Cervical myelopathy in an adult due to atlantoaxial subluxation associated with Down syndrome: a case study.

Atlantoaxial subluxation resulting in cervical myelopathy in patients with Down syndrome has been well documented. The risk of cervical myelopathy is reported to decrease with age, and reports of adult-onset cases are limited. We report an adult patient with Down syndrome who developed cervical myelopathy and was successfully treated by surgery. Because there is little information on this condition with adult onset, we report the features of the radiographic findings. Particular care over the long term should be taken in those who have atlantoaxial subluxation combined with odontoid hypoplasia or accessory ossicles, as they are at particular risk of cervical myelopathy even during adulthood.