Dr. Parag MoonSenior resident

GMC, Kota

Paired venous sinus, on either side of body of sphenoid.

2cm in length, height of 1cm

Traversed by numerous trabeculae, dividing it into a several caverns (spaces) hence cavernous.

Relations: ◦ Medial – pituitary above, sphenoidal air cell below

◦ Lateral – temporal lobe, uncus

◦ Anterior - superior orbital fissure

◦ Posterior - petrous apex

◦ Superior – optic chiasm

Tributaries:

– Superior and inferior opthalmic veins

– Sphenoparietal sinus

– Inferior cerebral veins

– Superficial middle cerebral veins

– Central vein of retina

Drainage:

– Superior petrosal sinus---> transverse sinus

– Inferior petrosal sinus --->internal jugular vein

Communication:

– Intercavernous sinuses – communication between the 2

– Pterygoid plexus – via emissary veins passing through foramen ovale, emissary sphenoidalforamen and foramen lacerum.

– Pharyngeal plexus – via a vein passing through carotid canal.

– Facial vein – via superior opthalmic vein.

Contents of cavernous sinus

- Internal Carotid artery with sympathetic plexus

- CN 3

- CN 4

- CN 5 (1st and 2nd divisions)

- CN 6

Includes cases of phlebitis, thrombo-phlebitis and aseptic thrombosis

Septic type (most common) - coagulasepositive staphylococcus

Aseptic types may follow trauma, local stasis or a failing circulation.

Septic CST

Infectious

Aseptic CST Trauma Post surgeryRhinoplastyBase of skullTooth extraction Hematologic MalignancyNasopharyngeal Ca. Dehydration

More commonly seen with sphenoid and ethmoid and to a lesser degree with frontal sinusitis

Staphylococcus aureus -70% of all infections. Streptococcus pneumoniae, gram-negative bacilli, and anaerobes can also be seen.

Fungi are a less common pathogen and may include Aspergillus and Rhizopusspecies(more common in diabetics)

No valves in dural sinuses, cerebral and emissary veins

Infection of upper lip, vestibule of nose and eyelids-> spread by way of angular, supraorbital, supratrochlear veins to ophthalmic veins=commonest route

Intranasal operation of septum, turbinates, ethmoid/sphenoid sinus infection->through ethmoidal veins

Operation of tonsil, peritonsillar abcess, maxillary osteomyelitis/surgery, dental extraction->spread by pterygoid plexus or direct extension in internal jugular vein

Involvement of middle ear/mastoid -> retrograde spread through petrosal sinus to cavernous sinus

Sources:

Nose – Paranasal 40%

Orbit- Face 35%

Mouth – Teeth 13%

Ear 9%

Other – tonsil, soft palate, pharynx, posterior portions of the superior and inferior alveolar arches 3%

1. Sepsis

2. Venous obstruction

3. Involvement of cranial nerves

Pyrexia

Rapid, weak, thready pulse

Chills and sweats

Delirium - meningitis supervenes terminally

Septic emboli to various other parts of body.

Proptosis (first oedema & chemosis)

Oedema of eyelids and bridge of nose

Dilatation and tortuosity of retinal veins

Retinal hemorrhages

Involvement of the contralateral eye – (48 hours)

When pterygoid plexus is occluded along with sinus, - oedema of the pharynx or tonsil

First CN involved is VI

Ptosis - paralysis of oculomotor nerve

Dilatation of pupil- third nerve and stimulation of sympathetic plexus

Decreased abduction (paralysis of abducensnerve)

Complete opthalmoplegia

Loss of vision

Retro-orbital pain and supra-orbital headache->V

Strong clinical suspicion

1)Orbital venography

Not recommended

Difficult to puncture facial veins in odema

May help in dissemination of infection

2) Contrast enhanced CT

Slice thickness 3mm or less

Shows enlargement and expansion of cavernous sinus cavity with flatening or convexity of lateral wall

Multiple or single filling defect with enhancing CS.

Exopthalmos, soft tissue edema

Dilation of superior ophthalmic vein

3) MRI:

– A sensitive, noninvasive

Can be combined with venography to demonstrate lack of blood flow in the cavernous sinus

Show associated meningitis, involvement of pituitary gland

4) CSF examination

Elevated protein

Normal sugar

Mild pleocytosis

5) Complete blood count

Elevated TLC

Leucocytosis

6) Blood culture

7) Local tissue culture

Intracranial extension of infection-> meningitis, encephalitis, brain abcess, pituitary infection,epidural, subdural empyema

Cortical vein thrombosis->hemorrhagic infarction

Extension to other sinuses

Orbital cellulitis–differentiated from CST by B/L involvement, papillodema, dilated pupil, decreased periocular sensation, abnormal spinal fluid in latter

Preseptal cellulitis- no proptosis

Orbital apex syndrome- more visual loss, opthalmoplegia, less proptosis, periorbitalodema

Sinusitis

Orbital malignancy

Facial Cellulitis

Glaucoma-angle closure

Immediate empiric antibiotic coverage must include gram-positive, gram-negative and anaerobic bacteria.

Later treatment can be narrowed, adjusted to cultures and sensitivities

Third generation cephalosporin+vancomycinwith metronidazole

Duration- 3-4 weeks

Used in setting of fungal sinusitis

More common in diabetics

Aspergillus more common

Parentral amphotericin B for 3 weeks followed by posaconazole(400mg BD) prophylaxis

Dose-0.5-1.5mg/kg/day(deoxycholate), 5-10mg/kg/day(liposomal)

Intravenous heparin (maintaining the partial thromboplastin time or thrombin clot time at 1.5 to 2 times that of the control)->24,000-30,000 U/day.

Warfarin sodium (maintaining the prothrombin time at 1.3±1.5 times the control) -continued for 4 to 6 weeks to allow adequate collateral channels to develop

Mortality was lower among patients who received heparin treatment, 14% vs. 36%

Early administration of heparin may serve to prevent spread of thrombosis to the other cavernous sinus as well as to the inferior and superior petrosal sinuses.

Not influence mortality

May prevent residual cranial nerve dysfunction caused by inflammation.

Dexamethasone used most commonly

Surgical drainage of affected sinuses

Endoscopic sinus surgery

Surgical debridement in fungal sinusitis

Surgical drainage of any collection

100% mortality prior to antibiotics

30% mortality despite aggressive treatment

44% of survivors remain with chronic sequelae,

Roughly one sixth of patients are left with some degree of visual impairment

One half have cranial nerve deficits

Hypopituitarism- rare, can occur before or after 1 year.

Septic cavernous sinus thrombosis-Neurology and Neurosciences;2014;4:117-118

Treatment of Cavernous Sinus Thrombosis; IMAJ 2002;4:468±469

Septic thrombosis of cavernous sinus-Arch Intern Med;2001;161:2671-2676