Posterior fossa horns; a new calvarial finding of mucopolysaccharidoses with well-known cranial MRI features

Abstract

Background/aim: Mucopolysaccharidoses (MPS) are a group of hereditary metabolic diseases. The aim of this study was to share the previously unreported calvarial finding of internal hypertrophy of the occipitomastoid sutures (IHOMS) together with some other wellknown cranial MRI findings in this patient series. Materials and methods:A retrospective evaluation was conducted of 80 cranial MRIs of patients who had been diagnosed and followed up with MPS from 2008 to 2019 in our center. Of these patients, 11 had Hurler, 14 had Hunter, 24 had Sanfilippo, 15 had Morquio, 14 had Maroteaux-Lamy, and 2 had Sly disease. The cranial MRIs were assessed in two main groups as parenchymal intradural cranial MRI findings and extradural calvarial findings. Results:The most common parenchymal intradural cranial MRI findings were white matter signal alterations (n = 51, 63%) and perivascular space enlargements (n = 39, 48%). The most common extradural calvarial findings were J-shaped sella (n = 45, 56%) and tympanic effusion (n = 44, 55%). Although IHOMS was defined in a relatively small number of the patients (n = 12, 15%), the prevalence rate was high in MPS type I (n = 6, 54%). Conclusion:The abnormal cranial MRI findings of the MPS patients, including the newly identified IHOMS, may provide diagnostic clues to differentiate the type of the disease in radiological imaging.

Mucopolysaccharidosis Type 1 among Children—Neuroradiological Perspective Based on Single Centre Experience and Literature Review

“…Other cranial deformities were also noticed. Having analysed a complex group of MPS patients, they concluded that cranial pathologies might help in differentiating MPS types [ 33 ]. Similarly to Damar, IHOMS of varying expression degree were detected in all five of our children.…”

“…Enlarged PVS are isointense to cerebrospinal fluid (CSF) and were reported within the white matter (WM), corpus callosum (CC), basal ganglia and brainstem. Among these, the involvement of CC appears to be the most distinctive upon comparison of MPS 1 patients and healthy controls [ 33 ]. A reduced CC volume had been reported among Hurler syndrome patients, standing out from attenuated phenotypes, and even more markedly from the healthy control group [ 34 ].…”