A 34-year-old right-handed woman, with frequent episodic headaches, typical of migraine with visual aura, presented in December 2010. Two months later, she reported episodes of transient numbness over the left side of her face, arm and leg. There were several brief episodes of diplopia and the sudden onset of painless persistent scotoma in the lower visual field. She attended the ophthalmology clinic and was diagnosed with a left superior temporal branch retinal artery occlusion (figure 1). There was no relevant past or family history and no alcohol or recreational drug history. She had no vascular risk factors.

One month later, she developed increasing migraine with visual aura and hemisensory disturbances. Cardiac and neurological examinations were normal. She was started on aspirin. Initial MR brain imaging and MR angiography of the intracranial and extracranial arteries were normal. In May 2011, she started getting more migrainous headaches associated with vomiting, non-positional prolonged isolated vertigo and an episode of word-finding difficulty. A …