mercoledì 5 marzo 2008
Diastematomyelia of cervical spine
T2 images demonstrate complete splitting of the cervical spinal cord into 2 complete hemicords without associated syrinx. The cord splits just caudal to the medulla and reunites distally at the upper thoracic spine. There are associated cervical segmentation anomalies, including intersegmental laminar and vertebral body fusion, without a dividing spur.
Diagnosis: Diastematomyelia of cervical spine
Diastematomyelia usually presents in childhood with a female predilection. Adult presentation is rare, but when patients present older, there is a slight male predilection. Patients usually present with stable or progressive disability, scoliosis, and neurologic and muscular abnormalities. Often, Diastematomyelia is clinically indistinguishable from a tethered cord.
Treatment consists of surgical tethered cord release, spur resection, scoliosis correction, and dural repair.
Diastematomyelia occurs between T9 and S1 85% of the time.
Diastematomyelia often occurs when a fibrous osseous spur splits the cord sagittally into 2 hemicords that usually unite cranial and caudal to the cleft. In the patient presented above, the salient lesion was a lipoma, which was surgically resected.
85 % of Diastematomyelia patients have associated congenital spinal anomalies such as segmentation and fusion anomalies, intersegmental laminar fusion, dysraphism, tethered cord, syringohydromyelia, scoliosis, and Chiari II malformations. Intersegmental laminar fusion is virtually pathognomonic.
Meningocele manqué – Tethered cord due to nerve roots adhering to the dura.
Half of diastematomyelia patients present with cutaneous stigmata such as a "fawn's tail" hair patch at the level of the lesion.
Type I Split cord malformation
- Separate dural sac
- Osseous spur
- More commonly symptomatic
Type II Split cord malformation
- Single dural sac
- No osseous spur, may see adherent fibrous bands tethering cord
- Usually asymptomatic unless associated with tethering or hydromyelia