(F)

(E)

(D)

(C)

(B)

(A)
Clinical History: Twelve year-old boy who presented with hydrocephalus and scoliosis at an earlier age.
Radiologic Findings: Image (A) is an AP plain film of the chest and abdomen, demonstrating the course of a ventriculo-peritoneal (VP) shunt. Also notable are the child's scoliosis, cervical-spinal dysraphism, and oblique orientation of a bony diastem, radiographed in tangent, in the upper thoracic spine. Image (B) is a lateral radiograph of the child's cervical spine, demonstrating fusion of the posterior elements of the sixth and seventh cervical vertebrae. T1-weighted axial MR images in the cervical (C) and thoracolumbar (D) regions demonstrate the primary finding associated with the entity of diastematomyelia - a longitudinally split spinal cord. The bony diastem, itself, can be noted on axial CT image (E), of the cervical spine. T1-weighted sagittal MR image of the thoracolumbar spine (F) demonstrates the extension of the conal portion of the spinal cord to the level of L4, consistent with cord tethering, along with a syrinx in the lumbar portion of the cord; both findings have been closely associated with the entity of diastematomyelia.
Diagnosis: Diastematomyelia (Type II)
Discussion: The congenital entity of diastematomyelia results from a splitting of the notochord during early development; the etiology of this phenomenon is, at present, uncertain. The result is a complete, longitudinal division of the spinal cord over a variable distance. The abnormality is most frequently encountered in the upper lumbar region, but may occur anywhere else along the length of the spinal cord. Division of the cord is often asymmetrical (i.e.), parasagittal); however, each hemicord possesses it's corresponding anterior and posterior horn cells and ipselateral nerve roots. Two subdivisions are recognized, and are described as follows:
Type I (50%): split cord, surrounded by a normal undivided arachnoid-dural sleeve; no septum (diastem)
Type II (50%): split cord; however, each hemicord is invested by a separate dural sleeve, divided by a fibrous, cartilaginous or bony septum (diastem).
Associated clinical/radiographic findings:
Vertebral anomalies associated with defective neural tubeclosure, resulting in the gamut of spinal dysraphisms.
Tethered cord, thickend filum terminale )75%)
Meningomyelocele
Intra/extradural lipoma
Dermal sinus References: 1. Barkovich, AJ, and Naidich TP. Congenital Anomalies of the Spine.In: Pediatric Neuroimaging, pages 227-271. D Norman, Ed. Raven Press, 1990.
2. Kirkwood, JR. Spine. In: Essentials of Neuroimaging, pages 365-452.Churchill-Livingstone, Inc., 1990.
3. Willing, SJ, Congenital Diseases of the Spine. In: Atlas of Neuroradiology,pages 501-530. WB Saunders Company, 1995.
Submitted by:Alan D. Bortz, M.D.Charles F. Lanzieri, M.D.Robert W. Tarr, M.D.Craig S. Kamen, M.D.