Teaching NeuroImages: Thermal imaging in Horner syndrome

Abstract

A 50-year-old woman with a history of fibromuscular dysplasia presented to the emergency department with 1 day of right ear pain. Examination demonstrated 2 mm anisocoria, left pupil larger than right, with brisk pupillary light reactions bilaterally; 2.5 mm right ptosis; and anhidrosis of the right forehead, as determined by the spoon test. Thermal imaging was consistent with this finding (figure). She was diagnosed with acute, painful Horner syndrome. MRI/magnetic resonance angiography demonstrated right internal carotid artery dissection. Due to the risk of stroke immediately following internal carotid dissection,1 she was treated with heparin drip, then later transitioned to aspirin and clopidogrel therapy.2