What is demonstrated in the cord, and why is this present?
A syrinx is present due to abnormal CSF flow secondary to crowding of the foramen magnum and low lying cerebellar tonsils, which in this case extend down to C2.
What other congenital spinal abnormality is present (frequently seen in patients with Chiari II malformation)?
Congenital fusion of C3 and C4.
What abnormality are you expecting in the lumbosacral spine?
Spina bifeda aperta / myelomeningocoele and a tethered cord.
The low lying tonsils in the foramen magnum are noted and the cervical spine shows a local syrinx between C6 - T2. Additionally, the C3 and C4 vertebral bodies are congenitally fused.