Diastematomyelia

Diastematomyelia is a combined defect in the development of the spinal canal, consisting in its separation by bone, cartilaginous or fibrous spines or septa, accompanied by splitting and / or doubling of the spinal cord, its elements and membranes. Typical for diastematomy is the tetrad of the following clinical and radiological signs:

1. congenital malformations and dysplasia of limbs.
2. abnormalities of the skin - hemangioma, pigment spots, skin entrainments, local hypertrichosis, etc. Over the spine and in the paravertebral zones;
3. spinal anomalies;
4. widening of the interpedicular distance on the direct X-ray in the zone of the septal localization.

Diastematomyelia is rarely found in the form of an isolated vertebral canal defect. Typically, its combination with violations of segmentation of the vertebrae, less often - with violations of fusion and the formation of posterior structures, spinal hernias. It is possible to combine diastematomy with the voluminous formations of the spinal canal of embryonic origin - dermoids, lipomas, teratomas, dermal sinus.

In the available literature, we were unable to detect classifications of diastematomyelia.

Diastematomyelia (working classification scheme)

Classification features	Clinical and radial variants
Prevalence	Local - within 1-2 vertebral segments, Common - within 3 or more segments.
Morphological structure of the septum	a) bone, b) cartilaginous, c) fibrous, d) mixed
Shape of septum	a) cylindrical, b) mushroom-shaped, c) spiny ("spicule", often occupies only part of the lumen of the spinal canal), d) complex or tumorous
The presence of neurological disorders	A) without neurological disorders, b) with primary neurologic disorders (type of myelodysplasia) Without progression With deepening of symptoms in the process of growth C) with secondary neurologic disorders (by type of myelopathy)
Relationship with the contents of the spinal canal	A) without cleavage of the dura mater, B) with splitting of the dura mater, incl. With cleavage of one of the walls of the dural sac -with the formation of isolated dural sacks C) with isolated splitting of shells and elements of the horse tail, D) with complete splitting of the spinal cord and its membranes (symmetrical or asymmetric)
Localization of the base of the septum relative to the walls of the spinal canal	A) coming from the back surface of the vertebral bodies, B) originating from the lateral wall of the spinal canal, C) originating from the arcs of the vertebrae (posterior wall of the spinal canal).
Character of splitting of the spinal cord	A) actually diastematomyelia, B) Diplemia

[1], [2], [3], [4], [5], [6], [7], [8], [9]