J Int Adv Otol 2016; 12(2): 161-5 • DOI: 10.5152/iao.2016.2439 Original Article INTRODUCTION As the most common pathology among congenital neural pathologies, hearing loss may cause various problems in every stage of life [1] . Hearing loss afects 1–3 of every 1,000 infants and 11% of school-aged children [2] . Regarding unilateral sensorineural hearing loss (USNHL), the condition afects 3% of school-aged children [3] . As neonatal screening has become widespread, more realistic results pertaining to the incidence of hearing loss have been obtained. In a study conducted in Finland, the prevalence of USNHL was found to be 1.7 per 1,000 infants [4] . The incidence of bilateral hearing loss in infants was found to be 3.32% and that of unilateral hearing loss was found to be 1.40% in a study conducted at Eskişehir Turkey [5] . Bilateral hearing loss shows its signs in the early stages because of the impairment of language development; however, because the child continues to communicate through the intact ear, the diagnosis of USNHL may be delayed until the primary school period [6] . Children with USNHL do not have the advantage of binaural hearing and thus have a difculty with auditory perception. Because the vestibular system may also be afected in cases with USNHL, imbalance and vertigo may also be present [1] . All of these negative efects may manifest in low academic performance, difculties in social life, and lack of self-confdence [3, 7-11] . Although many examinations are conducted in cases of SNHL to determine the etiology, it is not always possible to obtain a defnite result. Because inner ear anomalies and mass lesions are more common risk factors for USNHL than bilateral hearing loss, computed tomography (CT) and magnetic resonance imaging (MRI) investigations are necessary [12] . In unilateral hearing loss, the vestibular system is generally afected in addition to the cochlea. Clinical fndings may vary, but the vestibular impairment may be asymptomatic because of central compensation. When the vertigo becomes symptomatic, the phys- ical and emotional health of the child is adversely afected [13] . Corresponding Address: Leman Birdane E-mail: lemanvezir@yahoo.com Submitted: 28.03.2016 Accepted: 01.04.2016 ©Copyright 2016 by The European Academy of Otology and Neurotology and The Politzer Society - Available online at www.advancedotology.org Evaluation of the Vestibular System and Etiology in Children with Unilateral Sensorineural Hearing Loss OBJECTIVE: The aim of this study was to evaluate the vestibular system of children with unilateral sensorineural hearing loss (USNHL), investigate the etiological factors of USNHL and analyze whether a genetic predisposition exists. MATERIALS and METHODS: Thirty-three children aged less than 18 years with USNHL, who visited the ear, nose, and throat (ENT) department between January 2004 and December 2012, were included in this study. Cases with conductive hearing loss were excluded from the study. The patients were subjected to etiologic, genetic, and ophthalmologic evaluation; radiologic imaging; electronystagmography (ENG); and vestibular evoked myogenic potential (VEMP) tests. The control group, which included 25 healthy children (13 males and 12 females), had undergone audi- ological assessment and were subjected to ENG and VEMP tests. RESULTS: All of the patients had severe-to-profound hearing loss. Mumps immunoglobulin G was positive in 22 (66.7%) of 33 patients. The 35delG mutation was not found in any of the patients. All of the patients underwent temporal computed tomography (CT) and magnetic resonance im- aging (MRI). Inner ear anomaly was present in 51.5% of the patients. Overall, 21 of 31 ENG patients had canal paresis in the afected ear. The VEMP response was absent on the afected side in three patients. The n23 latency average of the patient group was longer than that of the control group. CONCLUSION: Because USNHL causes irreversible problems in children, early diagnosis and auditory rehabilitation are very important. As USNHL is accompanied by inner ear anomaly, children with USNHL should undergo temporal bone CT and MRI. To evaluate the vestibular system, ENG and VEMP are non-invasive and diagnostic tests. KEYWORDS: Children with unilateral hearing loss, electronystagmography, vestibular evoked myogenic potentials Leman Birdane, Armağan İncesulu, Erkan Özüdoğru, Cemal Cingi, Hamdi Caklı, Melek Kezban Gürbüz, Baki Adapınar Department of Otorhinolaryngology, Yunus Emre State Hospital, Eskişehir, Turkey (LB) Department of Otorhinolaryngology, Eskişehir Osmangazi University School of Medicine, Eskişehir, Turkey (Aİ, EÖ, CC, HC, MKG) Department of Radiology, Eskişehir Osmangazi University School of Medicine, Eskişehir, Turkey (BA) 161