Describe the typical etiology and imaging hallmark of pediatric arterial ischemic stroke.

• A. Arteriopathy or risk factors such as dehydration or sickle cell disease; imaging hallmark is restricted diffusion on DWI with possible arterial occlusion on MRA/CTA
• B. Global hypoxic injury with diffuse edema
• C. Venous sinus thrombosis without arterial involvement
• D. Migraine with aura

Answer: (A)

Pediatric arterial ischemic stroke usually arises from an arterial problem, such as intrinsic arteriopathy or risk factors that promote arterial narrowing or occlusion (for example dehydration or sickle cell disease, plus other conditions like Moyamoya, dissection, or congenital heart disease). The imaging hallmark of an acute arterial ischemic event is restricted diffusion on diffusion-weighted imaging, reflecting cytotoxic edema in the involved brain tissue. This focal diffusion abnormality is often accompanied by evidence of arterial involvement on vascular imaging, with MR angiography or CT angiography showing an occluded or narrowed feeding artery in the affected territory. In contrast, global hypoxic injury presents with diffuse edema rather than a focal diffusion restriction, venous sinus thrombosis involves the venous system rather than an arterial occlusion, and migraine with aura does not produce a consistent focal diffusion-restricted infarct pattern.