Cerebral venous thrombosis: diagnostic imaging and clinical presentation

Q: What risk factors and etiologic causes lead to the development of cerebral venous thrombosis?

The following risk factors and causes lead to the development of cerebral venous thrombosis: - Intracranial infections, including bone or air sinus infections. - Local trauma. - Dehydration. - Pregnancy. - Oral contraceptive use. - Smoking. - Vasculitis, especially Behçet's disease. - In the absence of obvious triggering factors, screening for thrombophilia is necessary.

Q: Which superficial (cortical) cerebral veins can be involved in thrombosis?

Superficial cortical veins may be involved in thrombosis — either in isolation or as part of extensive thrombosis. In the clinical case, the right vein of Labbé was involved, accompanied by the "cord sign".

Clinical presentation and localization

Patients with cerebral venous thrombosis (Cerebral Venous Thrombosis) most commonly present to the hospital with acute headache, seizures, altered mental status, and focal neurological deficits (e.g., right-sided hemiparesis). The severity of the condition directly depends on the thrombus location and the development of secondary circulatory disorders.

The pathological process may involve:

Cortical veins: for example, the vein of Labbé (vein of Labbé).
Dural venous sinuses: the lateral sinus is most frequently affected.
Deep venous system: internal cerebral veins and the straight sinus.

Neuroimaging: involvement of cortical veins and sinuses

Timely imaging is critically important to confirm the diagnosis. Both non-contrast and contrast-enhanced methods are utilized.

Computed tomography (CT):

On unenhanced CT in cortical vein thrombosis, a serpiginous hyperattenuation (increased density) of the vessel is visualized on the brain surface. This pattern is known as the cord sign (string sign).
On CT venography, confirmation of the diagnosis is provided by the presence of a filling defect (filling defect) within the affected venous lumen (e.g., in the lateral sinus).

Magnetic resonance imaging (MRI):

T2-weighted images can reveal areas of early venous ischemia and pronounced perifocal parenchymal edema (high signal intensity).
On susceptibility-weighted imaging (SWI), acute-stage blood degradation products produce a hypointense signal.
A key sign on T2-weighted and FLAIR sequences is the loss of the normal flow void (signal void) effect in the affected sinus.
MR venography demonstrates a complete absence of blood flow signal in the occlusion zone.

Test your knowledge on the topicTasks from the "Diagnostic Radiology" course bank — instant answers and explanations.

Deep cerebral venous thrombosis

Involvement of the deep veins (internal cerebral veins and straight sinus) causes severe venous hypertension.

Initial MRI scans in such cases reveal altered signal intensity and edema in the thalamus, corresponding to ischemic changes. The FLAIR sequence clearly shows abnormal signal intensity and dilation of the thrombosed vessels.

With clinical deterioration, the condition progresses rapidly:

Venous infarction and massive hemorrhage develop in the thalami (often bilateral) and the lentiform nucleus.
Intraventricular hemorrhage occurs.
Hydrocephaly develops, while CT imaging maintains the hyperattenuation of the internal veins.

Association with subarachnoid hemorrhage (SAH)

Cortical vein and dural sinus thrombosis is a rare cause of spontaneous subarachnoid hemorrhage (Subarachnoid Haemorrhage), alongside AVMs and arterial dissections (whereas 80% of SAHs are caused by ruptured aneurysms).

SAH presents with a thunderclap headache and carries an extremely high mortality rate (approximately 50%). It is diagnosed using:

Non-contrast CT: sensitivity reaches 98% within the first 12 hours after onset, detecting increased CSF density (primarily in the basal cisterns).
MRI (T2* gradient-echo and FLAIR sequences): standard spin-echo sequences are unreliable. The FLAIR sequence shows high CSF signal intensity due to protein content and may remain positive for up to 45 days. However, high sulcal signal on FLAIR is non-specific and can be falsely positive (e.g., due to oxygen therapy or vascular congestion).
Lumbar puncture: performed when SAH is suspected and CT is normal, strictly no earlier than 6–12 hours after onset (time required for erythrocyte lysis and the appearance of breakdown products such as bilirubin).

Briefly: answers to topical questions

Which veins form the deep venous system of the brain?

The deep venous system of the brain is formed by vessels that collect blood from subcortical structures and ventricular walls, establishing outflow pathways into the straight sinus. The main veins of this system include:

Thalamostriate vein (v. thalamostriata) — collects blood from the thalamus and corpus striatum.
Internal cerebral vein (v. cerebri interna) — a paired vein formed by the junction of the septal vein and the thalamostriate vein.
Basal vein (of Rosenthal) (v. basalis Rosenthal) — a paired vein involved in draining the basal structures of the brain.
Great cerebral vein (of Galen) — a large collector vessel receiving blood from the internal cerebral and basal veins.
Precentral cerebellar veins — also participate in deep venous drainage.

What risk factors and etiologic causes lead to the development of cerebral venous thrombosis?

Cerebral venous thrombosis is triggered by the following risk factors and causes:

Intracranial infections, including infections of the bones or paranasal sinuses.
Local trauma.
Dehydration.
Pregnancy.
Oral contraceptive use.
Smoking.
Vasculitides, particularly Behçet's disease.
In the absence of clear triggering factors, screening for thrombophilia is necessary.

Which superficial (cortical) cerebral veins can be involved in thrombosis?

Thrombosis can involve superficial cortical veins — either in isolation or as part of extensive thrombosis. In the clinical case, the right vein of Labbé (vein of Labbé) was involved, accompanied by the cord sign.

Class and exam questions

What does cortical vein thrombosis look like on unenhanced CT?

The cord sign is present — a serpiginous hyperattenuation (increased density) of the vessel on the brain surface, indicating the presence of a thrombus.

Which MRI sign indicates venous sinus thrombosis?

T2-weighted and FLAIR sequences show a loss of the normal flow void (signal void) effect, while MR venography demonstrates an absence of blood flow signal.

Why is lumbar puncture not performed immediately when hemorrhage is suspected?

The lumbar puncture is performed at least 6–12 hours after onset. This time is necessary for erythrocyte lysis in the CSF to allow the detection of bilirubin and other blood breakdown products.

What complications are characteristic of deep cerebral venous thrombosis?

The process can lead to venous infarction, extensive parenchymal hemorrhages (in the thalami and basal ganglia), intraventricular hemorrhage, and hydrocephalus.

Confused about something? Ask the AIThe WhiteCoat Pro AI tutor has reviewed the material on "Cerebral Venous Thrombosis" and will explain it in simple terms.

What else to study on this topic

Nonaneurysmal perimesencephalic subarachnoid hemorrhage
Differential diagnosis of thunderclap headache causes
MRI artifacts and false-positive results on FLAIR sequences
Reversible cerebral vasoconstriction syndrome
Radiological patterns of blood distribution in ruptured intracranial aneurysms

Master the entire topic in the "Diagnostic Radiology" course

This is a summary. The course covers everything tested in classes and exams.

Complete study guide on "Cerebral Venous Thrombosis" and 2,199 more pages of the subject
Assignments and quizzes after every topic — just like in a colloquium
AI tutor answers questions on the topic anytime
10 video lessons on the subject

Open full review Subject curriculumfrom 599 ₽ per month

Cerebral venous thrombosis