Case 24
History:
12 year old male with mental retardation, short stature, head and neck pain.
Findings:
Brain MRI showing diffuse bilateral dilatation of the perivascular spaces. In addition, there is cord compression at C1—C2 secondary to focal dural thickening resulting in cord edema and/or gliosis.
Diagnosis:
Discussion:
Hunter syndrome (HS) is an inherited metabolic disorder secondary to a deficiency of lysosomal enzymes required for the degradation of mucopolysaccharides. The inheritance is X-linked recessive, meaning that women carry the disease and pass it most often to their sons but the mothers aren’t affected by the disease.
There classically are two forms of HS: a severe form, or type A, (usually diagnosed between 2 and 4 years of age), and a milder form, or type B (usually diagnosed around the teenage years). Suggestive clinical features may include coarse faces including thickening of the lips, tongue and nostrils, a short stature, bony deformities, organomegaly, joint stiffness, vision loss or impairment and mental retardation. Atlantoaxial subluxation may occur as a result of transverse ligament laxity or hypoplasia or absence of the dense. Flexion extension views are necessary. Another cause of cord compression is dural thickening from intradural collagen and mucosaccharidoses deposition usually at C1-C2 as in our case. The vertebral bodies may show a wedge-shaped appearance with blunted spinous processes.
References:
- Murata R, Nakajima S, Tanaka A, et al. MR imaging of the brain in patients with mucopolysaccharidosis. AJNR Am J Neuroradiol 1989;10:1165–1170.
- Banna M. Compressive meningeal hypertrophy in mucopolysaccharidosis. AJNR Am J Neuroradiol 1987;8:385–386.
- Kulkarni MV, Williams JC, Yeakley JW, et al. Magnetic resonance imaging in the diagnosis of the cranio-cervical manifestations of mucopolysaccharidoses. Magn Reson Imaging 1987;5:317–323.
