A patient presented with painful ophthalmoplegia. On CT scan, there was enlargement of the cavernous sinus on one side. The most likely diagnosis is:

C i.e. Tolosa Hunt Syndrome Painful opthalmoplegia can be seen in cavernous sinus thrombosis, Tolosa Hunt syndrome & orbital pseudotumor. These are differentiated by? Orbital pseudotumor There is enlargement of extraocular muscles (not cavernous sinus)Q Gradeniego's syndrome CT scan show - enhancement of cavernous sinusQ (not enlargement) - petrous apicitis of temporal bone including opacification of mastoid air cells - bony erosion with in petrous apex Idiopathic orbital inflammatory disease (Pseudo tumor) It is non neoplastic, non infectious, non specific space occupying orbital lesion (a diagnosis of exclusion). Unilateral disease is the rule in adults, although may be bilateral in children. It usually presents in 30-60 years male with acute unilateral periorbital (lid) redness, swelling and pain with proptosis. Rarely opthalmoplegia and optic nerve dysfunction may occur in severe cases. It may 1/t intermittent episodes with spontaneous recovery without sequelae or prolonged course resulting in frozen orbit characterized by opthalmoplegia, ptosis & visual impairment. USG shows diffuse infiltration of hetrogenous consistency CT scan shows ill defined orbital opacification & loss of definition of contents, diffuse thickening of the extraocular muscles including their tendinous inseion, which differentiates it from thyroid eye disease where the muscle enlargement is confined to the muscle belly and spares the terminal tendinous poionQ. Steroids, radiotherapy (in unresponsive cases) and cyclophosphamide are used to treat. Tolosa-Hunt Syndrome It is a rare diagnosis of excision, caused by non specific granulomatous inflammation of the cavernous sinus, superior orbital fissure and /or orbital apexQ. The clinical course is characterized by remissions and recurrences. It is characterized by acute, painful, opthalmoplegia, with or without involvement of optic nerve and ophthalmic division of trigeminal nerve and it responds promptly to steroid treatment (in 24-48 hrs). It presents with diplopia a/w ipsilateral periorbital or hemicranial pain, mild proptosis, ocular motor nerve palsies often with involvement of pupil and sensory loss along the distribution of 1st & division of trigeminal nerve. Original cases had granulation around carotid aery in cavernous sinus. Full investigation to exclude diagnosis of carotid- cavernous fistula, infraclinoid aneurysm, pituitary tumor, meningioma & orbital tumor. Other lesions may be responsive to steroids but neither is the remission complete nor it occurs so rapidlyQ. THS should not be diagnosed with out aeriography and venography or when there are atypical features (clinical /radiological/in resonse to treatment). Thin slice high magnetic field MRI of cavernous sinus including coronal sections with & without contrast and fat suppressed cuts of orbital regions is modality of choice Inflammatory changes in cavernous sinus, superior orbital fissure & /or orbital apex are observed on high resolution contrast enhanced imaging. Enlargement of optic nerve &/or extra ocular muscles.