Cavernous Sinus Thrombosis: Case Report

Case Report: 55y male, known diabetic, presents with headache, fever, left eye pain with swelling, ptosis, left eye vision loss, altered sensorium of acute onset.

MRI brain & orbits findings  ( CEMRI not done, in view of elevated serum creatinine) –

-     Proptosis of left eyeball with altered signal/fat stranding in intraconal & superomedial extraconal compartment of left orbit with bulky superior/medial rectus/superior oblique  muscles & bulky STIR hyperintense left optic nerve – suggesting orbital infective / inflammatory changes like cellulitis with acute optic neuritis.

    Patchy mucosal thickening with T2 iso to hypointense signal in ethmoid sinus & mild expansion of sinus with ill defined left lateral wall of the ethmoid sinus – suggesting sinusitis (like fungal/other bacterial). Fluid signal seen in sphenoid sinus along with mucosal thickening in both maxillary sinuses.

    Left cavernous sinus is ill defined/ bulky with T1 hypointense signal with effacement of fat signal in it & T2 altered isointense signal with thin soft tissue in its margin reaching upto left orbital apex – likely suggesting septic thrombosis of the left cavernous sinus.

-    Focal diffusion restriction in left hypothalamus / left anterior commissure near midline & left temporal lobe inferomedially – acute infarcts, likely due to infective vasculitis.  Ill defined mild diffusion restriction in left basifrontal lobe white matter – could be acute ischemic lesion or due to encephalitis. Loss of T2 flow void with smaller caliber of left ICA in carotid canal & cavernous segments ( cavernous more than carotid canal) – suggesting thrombosis.

Discussion by Dr MGK Murthy, Dr GA Prasad 

•          Cavernous sinus is extradural venous plexus surrounded by a dural fold in the middle cranial fossa containing internal carotid artery with its periarterial sympathetic plexus, abducens nerve lateral to the internal carotid artery, but medial to the oculomotor and trochlear nerves and the ophthalmic and maxillary divisions of the trigeminal nerve, which run superior to inferior within the lateral dural border of the cavernous sinus.
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•          Thrombosis of the cavernous sinus is usually caused by bacterial or fungal invasion complicating sinusitis in patients with poorly controlled diabetes or immunosuppression.
•           Clinically  characterized  by multiple cranial neuropathies with impairment of  ocular motor nerves, Horner’s syndrome, and sensory loss of the first or second divisions  of the trigeminal nerve in various combinations. The pupil may or may not be involved.
•          CT and MR imaging direct signs are changes in signal intensity and in the size and contour of the cavernous sinus, and indirect signs are dilatation of the tributary veins, exophthalmos, and increased dural enhancement along the lateral border of the cavernous sinus.

  Few infective agents are-

Actinomycosis -  mostly immunocompetent patients( men >women), bacteria generally gain access to the central nervous system by direct extension from the ear or sinuses or hematogenous spread from a distant source &  may appear as an irregularly marginated, rim-enhancing abscess, meningoencephalitis, or as a mass lesion.

Rhinocerebral Mucormycosis fungi cause fulminant infection in immunocompromised and diabetic patients. After inhalation into  the nasal cavity and paranasal sinuses, the fungi cause necrotizing vasculitis, thrombosis, or infarction of the nose and sinuses and  can then rapidly extend into the orbits, deep  nervous system may be invaded directly by extension  through the skull base or indirectly  through involvement of the carotid artery and  cavernous sinus.

Aspergillosis  - most commonly as a  result of hematogenous spread and occasionally

by direct extension of infection from the  paranasal sinuses, middle ear, or orbit, mostly in immunocompromised patients, tend to invade vessels. Decreased signal intensity on T1-weighted  imaging and very low signal intensity on T2- weighted imaging are characteristic findings  in paranasal sinus aspergillosis and are attributed  to paramagnetic elements by hemorrhage or aspergillus fungal colonies, mainly iron and magnesium.

Noninfectious Inflammation of cavernous sinus are -

Tolosa-Hunt Syndrome -  recurrent painful ophthalmoplegia due to nonspecific granulomatous

inflammation in the anterior  cavernous sinus, superior orbital fissure, or orbital apex with  MR

findings include nonspecific inflammatory lesions isointense to T1- and T2-weighted images in the anterior cavernous sinus, the superior orbital fissure, or the orbital apex  with contrast enhancement.

Inflammatory Pseudotumor -  idiopathic inflammatory lesions with rare  skull base involvement.  MR findings include soft-tissue lesions infiltrating the skull base

with intracranial dural involvement, bone destruction, iso- to hypointensity on T2-weighted

images according to the fibrosis and high cellularity, and contrast enhancement