Hunter syndrome

Cervical spine: the vertebral bodies have a distinctive morphology, tapered anteriorly. There is partial fusion of the vertebral bodies of C3 and C4 with partial fusion also of the posterior elements at this level. The atlantoaxial articulation is normal.

Thoracic spine: abnormal configuration of the vertebral bodies is again noted, spinal alignment appears satisfactory in the upper mid and lower thoracic spine.

Lumbar spine: the L2 lumbar vertebral body is far more hypoplastic and the adjacent lower thoracic and upper lumbar vertebral bodies causing a marked kyphosis at the L1/L2 level on this lateral erect view. There also appears to be a degree of spondylolisthesis of L5 on S1 and there is probably bilateral pars defects at this level. On these views the lumbosacral articulation and suspected spondylolisthesis of L5 on S1 are not well visualized and formal views of this region in the lateral projection should be performed for better evaluation.

CT demonstrates a tracheostomy and nasogastric tube. The brain is abnormal (see subsequent MRI). Fusion of C3/C4 and hypoplasia of C5, C6 and C7 is present with reversal of normal cervical curvature. The thoracic spine is relatively normal. The lumbar spine, in contrast, has a very hypoplastic L2 vertebral body, anteriorly pointed, with a kyphosis. Bilateral L5 pars defects and anterolisthesis noted. 

There is gross white matter volume loss and hyperintensity throughout the cerebral hemispheres and patchy signal abnormality in the pons. Innumerable tiny CSF spaces most pronounced on the grey-white interfaces, within the basal ganglia, thalamus and midbrain and about the dentate nucleus presumably represent enlarged and perivascular spaces.

The lateral and third ventricles are enlarged. The cerebellar volume is relatively normal.

There is no parenchymal diffusion restriction or susceptibility artefact.

There is developmental fusion across the C3/4 disc space and posterior elements. 

Multiple vertebral body deformities include anterosuperior corner deficiency at numerous levels, for example between C3 and T1, with less marked changes through the thoracic spine. In the lumbar spine, there is a deficiency of the anterosuperior and anteroinferior corners of L2 with an associated mild focal gibbus deformity. L3 and L4 have an anterior beaking appearance. 

There is no abnormal cord signal.

Conus terminates at L1/L2 level. At L5/S1 there is grade 2 anterolisthesis secondary to bilateral pars defects resulting in severe bilateral foraminal stenosis with exiting L5 nerve root compression. The extraforaminal right L5 nerve root is associated with multiloculated cysts.