Internal carotid artery thrombus: an underdiagnosed source of brain emboli in neonates?

We report a full-term neonate with a left middle cerebral artery infarct, narrowing of the internal carotid artery detected by magnetic resonance angiography and B-mode ultrasonography, and a large thrombus at the origin of the internal carotid artery detected by B-mode ultrasonography. Internal carotid arterial thrombus is seldom considered the source of middle cerebral arterial embolus in neonates. We suggest that B-mode ultrasonography of the carotid artery be included in the diagnostic evaluation of middle cerebral artery infarcts in neonates.