The location of origin of spontaneous extracranial internal carotid artery dissection is adjacent to the skull base.

Introduction: The traditional view is that spontaneous extracranial internal carotid artery (ICA) dissection (CAD) extends cranially from an intimal tear located just beyond the carotid bulb. This paper demonstrates that CAD originates in and primarily involves a more distal segment of the artery.

Methods: A retrospective study of 54 dissected ICAs in 50 consecutive patients with spontaneous or traumatic CAD was undertaken.