Cerebral amyloid angiopathy with symptomatic or occult subarachnoid haemorrhage.

araiosis ( fig. 1 ). Routine blood tests including markers for vasculitis and coagulopathy were negative. A drug abuse screen was negative. A four-vessel digital subtraction angiogram was normal. A brain and dura biopsy of the right frontal lobe was performed to exclude primary CNS vasculitis. The biopsy showed hyaline thickening of the walls of mediumand small-sized arteries and arterioles in the meninges, with apple-green birefringence on Congo red staining ( fig. 2 ). The patient was diagnosed with clinically probable CAA with supporting pathology [5] . She was readmitted 8 weeks later with a recurrent acute SAH as evidenced by acute headache and subarachnoid blood on CT over the left parietal area. This was managed conservatively and on review 12 months later she remains well.