Cortical Vein Thrombosis (Suppurative Intracranial Thrombophlebitis)

Definition

• Bacterial meningitis
• Subdural empyema (SDE)
• Epidural abscess
• Infection in the skin of the face, paranasal sinuses, middle ear, or mastoid

Anatomy and Pathophysiology

• The largest of the venous sinuses
• Receives blood from frontal, parietal, and occipital superior cerebral veins and the diploic veins
• The diploic veins communicate with meningeal veins and provide a route for spread of infection from meninges, especially from purulent exudate near the SSS
• Infection can also spread from nearby SDE or epidural abscess
• Additional contributors: dehydration from vomiting, hypercoagulable states, immunologic abnormalities (including circulating antiphospholipid antibodies)
• Thrombosis may extend from one sinus to another - at autopsy, thrombi of different histologic ages can be detected in several sinuses
• SSS thrombosis is often associated with thrombosis of superior cortical veins and small parenchymal hemorrhages

• SSS drains into the transverse sinuses
• Transverse sinuses also receive venous drainage from middle ear and mastoid cells
• Transverse sinus → sigmoid sinus → internal jugular vein
• Septic transverse/sigmoid sinus thrombosis can complicate acute and chronic otitis media or mastoiditis
• Infection spreads via emissary veins or direct invasion from mastoid air cells

• Inferior to SSS, at the base of the skull
• Receives blood from facial veins via superior and inferior ophthalmic veins
• Bacteria enter from facial veins or via emissary veins from sphenoid and ethmoid sinuses
• Sphenoid and ethmoid sinuses are the most common sites of primary infection in septic cavernous sinus thrombosis

Clinical Manifestations

Superior Sagittal Sinus Thrombosis

• Headache, fever, nausea and vomiting, confusion
• Focal or generalized seizures
• Rapid development of stupor and coma
• Weakness of lower extremities with bilateral Babinski's signs, or hemiparesis
• When complicating bacterial meningitis: nuchal rigidity, Kernig's and Brudzinski's signs

Cavernous Sinus Thrombosis

• Fever, headache, frontal and retroorbital pain, diplopia
• Classic signs: ptosis, proptosis, chemosis, extraocular dysmotility (due to CN III, IV, VI deficits)
• Hyperesthesia of ophthalmic and maxillary divisions of CN V + decreased corneal reflex
• Dilated tortuous retinal veins and papilledema

Transverse/Sigmoid Sinus Thrombosis

• Headache and earache are most frequent symptoms
• Otitis media, sixth nerve palsy, retroorbital or facial pain = Gradenigo's syndrome
• Sigmoid sinus and internal jugular vein thrombosis may present with neck pain

Diagnosis

• Absent flow void within the affected venous sinus on MRI is the key suggestive finding
• Confirmed by: contrast-enhanced MR venography, CT venography, or venous phase of cerebral angiography
• Thrombophlebitis of intracerebral and meningeal veins is suggested by presence of intracerebral hemorrhage but requires venous phase of cerebral angiography for definitive diagnosis

Treatment

Antimicrobial Therapy

• Based on the bacteria responsible for the predisposing or associated condition
• Optimal duration unknown; antibiotics usually continued for 6 weeks or until radiographic evidence of resolution of thrombosis

Anticoagulation

• Unfractionated or low-molecular-weight heparin is recommended for:
  1. Aseptic venous sinus thrombosis
  2. Septic venous sinus thrombosis complicating bacterial meningitis with progressive neurologic deterioration despite antimicrobial therapy and IV fluids
• A small intracerebral hemorrhage from septic thrombophlebitis is not an absolute contraindication to heparin therapy

Surgical/Interventional

• Removal of infected tissue and thrombus in septic lateral or cavernous sinus thrombosis
• Successful management of aseptic cases has been reported with:
  • Surgical thrombectomy
  • Catheter-directed urokinase therapy
  • Combination of intrathrombus rtPA + IV heparin
• However, insufficient data to recommend these in septic venous sinus thrombosis

Quick Summary Table for Exam