Intracranial arteries (variants)

Last revised by Dr Amir Mahmud on 23 Jun 2020

Intracranial arterial variants, of which there are many, are collectively common. Their clinical significance may be variable but knowledge and recognition of these variants is fundamental, especially if surgical or endovascular treatments (e.g. for acute stroke, aneurysms or other vascular pathologies) are being considered.

Variant anatomy

Anatomical variations in intracranial arterial anatomy include:

Internal carotid artery
Vertebral and basilar arteries
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Persistent carotid-vertebrobasilar artery anastomoses 

Persistent carotid-vertebrobasilar anastomoses including: 

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: common variants of the COW
    Drag here to reorder.
  • Case 1: ACA fenestration
    Drag here to reorder.
  • Case 2: persistent trigeminal artery
    Drag here to reorder.
  • Case 3: accessory MCA
    Drag here to reorder.
  • Case 4: aplastic A1
    Drag here to reorder.
  • Case 5: aplastic A1
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.