Cerebral Venous Thrombosis
Epidemiology
0.5-1% of strokes
May account for 5% of ICH in young people
Female predominance 2/3rds
o 3x risk in women of child bearing age
o The incidence is equal between sexes in patients aged >55yrs
More often in young patients
o 78% occurring in pts <50yrs old
o Mean age 33yrs
Risk factors
|
Gender specific risk
factors |
% (rounded) |
|
OCP |
54 |
|
Puerperium |
14 |
|
Pregnancy |
6 |
|
HRT |
4 |
|
Systemic conditions |
|
|
Iron deficiency anaemia |
9 |
|
Malignancy |
7 |
|
Myeloproliferative disease |
3 |
|
Dehydration |
2 |
|
IBD |
2 |
|
SLE |
1 |
|
Bechets |
1 |
|
Thyroid disease |
2 |
|
Neurosarcoidosis |
0.2 |
|
Obesity |
? |
|
Thrombophilia |
|
|
APLS |
6 |
|
Hyperhomocysteiaemia |
5 |
|
Factor V leiden |
- |
|
Prothrombin gene mutation |
- |
|
Protein C/S deficiency |
- |
|
Antithrombin deficiency |
- |
|
Nephrotic syndrome |
0.6 |
|
Polycythaemia/thrombocythaemia |
- |
|
Infection |
|
|
Ears, sinus, mouth, face, neck |
8 |
|
Other |
4 |
|
CNS |
2 |
|
Mechanical factors |
|
|
Surgery |
3 |
|
LP |
2 |
|
Head trauma |
1 |
|
Drugs |
|
|
Cytotoxic |
1 |
|
Lithium |
- |
|
Vitamin A |
- |
|
IVIG |
- |
|
Ecstasy |
- |
|
Vascular abnormalities |
|
|
Dural AVF |
2 |
|
AVM |
0.2 |
|
Other venous abnormalities |
0.2 |
|
|
|
In young women very likely related to hormonal cause
Risk may be amplified by obesity
Patients >55 years consider malignancy (accounts for 25% of patients)
In young men with no other risk factors consider head and neck infections (mastoiditis)
Clinical
Onset often subacute (i.e. Over >48hours in 56%)
Headache 90% - often diffuse and slowly progressive.
o Only symptom in 25% of patients
o Can be thunderclap rarely
Symptoms related to raised ICP
o Papilloedema
o Diplopia 6th nerve palsy
Focal ischaemic/haemorrhagic injury 40%
o Often more gradual onset than arterial stroke
o Infarction present in 36.4%
o Haemorrhagic transformation in 17.3%
o Intraparenchymal haemorrhage 3.8%
Seizures common 40%
Reduced consciousness
o Can occur with bilateral thalamic involvement
Cavernous sinus thrombosis
o Orbital pain
o Chemosis and proptosis
o Ophthalmoplegia
When to consider diagnosis in a patient presenting with headache:
Presence of risk factors
New or different type of headache
Signs or symptoms of raised ICP
New focal neurological signs
Altered consciousness
Seizures
Diagnosis
Routine bloods
Specific bloods looking for secondary causes
LP
o Not routinely recommended if done a raised opening pressure may be observed
D-dimer may help to exclude (mixed evidence)
CT
o Plain CT may show specific abnormality in 30%
o Venous sinus hyperintensity
- Dense triangle sign in sagittal sinus
- Cord sign in transverse sinus
o May also show other associated features ischaemia, SAH, ICH, oedema,
CT with CT venogram
o 95% sensitivity and 91% specificity
o Not as good for deep system
o Empty delta sign in sagittal sinus
MRI with TOF MRV
o Probably similar accuracy to CTV, very technique dependent
o Lack of data to define sensitivity and specificity cut-offs
o Better for deep system infarcts.
o SWI can be helpful to identify clot
MRI with contrast
o Very good accuracy, concern about use for screening, given contrast load.
Cerebral angiograpy
o Venous phase very good resolution
o Useful if suspicion of associated dural AVF
Direct cerebral venography
o Injection of contrast into sinuses via a catheter inserted into jugular vein usually only done as part of clot removal procedure.
NOTE:
o Asymmetry of venous system makes diagnosis difficult
o 49% of transverse sinuses are asymmetrical with 20% having unilateral absence of this vein.
Treatment
Elements of treatment
Address triggers/reversible causes
Anticoagulation
Control seizures
Treat raised ICP
Anticoagulation
Probable small benefit in all patients regardless of presence infarction or ICH on initial imaging
UFH or LMWH both have evidence
o One open label trial suggested LMWH is more effective with lower risk of bleeding
o LMWH recommended in guidelines
Long term anticoagulation
o Patients should then be transitioned to warfarin or DOAC
- Warfarin target INR 2.5 (range 2-3)
o Consider waiting for anti-phospholipid lipid syndrome to be ruled out before starting DOAC.
o If provoked by reversible factor anticoagulation for 3-6months
o Unprovoked anticoagulation for 6-12months
o Patients with recurrent CVT or thrombophillia - lifelong
Direct thrombolysis or thrombectomy
Small trials showing efficacy but with significant morbidity overall no routine benefit.
Recommended to be reserved for failed anti-coagulation in rare circumstances
ICP
If signs of raised ICP (in particular progressive visual loss) then treatment of raised ICP medically and surgically can be considered.
Decompressive hemicraniectomy has been used.
Other therapies:
Steroids small studies suggest overall detrimental effect avoid
Acetazolamide can be used to help reduce ICP
Evidence for treatment
Anticoagulation
· Einhaupl et al. Lancet 1991
o 44 pts, IV heparin vs placebo, started at avg. 4 weeks post onset
o Positive - Stopped early due to excess mortality in placebo arm
· De Bruijn et al Stroke 1999
o 60pts, nadroparin vs placebo
o Non-significant improvement in pts achieving good outcome
· Cochrane review of 2 above trials (2002)
o Death or dependency RR 0.46 (CI 0.16-1.31) i.e. trend to better outcomes with LMWH
o 3 patients developed new ICH all in the placebo arm
DOAC
Re-SPECT CVT trial.
o 120 pts, dabigatran vs warfarin for 6 months
o No recurrent events in either group
o Major bleeding in one DOAC group and 2 warfarin group
Prognosis and complications
Risk of recurrent CVT 2-7% per year and risk of other venous thrombosis 4-7% per year
Complete functional recovery 75%
Death
o Acute ~4%
o Long term ~10% (1/2 of deaths due to the underlying condition rather than the CVST)
Seizures
o 10% develop remote symptomatic seizures
Recanalisation
o 85%
o Most occurs in the first few months, can take up to 1 year
o Association between recanalization and long term symptoms is unclear
o Association between recanalization and risk of recurrence is unclear
High rate of post event depression/anxiety and cognitive impairment