A Prospective Study of Etiology and Auditory Profiles in Infants with Congenital Unilateral Sensorineural Hearing Loss

Abstract

Congenital unilateral sensorineural hearing loss (uSNHL) is associated with speech-language delays and academic difficulties. Yet, controversy exists in the choice of diagnosis and intervention methods. A cross-sectional prospective design was used to study hearing loss cause in twenty infants with congenital uSNHL consecutively recruited from a universal neonatal hearing-screening program. All normal-hearing ears showed ≤20 dB nHL auditory brainstem response (ABR) thresholds (ABRthrs). The impaired ear median ABRthr was 55 dB nHL, where 40% had no recordable ABRthr. None of the subjects tested positive for congenital cytomegalovirus (CMV) infection. Fourteen subjects agreed to participate in magnetic resonance imaging (MRI). Malformations were common for all degrees of uSNHL and found in 64% of all scans. Half of the MRIs demonstrated cochlear nerve aplasia or severe hypoplasia and 29% showed inner ear malformations. Impaired ear and normal-hearing ear ABR input/output functions on a group level for subjects with ABRthrs < 90 dB nHL were parallel shifted. A significant difference in interaural acoustic reflex thresholds (ARTs) existed. In congenital uSNHL, MRI is powerful in finding a possible hearing loss cause, while congenital CMV infection may be relatively uncommon. ABRs and ARTs indicated an absence of loudness recruitment, with implications for further research on hearing devices.

Genetic Underpinnings and Audiological Characteristics in Children with Unilateral Sensorineural Hearing Loss

“…For patients without a definite genetic diagnosis in this study, CND accounted for 64.3% of their etiologies, and cCMV infection was responsible for a small proportion of USNHL cases (Supplemental Figure S1). Our results are compatible with previous findings that CND and inner ear malformations are common causes of USNHL 48 . Nevertheless, there may still be genetic determinants that underlie these two origins.…”

Congenital Nonprofound Bilateral Sensorineural Hearing Loss in Children: Comprehensive Characterization of Auditory Function and Hearing Aid Benefit

“…However, three subjects did not like to, or could not, complete or participate in the MRI, which limits the conclusions possible to draw from the MRI. (For a completely different study group, the congenital unilateral SNHL as identified at birth, MRI revealed malformations in 64% of all scans [ 93 ].)…”

A Prospective Study of Genetic Variants in Infants with Congenital Unilateral Sensorineural Hearing Loss

“…The subjects were recruited from a UNHS program based on multiple transient-evoked otoacoustic emission (TEOAE) recordings and an automatic auditory brainstem response (aABR) (Region Stockholm, years 2019–2020, newborns screened estimated to ≈51,600 [ 20 ]). The UNHS program [ 2 , 20 , 21 , 22 , 23 ], and the multiple steps that were undertaken to invite all children with uSNHL born during this 2 year period have been described in detail elsewhere [ 20 ].…”

“…The results of the auditory tests (ABRs, TEOAEs, distortion-product OAEs (DPOAEs), tympanograms, and acoustic reflex thresholds (ARTs)), and congenital cytomegalovirus (CMV) infection testing at the first visit has been described previously [ 20 ]. An experienced otologist also performed otomicroscopy on all subjects.…”

“…The aim was to describe genetic causes for congenital uSNHL in detail in a representative sample of infants with congenital uSNHL born in a developed country (i.e., Sweden), and to describe these findings together with previously published auditory profiles and magnetic resonance imaging (MRI) results [ 20 ].…”