Diastematomyelia

This patient presented in her 40s for assessment of possible metastatic malignancy. An incidental finding of diastematomyelia was made. There was associated fusion anomaly of vertebrae at the thoracolumbar junction. A small syrinx was present above the cord split.
At the level shown, the cord is split into two hemicords, and divided by a fibrous or osseous spur.
Diastematomyelia is associated with congenital spinal deformity in 85%, including segmentation anomalies, laminar fusion, dysraphism, tethered cord, thickened filum terminale, and scoliosis. There is an association with Chiari II malformation.
Diastematomyelia may be classified as type I (two separate dural sacs surround each hemicord) or type II (single dural sac and arachnoid space, no osseus spur).

Reference: Ross JS, et al. Diagnostic Imaging: Spine. Amirsys 2004

Credit: Dr Laughlin Dawes