Radiologic and neuroradiologic findings in the mucopolysaccharidoses

The mucopolysaccharidoses (MPS) represent a group of inheritable, clinically heterogeneous lysosomal storage disorders, in which progressive accumulation of glycosaminoglycans (GAGs) can affect organs and tissues all over the body. The current paper discusses the skeletal X-ray and neuroimaging findings in MPS patients, and the imaging techniques that can be used for diagnosing and monitoring abnormalities in the skeleton and central nervous system. Most MPS types show a typical radiologic expression, called dysostosis multiplex, which manifests as malformations of the skeletal system involving bones in the skull, thorax, spine, pelvis, long bones, and hands. Abnormalities of the spine and GAG deposits in the meninges surrounding the spinal cord can result in spinal cord compression, which, if untreated, can lead to compressive myelopathy. Magnetic resonance imaging (MRI) is the most powerful imaging technique for detecting spinal cord compression, but also radiography and computed tomography are useful. GAG deposits in the brain and surrounding tissues can result in brain anomalies, i.e. white matter lesions, brain atrophy, and hydrocephalus, which can be detected using MRI. Skeletal X-ray and neuroimaging findings can play an important role in diagnosis, follow-up, surgical or medical planning, and assessment of treatment response in MPS patients. There is a need for standardized procedures in evaluating and monitoring neurologic complications in these patients.