Diastematomyelia (occasionally diastomyelia) is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra.
The term split cord malformation (SCM) was first introduced in 1992 by Pang et al., in an attempt to resolve the confusion existing in the pathological definition and the clinical significance of previously existing terminologies in the literature, diastematomyelia and diplomyelia, and the inconsistent usage of these two terms 1).
Diastematomyelia is a rare congenital anomaly that results in the “splitting” of the spinal cord in a longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous (bone), cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as a Diplomyelia, or true duplication of the spinal cord.