Radiology Quiz-What is the Diagnosis?
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%)