Pediatric Sensorineural Hearing Loss, Part 2: Syndromic and Acquired Causes

Abstract

SUMMARY:This article is the second in a 2-part series reviewing neuroimaging in childhood SNHL. Previously, we discussed the clinical work-up of children with hearing impairment, the classification of inner ear malformations, and congenital nonsyndromic causes of hearing loss. Here, we review and illustrate the most common syndromic hereditary and acquired causes of childhood SNHL, with an emphasis on entities that demonstrate inner ear abnormalities on cross-sectional imaging. Syndromes discussed include BOR syndrome, CHARGE syndrome, Pendred syndrome, Waardenburg syndrome, and X-linked hearing loss with stapes gusher. We conclude the article with a review of acquired causes of childhood SNHL, including infections, trauma, and neoplasms.ABBREVIATIONS: BOR ϭ branchio-oto-renal; CISS ϭ constructive interference in steady state; IAC ϭ internal auditory canal; NF-2 ϭ neurofibromatosis type II; SCC ϭ semicircular canal; SNHL ϭ sensorineural hearing loss; T1WI ϭ T1-weighted image; T2WI ϭ T2-weighted image T he estimated prevalence of SNHL in patients younger than 18 years of age is 6 per 1000, 1 making it one of the leading causes of childhood disability and a common reason for otolaryngology referrals. Cross-sectional imaging is now routinely performed in these patients because it provides important information about potential etiologies for hearing loss, defines the anatomy of the temporal bone and the central auditory pathway, and identifies additional intracranial abnormalities that may require further work-up. In the first part of our series, we reviewed some of the practical aspects related to imaging children with SNHL, including epidemiology, clinical work-up, and choices of imaging technique; we also discussed the classification of congenital inner ear malformations and congenital nonsyndromic causes of SNHL. In this article, we continue our discussion of neuroimaging for childhood SNHL, focusing on several of the most common syndromic hereditary forms of SNHL as well as acquired causes of hearing loss.

Spectrum of Temporal Bone Abnormalities in Patients with Waardenburg Syndrome andSOX10Mutations

“…Total absence of the SCCs is found in coloboma, heart malformation, choanal atresia, growth retardation, genital hypoplasia, and ear abnormalities (CHARGE) syndrome, often with a hypoplastic vestibule and variable cochlear deformities, including abnormal partitioning; moreover, cochlear nerve canal atresia with cochlear nerve aplasia is common. 10,24 While absence of all the SCCs is more common, absence of only 1 or 2 has also been described in CHARGE. 25 Nevertheless, abnormalities of the middle ear structures, such as ossicular malformations, facial canal malposition, and oval window aplasia, are usually associated, 24 and the clinical spectrum in CHARGE is different from that in WS.…”

“…[3][4][5] Characteristic radiologic abnormalities of the temporal bone have been reported in a subset of patients, [6][7][8][9] enabling imaging to contribute to the differential diagnosis of syndromic SNHL. 10 Because none of these studies included mo-lecular analyses, however, these inner ear malformations have not been linked to a particular molecular defect. WS is clinically and genetically heterogeneous (for a review see Pingault et al 2 ).…”

Genetic Hearing Loss Associated with Craniofacial Abnormalities

“…Inner and middle ear anomalies ranges from cochlear hypoplasia, semicircular canals hypoplasia, ossicular anomalies, external auditory canal stenosis or atresia, vestibular displasia, enlarged aqueductus or endolymphatic sac (the last seems to predispose to more severe hearing impairment), absence of stapedium muscle or Eustachian tube dilation and cochlear nerve deficiency. (Huang et al, 2011;Kemperman et al, 2004) …”

Spectrum of Third Window Abnormalities: Semicircular Canal Dehiscence and Beyond

“…40,41 Female carriers of the gene may be healthy or may have less severe hearing loss. 42,43 The spectrum of abnormalities on CT includes cochlear hypoplasia with modiolar deficiency, absence of the lamina cribrosa, an enlarged internal auditory canal, and an enlarged labyrinthine facial nerve canal (Fig 14). [44][45][46][47] On audiometry, patients with X-linked stapes gusher typically demonstrate a mixed hearing loss.…”