[Changes in the cranio-cervical junction in Down's syndrome].

Twenty-eight subjects with Down syndrome, 9-29 years old, were examined for instability of the cervical spine at the atlanto-axial and atlanto-occipital joints. This region was studied by evaluating the atlanto-odontoid space and the basilar line both in neutral position and during functional movements. Two patients (7.2%) presented atlanto-axial anomalies, while 3 patients (10.7%) showed atlanto-occipital instability. Clinical goniometric measurements demonstrated specific and significant improvement in the extension movement of Down patients, when compared to the control group.