Brain MRI and hearing loss
Few studies have examined the relationship between non-specific findings on brain MRI and the risk of long-term sequelae in children with sensorineural hearing loss. Chilosi et al. found that 48 out of 100 children with sensorineural hearing loss had neurodevelopmental disorders (5). Additionally, 19 children had language disorders, which were not classified as coexisting impairments in this particular study. The risk of coexisting impairments was twice as high when changes in the white matter were detected on MRI. It was also somewhat higher in the presence of migration disorders (5).
Independent of hearing status, several studies have examined the relationship between non-specific findings on brain MRI in children and the risk of long-term sequelae. The results are highly heterogeneous: 7.9–39.4 % (6–10). Children with known risk for brain injury, but without pathological findings on brain MRI, may also have neurodevelopmental impairments (11).
The divergent results may explain why pathological MRI findings alone do not result in children receiving further follow-up. However, methodological differences in image acquisition protocols, and differences in outcome parameters and duration of follow-up make it difficult to compare studies. Technological developments have led to improvements in the diagnostic capabilities of brain MRI compared to 20–30 years ago. There is a need for studies with longer follow-up (to school age, possibly adolescence), and which examine balance, coordination, vision, cognition and psychopathology.
Dettmann et al. found that children with sensorineural hearing loss attributable to environmental factors have poorer receptive language standard scores after cochlear implant surgery than children with genetic non-syndromic hearing loss, as well as a higher degree of comorbidity (59 % vs. 8 %) (12).
There is international consensus that early diagnosis and follow-up of hearing loss in children is important for the children to achieve good language outcomes (13, 14). Other factors shown to have a positive impact on language acquisition include high maternal educational level and the absence of coexisting impairments in the child (14). However, many of the children have poor language acquisition of unknown aetiology. Examining brain MRI and aetiological factors might contribute to a better understanding.