Benign CNS arteriopathy

This 49 year old woman presented with a number of thunderclap headaches over a period of weeks. The initial CTA demonstrated no vascular anomaly, and no blood was identified on CSF.

Repeat CTA three days later, after a further headache revealed marked beading of all intracranial branches, best demonstrated in the ACAs. 

The patient also developed an occipital infarct.