Unilateral proptosis and bilateral 6th nerve palsy are seen in?

Cavernous sinus thrombosis is usually a unilateral condition which caused rapid unilateral proptosis. The 6th nerve passes through the cavernous sinus, So bilateral 6th nerve palsy is seen. Later 3rd and 4th nerves are also involved. Clinical features of cavernous sinus thrombosis: Onset of cavernous sinus thrombosis is abrupt with chills and rigors. The patient is acutely ill. Eyelids get swollen with chemosis and proptosis of the eyeball. Cranial nerves 3,4 and 6 which are related to the sinus get involved individually and sequentially causing total ophthalmoplegia. The pupil becomes dilated and fixed, optic disc shows congestion and oedema with diminution of vision. Sensation in the distribution of ophthalmic division of trigeminal nerve is diminished. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 226)