A blockage of the atlanto-occipital joint causes unfocused dizziness, which in older people may well be accompanied by unstable gait, and, additionally, often headache and sensations of eye ...

Atlanto-occipital Dislocation (AOD): A severe injury involving the dislocation of the joint between the skull and the first cervical vertebra, often resulting from trauma. Ligamentous Instability ...

The shock of the accident was so violent that it caused what is called an "atlanto-occipital dislocation", a phenomenon that is generally fatal and that separates the skull from the spine.