all are true regarding toloso hunt syndrome except ?

Tolosa-Hunt Syndrome * Retro-orbital pseudotumor extending to the cavernous sinus * Clinical triad -- Unilateral ophthalmoplegia -- Cranial nerve palsies -- Dramatic response to systemic coicosteroids * Usually unilateral but may be bilateral (5%) * Histopathology = low-grade nonspecific inflammatory process with lymphocytes and plasma cells * MR Imaging -- Enlarged cavernous sinus containing abnormal soft tissues that are isointense to muscle on T1-weighted images and dark or bright on T2-weighted images and display contrast enhancement with focal narrowing of the ICA ref : harrisons 21st ed