Neuro Disorders: Cavernous Sinus Syndrome

Cavernous Sinus Syndrome refers to the various neurological manifestations secondary to pathologies involving the cavernous sinus.

Sometimes the term Cavernous Sinus Syndrome is used just only with the thrombosis (clot) formation within the cavernous sinus; sometimes it is used for a variety of pathologies involving this sinus. In this article the term is used with the later sense (varieties of pathologies).

Cavernous sinus is one of the many venous sinuses inside the skull cavity and the blood from the veins pass through these sinuses before reaching the systemic circulation. It is located as one on either side of the pituitary fossa at the base of the skull.

This particular sinus is susceptible to various pathological conditions including its thrombosis.

The importance of this sinus lies with the fact that in addition to carrying venous blood through it, there are also several cranial nerves pass through it (3rd, 4h, branches of 5th and 6th) and internal carotid artery too passes through it. Depending upon these structures, they either pass through its blood or along its wall.

So the pathologies of this sinus can affect many important structures, and this is obviously a concerning issue.

As mentioned above there are myriad conditions that can affect this sinus.

The common causes include;

• Infectious (usually bacterial or fungal)
• Inflammatory causes
• Tumors infiltrating the sinus
• Traumatic complications
• Granulomatous condition (Tolosa Hunt Syndrome)
• Dehydration, hormonal factors etc might themselves trigger or have a contributory role for this syndrome

The clinical presentation is related with the involvement of this sinus itself, as well as with the related structures involved.

The involvement of the sinus can cause lot of pain especially over the face and also as headache. Nausea and vomiting may be experienced too. The hindrance to the venous blood flow through the sinus can cause swelling of the face including the eye lids. The eye may bulge out.

The cranial nerve involvement can cause problem with eye ball movements (so double vision), drooping of eyelid, abnormalities with facial sensation etc may occur.

Involvement of the internal carotid artery can cause serious complications like stroke due to bleeding or blockage of the blood flow (infarct). Sometimes a fistula may develop (a communication between an artery and vein) with its own set of complications.

An MRI of the brain focusing on the cavernous sinus area is an enormously useful test to clinch the diagnosis. A CT is useful but generally MRI is superior.

Other tests that are sometimes performed include MRV (magnetic resonance venogram), cerebral angiograms etc.

If infection is suspected blood culture are ordered. Sinus culture and/or biopsy are required sometimes.

High dose powerful antibiotics are given by intravenous dose if infection is suspected. The role of blood thinners like heparin is controversial.

Steroids or other immunosuppressive agents are useful with Tolosa Hunt Syndrome. If any tumors or inflammatory/autoimmune conditions are identified then they are treated appropriately.

A neurologist is frequently involved in the care of patients with Cavernous Sinus Syndrome.