Cerebral Venous Sinus Thrombosis

Diseases,

Synonyms:

Cerebral venous thrombosis CVT or cerebral venous sinus thrombosis/dural sinus thrombosis CVST and also Cortical cerebral venous thrombosis:
 

Diagnosis:

By neuroimaging including CT venography, MR venography or catheter angiography revealing thrombus in the cerebral venous sinuses. May be clinically symptomatic or asymptomatic
 

Pathology:

Any combination of the following may be involved:

  • Venous sinuses (sagittal sinus, torcula herephili, transverse sinus, straight sinus, sigmoid sinus, internal jugular vein, cavernous sinus)
  • Deep veins
  • Superficial (cortical) veins
  • Note. in carvernous sinus thrombosis the vasavasorum of the ICA may be involved causing infarction in ICA territories, especially if due to infectious thrombosis

 

Clinical features:

  • Headache, seizure, decreased consciousness
  • Fluctuating symptoms
  • Focal symptoms & signs including papilloedema

 

Findings on Investigations:

  • LP: Raised opening pressure

MR venography MRV, (Time-of-flight TOF, contrast-enhanced MRV, Phase-Contrast PC MRV):

  • Absence of filling in the sinus or veins
  • Phase contrast MRV: shows flow only but not thrombus
  • False positives occur in: Variant anatomy: high bifurcation of torcula, asymtrical bifurcation of torcula, atresia/hypoplasia of transverse sinus, arachnoid granulations
  • TOF: flow gaps

MRI with contrast:

  • Thrombus features:
    • T1: Thrombus is initially isointense & hyperintense (methemoglobin) later on
    • T2:- Thrombus is hypointense “pseudo flow void”, later on hyperintense (methemoglobin),
    • FLAIR: Thrombus=hyperintense
    • T2 gradient echo GRE: Thrombus= hypointese
    • T1 +contrast: Clot= periclot enhancement early, all structures enhance later on.
  • Brain parenchyma effects, oedema/Infarct /hemorrhage:
    • DWI: may have hyperintense areas ADC map: high (vasogenic oedema) or low (cytotoxic oedema)
    • T1: brain= hypointense & swollen, Hemorrhage that starts from the center of the lesion
    • Venous infarcts: irregular edges
    • T2: brain= hyperintense & swollen
    • FLAIR: brain= hyperintense
    • Gradient echo GRE: Brain= hypointense venous hemorrhage
    • T1 +contrast: Brain= no enhancement, or patchy enhancement

Catheter angiography DSA:

  • Occluded sinuses or Occluded cortical veins.
  • Opacified draining veins. corkscrew appearance of rerouting veins.
  • Enlarged collateral veins e.g. pterygoid veins

CT venogram CTV

  • CT:
  • Hemorrhagic infarction: irregular borders
  • Hypodensity in one or both thalami (internal cerebral vein, straight sinus)
  • Posterior temporal lobe oedema and petechial hemorrhage or large hemorrhage (transverse sinus, middle cerebral veins, vein of Labbe)
  • Parasagittal lesion with superior sagittal sinus thrombosis
  • Subarachnoid hemorrhage SAH blood over the cortex
  • Thrombus: Hyperdensity in the sinus
  • Delta sign (enhancement around a clot in the sagittal sinus)
  • Cord sign= dense vessel sign= hyperdense veins e.g. in internal cerebral veins, cortical veins
  • Prominent medullary veins: collateral circulation
  • Hydrocephalus, hypodensity (venous infarction) with hemorrhagic conversion,

 

Investigations to consider:

  • CT
  • CTV or MRV
  • LP: IIncreased opening pressure, Pleocytosis if septic
  • Thrombophilia screen
  • Monitor:
    • No need for aggressively repeating imaging if no change in clincial status. However low threshold for imaging if clinical changes occur

 

Treatment:

Anticoagulation even if intracerebral hemorrhage is present [RCT of 20 patients, RCT 60 patients] :

  • Heparin I.V.
  • LMW heparin: enoxaparin, nadroparin or others
  • Followed by warfarin for 3-6 months

If refractory consider endovascular therapy:

  • Mechanical thrombectomy
  • Local thrombolysis via venous approach