Computer-tomographic investigations in malformations of the occipito-cervical junction.

The diagnosis of occipito-cervical dysplasias has been improved markedly by computer-tomography. Two millimetre transverse cuts with sagittal and coronal reconstructions are necessary. Based on nine cases with nearly all types of malformations it is shown that even complex osseous (mesodermal) malformations and dysplasias as well as isolated or combined neuroectodermal dysplasic or secondary compressive lesions of the medulla oblongata and cord can be detected. Transverse and AP diameters of the foramen magnum and spinal canal and the classical lines and angles can be measured. This time-consuming procedure will give more information than the classical radiological methods and avoid myelographic and cisternal examinations. Its disadvantages are the impossibility of dynamic functional studies and the length of the procedure.