1.Cavernous SinusByDr. Noura El Tahawy

2. Position & Extension-on the side of the body of sphenoid,-extending from the apex of the petrous temporal bone (behind)to the medial end of the superior orbital fissure (in front).-Each sinus is 2 cm long and 1 cm wide, 3. Relations 4. * Medially: Sphenoidal air sinus. Hypophysis cerebri.* Laterally: Trigeminal ganglion. Uncus of the temporal lobe.* Nerves in its lateral wall: (from above downwards) Oculomotor nerve. Trochlear nerve. Ophthalmic division of trigeminal nerve. Maxillary division of trigeminal nerve.* Structures within its cavity. Internal carotid artery. Abducent nerve (on the lateral side of the artery). -carotid sympathetic plexus N.B.: The internal carotid artery may rupture inside the cavernous sinus due tofracture base of the skull. This results in a pulsating swelling behind the orbit. 5. Coronal section of the cavernous sinus. 6. Cavernous sinus. 7. Cavernous Sinuses Optic ChiasmaInternal Carotid ArteryUncusofPituitary SphenoidalTemporal Lobe GlandAir Sinus Sphenoidal AirSinusesBody ofSphenoid Bone 8. Medial end ofThe superior orbital fissureUncus Optic Chaisma Temporal lobe Apex of petrous Trigeminal Ganglion 9. Content of the Cavernous SinusesOcculomotor NerveTrochlear NerveOphthalmic NerveMaxillary Nerve Internal carotid Artery Abducent Nervewith Sympathetic Plexus 10. Tributaries andcommunications 11. Anteriorly: Ophthalmic veins (connect it with the facial vein in the face). Sphenoparietal sinus.Posteriorly: Superior petrosal sinus (connects it with the transverse sinus). Inferior petrosal sinus (connects it with the internal jugular vein).Medially: Anterior and posterior intercavernous sinuses (connect the 2cavernous sinuses together).Superiorly: Superficial middle cerebral vein (from the lateral surface of the brain). Cerebral veins from the inferior surface of the brain.Inferiorly: Emissary vein through the carotid canal (connects it with the internal jugular vein). Emissary vein through the foramen ovale (connects it with the pterygoid plexus ofveins). 12. Superior and inferiorOphthalmic veinsPlexus of emissary veins through carotid canal to internal jugular vein inferiorPetrosal sinus 13. Tributaries of Cavernous SinusAnteriorly, Posteriorly, Medially and Superiorly 14. Infe Ce rio Cerebral vein nt roth ral Superficial middle Supe phe ve thre in Sphenoparietal sinus r io al tin orom a fphicth ve al inmSuicpever io in roph th Rialg mveinsInht fe ic sinusrioveCa inInferior cerebral roveph rnSuperior petrosal thalou m sicSCeve ininu nt sth ral v e re eintin oa fLef In tC In f a te erior vercrnsin ave sin pet ouus rn us r os es ou a l ssSinus Inf eriorsin petus r os a lveins Sphenoparietal sinus Su peInferior cerebralrioCerebral veinsi r pnu etSuperficial middle s rosal 15. InferiorTributaries of Cavernous Sinus 16. s i nu S s n ou rveCa htRig usS insoue rnavtC Lef Foramen Vesalius Foramen Ovale Foramen Lacerum PharyngealPterygoid Plexus Plexus 17. 8- Inferior Petrosal Sinus s i nu S s n ou rveCa htRig usS insoue rnavtC Lef Foramen VesaliusForamen Ovale 1- Superior Ophthalmic Vein Foramen Lacerum2- Inferior Ophthalmic Vein3- Sphenoparietal sinus4- Anterior Facial VeinPharyngealPterygoid Plexus Plexus 18. Dangerous area of the Face 19. -The flow of blood in all the tributaries and communications of the cavernous sinus is reversible because they possess no valves.-Spread of infection to the cavernous sinus leads to its thrombosis.-The cavernous sinus communicates with the veins draining the middle area of the face (dangerous area of the face) through 2 routes:1-Superior ophthalmic vein.2-Deep facial vein, pterygoid plexus of veins and emissary vein through the foramen ovale. 20. Cavernous Sinus Thrombosis 21. If the cavernous sinus is thrombosed what are the important structures that may be affected?? Q. What is the clinical picture of CST ? A. Clinical features of CST General features of infection: fever, rigors, malaise, and sever frontal and orbital headache. Unilateral exophthalmos and tender eye ball Oedema of the eyelid and chemosis of the conjunctiva (due to obstruction of the superior and inferior ophthalmic veins).Third, fourth, sixth cranial nerves and ophthalmic and maxillary divisions of the fifth cranial nerve may be affected(paralysis or paresis): * Clinical picture of oculomotor paralysis: External ophthalmoplegia: Paralysis of movements of the affected eye (upward, downward and medial). Ptosis: dueto paralysis of the levator palpebrae superioris. Slight exophthalmos. Internal ophthalmoplegia: Dilated fixed pupil with loss of accommodation reflex. (due to paralysis of the sphincterpapillae and cilliary muscles).*Paralysis of abducent nerve: Paralysis of outward movement of the affected eye.( due to paralysis of lateral rectusmuscle)* Paralysis of trochlear nerve: Paralysis of outward and downward movement of the affected eye. (due to paralysis ofsuperior oblique muscle) * Anesthesia in the distribution of ophthalmic division of the trigeminal nerve, decreased or absent corneal reflex andpossibly anesthesia in the maxillary branch distribution. 5 . Infection can spread to the contralateral cavernous sinus within 2448 hr of initial presentation. The earliest feature ofsuch spread is affection of the abducent nerve (6 th cranial nerve) on the opposite side (paralysis of outward movement of theaffected eye). 22. Thanks