Cochlear implantation effective in treating children with Pendred syndrome

Pendred syndrome is an autosomal recessive disorder that is classically defined by the combination of sensorineural deafness/hearing impairment, goiter, and an abnormal organification of iodide with or without hypothyroidism.

The hallmark of the syndrome is the impaired hearing, which is associated with inner ear malformations such as an enlarged vestibular aqueduct (EVA). The thyroid phenotype is variable and may be modified by the nutritional iodine intake.

Pendred syndrome is caused by biallelic mutations in the SLC26A4/PDS gene, which encodes the multifunctional anion exchanger pendrin. Pendrin has affinity for chloride, iodide, and bicarbonate, among other anions.

However, in the inner ear, pendrin functions as a chloride/bicarbonate exchanger that is essential for maintaining the composition and the potential of the endolymph. While, in the thyroid, pendrin is expressed at the apical membrane of thyroid cells facing the follicular lumen.

Taylor E.Patterson and associates from the University of Mississippi School of Medicine, United States of America examined the outcomes of cochlear implantation in children with Pendred Syndrome.

A retrospective case series of nine pediatric patients with Pendred syndrome undergoing cochlear implantation at a tertiary academic medical center was carried out.

All patients were diagnosed with bilateral mild-to-profound to severe-to-profound sensorineural hearing loss and used hearing aids prior to implantation. Preoperative imaging results revealed that all patients exhibited bilateral enlarged vestibular aqueducts and 8 of 9 had cochlear dysplasia equivalent to Incomplete Partition II.

Despite inner ear malformations, all electrodes were successfully implanted with minimal complications and favorable post-operative audiological outcomes.

As a result, the authors concluded that with early intervention, cochlear implantation allows speech and cognitive development in Pendred children comparable to that of normal hearing individuals, allowing patients to learn in a mainstream educational setting.

Therefore, they further inferred that cochlear implantation is an effective and successful treatment for severe-to-profound hearing loss in children with Pendred syndrome and for whom traditional amplification aids provide limited benefit.

https://doi.org/10.1016/j.amjoto.2021.103087