The mucopolysaccharidoses (MPSs), which constitute a hereditary subgroup of the lysosomal storage disorders, have distinctive cerebral manifestations.
The mucopolysaccharidoses are characterised by excessive accumulation of mucopolysaccharides secondary to deficiencies in specific enzymes (lysosomal hydrolases) responsible for degradation of mucopolysaccharides (also known as glycosaminoglycans) 1.
For a general discussion of the underlying condition, please refer to the article mucopolysaccharidoses.
Radiologic features
MRI
Their characteristic neuroimaging features are best appreciated on MRI 2.
Brain
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perivascular (Virchow-Robin) spaces dilatation:
usually seen within the periventricular/peritrigonal white matter, corpus callosum, basal ganglia, subcortical white matter, thalami, or brainstem
the spaces usually have a radial orientation from the subependymal region toward the cortex 2
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one of the most common findings
appear as focal or confluent areas of T2/FLAIR hyperintensity, sometimes coalescent and large, simulating leukodystrophy
lesions usually occur within the periventricular white matter but can also occur in the subcortical white matter; lesions frequently start at the peritrigonal regions
hydrocephalus: usually communicating; slowly progressive and typically manifests as ventricular and subarachnoid space dilatation
brain atrophy: common
Musculoskeletal
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skull abnormalities:
e.g. thickening of the diploe, skull base abnormalities (such as a J-shaped sella), and macrocephaly
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cervical spinal canal stenosis:
usually occurs at the level of the atlantoaxial joint; a dysplastic odontoid process associated with surrounding soft-tissue thickening is also common
can occur in the thoracic and/or lumbar spine
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other spinal manifestations:
e.g. wedge-shaped vertebrae, platyspondyly, anterior beaking and posterior scalloping (bullet-shaped vertebrae), wide disc spaces, scoliosis, and thoracolumbar kyphosis (or gibbus deformity)
Differential diagnosis
Possible considerations include:
Baraitser-Winter cerebrofrontofacial syndrome
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