Cervical myelopathy secondary to atlas hypoplasia - reports of 3 adult cases

There have been paucity of reports on atlas hypoplasia, and as a result this condition is not clearly defined, nor well understood. The authors reported three cases of atlas hypoplasia that were found in adults who presented with myelopathic symptoms. On radiographic examination, it was found that the anterior-posterior diameter of the atlas was remarkably narrower in all three cases in comparison with normal persons. The MRI in all three cases also revealed intramedullary high signal lesions at the levels where severe spinal cord compression was present. This led to our diagnosis of atlas hypoplasia causing myelopathy.