Intracranial dissection and extracranial hypoplasia of the internal carotid artery

Dissection of the intracranial portion of the internal carotid artery (ICA) is anuncommon cause of stroke or transient ischemic attack (TIA). Congenitalanomalies of the ICA have been rarely associated with cerebral ischemia.However, unilateral ICA hypoplasia can be frequently associated withintracranial arterial anomalies and altered hemodynamics.1We describe the case ofa woman who had sudden onset of right facial pain and transient left hemiparesis.Diffusion-weighted magnetic resonance imaging (MRI) findings were negative foracute ischemia. Magnetic resonance angiography (MRA) and sonography showedhypoplasia of the right extracranial ICA and vertebral artery (VA) and dissection ofthe intracranial portion of the right ICA and right middle cerebral artery (MCA), withinverted flow of the right anterior cerebral artery (ACA). At 12-month imaging stud-ies, the intracranial hemodynamics appeared normalized, whereas the extracranialfindings were unchanged. This case shows an association between hypoplasia, dis-section of the ICA, and cerebral ischemia