Options for hearing rehabilitation in children with cochleovestibular nerve dysplasia

Abstract

Introduction Nowadays, children with limited abilities to develop open-speech understanding are considered as cochlear implant candidates. Children with anatomical abnormalities of the inner ear and particularly with deficiency of the cochleovestibular nerve (CVN) represent such great challenges. The achievement of speech development in these patients may be impossible (Nikolopoulos and Kiprouli, 2004). In 1997, Casselman et al. described for the first time the malformations of CVN, with the help of magnetic resonance imaging (MRI). A classification of abnormalities of three types, based on embryologic knowledge, was proposed. Type one includes aplasia of the CVN which is associated with stenosis of the internal auditory canal. Type two describes common CVN with aplasia or hypoplasia of its cochlear branch and finally type three refers to the presence of a common CVN with aplasia or hypoplasia of the vestibular branch (Casselman et al., 1997). Due to the wide use of MRI, CVN dysplasias were better identified and examined (Adunka et al., 2006). In this way, different methods of diagnostic assessment and therapeutic intervention were suggested in case series, presenting each of them one sole solution to the problem, either cochlear or auditory brainstem implantation (Govaerts et al., 2003; Colletti and Zoccante, 2008; Song et al., 2010). Systematic approach and universally established algorithms are still missing, though. The aim of this study was to present a variety of diagnostic and treatment options when dealing with CVN dysplasia.