=====Atlantoaxial instability (AAI)=====
see [[Atlanto-axial subluxation]].

Central Atlantoaxial Instability: A New Clinical Entity?
((Smith JS. Central Atlantoaxial Instability: A New Clinical Entity? Neurospine.
2019 Jun;16(2):212-213. doi: 10.14245/ns.19edi.005. Epub 2019 Jun 30. PubMed
PMID: 31261456.
)).