Inner Ear Malformations and Unilateral Sensorineural Hearing Loss-the Elephant in the Room

A Case Report of Malignant Cerebellopontine Angle Lesion Highlighting the Interdisciplinary Diagnostic Challenge in the Case of Unilateral Progressive Hearing Loss

The authors present the case of a young boy who experienced progressive unilateral hearing loss initially believed to be unrelated to any other medical condition. Methods: The patient received a thorough evaluation, which included a comprehensive battery of audiological tests, a CT scan, and a gadolinium-enhanced MRI. Results: A repeated imaging investigation revealed the presence of a mass that mimicked a vestibular schwannoma (VS), but despite this, the boy was ultimately diagnosed with cerebral manifestations of B-cell acute lymphoblastic leukemia (B-ALL). Conclusions: Cerebral lesions originating from the internal auditory canal are rare in cases of B-ALL. In this case, the initial signs and symptoms of the disease were solely related to the audiovestibular system, making the diagnostic process particularly complicated. Unilateral hearing loss cases may indicate the presence of potentially life-threatening conditions, even if the hearing loss appears to be clinically non-syndromic. For these reasons, unilateral hearing losses necessitate a comprehensive interdisciplinary diagnostic approach from the very start of auditory manifestation and, in particular, if the hearing impairment demonstrates threshold progression.

Correlation of cochlear aperture stenosis with cochlear nerve deficiency in congenital unilateral hearing loss and prognostic relevance for cochlear implantation

The use of neonatal hearing screening has enabled the identification of congenital unilateral sensorineural hearing loss (USNHL) immediately after birth, and today there are several intervention options available to minimize potential adverse effects of this disease, including cochlear implantation. This study aims to analyze the characteristics of the inner ear of a homogeneous group of congenital non-syndromic USNHL to highlight the features of the inner ear, which can help in clinical, surgical, and rehabilitative decision-making. A retrospective chart review was carried out at a tertiary referral center. Systematic diagnostic work-up and rigorous inclusion-exclusion criteria were applied to 126 children with unilateral hearing impairment, leading to a selection of 39 strictly congenital and non-syndromic USNHL cases, undergoing computed tomography (CT) and magnetic resonance (MR) imaging studies. The frequency and type of malformations of the inner ear in USNHL and unaffected contralateral ears were assessed, with an in-depth analysis of the deficiency of the cochlear nerve (CND), the internal auditory canal (IAC) and the cochlear aperture (CA). Inner ear anomalies were found in 18 out of 39 (46%) of the USNHL patients. In 1 subject, the anomalies were bilateral, and the CND resulted in the predominant identified defect (78% of our abnormal case series), frequently associated with CA stenosis. Only 3 out of 14 children with CND presented stenosis of the IAC. CND and CA stenosis (and to a much lesser extent IAC stenosis) are a frequent association within congenital and non-syndromic USNHL that could represent a distinct pathological entity affecting otherwise healthy infants. In the context of a diagnostic work-up, the evaluation with CT and MRI measurements should take place in a shared decision-making setting with thorough counseling. Both imaging techniques have proven useful in differentiating the cases that will most likely benefit from the cochlear implant, from those with potentially poor implant performance.

Rare Causes of Unilateral Sensorineural Hearing Loss in Adults: Our Experience

Bilateral hearing loss is attributed to almost 50% of times with genetic etiology, while most unilateral sensorineural hearing loss (USNHL) are not attributable to it. Limited literature is available on epidemiology of USNHL. Etiology of USNHL is very diverse and vast, it ranges from as common as Meniere's disease to as rare as an electric shock injury. A prospective study was carried out to find rare causes of USNHL in adults. In this manuscript, we present a case series of 7 rare etiologies of USNHL in adults like auditory neuropathy, chemoradiotherapy, dialysis-induced SNHL, common cavity inner ear malformation, multiple sclerosis, acute otitis media-induced SNHL and vertebrobasilar dolichoectasia. This study discusses the rare possible etiologies of USNHL that can be easily missed if these are not ruled out properly. We present these cases to consider these heterogeneous and distinct causes of USNHL because of rarity of these etiologies. If such an etiology is diagnosed in time, they may be managed effectively.