Cerebral venous thrombosis

Question 1

Define cerebral venous (sinus) thrombosis.

Answer 1

A thrombotic obstruction of the cerebral veins and/or related anatomical structures (dural sinuses) which drain blood from the brain

Question 2

Name common subtypes of CVST.

Answer 2

• Transverse sinuses thrombosis

- Superior sagittal sinus thrombosis

Question 3

What are the non-infectious causes of CVST?

Answer 3

• Hypercoagulable states (pregnancy, COCP, blood clotting disorders)
• Head trauma
• Neurosurgical procedures (e.g. lumbar puncture)

Question 4

What are the infectious causes of CVST?

Answer 4

• Rhinogenic (after sinusitis)
• Mid-facial infections (cellulitis or abscess)
• Dental infections
• Otogenic (acute otitis media)
• Meningitis
• Pharyngitis
• Tonsillitis
• Orbital and periorbital cellulitis

Question 5

Describe the pathophysiology of CVST.

Answer 5

• Thrombogenesis occurs in the cerebral venous system, including the dural sinuses –> reduced cerebral drainage –> raised ICP –> clinical features

Thrombus formation –> congestion within the venous system of the brain –> blood stasis –> reduced oxygenated blood in brain tissue –> cerebral oedema and/or infarcts/stroke

Question 6

What are the clinical features of CVST?

Answer 6

• Headache
• Bilateral papilloedema
• Visual impairment (diplopia, vision loss)
• N+V
• Impaired level of consciousness
• Seizures (focal or generalised)
• Cranial nerve dysfunction: diplopia, tinnitus, unilateral deafness, facial palsy, cavernous sinus syndrome)
• Focal neurological deficits
• Behavioural changes

Question 7

What is cavernous sinus syndrome?

Answer 7

A condition caused by compression of the cranial nerves that pass through the cavernous sinus 
Symptoms:
- ophthalmoplegia
- conjunctival congestion 
- proptosis
- sensory loss over forehead and cheek 
- Horner's syndrome

Question 8

What is the imaging of choice in CVST?

Answer 8

MR venogram

Question 9

What investigations should be done for CVST?

Answer 9

• D-dimer
• FBC
• LFTs
• Coagulation studies
• CRP and ESR
• Blood cultures
• LP
• EEG (if having seizures)

Question 10

How should CVST be managed?

Answer 10

• Anticoagulation (enoxaparin 1st line, UFH 2nd line)
• Long-term anticoagulation (warfarin)
• Empiric abx therapy if septic CVT is suspected
• Supportive care (fluid resuscitation, neuroprotection, ICP management, anticonvulsants)

Surgical interventions

• If there is worsening neuropathy
• Procedures include decompressive craniectomy, haematoma evacuation, shunt placement, abscess drainage