Modiolar ossification in paediatric patients with auditory neuropathy

A systematic review on the imaging findings in auditory neuropathy spectrum disorder

Purpose

The present systematic review examined imaging findings in the Auditory Neuropathy Spectrum Disorder (ANSD) population.

Methods

Electronic databases such as Pub Med, Google Scholar, J Gate, and Science Direct were used to conduct a literature search. The articles retrieved through the literature search were assessed in two stages. In the first stage, title and abstract screening were done; in the second stage, a full-length article review was done. From the 379 shortlisted records, 19 articles were chosen for the full-length review.

Results

The selected articles performed imaging using Computerized tomography (CT) and magnetic resonance imaging (MRI). In most studies, cochlear nerve deficiency (CND) was the most prevalent anomaly in the ANSD group. Also, MRI was the imaging modality of choice recommended in most studies. It was also noted that CND was a characteristic feature of unilateral ANSD.

Conclusion

From this systematic review, it is clear that integrating imaging studies into diagnostic protocol would help to understand the underlying pathology better and expedite decision-making and intervention for ANSD patients.

Findings from aetiological investigation of Auditory Neuropathy Spectrum Disorder in children referred to cochlear implant programs

OBJECTIVES

Auditory neuropathy spectrum disorder (ANSD) is an audiological diagnosis characterised by hearing dysfunction in the presence of intact outer hair cell function in the cochlea. ANSD is thought to account for 7-10% of all childhood permanent hearing impairment, and can result from a range of pathological processes. This paper describes the rationale, methods and findings from the aetiological investigation of ANSD.

METHODS

Retrospective audit of four cochlear implant programmes.

RESULTS

97 patients were identified. 79% of patients were identified before the age of one. Prematurity and jaundice were the most frequently identified aetiological factors. 33 patients had cochlear nerve deficiency on imaging. Genetic diagnoses identified included otoferlin, SX010 gene, connexin 26 and A1FM1 gene mutations. ANSD was seen in conjunction with syndromes including Kallman syndrome, CHARGE syndrome, X-linked deafness, SOTOS syndrome, Brown Vieletto Van Laere syndrome, and CAPOS syndrome.

DISCUSSION

We present a two-level system of aetiological investigation that is clinically practical. Patients with ANSD sufficiently severe to consider cochlear implantation are generally identified at an early age. Aetiological investigation is important to guide prognosis and identify comorbidity.

CONCLUSION

Prematurity and jaundice are the most commonly identified aetiological factors in ANSD. Imaging findings identify crucial factors in a significant minority. An important minority may have genetic and syndromic diagnoses that require further management.