Dural Sinus Thrombosis with Nonsymptomatic Persistent Falcine Sinus: A Case Report

A 24-year-old woman was admitted to our hospital after convulsive status epilepticus. A cerebral magnetic resonance venography revealed a persistent fetal falcine sinus. Additionally, the posterior third of the superior sagittal sinus was hypoplastic and the abnormal deep venous drainage was accompanied. These abnormalities had already been detected by magnetic resonance imaging several years ago. In the present scan, we discovered a sinus thrombosis in the hypoplastic superior sagittal sinus. In the cerebral angiography, we observed delayed venous return in the left parieto-occipital lobe and hypothesized that cerebral venous stasis due to the thrombus caused the convulsive status epilepticus. The patient was treated with intravenous administration of heparin along with an antiepileptic drug, and she recovered with no neurological defects. In the present case, the falcine sinus and the anomalous venous return were likely congenital while the status epilepticus was derived from thrombosis in the hypoplastic superior sagittal sinus. Although the falcine sinus functioned as an alternative pathway for the superior sagittal sinus, the hypoplastic superior sagittal sinus itself may also play an important role as a venous drainage channel.

Superior Sagittal Sinus Thrombosis Related to the Use of Tamoxifen: A Case Report and Review of Literature

Tamoxifen is a selective estrogen- receptor modulator commonly associated with an increased risk of thrombotic events, including cere- bral venous thrombosis. Ihe superior sagittal sinus appears to be the most affected site of cerebral venous thrombosis in patients with a history of malignancy. However, the underlying mechanism of tamoxifen- induced hypercoagulability and location of cerebral venous thrombosis are notwellunderstood. Here, we present a case of a 47-year-old female with a history of breast cancer, on tamoxifen for 10 months, found to have superior sagittal sinus thrombosis with additional thrombosis of the draining cortical veins. Furthermore, we review similar cases published in literature. We recommend that physicians should be aware ofthe potential of developing superior sagittal sinus thrombosis in patients who take tamoxifen and warn patients of this adverse event when prescribing the medication.

Chronic superior sagittal sinus thrombosis with phlebosclerotic changes of the subarachnoid and intracerebral veins

An autopsy case of chronic thrombotic occlusion of the superior sagittal sinus (SSS) with an unusually protracted clinical course is reported. The patient was an 84-year-old man without any predisposing conditions for thrombosis. The clinical features were atypical and were characterized by recurrent cerebral subcortical hemorrhages. The autopsy revealed a large, organized thrombus in the SSS and extensive hemorrhagic infarction of the bilateral parasagittal region of the cerebral hemispheres. The hemorrhagic infarction was comprised of the aggregation of numerous minute foci of coagulation necrosis associated with petechial hemorrhages. Marked phlebosclerotic changes were observed in the subarachnoid and intracerebral veins, which were considered to be reactive changes of the venous walls against a persistent elevation in peripheral venous pressure caused by thrombosis of the SSS.

A new model of reversible sinus sagittalis superior thrombosis in the rat: magnetic resonance imaging changes

OBJECTIVE

The causes of cerebral sinus and vein occlusion and the accompanying parenchymal changes remain largely unexplained. The clinical variability and low incidence of the disease complicate systematic clinical investigations. Animal studies are indispensable; however, existing animal models of sinus thrombosis do not allow for long-term follow-up studies and are not suitable for pharmacological recanalization because sinus thrombosis is induced by ligation and injection of thrombogenic substances and does not resemble sinus thrombosis in humans.

METHODS

We induced thrombosis of the superior sagittal sinus (SSS) by careful topical application of ferric chloride onto the SSS of rats, leading to highly reproducible occlusions. Magnetic resonance imaging was performed immediately after initiation of thrombosis and on postoperative Days 1, 2, and 7. Diffusion- and T2-weighted images allowed for calculation of the apparent diffusion coefficient and T2 relaxation time. Vascular status was assessed by venous magnetic resonance angiography. Neurological deficits were assessed with the rotarod test.

RESULTS

Seven days after induction of thrombosis, partial recanalization (50.7% of the SSS remaining occluded) was accompanied by a resolution of early generalized changes of the apparent diffusion coefficient and of T2 relaxation time, indicating edema of the entire brain parenchyma. Compared with sham-treated animals, clinical skills in the experimental group improved over time, which was statistically independent from the degree of recanalization. Histopathological analysis revealed no signs of cerebral infarction.

CONCLUSION

This is the first animal model of SSS thrombosis that offers the possibility to investigate pathophysiological aspects of the disease as well as the influence of therapy on the nature of disease progression.

A new animal model of cerebral venous infarction: ligation of the posterior part of the superior sagittal sinus in the cat

QUESTIONS UNDER STUDY

Dural sinus occlusion is an infrequent but potentially devastating cause of stroke. The pathophysiological course of events underlying it is, as yet incompletely understood.

METHODS

In a cat model, regional cerebral blood flow (CBF) was measured during control and 2, and 24 hours after superior sagittal sinus occlusion. Around 48 hours after superior sagittal sinus occlusion, experimental settings were terminated by perfusion fixation with 4% paraformaldehyde solution, and haematoxylin and eosin histology.

RESULTS

CBF was significantly reduced over the time-period of measurement (p < 0.05) covering about 45% of the brain in planes that were affected by occlusion. Histologically, in all cases signs of subacute venous infarction could be demonstrated.

CONCLUSIONS

Based on the newly-developed model of microsurgical ligation of the superior sagittal sinus in cats, we present for the first time an animal model for cerebral venous infarction that leads to a histologically proven subacute venous infarction with a good reproducibility. The further advantage of this model is the fact that it mimics the clinical situation as far as possible by its inter- and intra-individual variance of extension of the venous infarction and by the slow reduction of CBF over 24 hours. Sequential PET imaging is a favourable, non-invasive method to gain further insight into the pathophysiological characteristics of experimental cerebral venous infarction. Therefore, the new-developed cat-model as demonstrated in this study will be of great value for further and more detailed investigations of cerebral-venous infarctions, and for the experimental evaluation of therapeutic strategies.

Adult pial arteriovenous fistula and superior sagittal sinus stenosis: angiographic evidence for high-flow venopathy at an atypical location. Case report

The authors present the case of a 69-year-old man who suffered from bilateral cortical venous hypertension due to a brain pial arteriovenous malformation (AVM) with a high-flow fistula. The AVM became complicated by the development of a high-grade stenosis of the posterior superior sagittal sinus (SSS). A comparison of cerebral angiograms obtained at different times revealed that the severe SSS stenosis had developed within a 5-year period and was located distal to the nidus of the left parietal AVM nidus, away from the entrance of the dominant superior superficial cortical draining vein into the SSS. The high-flow fistula was occluded with detachable coils and the AVM nidus was further embolized with acrylic. The SSS stenosis was mechanically dilated by means of balloon angioplasty and stent placement. This case provides angiographic evidence to support the hypothesis that a pial arteriovenous fistula in an adult can cause high-flow occlusive venopathy in a major sinus within a relatively short time and that this acquired high-flow occlusive venopathy can develop at an atypical location distant from the nidus of the AVM.

Superior sagittal sinus thrombosis occurring at high altitude associated with protein C deficiency

A 42-year-old male presented with right-sided weakness, dysphasia and seizures while climbing the French Alps at an approximate altitude of 3,000 m. Imaging studies were consistent with superior sagittal sinus thrombosis with hemorrhage. Laboratory testing for thrombophilic states, 18 days after presentation at our hospital, showed a low protein C level (0.32 U/ml, normal 0.80-1.60 U/ml). A family member was also found to have protein C deficiency without a history of thrombosis. The patient gradually improved and was discharged on warfarin and valproic acid. This is the first reported case of cerebral venous thrombosis in a patient with congenital protein C deficiency who ascended to high altitude. We postulate that the ascent to high altitude represented an additional prothrombotic risk factor to the congenital protein C deficiency leading to cerebral thrombosis.