[A case of Takayasu arteritis complicated with cavernous sinus syndrome presenting as unilateral optic nerve DWI hyperintensity].

A 47-year-old male patient with a history of Takayasu arteritis presented with prominent symptoms of left eyeball fixation, protrusion, and visual loss. Orbital magnetic resonance imaging revealed hyperintensity on diffusion-weighted imaging of the left optic nerve, with corresponding low signal on apparent diffusion coefficient maps, suggestive of acute infarction of the left optic nerve. Combined with the patient's cranial magnetic resonance imaging findings, the diagnosis of cavernous sinus syndrome was established.