Dental surgery reveals a vascular anomaly

A right-to-left shunt is thought to be caused by a patent foramen ovale - or was it?

Michelle is 59 and has a past history of a transient ischaemic attack (TIA) 10 years ago.

She presents to ED with headache, vomiting, and right retro-orbital pain. She is systemically well with no signs of meningism.