An unusual form of occipitocervical assimilation presenting with spastic tetraparesis in a child.

A diagnosis of 'cerebral palsy' in childhood is relatively common. Abnormalities of the upper cervical spine causing spinal cord compression are rare, but can be a cause of symptoms and signs that may otherwise be attributed to brain injury acquired during development. We present an interesting case of a congenital abnormality of the atlas causing severe cervical spinal cord compression in a 9-year-old child, together with a discussion of the relevant aspects of spinal development and a review of the literature.