We experienced a case of atlanto-axial subluxation associated with hypoplasia of the atlas.
A 57 years old man was admitted to our hospital in July 1998, complaining of continuous headache. He had no family and past history of any significant disorders, but experienced head confusion a month ago. On examination, he did not have sensory disturbance, pathological reflex and hyperreflex except headache. In X-ray, atlanto-dental interval was 6mm (flexion position) and 2mm (extension position). In addition, space available for the spinal cord was 11mm. But there was no spinal stenosis between C2 and C7.
In this paper, we focused on the size of the atlas of this case, and discussed it.
