma folic acid (-0.55; 95% CI, -0.75 to -0.36) and vitamin B12 (-0.34; 95% CI, -0.55 to -0.13). Reduced levels of folic acid and vitamin B12 may be independent risk factors of VT. Moreover, a qualitative systematic review indicated that low level of vitamin B6 was an independent risk factor of VT. Randomized clinical studies of B-group vitamins supplementation showed varying results on VT prevention. Multivitamin supplementation for VT prevention, regardless of homocysteine level, would be of interest. Further prospective clinical studies are needed to provide additional evidence on the clinical benefits of B-group vitamin supplementation for VT.

Hyperhomocysteinemia and methylenetetrahydrofolate reductase C677T polymorphism in cerebral veno-sinus thrombosis

There is limited data on the role of hyperhomocysteinemia as a risk factor for cerebral veno-sinus thrombosis (CVT) in Indians. We examined the association between plasma homocysteine (Hcy), methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, and CVT in 185 patients with aseptic CVT (puerperal 80 and nonpuerperal 105) and 248 healthy controls (puerperal 67 and nonpuerperal 181). Fasting Hcy was higher in patients compared to controls (20.25 ± 5.97 vs 9.81 ± 5.19 μmol/L, P < .001) and associated with 4.54-fold (95% confidence interval [CI]: 2.74-7.53) increase in risk of CVT. Risk was higher in puerperal (odds ratio [OR]: 8.7, 95% CI: 2.73-26.91) compared to nonpuerperal CVT (OR: 3.82, 95% CI: 2.09-6.96). Plasma Hcy was higher in MTHFR 677TT compared to 677CT and 677CC genotypes (34.44 ± 32.8 vs 25.81 ± 33.3 vs 18.50 ± 23.7 μmol/L, respectively, P < .001), but the risk associated with MTHFR 677TT was insignificant (OR: 1.91, 95% CI: 0.53-7.06). We conclude that hyperhomocysteinemia is a risk marker for Indian patients with aseptic CVT. MTHFR 677TT genotype is not linked with CVT but is a determinant of plasma Hcy.

Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND

The purpose of this statement is to provide an overview of cerebral venous sinus thrombosis and to provide recommendations for its diagnosis, management, and treatment. The intended audience is physicians and other healthcare providers who are responsible for the diagnosis and management of patients with cerebral venous sinus thrombosis.

METHODS AND RESULTS

Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represent different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 1966 and used the American Heart Association levels-of-evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee.

CONCLUSIONS

Evidence-based recommendations are provided for the diagnosis, management, and prevention of recurrence of cerebral venous thrombosis. Recommendations on the evaluation and management of cerebral venous thrombosis during pregnancy and in the pediatric population are provided. Considerations for the management of clinical complications (seizures, hydrocephalus, intracranial hypertension, and neurological deterioration) are also summarized. An algorithm for diagnosis and management of patients with cerebral venous sinus thrombosis is described.

Hyperhomocysteinaemia, low folate concentrations and methylene tetrahydrofolate reductase C677T mutation in acute mesenteric venous thrombosis

OBJECTIVES

Acute mesenteric venous thrombosis (AMVT) was first reported by Fagge and was recognised as a distinct clinical entity by Warreen in 1935. However, its pathogenesis is still unclear. Elevated plasma levels of homocysteine (Hcy) are associated with an increased risk of deep vein thrombosis. This case-control study examines the potential association among hyperhomocysteinaemia (hyper-Hcy), low serum folate and vitamin B(12) levels and the common C677T mutation of the MTHFR gene in patients with AMVT.

MATERIALS AND METHODS

Sixty-three patients with AMVT and 75 sex- and age-matched healthy controls were recruited, and their plasma Hcy, folate and vitamin B(12) levels were measured by high performance liquid chromatography (HPLC) and immunological assays. The polymorphism of MTHFR C677T was detected by PCR-RFLP.

RESULTS

The mean plasma Hcy levels were significantly higher in patients with AVMT compared with controls (23.5 standard deviation (S.D.) 8.8 vs. 12.6+/-6.6micromoll(-1), P<0.01). The fasting Hcy correlated negatively with folate (AMVT: r=-0.42, P<0.01;

CONTROL

r=-0.40, P<0.01). The frequency of homozygous (TT) genotype in MTHFR C677T mutation was significantly higher in patients with AMVT than that in control subjects (33% vs. 17%; chi square (chi(2))=6.31, P<0.05; odds ratio (OR)=2.80; 95% confidence interval (CI): 1.25-6.25). Compared with the control subjects, the mean serum vitamin B(12) levels were lower in patients, but it was not statistically significant (365+/-88pmoll(-1) vs. 408+/-108pmoll(-1), P>0.05).

CONCLUSIONS

Hyper-Hcy and low serum folate levels were associated with an increased risk of AMVT. The homozygous (TT) genotype of MTHFR gene mutation may be a crucial hereditary risk factor in the development of AMVT for a Chinese population.