Anatomic Anomalies Common to Myelomeningocele of Infancy and Syringomyelia of Adulthood Suggest a Common Origin
THE fact that an infant with myelomeningocele may have a syrinx in association with the Arnold-Chiari malformation,1,2 together with the fact that this same association occurs in the adult with syringomyelia3–6 led to a search of the literature for other anatomic anomalies shared by the infant with myelomeningocele and the adult with syringomyelia. This search revealed that each may have hydrocephalus, hydromyelia (dilatation of the central canal), syringomyelia (syrinx or cavity paralleling the central canal), Arnold-Chiari malformation, Dandy-Walker malformation, membranes enclosing the foramens of the fourth ventricle, glial heterotopia, and skeletal anomalies—scoliosis, hemivertebra, fused vertebrae, anomalous ribs, deformity of the feet, enlargement of the skull and of the vertebral canal.
In most cases of myelomeningocele there is increased intracranial pressure and progressive dilatation of the ventricles, indicating an uncompensated hydrocephalus. This hydrocephalus may be of the communicating or of the noncommunicating variety.7 It is not widely known that syringomyelia in the adult may be accompanied by dilated ventricles but with normal intracranial pressure, i.e., compensated hydrocephalus. Netsky8 found dilatation of the ventricles in three of four cases of syringomyelia in which the brain was examined at necropsy (Fig. 1). Encephalography likewise will show that the ventricles frequently are dilated in patients with syringomyelia and that they may or may not communicate with the subarachnoid space.3–5 Thus, we find that hydrocephalus occurs both in the infant with myelomeningocele, and in the adult with syringomyelia, and that it may be communicating or noncommunicating. The conditions differ in that. . .