Other than the main cord abnormality, what other features do you note?
Hydromyelia above, and spina bifida.
This condition is classified into two types. Can you describe the main features of each?
Type I: duplicated dural sac, with common midline spur and usually symptomatic; Type II: single dural sac containing both hemicords - impairment less marked. (read related article for more information).
What vertebral anomalies are frequently encountered in these patients?
Hemivertebrae, butterfly vertebrae and spina bifida. Fusion of laminae of adjacent levels is also seen and is said to be characteristic of this condition.
How do patients with type I split cord malformation typically present?
Scoliosis and tethered cord syndrome.
MRI through the lower spinal cord demonstrates an uneven split from T9 to L1. The dura appears to be a single sac without a dividing septum/spur. Above the split the lower thoracic cord demonstrates hydromyelia. L1 and possibly L2 (incomplete images) appear to have unfused lamina (spina bifida).