Double Down on Double Vision: An Unusual Case of Painful Diplopia.

Tolosa-Hunt syndrome (THS) is a rare neuro-immunological disorder characterized by severe periorbital headaches and ophthalmoplegia. In some patients, THS may occur in parallel with other autoimmune disorders. The underlying etiology of THS remains to be definitively established. However, inflammation of the cavernous sinus or orbital apex represents a hallmark feature; magnetic resonance imaging, therefore, plays a key role in establishing a diagnosis. We describe a patient who presented with concomitant THS and granulomatosis with polyangiitis. In addition, we describe the clinical and imaging findings of THS and review treatment options for this rare condition.