Abnormal development of cerebral arteries and veins in offspring of experimentally preeclamptic rats: Potential role in perinatal stroke.

Preeclampsia, a hypertensive disorder of pregnancy, complicates up to 10 % of all pregnancies and increases the risk for perinatal stroke in offspring. The mechanism of this increase is unknown, but may involve vascular dysfunction. The goal of this study was to evaluate the effect of experimental preeclampsia (ePE) on cerebrovascular function in offspring to eludciate a possible mechanism for this association. Dams were fed a high cholesterol diet beginning on day 7 of gestation to induce experimental preeclampsia. Middle cerebral arteries (MCA) and the Vein of Galen (VoG) were isolated from pups from ePE dams and compared to pups from normal pregnant (NP) dams at postnatal days 16, 23, and 30 and studied pressurized in an arteriograph chamber. Markers of inflammation and oxidative stress were measured in serum. Our results suggest altered structure and function in both MCA and VoG of ePE pups. We also found evidence of systemic inflammation and oxidative stress in ePE pups. These findings provide a potential link between preeclampsia and the occurrence or severity of perinatal stroke.

Cerebral perfusion change of venous hypertension on near-infrared spectroscopy signals after operation for dural arteriovenous fistula.

A dural arteriovenous fistula (AVF) is an arteriovenous shunt in the dura and is associated with a risk of intracranial hemorrhage and neurologic deficit. The morbidity of this disease depends on venous hypertension, and the classification of this disease is based on the pattern of venous drainage. The pattern of venous drainage relates to the clinical features of the disease, especially to the probability of intracranial hemorrhage. We report 1 case of dural AVF with retrograde leptomeningeal venous drainage. Cerebral hemodynamics were monitored using near-infrared spectroscopy imaging before, during, and after the 2-stage operative treatment. Preoperative functional near-infrared spectroscopy (fNIRS) showed an increase in deoxyhemoglobin (HbR) during a motor task. After partial coil embolization of the shunt points (stage 1), HbR increased during the first half of the task and decreased later, whereas oxyhemoglobin (HbO2) decreased in the first half of the task and increased later. After complete embolization (stage 2), fNIRS showed a pattern similar to that of a normal adult. The patient's symptoms improved gradually, and angiography showed a reduction of the retrograde venous drainage and venous congestion after this 2-stage operation. The reduction in venous hypertension may be the underlying mechanism behind the changes observed with fNIRS.

Thrombophilic factors and the formation of dural arteriovenous fistulas.

OBJECT: Dural arteriovenous fistulas (DAVFs) are distinct neurovascular entities. Although their exact origins are unknown, venous thrombosis and venous hypertension are likely to be major inducing factors. To address the relationship between DAVFs and thrombophilic factors, the authors conducted a case-control study at a single institution and performed a metaanalysis of the literature. METHODS: Forty patients with DAVFs at Toronto Western Hospital were recruited to complete a questionnaire and to donate blood samples for factor V Leiden mutation and factor II G20210A mutation screening and assessment of coagulation factors. The questionnaire was designed to collect information on each participant's specific history of venous thrombosis, medications, and race. A control group of 33 healthy volunteers agreed to the same protocol. A MEDLINE search of the literature from 1966 to the present was conducted and three relevant series were found. The results of the present study were pooled with the data from the literature. RESULTS: Combining institutional results with the results from the literature yielded a total of 121 patients and 178 control group members. Thrombophilic mutations were present in 16 patients and four healthy volunteers, with an odds ratio (OR) of 4.69 for factor V Leiden (95% confidence interval [CI] 1.24-17.69) and an OR of 10.87 for the prothrombin G20210A allele (95% CI 1.32-89.51). Levels of the basic coagulation profile, fibrinogen, and factor VIII were within normal limits. CONCLUSIONS: Patients with the factor V Leiden and factor II G20210A mutations are at a higher risk for DAVFs. However, because these mutations are not implicated in the vast majority of DAVFs, routine screening is not recommended.

Plasma vascular endothelial growth factor and serum soluble angiopoietin receptor sTIE-2 in patients with dural arteriovenous fistulas: a pilot study.

Our aim was to correlate concentrations of circulating vascular endothelial growth factor (VEGF) and serum soluble angiopoietin receptor (sTIE-2) before and after endovascular treatment with the grading in human dural arteriovenous fistulas (DAVFs). In ten patients with DAVFs undergoing diagnostic cerebral angiography and endovascular intervention, pre-treatment and post-treatment levels of plasma VEGF and serum TIE-2 were examined in a prospective study design. A total of 32 plasma samples and 19 serum samples was collected from the cubital vein, the arterial sheath before and--if applicable--after intervention. Plasma VEGF and serum Tie-2 levels were measured by standardized ELISA protocols. In eight of ten patients with DAVF increased circulating VEGF levels (elevation of more than mean + 2 SD of published normal values) were found, whereas two patients showed increased sTIE-2 levels. Six of the seven patients treated by endovascular embolization displayed a post-interventional decrease of VEGF values. The serum TIE-2 levels decreased slightly after intervention. Pre-treatment vVEGF levels varied significantly between patients with grades I and II/III fistulas according to the Cognards classification system. Our pilot study suggests that assessment of angiogenesis parameters in patients with DAVFs might correlate with the DAVFs' grade. To support the hypothesis that a change in angiogenic indicators may serve as indicators for a response to therapy, a larger number of patients should be followed for a longer time period.

Molecular analysis of thrombophilic risk factors in patients with dural arteriovenous fistulas.

Dural arteriovenous fistulas (DAVFs) are direct artery-to-cerebral venous sinus shunts. Our recent finding of a significantly increased prevalence of factor V (FV) Leiden in patients with DAVFs prompted us to evaluate prothrombinG20210A, MTHFRC677T, beta-fibrinogenG455A, PAI-14G/5G and FXIIIVal34Leu as additional risk factors for thrombophilia in 26 patients with DAVFs and a group of age- and gender-matched controls. There was no significantly increased prevalence of these risk factors in DAVF patients. We conclude that FV Leiden is of pathogenetic significance in the aetiology of a subgroup of DAVFs whereas the other thrombophilic risk factors are not likely to be involved.