[A case of dural arteriovenous fistula accompanied by sinus occlusion. A serial study with CT scan]

A dural arteriovenous fistula (AVF) of the posterior fossa was found in a 58-year-old businessman suffering from a month's history of dementia. Bilateral transverse sinus thrombosis was also found and his symptom was attributed to venous congestion caused by the sinus occlusion. He had received partial resection of the right trigeminal neurinoma two years before, and the operation was thought to have caused the sinus occlusion. Dural AVF of the posterior fossa usually causes tinnitus or headache, whereas dementia seen in present case is relatively rare. In the present case, serial study of cranial CT scan demonstrated evolution of dural AVF after sinus occlusion. Venous congestion was thought to re-open the physiological micro-AVF to cause the dural AVF.

[Cavernous dural fistulas: Importance of trans-ocular Doppler ultrasound in evaluating venous patency and therapeutic choices]

Transcranial Duplex scan is a relatively recent diagnostic tool with many unexplored clinical potentials. The authors insist on the role of transocular exploration, as a non-invasive substitute to angiography and discuss two patients with cavernous meningeal arteriovenous fistula, a benign but relatively uncommon disease. In the first patient, in whom symptoms recurred, Duplex scan was able to rule out thrombophlebitis and to show increased flow in the fistula, thus leading to proper treatment. In the second patient, the identification of a periorbital thrombophlebitis innocented the fistula and prompted anti-coagulation. We conclude that besides its diagnostic capabilities, Duplex scan may be helpful in selecting proper treatment and follow-up in specific neurovascular conditions.

Superior sagittal sinus thrombosis associated with primary antiphospholipid syndrome--case report

A 36-year-old female with a history of recurrent pregnancy loss experienced sudden onset of disturbance in consciousness, with right hemiparesis and total aphasia. Computed tomography revealed a massive hemorrhage in the left frontal lobe, and angiography showed occlusion of the anterior two-thirds of the superior sagittal sinus. Laboratory investigations detected the presence of lupus anticoagulant, elevation of the anticardiolipin beta 2-glycoprotein I complex antibody level, and a decreased protein S activity level. There were no underlying conditions, such as connective tissue disorders, malignancies, infectious diseases, and drug-induced disorders, so the diagnosis was primary antiphospholipid syndrome. Primary antiphospholipid syndrome should be considered in the evaluation of patients with "idiopathic" or "primary" sinus and cerebral venous thrombosis.

Transverse sinus thrombosis and venous infarction of the brain following unilateral radical neck dissection

Radical neck dissection is one of the commonest procedures performed in any unit dealing with head and neck surgery. Intracranial complications following this procedure are uncommon. Transverse sinus thrombosis and venous infarction of the brain following unilateral radical neck dissection have not been reported in the literature. We present a case in which this complication occurred following an uneventful radical neck dissection.

[A case of intracranial hemorrhage following superior sagittal sinus thrombosis associated with nephrotic syndrome]

A case of intracranial hemorrhage due to superior sagittal sinus thrombosis occurring in a boy with nephrotic syndrome is described. A twelve-year-old boy with nephrotic syndrome presented sudden onset of generalized convulsions. CT scan revealed a subcortical hematoma in the left frontal lobe. A left carotid angiography revealed the occlusion of the superior sagittal sinus. Neurological findings included disturbance of consciousness, right hemiparesis, and motor aphasia after the convulsions. All symptoms and signs disappeared immediately. There has been no evidence of rebleeding or convulsions for the last two years. This case had no abnormality of the coagulation system in routine investigation, but nephrotic syndrome and steroid therapy appeared to be associated with several disorders of the coagulation system. The authors suggested that it was necessary to pay attention to possible intracranial hemorrhage caused by cerebral venous sinus thrombosis in patients with nephrotic syndrome or who had undergone steroid therapy.

Cerebral venography: comparison of CT and MR projection venography

OBJECTIVE

The purpose of the study was to show equivalence or superiority of CT venography compared with the existing test of choice--MR venography--in the evaluation of dural sinus thrombosis and in the identification of cerebral veins and dural sinuses.

MATERIALS AND METHODS

Twenty-four patients underwent both CT and MR venography of the intracranial venous circulation. Seventeen patients were examined for suspected dural sinus thrombosis. Four patients underwent projection venography to assess tumor invasion of a major dural sinus. The remaining three patients were examined for cavernous sinus thrombosis, arteriovenous malformation, and an elevated jugular bulb. Without knowledge of the patients' case histories, two radiologists evaluated each CT venogram and MR venogram. The radiologists then arrived at a consensus regarding the absence or presence of dural sinus thrombosis. Later, the radiologists conducted a second interpretation with knowledge of the patients' clinical histories during which time MR and CT venograms were compared with regard to the advantages and disadvantages of each imaging technique. In addition, the venograms were assessed for the presence of 12 different venous structure. Projection venograms were displayed using a maximum-intensity-projection (MIP) algorithm, and the individual source images were also evaluated. The CT venograms were also displayed using shell-MIP and integral display algorithms.

RESULTS

Using MR venography, the two radiologists diagnosed dural sinus thrombosis in eight of the 17 patients with suspected dural sinus thrombosis. In these eight patients, the diagnosis was also made with CT venography. The diagnosis was confirmed by follow-up CT in four patients and by follow-up MR imaging in two patients. The MIP algorithm did not allow direct visualization of thrombus by either the CT or the MR imaging technique; however, the CT integral display algorithm enabled direct visualization of thrombus on the three-dimensional projection venograms. The systematic comparison of imaging techniques showed that CT venography reliably reveals all cerebral veins and sinuses when they are seen with MR venography. In addition, CT venography more frequently visualizes sinuses or smaller cerebral veins with low flow as compared with MR venography.

CONCLUSION

Cerebral CT venography is superior to MR venography in the identification of cerebral veins and dural sinuses and is at least equivalent in the diagnosis of dural sinus thrombosis. CT venography is a viable alternative to MR venography in the examination of patients with suspected 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.

Septic thrombosis of orbital vessels due to cutaneous nasal infection

The authors describe two cases of cutaneous nose infection that quickly spread and extended to the orbital venous complex. At first glance, the clinical presentation could be mistaken for a complicated sinusal infection; therefore, the evaluation of the sinuses, by means of physical examination and radiological investigation, was of great concern, showing that there was no important pathology in the sinuses. The CT scan and the color Doppler imaging (orbital ultrasound with Doppler) demonstrated, throughout the development of the disease, that the superior ophthalmic vein was affected in both patients and the cavernous sinus in one of them. On physical examination, chemosis of the conjunctiva, proptosis, and edema of the eyelids were prominent. Patients improved only after appropriate intravenous antibiotic therapy against staphylococcus (clindamycin) and corticosteroids, making one conclude that treatment of this disease should be initiated as soon as possible in order to decrease morbidity and mortality.

[Gradenigo syndrome and cavernous sinus thrombosis in fusobacterial acute otitis media]

In this era of antimicrobial medication, intracranial complications following otitis media are rare. We present a 5-year-old boy who suffered from petrositis (Gradenigo syndrome) and cavernous sinus thrombosis as combined complications of acute otitis media caused by fusobacteria. The diagnosis was made using imaging methods suited to the various structures of the skull. Cure was achieved by prolonged conservative treatment with antibiotics, with gallium scan for evaluation of the bone inflammation.

Transtemporal power- and frequency-based color-coded duplex sonography of cerebral veins and sinuses

PURPOSE

To determine the ability of transtemporal power- and frequency-based transcranial color-coded duplex sonography to aid in the assessment of cerebral veins and sinuses, as well as to provide reference data for flow direction and velocity.

METHODS

Using a color duplex device equipped with a 2.0/2.5-MHz sector scan, we insonated 120 healthy volunteers and three patients with cerebral venous thrombosis.

RESULTS

In subjects 20 to 59 years old, deep middle cerebral veins were identified in 88%, basal veins in 97%, straight sinuses in 60%, and transverse sinuses in 42%. The corresponding values for subjects 60 to 79 years old were 53%, 86%, 23%, and 20%, respectively. Velocities were highest in transverse and straight sinuses, slower in basal veins, and slowest in deep middle cerebral veins. Flow was directed lateromedially in the deep middle cerebral vein, rostrocaudally in the basal vein and straight sinus, and mediolaterally in the transverse sinus. Two patients with straight sinus thromboses showed reversed flow direction in the basal veins, and one patient with superior sagittal sinus thrombosis showed elevated velocities in a deep middle cerebral vein.

CONCLUSION

Transtemporal power- and frequency-based color-coded duplex sonography enabled imaging and velocity measurements in deep cerebral veins in subjects 20 to 59 years old, but detection of the straight and transverse sinuses was low. In older subjects, only the basal vein was regularly assessed.

Clinics in diagnostic imaging (30). Vein of Galen and straight sinus thrombosis

A 40-year-old lady presented with acute onset of confusion and disorientation. CT and MRI scans showed vein of Galen and straight sinus thrombosis. The clinical and imaging features of venous sinus thrombosis are described.

Dural puncture and activated protein C resistance: risk factors for cerebral venous sinus thrombosis

OBJECTIVES

Dural puncture is regarded a safe procedure when contraindications are carefully excluded and has so far not been recognised as a risk factor for cerebral venous sinus thrombosis (CVST). Five patients are described with CVST after dural puncture in the presence of additional risk factors.

METHODS

In four out of five patients complete investigations for thrombophilia were performed at least one month after withdrawal of oral anticoagulation.

RESULTS

In three out of four patients tested, activated protein C (APC) resistance due to heterozygous coagulation factor V R506Q mutation (factor V Leiden) was found. One patient was using oral contraceptives as a circumstantial risk factor and three had had spinal anaesthesia for surgical procedures. Family history of venous thromboembolism was negative in all patients. Retrospective evaluation of 66 patients with CVST disclosed that dural puncture was the fourth most common risk factor (8%) possibly contributing to thrombosis.

CONCLUSION

Dural puncture may constitute an additional risk factor for CVST especially in patients with APC resistance or surgery. In such patients a thrombophilia screen is indicated.

Venous microembolic signals detected in patients with cerebral sinus thrombosis

BACKGROUND AND PURPOSE

We sought to assess the usefulness of the Doppler technique in the monitoring of microembolic signals in the main venous outflow pathways in superior sagittal sinus thrombosis.

METHODS

Transcranial Doppler ultrasound was performed with a range-gated 2-MHz transducer in 6 patients with superior sagittal sinus thrombosis, in 5 subjects with platelet hyperaggregability, and in 20 healthy volunteers. Emboli monitoring was performed mainly in one distal internal jugular vein for 10 to 15 minutes.

RESULTS

Three of the six patients (50%) with superior sagittal sinus thrombosis had microemboli. None of the patients with platelet hyperaggregation or healthy volunteers revealed microemboli.

CONCLUSIONS

Microemboli can be found in superior sagittal sinus thrombosis by Doppler ultrasound. Their prognostic significance remains to be determined.

Dural sinus thrombosis: CT and MR imaging of different stages

Cerebral dural sinus thrombosis remains an uneasy clinical diagnosis because it may present with a spectrum of nonspecific manifestations. CT and MR findings have been described to help recognize this entity. We report here a case with different stages of thrombosed superior sagittal and right transverse dural sinuses demonstrated by CT and MR imaging.

Echocontrast-enhanced transcranial color-coded sonography for the diagnosis of transverse sinus venous thrombosis

BACKGROUND AND PURPOSE

Early diagnosis of cerebral transverse sinus venous thrombosis (TSVT) is difficult because of nonspecific and variable clinical presentations. Therefore, we evaluated the diagnostic value of transcranial color-coded duplex sonography (TCCS) after administration of an echocontrast-enhancing agent (cTCCS) in clinically suspected TSVT.

METHODS

We examined 14 patients (6 men, 8 women; mean age, 48 years; range, 18 to 70 years) with signs and symptoms suggestive of cerebral TSVT. Color-coded signals from the contralateral transverse sinus were displayed transtemporally before and after injections of an echocontrast agent by TCCS. Sonographic findings were correlated with MRI and MR venography (MRV).

RESULTS

Before echocontrast enhancement, TCCS displayed color Doppler signals in 7 of 28 transverse sinus. Echocontrast TCCS obtained sufficient color signals in 27 of 28 transverse sinus. Thus, diagnostic confidence was achieved in all but 1 patient. In 13 patients, cTCCS identified 3 cases with symmetrical blood flow in the transverse sinus, which was confirmed by MRV. Accordingly, asymmetry of venous blood flow was correctly assessed by cTCCS in the other 10 patients. In 6 of these 10 patients, cTCCS demonstrated residual color flow signals, which on MRI/MRV corresponded to partial TSVT (4 cases) and to hypoplasia (1 case) of the transverse sinus. One case of complete thrombotic occlusion of the transverse sinus was missed by cTCCS because of color Doppler signals originating from an adjacent dural fistula. Echocontrast TCCS diagnosis of occlusion of a transverse sinus was confirmed by MRI/MRV in all cases (aplasia of transverse sinus, n = 1; complete TSVT, n = 3). Systolic peak flow velocities were significantly decreased in hypoplastic or partially occluded transverse sinus (9.4 +/- 4.0 cm/s) and significantly increased contralaterally (28.4 +/- 6.5 cm/s) with respect to patients with symmetrical appearance of the transverse sinus (17.5 +/- 1.9 cm/s) (P < .05).

CONCLUSIONS

TCCS examination of the cerebral venous system is difficult without contrast media application and almost useless for the study of TSVT. However, cTCCS is of practical value in the initial workup of patients with clinically suspected TSVT and may provide further insight for follow-up studies in view of monitoring the recanalization.