Recurrent Syncopal Episodes Due to Atlanto-Axial Instability – An Unusual Presentation of Os Odontoideum

Abstract

Os odontoideum is a rare cause of atlantoaxial instability. Despite being first described in 1886, its pathogenesis is still unclear, with theories for both congenital and traumatic etiologies. We report on an atypical presentation of this pathology, in a patient who was being investigated for recurrent syncopal episodes during performance of everyday activities, and who was unexpectedly found to have an os odontoideum. The patient underwent occipito-cervical fusion and had complete resolution of all her symptoms postoperatively.