Characterization of Hearing Loss in Children with Mucopolysaccharidosis

Hearing impairment is common in patients with mucopolysaccharidoses (MPS) in the preschool age. Conductive or mixed hearing loss is the most frequent occurrence while the involvement of the inner ear or central auditory pathways may occur in more severe forms. A retrospective review of 82 children with MPS admi ed at the Pediatric Department of the University of Milano Bicocca was performed to determine the inci- dence of otological symptoms. We focused particularly on audiological investigations in a subgroup of 47 children diagnosed before 6 years of age (MPS I, n = 11 patients; MPS II, n = 10; MPS III, n = 7; MPS IV, n = 14; MPS VI, n = 5). In 37 children, a magnetic resonance imaging (MRI) of the brain and cervical spine was also performed in order to correlate the audiological ndings with the imaging of the middle and inner ear. A total of 40 out of 47 children (86%) showed some degree of hearing impairment: sensorineural or mixed hearing loss in 23 cases (48.93%) and retrocochlear in 4 (8.51%). MRI ascertained mul- tiple CNS abnormalities in 13 (35.3%): dilated perivascular spaces in 5 (38.5%); dilated ventricular cavities in 5 (38.5%); demyelinated and gliotic areas in 3 (23.0%). Conversely, one-fourth of the children’s inner ears showed some morphological anomaly (24.3%).