Collected Papers of the Mayo Clinic Volume 12

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: ...spina bifida; the Greek designation, rachischisis, is customarily reserved for the most marked type of the defect, in which the entire medullary canal fails to close. The defect may appear as a spina bifida cystica or as a spina bifida occulta; the majority are of the cystic type (Fig. 197). Subdivision of the cystic type depends on whether the walls of the tumor include only the membranes of the cord, that is, a meningocele (Fig. 198), or whether they include both the membranes and the cord, a meningomyelocele; the central canal of the cord may be dilated, when the growth is termed a syringomyelocele, or the cord may be turned completely inside out, when the sensory roots come to lie laterad and ventrad to the motor roots. The nomenclature is not uniform. Because of this and because of the difficulty of determining the exact relations by clinical means alone, I have not attempted to classify the cases further than by evidence of accompanying cord involvement, which was found in 67 per cent of the cases (Fig. 197). Presented before the Southern Minnesota Medical Association, Mankato, November. 1920. Reprinted from Minnesota Medicine, 1921, iv, 244-259. 693 A very important condition allied to spina bifida, although it represents only a fraction of such cases, is an analogous developmental defect of the spinal cord, that is myelodysplasia without demonstrable bony defect. It is important from both the biologic and the clinical standpoints. Spina bifida is usually posterior, but may be lateral; it occurs anteriorly (Budde), although very rarely, and then it has an altogether different embryologic significance. Fio. 198.--(Case 329299). Large meningocele without any demonstrable involve ment of the spinal cord. THEORIES OF THE ETIOLOGY The causes for the devel...