Surgical management of cervicomedullary compression in achondroplasia.

Achondroplasia is often associated with cervicomedullary dysfunction. MRI sagittal imaging was performed to determine whether surgical intervention was necessary to relieve cervicomedullary compression. Cervicomedullary compression was classified into severe and mild types based on the ratios of the brain stem diameter at the foramen magnum, the site of the most severe stenosis to the diameter at the pontomedullary junction and C3 level, where it is normal. This classification was found to be closely correlated with the severity of clinical symptoms and important in determining whether surgical intervention is necessary. Moreover, since the incidence of sudden death is high in patients aged 4 years or younger with achondroplasia, surgical intervention should be considered in all such patients if cervicomedullary compression is present.