Cavernous Sinus Anatomy & Cavernous Sinus Syndrome

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Page 436: Cavernous sinus.

What is the Cavernous Sinus? Cavernous sinus is a collection of venous sinuses on either sides of the pituitary.

Describe the drainage through the cavernous sinus? Blood from the eye and superficial cortex drain into the cavernous sinus, and then eventually makes its way into the internal jugular vein.

Name the nerves and vessels that pass through the cavernous sinus on their way to the orbit? the nerves and vessels that pass through the cavernous sinus on their way to the orbit include:

–          CN III: [occulomotor nerve]

–          CN IV: [trochlear nerve]

–          CN V1: [ophthalmic nerve]

–          CN V2: [maxillary nerve]

–          CN VI: [abducence nerve]

–          Postganglionic sympathetic fibers

–          Cavernous portion of the internal carotid artery

All these pass through the cavernous sinus in route to the orbit.

One thing to note is that CN V1 and V2 are the only two things that pass through the cavernous sinus that help control the extra-ocular muscles, but CN V3 doesn’t pass here because it doesn’t control extra-ocular muscles.

Describe the picture of the cavernous sinus? We’ll start with the optic chiasm. Right below it you see the hypophysis (the pituitary gland). On either side you see the cavernous sinus. We also see two internal carotid arteries which is the cavernous portion of the internal carotid artery. There’s also the anterior clinoid process, the occulomotor nerve [ CN III], trochlear nerve [CN IV], Ophthalmic nerve [CN V1], Maxillary nerve [CNV2], Abducence nerve [CN VI], the dura, arachnoid and the pia matter.

What is cavernous sinus syndrome? Cavernous sinus syndrome is a condition that occurs due to mass effect, that happens if there’s any sort of tumor at the Hypophysis, pituitary adenoma. These tumors can get large in size and they will create a mass effect due to the size of the tumor and that can cause compression of nearby nerves, and that would lead to ophtalmoplegia and decrease in corneal and maxillary sensation with normal vision.

Define ophthalmoplegia? Ophthalmoplegia is paralysis of the muscles within or surrounding the eye.

 
 
 

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