Clinical Presentation

A 24-year-old postpartum patient with a history of headache.

Further Work-up

(A) Nonenhanced computed tomography (CT) of the brain demonstrates subarachnoid hemorrhage in the left frontal convexity (arrows). (B) Diffusion-weighted image shows a tiny focus of acute ischemia in the right centrum semiovale (arrowhead). Fluid-attenuated inversion recovery images (not shown) confirmed subarachnoid hemorrhage in the left convexity. (C) CT angiography, sagittal maximum-intensity-projection image, reveals a beaded appearance of some of the left middle cerebral artery (MCA) branches. (D) Lateral projection of a digital subtraction angiogram of the left internal carotid artery (ICA) shows multiple areas in the anterior cerebral artery and MCA branches with alternating segments of narrowing and dilatation (i.e., beading; arrows).

Differential Diagnosis

• Central nervous system vasculitis: