Atlanto-occipital dissociation with vertebral artery transection

Case contributed by Chris Newman
Diagnosis certain


Motor bike accident

Patient Data

Age: 40 years
Gender: Male
  • craniocervical dissociation with anterior displacement of the occipital condyles
  • significant prevertebral edema
  • marked increase in the basion-dens interval and the basion-axial interval
  • ETT and enteric tube in situ. Pelvic binder noted. No chest or abdominal injury identified on the X-ray


  • large volume sub-arachnoid hemorrhage, most pronounced within the basal cisterns and Sylvian fissures
  • preserved grey-white matter differentiation

Cervical spine

  • craniocervcial dissociation with significant inferior and posterior translation of C1 relative to the skull base
  • transverse right occipital condyle fracture. Further occipital bone fractures
  • mild widening of the right atlanto-axial joint - dens interval suggesting atlanto-axial articulation disruption
  • gross prevertebral edema without cervical spine fracture

Carotid/circle of Willis angiogram

  • transection of both vertebral arteries with non-opacification of the right vertebral artery at the level of C1 and the left vertebral artery at the skull base
  • contrast blush / extravasation of the left vertebro-basilar junction in keeping with active hemorrhage (causing large volume SAH)
  • minor luminal irregularity of both internal carotid arteries in keeping with low grade carotid blunt cerebrovascular injury
  • normal opacification of the major circle of Willis branches with reconstitution of flow to the posterior circulation via the circle of Willis

Case Discussion

Severe case of atlanto-occipital dissociation with both anterior displacement and superior distraction of the occipital condyles relative to the cervical spine.

This patient deceased shortly after these images were obtained and went onto have a nuclear medicine brain death study, which confirmed brain death.

This case illustrates the use of a cross-table lateral cervical spine radiograph in the setting of severe trauma.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

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

 Thank you for updating your details.