Isolated cortical venous thrombosis and ulcerative colitis

Aseptic cortical venous thrombosis is rare without concomitant dural sinus thrombosis. Ulcerative colitis is associated with both dural sinus thrombosis and isolated cortical venous thrombosis. We describe a 26-year-old woman with ulcerative colitis who had a spontaneous cerebral hemorrhage. An overlying thrombosed cortical vein was identified on spin-echo MR images and confirmed with angiography. Signal characteristics of thrombosed cortical veins are similar to those described in dural sinus thrombosis.     

CT angiography of cerebral venous circulation: anatomical visualization and diagnostic pitfalls in interpretation

PURPOSE: To show the frequency of visualisation of the dural sinuses and cerebral veins with CT-angiography (CTA) with special reference to anatomical variants. METHODS: 34 CTA (1 mm slice thickness, 120 ml nonionic KM, 2 ml/s flow, 40 s prescanning delay) were performed in 30 patients to examine the cerebral venous system. In an anatomic study of cadavers (n = 10) without known disease of the cerebral veins the great sinuses were opened and examined. RESULTS: The superior sagittal, the transverse, the sigmoid and the straight sinus could be evaluated in all cases (100%). The cortical and deep cerebral veins as well as the small sinuses were visualised in 12-97% of the examinations. A sinovenous thrombosis was diagnosed in 4 of the 30 patients. Asymmetric superior sagittal sinus bifurcation (12/30), a hypoplastic sinus transversus (2/30) and a persistent sinus occipitalis (4/30) were found as anatomical variants. In 10 of the 30 patients we discovered 17 dural sinus filling defects produced by large arachnoid granulations. Similar findings could be demonstrated in the pathologico-anatomic examination series. CONCLUSION: CT angiography is suitable for detailed evaluation of the cerebral veins. Anatomic variants, arachnoid granulations, as well as fibrous bands and septa, which may lead to misinterpretation in conventional CT, can be clearly demonstrated. The sensitivity and specificity of CT in diagnosis of sinovenous thrombosis were increased thereby.     

Radical resection of meningiomas and arteriovenous fistulas involving critical dural sinus segments: experience with intraoperative sinus pressure monitoring and elective sinus reconstruction in 10 patients

OBJECTIVE: Radical resection of meningiomas and dural arteriovenous fistulas involving functional major dural sinuses entails the risk of intracranial hypertension and venous infarction. Surgical reconstruction of dural sinuses and bridging veins increases the spectrum of dural sinus conditions that can be treated by complete resection, but indications for venous reconstructions and associated risks are still not well defined. We report our experience with sinus reconstruction based on the intraoperative assessment of collateral venous flow. METHODS: Radical resection of meningiomas (n = 5) or dural arteriovenous fistulas (n = 5) involving critical segments of dural sinuses was performed in 10 patients. All but two patients were suffering from recurrent disease after incomplete treatment. Tolerance of sinus occlusion was assessed intraoperatively by measuring stump pressure in the superior sagittal sinus during test clamping of the involved sinus segment. RESULTS: In five patients, the results of pressure monitoring suggested that occlusion of the sinus might not be tolerated. In two other patients, major bridging veins entered the diseased segment. In these patients, the resected sinus segment was reconstructed and bridging veins were reinserted as far as possible. Postoperative graft occlusion occurred in two patients. One patient who was managed without reconstruction sustained a transient postoperative neurological deficit resulting from venous congestion in the vein of Labbé. Postoperative imaging confirmed total elimination of the pathological process in all 10 patients. There was no recurrence of disease during follow-up periods of up to 8 years. CONCLUSION: The monitoring of sinus pressure, together with the possible reconstruction of the diseased sinus, allows complete surgical treatment of dural sinus abnormalities and involves acceptable risk.     

Scalp veins as collateral pathway with parasagittal meningiomas occluding the superior sagittal sinus

In 3 cases with occlusion of the superior sagittal sinus (SSS) with parasagittal meningiomas, carotid angiography demonstrated scalp veins as an important collateral venous pathway. The authors believe that occlusion of the SSS is best seen in half axial oblique carotid phlebograms under contralateral carotid compression. Direct sinography is time consuming and troublesome. In the presence of scalp veins as important collaterals, strategic consideration for surgical treatment is discussed.     

No evidence for an ischemic penumbra in massive experimental intracerebral hemorrhage

OBJECTIVES: To determine the effect of massive intracerebral hemorrhage (ICH) on regional cerebral blood flow (rCBF) and metabolism, and to test the hypothesis that there is persistent ischemia in the perihematoma region after ICH. BACKGROUND: Cerebral ischemia is postulated to be one of the mechanisms of neural injury after ICH. Presumably the hematoma induces ischemia by mechanical compression of the surrounding microvasculature. METHODS: The authors induced ICH in eight anesthetized mongrel dogs by autologous blood injection (7.5 mL) under arterial pressure in the deep white matter adjacent to the left basal ganglia. They measured serial rCBF using radiolabeled microspheres in regions around and distant to the hematoma, as well as cerebral oxygen extraction, oxygen consumption (CMRO2), glucose utilization, and lactate production by serial sampling of cerebral venous blood from the sagittal sinus. Mean arterial pressure (MAP) and intracranial pressure (ICP) were monitored continuously. All measurements were recorded at 0.5, 1.0, 2.0, 3.5, and 5.0 hours after induction of ICH and compared with prehematoma values. Evans Blue dye was injected at the end of the experiment, and intensity of staining was compared with three control animals. RESULTS: Compared with prehematoma ICP (12.5+/-2.0 mm Hg, mean+/-standard error), significant elevation in ICP was observed after ICH peaking at 5 hours (34.4+/-5.2 mm Hg). Compared with prehematoma MAP (125.8+/-7.0 mm Hg), significant elevation in MAP was observed at 120 minutes after onset of hematoma (139.1+/-4.6 mm Hg), with return to the prehematoma value by 5 hours. There were no significant changes observed in cerebral oxygen extraction (51.4+/-4.3% versus 44.8+/-4.9%) and CMRO2 (1.8+/-0.3 versus 1.64+/-0.2 mL O2/100 g/min) at 5 hours posthematoma (or any other posthematoma measurement) compared with prehematoma values. There were no significant differences observed in rCBF in the perihematoma gray (18.2+/-0.9 mL/100 g/min versus 20.1+/-1.5 mL/100 g/min) or white matter (15.6+/-1.4 mL/100 g/min versus 15.3+/-1.1 mL/100 g/min) at 5 hours posthematoma (or any other posthematoma measurement) compared with prehematoma values. No changes were observed in cerebral glucose utilization, lactate production, and rCBF in other regions after introduction of ICH. Permeability of the blood-brain barrier was more prominent in the ipsilateral hemisphere in animals with ICH compared with control animals. CONCLUSIONS: Despite a prominent increase in ICP and MAP after ICH, the authors found no evidence to support the presence of an ischemic penumbra in the first 5 hours after ICH. Thus, other mechanisms for acute neural injury and late rCBF changes after ICH must be investigated.     

Selective transvenous embolization of dural fistulas without occlusion of the dural sinus

Two patients with dural arteriovenous fistulas (DAVFs) and unsuccessful transarterial embolizations were treated with a technique for selective transvenous embolization. A 5F catheter was advanced from a femoral vein access into the internal jugular bulb and a catheter was navigated through the sinus lumen into the involved cortical veins or the parasinusal venous draining channels of the DAVFs. The venous recipients at the nidal level of the DAVFs were occluded by fibered platinum coils. Complete angiographic cure was effected in both patients, with occlusion of the venous recipients and the nidus, although the sinus segments next to the nidus of the DAVFs remained patent. Placement of coils in a transsinusal route into the venous channel of a DAVF yet outside the sinus lumen can result in complete obliteration of the fistula without damage to the physiological function of the dural sinuses.     

Dural-pial arteriovenous malformation after sinus thrombosis

BACKGROUND: We report an unusual case of acquired dural-pial arteriovenous malformation (AVM) following sinus thrombosis. CASE DESCRIPTION: Initial angiography performed in a 39-year-old man showed thrombosis of the superior sagittal sinus (SSS) and the right transverse sinus (TS) but no vascular malformations. Follow-up angiography 29 months later revealed recanalization of the SSS and the TS, retrograde cortical venous drainage which suggested that thrombosis of the sinuses probably propagated into the adjacent parietal cortical veins, and development of a dural-pial AVM at or near the site of thrombi in more than one cortical vein. Complete surgical excision of the lesion was accomplished without neurological deterioration. CONCLUSIONS: The present case suggests the possibility that the pial AVM is not only a congenital condition but also may develop as an acquired lesion.     

Effects of mild (33 degrees C) and moderate (29 degrees C) hypothermia on cerebral blood flow and metabolism, lactate, and extracellular glutamate in experimental head injury

The effects of mild (33 degrees C) and moderate (29 degrees C) hypothermia were investigated to determine which temperature was more effective against compression-induced cerebral ischemia. Eighteen cats were anesthetized. The animals were divided into three groups according to deep-brain temperature (control, 37 degrees C; mild hypothermia, 33 degrees C; and moderate hypothermia, 29 degrees C). Intracranial pressure (ICP) and cerebral blood flow (CBF) were monitored, the latter by hydrogen clearance. Arteriovenous oxygen difference (AVDO2) and cerebral venous oxygen saturation (ScvO2) were measured in blood samples from the superior sagittal sinus. The cerebral metabolic rate of oxygen (CMRO2) and the cerebral metabolic rate of lactate (CMR lactate) were calculated. Extracellular glutamate was measured by microdialysis. ICP was increased by inflation of an epidural balloon until CBF became zero, and this ischemia was maintained for 5 min, after which the balloon was quickly deflated. All parameters were recorded over 6 h. Evans blue was injected to examine vascular permeability changes. CBF was decreased by 56% by mild hypothermia and by 77% by moderate hypothermia. Mild hypothermia had a coupled metabolic suppression whereas moderate hypothermia significantly increased AVDO2 and decreased ScvO2, producing a low CBF/CMRO2 (relative ischemia). After balloon deflation, all three groups showed reactive hyperemia, which was significantly reduced by mild and moderate hypothermia. CBF then decreased to 50% of pre-inflation values and ScvO2 decreased (post-ischemic hypoperfusion). CBF/CMRO2, ScvO2, and AVDO2 did not differ significantly between the three groups. After balloon deflation, all three groups showed increased CMR lactate, which was significantly reduced by mild and moderate hypothermia. Extracellular glutamate increased in control animals (3.8 +/- 1.72 microM), an effect most effectively suppressed in the mild hypothermia group (1.0 +/- 0.46 microM). Damaged tissue volumes as indicated by Evans blue dye extravasation were 729 +/- 89 mm3 in control, 247 +/- 56 mm3 in mild hypothermia, and 267 +/- 35 mm3 in moderate hypothermia animals. These data suggest that mild hypothermia (33 degrees C) might be the optimal brain temperature to treat compression-related cerebral ischemia.     

The stroke syndrome of cortical vein thrombosis

Cortical vein thrombosis without sinus involvement is rarely diagnosed, although it may commonly be overlooked. We report four cases of cerebral venous thrombosis limited to the cortical veins. The diagnosis was made on surgical intervention in one patient and by angiography in three patients. Together with a survey of the published cases, the clinical and neuroimaging patterns of our patients allow delineation of several features suggestive of cortical venous stroke. Focal or generalized seizures followed by hemiparesis, aphasia, hemianopia, or other focal neurologic dysfunction in the absence of signs of increased intracranial pressure should suggest this possibility. Neuroimaging (CT, MRI) shows an ischemic lesion that does not follow the boundary of arterial territories and often has a hemorrhagic component, without signs of venous sinus thrombosis. Conventional angiography demonstrates no arterial occlusion but may show cortical vein thrombosis corresponding to the infarct, although these may also be nonspecific findings. The role of MR angiography, which is well-established in sinus thrombosis, remains to be assessed in patients with brain ischemia due to isolated cortical vein occlusion.     

Dural fistulae of the cavernous sinus and interventional neuroradiology. Apropos of 4 cases

PURPOSE: Our purpose was to show how difficult it is to diagnose a dural fistula of the cavernous sinus, which is an anomalous arteriovenous shunt within the dura mater extending from meningeal arteries to the cavernous sinus. CASE REPORT: A dural fistula was suspected in four female patients aged between 61 and 80, presenting with a red eye, dilated episcleral veins, exophthalmos and elevated intraocular pressure. A cerebral hyperselective angiography was performed in all cases. RESULTS: The cerebral angiography confirmed the diagnosis of a dural fistula in all cases, showing the early filling of the cavernous sinus followed by the draining vessel (posterior in case n. 4, anterior in cases n degrees 1, 2, 3). Case n degrees 2 was unilateral and cases n. 1, 3, 3 were bilateral. The blood flow was low in all cases. A successful embolization was performed in all patients with resolution of all symptoms. CONCLUSION: The diagnosis of dural fistulas is often difficult because of misleading clinical signs. It is documented by a cerebral angiography showing the feeding vessels and helping to choose either venous or arterial embolization which is the most suitable treatment.     

An attempt at reversibility and increase of the virulence of axenic strains of Entamoeba histolytica

Sequential changes of cerebral autoregulation were studied in 20 cats after recirculation of cerebral ischemia. The cerebral autoregulation was evaluated by autoregulation index (A.I.), calculating % delta cerebral blood flow (CBF)/delta cerebral perfusion pressure (CPP), with changing the mean arterial blood pressure (MABP) within 80-130 mmHg. Duration of ischemic insult was 15 min after disappearance of direct cortical response (DCR). Following recovery of cerebral circulation, MABP, CBF and intracranial pressure (ICP) were observed sequentially for at least 48 hours. In 6 of 20 cats the autoregulation was disturbed early after recirculation, and the ICP was increased, resulting in no cerebral blood flow (early deteriorated group). In the other 14 cats the autoregulation was restored immediately, but in 7 of the 14 cats it was disturbed again after 24 hours following recirculation (delayed deteriorated group), finally the ICP was elevated and the CBF became 0 as same as early deteriorated group. In another 7 cats it was not disturbed until 5 days. The changes in CBF following insult were five patterns. These were classified into type A (Gradual decrease), type B (Transient increase), type C (Constant maintenance), type D (Relatively rapid decrease) and type E (Rapid decrease). The delayed cerebral dysautoregulation occurred in the types except for type A and type E. These results suggested there was close relation between delayed dysautoregulation and delayed neuronal dysfunction that we reported previously. Moreover, we considered the delayed dysautoregulation could be speculated from the value of ICP/CBF immediately after recirculation and the pattern of the changes in CBF during ischemic insult.     

Risks and therapy options in dural arteriovenous fistulas between branches of the external carotid artery and the cavernous sinus. A case report and review of the literature

INTRODUCTION: Dural arteriovenous fistula of the Arteria carotis externa and the sinus cavernosus are rare vascular malformations. In the literature the prognosis and necessity of treatment is described very variable. PATIENTS AND METHODS: A 90 year old female presents in our outpatient clinic with acute exophthalmus, dilated episcleral veins, cerebral bruits and beginning orbital apex syndrome. After normal computerized axial tomography (CAT) without and with contrast medium, we were able to diagnose a dural AV-fistula by angiography. Shortly after dismission the patient had a spontaneous subarachnoidal haemorrhage with severe neurological symptoms. CONCLUSIONS: The suspect of an intracranial AV-malformation implies a detailed diagnostic search with precise localisation of the process. In any patient with intracerebral and intracranial fistula there has to be an individual check of possible and necessary treatment. It is impossible to classify dural AV-fistula as a benign disease with harmless clinical course.     

A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.     

Dural posterior fossa AVM producing raised sagittal simus pressure. Case report

A patient with raised intracranial pressure secondary to a dural arteriovenous malformation (AVM) of the posterior fossa is presented. Direct shunting of arterial blood into the transverse sigmoid sinus caused a considerable increase of the sagittal sinus pressure (SSP) and elevation of intracranial pressure (ICP). Both ICP and SSP returned to normal values following obliteration of the dural AVM by selective embolization.     

Rheographic assessment of cerebral blood volume and correlations with changes in intracranial pressure

The authors present a four electrode rheographic technique for simiquantitative continuous measurement of CBV, by examining changes in cerebral tissue impedance induced by changes in blood content of the brain parenchyma. Correlation between the data obtained and ICP measurements permits conclusions regarding the behaviour of the cerebral blood bed. pCO2 regulates CBV, and the phenomenon is reversible according to a hystereris shaped time course in acute experiments. The rebound of ICP after sudden injections of CSF into the cisterna magna is of a vasogenic nature. Changes in CSF volume induce contrary changes in CBV. Pharmacological effects can be studied. The validity of the method is discussed.     

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE: In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs. METHODS: Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated. RESULTS: The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels." CONCLUSIONS: The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.     

The apolipoprotein(a) promoter contains a retinoid response element

OBJECTIVE AND IMPORTANCE: Dural arteriovenous fistulas of the superior sagittal sinus (SSS) account for 8% of intracranial dural fistulas. Their association with a thrombosis of the posterior part of the SSS is rare. In such cases, the usual neurosurgical and endovascular approaches cannot provide a good technical solution for treatment of the lesion, and a combined neurosurgical and neuroradiological approach is therefore needed. CLINICAL PRESENTATION: A 68-year-old man presented with rapidly evolving dementia. Cerebral angiography revealed a dural arteriovenous fistula of the SSS associated with thrombosis of the posterior part of the SSS. Various endovascular and neurosurgical approaches failed to cure the fistula. INTERVENTION: A burr hole was drilled in the frontal region, in the neurosurgical room. The patient was then transferred to the angiographic room, and the SSS was occluded using free spirals. CONCLUSION: This procedure led to a complete anatomic cure of the fistula, and a slow clinical improvement was observed.     

The clinical assessment of attachment in children under five

Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital. The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier. This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.     

Venous territories of the brain

The venous return of the cerebral hemispheres is ensured by two systems. The first, superficial system, reaches the peripheral dural sinuses, i.e. the superior sagittal sinus, the lateral sinus and the cavernous sinus. The second, deep system, corresponds to Galen's vein. Anatomical and angiographic data from the literature enable the usual drainage territory to be defined for each of these collecting vessels. However, the variability of the superficial sylvian vein and the importance of cortical anastomotic vessels make impossible to delimit precisely the territory of each peripheral sinus. The functional role played by numerous centro-peripheral anastomoses is more difficult to assert in each individual. It is therefore probable that in the cerebral hemispheres there is a deep territory balancing the superficial territories.     

Metabolic and hemodynamic evaluation of brain metastases from small cell lung cancer with positron emission tomography

Brain metastases from small cell lung cancer respond to chemotherapy, but response duration is short and the intracerebral concentration of chemotherapy may be too low because of the characteristics of the blood-brain barrier. Positron emission tomography has been applied in a variety of tumors for studies of metabolic and hemodynamic features. This study was performed to determine regional cerebral metabolic rate of glucose (rCMRglu), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) in brain metastases from small cell lung cancer and the surrounding brain. Tumor rCMRglu, rCBF, and rCBV exerted a broad variability, but were higher than the corresponding values in white matter and higher than or similar to those of gray matter. Tumor rCMRglu and rCBF were highly correlated (P < 0.01, r = 0.79). No correlation between survival and metabolic or hemodynamic parameters could be demonstrated. After radiotherapy, mean tumor rCMRglu decreased from 0.40 to 0.31 micromol/g/min (not significant), and rCBF and rCBV remained unchanged. However, cortical rCBF demonstrated a trend of increased values after radiotherapy from 0.37 to 0.49 ml/g/min (P = 0.13). No change in rCMRglu was observed in gray or white matter after radiotherapy. Global CBF seems to be reversibly depressed by the metastases, but local hemodynamic changes in the tumor could not be detected with positron emission tomography in this study. An association between high tumor rCMRglu and rCBF as an indicator of hypoxia was not observed. Other methods for noninvasive in vivo analysis of tumor hemodynamics are needed, especially for discrimination between tumor necrosis and hypoxia.