Cervical spine MRI findings in patients with Mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is an X-linked, recessive, lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (EC 3.1.6.13). The purpose of this report is to describe cervical spine magnetic resonance (MRI) findings in MPS II patients and to correlate them with clinical phenotype. Seven cervical spine MRI examinations from Polish MPS II patients (mean age 11.4 years, median age 8 years, range 5-30) were evaluated. Six patients were classified as neurological (85.7%) and 1 as attenuated (14.3%). Five patients were treated with idursulfase (range 110-260 weeks, mean 195, median 200), while 2 patients never received the treatment. The following features were assessed: periodontoid thickening, spinal stenosis, dens hypoplasia, myelopathy, and vertebral and intervertebral disc abnormalities. Mean age at evaluation was 11 years (range 5-30, median 8). Cervical spine MRI was abnormal in all the patients and the most frequent abnormalities found were dens hypoplasia (100%), periodontoid thickening (100%), disc abnormalities (100%) and spinal stenosis (43%). There was no clear correlation between MRI findings and patients' phenotypes.