Owing to their frequency and possible consequences and considering the fact they frequently affect young people, trauma tic lesions of the thoraco lumbar spine represent a special point of interest within the field of Neurotraumatology. Traffic accidents are the commonest cause, which accounts for the high peak of occurrence between 15 and 24 years of age. It is also worth noting that according to published series nearly 50% ofthe cases affect the thoraco-lumbar junction. From an anatomical point of view, we must note the severity of thoracic spinal cord lesions especially of the thoraco-lumbar junction and of the lumbar region and be able to associate injuries ofthe conus medullaris and of the ca uda equina where there is a possibility of neurological recovery. Clinical evaluation is not always easy, but remains the basis for diagnosis and prognosis. The neurological classification proposed by FRANKEL et al. in 1969 and used at STOKE MANDEVILLE Hospital seems to retain its value. A more sophisticated study of medullary evoked potentials, as described by TsUBOKAWA can allow a more precise localisation and appreciation of the extent ofthe lesion as well as a better evaluation ofthe prognosis and ofthe evaluation of treatment in the acute phase. The neuro-radiological study should include standard views ofthe whole of the spine with antero-posterior and lateral tomograms of the fractured or luxated area. At present, the unquestionable contribution of the CT.

The Committee of Neurotraumatology of the World Federation of Neurosurgical Societies decided to elaborate a Glossary of Neuro- traumatology, and for this purpose appointed a subgroup of members of this Committee, headed by Dr. E. S. Gurdjian, whose report follows this preface. The main reason for the Committee's decision was the hope that the diffusion of the Glossary through "Acta Neurochirurgica" may bring about a better understanding of neurotraumatological terminology on a worldwide scale. The Glossary should facilitate the classification and the comparison of traumatic lesions of the Nervous System. It will consequently be easier to compile statistics and correctly interpret the informations thus obtained. The very commendable initiative of the Congress of Neurological Surgeons in revising the terminology of head injuries and in publishing this work in Vol. 12 (1966) of "Clinical Neurosurgery" constitutes an important contribution. In 1977 the Glossary now presented endeav- ours to complete and bring up to date the definitions of anatomical or physiological modifications in the neurotraumatological field. We wish to express our thanks to Dr. Gurdjian and to the other members of the Neurotraumatological Committee who were responsible for the elaboration of this Glossary and whose efforts to standardise, as much as possible, the language used by scientists of different nationalities, have resulted in a better understanding between neurosurgeons.