Cerebral venous thrombosis: causal factors, clinical manifestations and

imaging findings

S.Alj, M.Ouali Idrissi, N. Cherif El Idrissi El Ganouni, O.Essadki, A.Ousehal

Radiology department, Ibn Tofail Hospital , Cadi Ayyad University, Marrakech.

NR5

Introduction(1)

• Cerebral venous thrombosis : a relatively uncommon neurologic disorder.

• Clinical manifestations :varied but not specific.• Imaging , specially the MRI, plays a primary

role in the diagnosis.

Introduction(2)

• The aim of this study is to describe:- the normal venous anatomy,-clinical manifestations -causal factors -imaging finding in cerebral venous thrombosis.

Methods and patients :• Retrospective study from 2007 to 2010• Included in the study : Patients with cerebral

venous thrombosis • Computed tomography (CT) with contrast media

administration : performed in 10 patients.• All the patients underwent magnetic resonance

(MR) imaging : -axial FLAIR and T1 WI -Sagittal T2 WI -Diffusion WI -MR venography sequences.

Results

1-Epidemiological features:• Thirty one patients were included in the study.• Patients were aged between 16 and 52 years

(medium age of 31 years).• twenty five patients were women .

Results

• 1-Epidemiological features:• Causal factors were found in 19 patients

(61%):

Causal factor N (%)

Peripartum state 10 (32%)

Behcet disease 3 (9%)

lupus 1 (3%)

Other hypercoagulable states 3 (9%)

infection 2 (6%)

Results

2-Clinical manifestations :• Clinical manifestations included :-Headache :11 patients (35%) , -Intracranial hypertension:9 cases (29%)-Seizure: 6 cases (19%)-papillary edema : 5 cases (16%)

Results3-Imaging features:3.1- CT:• CT performed in 10 patients, suspected the

diagnosis in 9 cases (90%).

Figure 1: CT axial slices performed before and after contrast media administration. Increased attenuation in the sagittal sinus in unenhanced CT slice. Note the empty delta sign on the contrast enhanced slice.

Results3.2- MRI:• MRI showed focal brain abnormalities in 45%. *Oedematous lesions: (4)13% *Hemorrhagic lesions: (27)87%

Figure 2: axial slice T1 WI. Frontoparietal hemorrhage lesion secondary to trasverse sinus thrombosis

Figure 3: Bilateral hemorrhagic abnormalities of frontal parenchyma. note the hyperintensity of the sagittal sinus wich is thrombosed.

Figure 4: FLAIR WI and T1 WI axial slices. Oedematous lesion of the brainstaim and right parietal parenchyma related to right transverse sinus thrombosis.

Results

3.2- MRI:• Location of the thrombus:

Thrombus location N (%)

Transverse sinus 6 (19)

Superior sagittal sinus 5 (16)

Straight sinus 1 (3)

Multiple locations 14 (45)

Cortical veins 5 (16)

Figure 5: Same patient of the figure 3.Flair WI Axial slices and T1 WI sagittal slice show an hyperintensity of the sagittal sinus. The angio MRI shows a filling defect of this sinus.

Figure 6: T1 WI axial slices showing an hypersignal of the sagittal sinus.The angio MRI proved the thrombosis of the sinus.

Figure 7: sagittal slices T1 WI showing an hypersignal of the transverse sinus.The angio MRI shows a filling defect of the left transverse and lateral sinuses and jugular vein.

Figure 8: axial, coronal and sagittal T1 WI with contrast media administration slices. Sagittal and transverse sinuses enhancement after gadolinium administration : Chronic dural sinus thrombosis.

Figure 9: cortical veins occlusion. Hyperintensities cortical and subcortical in frontal and parietal parenchyma on Flair WI.

Discussion

• Cerebral venous thrombosis is uncommon disorder.• Annual incidence is estimated of 2 - 7 cases per million in the

general population .• Accuracy of the cross-sectional imaging methods for detecting

abnormalities in the cerebral venous sinuses has been proven.

• The knowledge of venous sinuses anatomy is necessery to establish the accurate diagnosis.

• and the knowledge of the causal factors may help in the diagnosis and the choice of the treatment.

Discussion

• Venous sinuses anatomy (1):

Figure 9: lateral view of MR venography, with a color overlay, demonstrates thedural sinuses:-superior sagittal sinus (green), -inferior sagittal sinus (light blue),-straight sinus (dark purple),-confluence of the sinuses (orange),-transverse sinuses (dark blue), -sigmoid sinuses (yellow). - internal jugular veins and bulbs (light purple).

Discussion1-Causal factors:• Many causes of venous thrombosis have been described

in the literature• Systemic factors :- Related to general clinical conditions- More frequent (18/19 cases in this study)- A peripartum state, and hypercoagulable states (protein

S and protein C deficiencies, malingnancies...).• Local factors: includes local infections, intracerebral

tumor developped near a venous sinus.

Discussion

2-Clinical manifestations:• Headache :is the more frequent symptom found in

75-95% of the patients, in this study it was found only in 35% of cases.

• Intracranial hypertension: occurs in 20%–40% of patients with cerebral venous thrombosis (29% in this study).

• focal neurologic symptoms : including seizure, are more often seen in patients with parenchymal abnormalities.

Discussion

3-Imaging features:3.1-Parenchymal abnormalities• Parenchymal changes have been identified in45% of patients:-Focal oedema depected in about 25% of cases in the litterature

(12% in this study).-Hemorrhage may coexist in the same region of oedema.• in some cases , the parenchymal changes may not correlate

with the location of venous occlusion• Parenchymal swelling (Sulcal effacement and diminished

cistern visibility )without signal abnormalities may occur.

Imaging features:

Discussion3.1-Parenchymal abnormalities: Diffusion abnormalities

• The value of ADC allows to distinguish between vasogenic and cytotoxic oedema, wich have a prognosis value.

• Patients with diminished ADC values (cytotoxic oedema) more often have parenchymal sequelae

• those with normal or increased ADC (vasogenic oedema) usually do not have sequelae.

Imaging features:

Discussion

3.2-Sinus abnormalities:Computerized tomography: - unenhanced CT: hyperattenuating thrombus in the occluded

sinus- contrast-enhanced imaging : the empty delta sign (a central

intraluminal filling defect)• Increased attenuation in the venous sinuses in unenhenced

CT can also be seen if:-deshydration,-an elevated hematocrit level, -A subarachnoid or subdural hemorrhage.

Imaging features:

Discussion

3.2-Sinus abnormalities:MRI:• Absence of a flow void with presence of abnormal signal

intensity in the sinus• Detect a thrombus on MR images,• Sinus enhancement after gadolinium administration may be

seen in chronic thrombosis.• The signal intensity of venous thrombi on T1- and T2-

weighted MR images varies in the time (Table 3)

Imaging features:

Discussionstage T2 WI signal T1 WI signal T2*

Acute: 0-5 days(Desoxyhemoglobin)

Iso intense Hypointense Hypo intense

Subacute: 6-15 days(Methemoglobin)

Hyperintense Hyperintense Hypointense

Chronic≥16 days

Hypo/iso/hyperintense

Hypo/iso/hyperintense

Hypointense

Imaging features:

Table 3: Signal abnormality of the thrombosed sinuses according to the stage of the thrombosis

Conclusion

• The clinical manifestations of cerebral venous thrombosis vary, depending on the extent and the location, of the venous thrombotic process.

• Causal factors are essentially systemic with peripartum state being the main cause.

• MRI plays a primary role in the diagnosis essentially Angio MR.

• Brain abnormalities are inconstant. • Anatomic distribution of thrombosed cerebral venous

structures vary.

References

1-Leach JL, Fortuna RB, Jones BV, Gaskill-Shipley MF. Imaging of cerebral venous thrombosis: current techniques, spectrum of findings, and diagnostic pitfalls. RadioGraphics 2006; 26:S19–S43.

2-Dormont D, Anxionnat R, Evrard S, Louaille C, Chiras J, Marsault C. MRI in cerebral venous thrombosis. J Neuroradiol 1994;21(2):81–99.

3-Provenzale JM, Joseph GJ, Barboriak DP. Dural sinus thrombosis: findings on CT and MR imaging and diagnostic pitfalls. AJR Am J Roentgenol 1998;170(3):777–783.9.