The early diagnosis of tumours of the cauda equina.

At present low backache, pain in the distribution of the lower lumbar or first sacral roots, or the combination of these symptoms, are so often found to be due to protrusion of an intervertebral disc that other and less frequent causes may be forgotten. The protruded disc often causes symptoms in the form of recurrent lumbago over a period of many years before symptoms of root compression appear, and then as a rule only a single root is affected. There are, however, exceptions to these general rules. The protrusion may cause root compression without preceding backache, and if it be centrally placed may compress the cauda equina. The symptoms may then be hardly distinguishable from those of some other space-occupying lesion such as a tumour. The majority of tumours of the cauda equina are benign and easily removable. They often cause pain and other symptoms for some time before there are any abnormal physical signs, and when such signs are present they may markedly resemble those of a protruded disc. The purpose of the present paper is to analyse the symptoms and signs in a series of 20 proved cases of cauda equina tumours with special emphasis upon the differential diagnosis from disc protrusion.