What is the workup and treatment for transverse sinus thrombosis?

Workup for Transverse Sinus Thrombosis

MRI with MR venography (MRV) is the preferred diagnostic imaging modality for transverse sinus thrombosis, combining both noncontrast time-of-flight and contrast-enhanced sequences to maximize diagnostic accuracy. 1, 2, 3

Initial Imaging Approach

First-Line Imaging

• MRI with MRV should be performed as the primary diagnostic test, as it is more sensitive than CT at detecting cerebral venous thrombosis at all stages and provides superior visualization of both the venous sinuses and brain parenchyma 4, 2, 3
• The optimal MRI protocol includes both noncontrast time-of-flight (TOF) MRV and contrast-enhanced MRV, as these sequences are complementary and maximize sensitivity (92.5%) and specificity (100%) 3
• Gradient echo T2 susceptibility-weighted imaging combined with MRV represents the most sensitive sequence combination for detecting transverse sinus thrombosis 1, 2, 3

Alternative Imaging When MRI Unavailable

• CT with CT venography (CTV) is an acceptable alternative in emergency settings, when MRI is contraindicated, or when rapid assessment is needed 1, 2, 3
• CTV demonstrates 95% sensitivity and 91% specificity compared to digital subtraction angiography and is as accurate as MRV for diagnosing cerebral venous thrombosis 3
• Noncontrast CT alone has limited utility, showing abnormalities in only 30% of cases, but may demonstrate hyperdensity of the transverse sinus in acute thrombosis 4, 1, 2, 3

Critical Diagnostic Principle

A negative plain CT or MRI does not rule out transverse sinus thrombosis—venographic imaging (CTV or MRV) must be performed when clinical suspicion exists. 1

Key Imaging Findings to Identify

Direct Signs of Thrombosis

• Absence of flow void on MRI sequences with alteration of signal intensity in the transverse sinus 4
• Filling defect within the transverse sinus on contrast-enhanced imaging (either CTV or MRV) 1
• "Empty delta" sign on contrast-enhanced CT or MRI showing central hypointensity with surrounding enhancement 2, 3
• Hyperdensity of the transverse sinus on noncontrast CT in acute cases (present in only one-third of cases) 4, 3

Secondary Parenchymal Changes

• Temporal lobe parenchymal abnormalities (edema, hemorrhage, or infarction) correspond specifically to transverse and sigmoid sinus thrombosis 4
• Ischemic lesions that cross usual arterial boundaries, particularly with hemorrhagic component, are highly suggestive of venous thrombosis 4, 3
• Hemorrhagic venous infarction occurs in 40% of cases 3

Important Diagnostic Pitfalls to Avoid

Anatomic Variants That Mimic Thrombosis

• Transverse sinus hypoplasia or atresia can be mistaken for thrombosis on TOF MRV 4, 1, 2
• Asymmetrical sinus drainage is a normal variant that may appear as reduced flow 1, 2
• Giant arachnoid granulations can appear as filling defects mimicking thrombosis 5
• Use gradient echo or susceptibility-weighted imaging to distinguish: nonthrombosed hypoplastic sinus will not show abnormal low signal, whereas thrombosed sinus will 4

Technical Imaging Artifacts

• Flow gaps are commonly seen on TOF MRV images and can affect interpretation 4, 2
• Slow flow states and complex flow patterns in the transverse sinus can create false-positive appearances 4
• Contrast-enhanced MRV helps overcome these limitations 4

When to Pursue Additional Imaging

Cerebral Angiography

• Reserve catheter angiography for situations where CTV or MRV results are inconclusive despite high clinical suspicion 4, 1, 2
• Also indicated when endovascular treatment is being considered 4, 1
• On angiography, thrombosis appears as a filling defect (nonocclusive) or complete nonfilling with "cupping appearance" (occlusive) 1

Follow-Up Imaging

• Early repeat CTV or MRV is recommended for patients with persistent or evolving symptoms despite anticoagulation treatment 4, 1, 2
• Follow-up imaging at 3-6 months after diagnosis is reasonable to assess for recanalization of the occluded transverse sinus 1, 2

Laboratory and Etiologic Workup

While not explicitly detailed in the imaging-focused guidelines, the comprehensive workup should include:

• Prothrombotic screening: inherited thrombophilias (protein C/S deficiency, antithrombin III deficiency, factor V Leiden) 2
• Female-specific risk factors: assess for oral contraceptive use, pregnancy, or postpartum state 2
• Other contributing factors: evaluate for malignancy, inflammatory conditions, and dehydration 2

Pediatric Considerations

• In neonates and young children, head ultrasound with Doppler may assess transverse sinus patency before fontanel closure 3
• MRI/MRV is preferred over CT/CTV for serial examinations in children to avoid radiation exposure 4, 3