Thrombosis of the cerebral sinuses or veins causes cerebral infarction but much rarer than arterial disease.
Seizures common and often focal.
Most commonly sagittal sinus thrombosis (47%) or transverse sinus thrombosis (35%)
Causes/Factors
- Anything that promotes a hypercoagulable state
- Pregnancy
- Combined Oral Contraceptive pill
- Head injury
- Dehydration
- Tumours
Symptoms
Symptom onset is gradual - days to weeks. Features are dependant on what sinus is affected
- Sagittal sinus - headache, vomiting, seizures, vision, papilloedema
- Transverse sinus - headache mastoid pain, focal CNS signs, seizures, papilloedemaa
- Sigmoid sinus - cerebellar signs, lower cranial nerve palsies
- Inferior petrosal sinus - V th and VI th cranial nerve palsies with temporal and retro-orbital pain
- Cavernous sinus - often due to spread from facial pustules or Folliculitis causing headache, chemosis (swelling of eye surface membrane), odematous eyelids, proptosis, painful ophthalmoplegia, fever
Cortical vein thrombosis
Usually occurs with a sinus thrombosis as it extends into the cortical veins causing infarction into venous territories. These cause slow onset, Stroke-like symptoms.
There are often an associated seizures and a “Thunderclap” headache which may come on suddenly
Diagnostic Tests
Exclude Subarachnoid haemorrhage if there is a thunderclap headache
- Thrombophilla blood screen
- CT/MRI venography
- LP if no increase in pressure
Management
Seek expert help
- Anticoagulation with heparin or LWMH
- Monitor carefully for signs of deterioration
Complications/red Flags
- Deterioration despite anticoagulation
- ICP
- Secondary cerebral haemorrhage