Symptomatic atlantoaxial subluxation in persons with Down syndrome.

In a prospective study 40 of 236 individuals with Down syndrome were found to have atlantoaxial instability. Whereas most of the 40 affected children were asymptomatic, seven patients exhibited various neuropathology. Historical data, neurologic findings, radiologic interpretations, and surgical management of these seven patients are described in detail. In addition, case reports of other individuals with Down syndrome and symptomatic atlantoaxial subluxation from the literature were analyzed. We conclude that early identification of these patients and appropriate surgical management, including reduction of the subluxation and posterior cervical spine fusion, will in most instances result in a favorable outcome; however, patients with long-standing symptoms and marked neuronal damage show no or only little improvement postoperatively.