Mystery Case: Migraine, hearing loss, and blurred vision in a young woman

A 39-year-old previously healthy woman presented with a 3-week history of progressive frontal headaches that were of pulsatile quality, moderate severity, and associated with occasional photophobia and nausea.She denied a history of headaches and managed her pain without medication.She reported generalized malaise and perioral and bilateral hand paresthesia.At the time of assessment, she also endorsed diminished hearing and tinnitus in her left ear and intermittent blurry vision in both eyes.On physical examination, the patient was apathetic and in no apparent distress.She denied subjective cognitive deficits, but her Montreal Cognitive Assessment (MoCA) 7.1 score was 26/ 30 (producing only 8 F-words on verbal fluency, impaired abstraction, and missing a word on delayed recall).On cranial nerve inspection, her visual acuity was 20/20 in both eyes and confrontation visual fields were full.Pupils were of equal sizes, with no relative afferent pupillary defect on either side.Dilated fundus examination revealed 1 cotton-wool spot in the right eye and 2 cotton-wool spots in the left eye, with sheathing of a nasal retinal arteriole in the right eye (figure ,A).Extraocular eye movements were full, with normal saccades and smooth pursuit.There was no appreciable auditory loss on bedside testing, and the remainder of the cranial nerves were intact.Motor examination revealed normal muscle bulk and tone, power 5/5, and reflexes 2+ with normal plantar responses.Sensory examination was intact to pinprick and vibration.Cerebellar examination revealed no dysmetria and normal rapid alternating movements.Gait was intact. Questions for consideration:1. What further investigations might assist in making the diagnosis?2. What features would you expect to see on brain MRI? 3. What are the differential diagnoses to consider?