What is Thrombosis of Cavernous Sinus?
The cavernous sinus is a cavity located in the hollow region at the base of the brain behind the eye sockets. The jugular vein which is a major blood vessel transmits deoxygenated blood from the brain through cavernous sinus to the heart. The blood clot in cavernous sinus leads to an infection called Thrombosis of the Cavernous Sinus or Cavernous Sinus Thrombosis.
The cavernous sinus thrombosis is an infection leading to blood clot caused by the complication of an infection in the paranasal or central face sinuses.
The infection may obstruct the blood flow from the brain due to the complicated neurovascular relationship. This obstruction can lead to damages in the brain, eyes and the neural structure connecting them.
Thrombosis of the Cavernous Sinus is a life threatening disorder as it is highly infectious and maybe lethal despite the use of antibiotics.
What are Signs and Symptoms of Thrombosis of Cavernous Sinus?
The signs and symptoms of Thrombosis of the Cavernous Sinus include a severe headache in the initial stage. However, other symptoms develop in 5-10 days. It includes:
- Boil on the face
- Sinusitis- an infection in the skull
- Infection in eyes- redness, swelling or irritation around the eyes
- High temperature
- Severe pain or numbness in the face
- Drooping eyelids
- Impaired vision
These symptoms of Thrombosis of the Cavernous Sinus may get intense if are not treated on time. The patient may also get into coma.
What are the Causes of Thrombosis of Carvernous Sinus?
The causes of Thrombosis of the Cavernous Sinus are:
- Bacterial infection in face, skull or teeth.
- A head injury.
- In rare cases, a severe blow to the head may cause cavernous sinus thrombosis.
- A condition which is prone to blood clotting like diabetes, obesity or pregnancy.
- Lupus or Behcet's syndrome- diseases that causes inflammation in the body.
- In rare instances, an infection in the ears and eyes can result into cavernous sinus thrombosis.
- Staphylococcus aureus is a bacteria that can cause sinusitis or boils- which are the symptoms of cavernous sinus thrombosis. However, these infections are rarely the cause of cavernous sinus thrombosis.
- Thrombosis is a process in which the immune system forms the blood clots to fight against bacteria in the body. These clots may increase the pressure in the brain by blocking the blood flow. This would result into damaging the brain- which may be lethal.
- People taking certain type of medications like contraceptive pills are prone to cavernous sinus thrombosis.
- Streptococcal, pneumococcal or fungal bacteria maybe the causative factor in rare instances.
Diagnosis of Thrombosis of Cavernous Sinus
The diagnosis of Thrombosis of the Cavernous Sinus is clinically done using the imaging techniques from proptosis, ptosis, chemosis and cranial nerve palsy in one eye associated to the other eye. The infection in the blood and cerebrospinal fluid are also tested to diagnose the Cavernous Sinus Thrombosis.
The laboratory tests and imaging techniques to clinically diagnose Cavernous sinus thrombosis includes:
- Blood tests include CBC, ESR and blood culture. However, these tests are useful in primary diagnosis of cavernous sinus thrombosis.
- The cerebrospinal fluid should be tested in patients with parameningeal inflammation.
- Lumbar Puncture should be carried out to diagnose meningitis.
- D-dimer maybe a helpful tool to diagnose patients with CSVT- Cortical Sinus Venous Thrombosis.
Various imaging techniques are used to diagnose Thrombosis of the Cavernous Sinus, like:
- Sinus Radiography - It is used to diagnose sphenoid sinusitis, sclerosis, opacification and air-fluid levels.
- Carotid Angiography - It is a tool that images the obstruction or narrowing of the intercavernous area in the carotid artery.
- Orbital Venography - It is an invasive, yet excellent tool that measures the blood clots in the veins. It helps in identifying occlusion in cavernous sinus.
- Computed Tomography (CT) Scan - It is a highly used imaging technique to diagnose Cavernous sinus thrombosis as it can measure the obstruction of the carotid artery. The contrast CT scan may depict the filling defects in the cavernous sinus and the thickening of superior ophthalmic vein. However, the CT scan results maybe unreliable.
- Magnetic Resonance Imaging (MRI) - This technique is a more sensitive tool, which identifies the deformities in the internal carotid artery and signal intensity in thrombosed vascular sinuses.
- MR Venogram (MRV) - MRI with MRV is the most preferred tool to measure the absence of venous flow in cavernous sinus.
- Cerebral Angiography - It is an invasive tool and is not too sensitive to measure the cavernous sinus thrombosis.
Differential Diagnosis of Thrombosis of Cavernous Sinus includes:
- Orbital cellulitis
- Acute Subdural Hematoma
- Internal carotid artery aneurysm
- Acute Angle Closure Glaucoma
- Orbital and Periorbital Infections
- Migraine headache
- Subarachnoid Hemorrhage
- Allergic blepharitis
- Epidural Hematoma
- Thyroid exophthalmos
- Brain tumor
- Epidural and subdural infections
How is Thrombosis of Cavernous Sinus Treated?
General Treatment for Thrombosis of the Cavernous Sinus:
The vital therapeutic intervention for cavernous sinus thrombosis is the antibiotic administration at an early stage. It includes:
- Third or Fourth generation cephalosporin.
- Penicillinase- A penicillin resistant.
- Fourth generation antibiotics to treat associated complications like meningitis, subdural empyema or brain abscess.
- Anaerobic treatment for treating any dental or other anaerobic infection.
- Corticosteroids can be used as an alternative treatment to eliminate swelling and inflammation.
- The antibiotic treatment for Thrombosis of the Cavernous Sinus may be prolonged to 3-4 weeks. However, it may exceed to 6-8 weeks to treat complications like intracranial suppuration.
If the medicines are ineffective to the patient, surgery is required.
Surgery for Thrombosis of the Cavernous Sinus:
Surgery on the cavernous sinus is difficult due to its complicated anatomical relationship. If the antibiotics are ineffective on the patient, a surgery is required to drain the fluid from the brain.
The surgical drainage of the fluid from the brain is done using sphenoidotomy in feasible infections like facial abscess or sphenoid sinusitis.
The complicated infection, septic emboli or continued sepsis should be identified during the antibiotic therapy.
Prevention & Complications of Thrombosis of the Cavernous Sinus
The prevention of Thrombosis of the Cavernous Sinus is less feasible. However, the patients should take antibiotics to treat pimples (abscesses) in the central area of the face in the initial stage.
Cavernous sinus thrombosis is an infectious disease with 30% of mortality rate, which is life-threatening. Despite the use of antibiotics, there may be some complications including carotid thrombosis, meningitis or brain abscess. The survivors often suffer from permanent sequelae. Treated patients may suffer from blindness, oculomotor weakness or pituitary insufficiency. Hence the earlier the treatment is taken, the lesser the long-term damage.