Kirkim Gunay, Serbetcioglu Bulent, Erdag Taner Kemal, Ceryan Kerim
Dokuz Eylul Universitesi Tip Fakultesi KBB AD, Inciralti-Izmir 35340, Turkey.
Int J Pediatr Otorhinolaryngol. 2008 Oct;72(10):1461-9. doi: 10.1016/j.ijporl.2008.06.010. Epub 2008 Jul 31.
Auditory neuropathy/auditory dyssynchrony (AN/AD) has become a well-accepted clinical entity. The combined use of oto-acoustic emissions (OAEs) and auditory brainstem response (ABR) testing in the universal newborn hearing screening (UNHS) has led to the easy recognition of this disorder. Although, we are now able to diagnose AN/AD reliably, little is known about its epidemiology, etiology, and especially the frequency of its occurrence. The primary goal of this study was to determine the frequency of AN/AD in the Western Anatolian region of Turkey. The secondary goal was to compare the detection rate of AN/AD before and after the implementation of the UNHS in the audiology department of Dokuz Eylul University Hospital.
Between 2005 and 2007, among the 23,786 newborns who were screened by automated click evoked oto-acoustic emissions (a-CEOAE) and automated auditory brainstem responses (a-ABRs), 2236 were referred to our department. All necessary audiological tests were performed for all the referred newborns. Among them, babies with deficient or abnormal ABR in combination with normal OAEs were considered as having AN/AD. These babies were evaluated with additional diagnostic audiological tests. Furthermore, comparison of the incidence of children diagnosed with AN/AD before and after the implementation of UNHS in our audiology department was also performed.
Among the referred newborns, 65 had abnormal or deficient ABR test results. Ten of these 65 newborn babies (mean diagnostic age: 5.7 months) with hearing impairment showed electrophysiological test results that were consistent with AN/AD. The frequency of AN/AD in these 65 children with hearing loss was 15.38%. Moreover, the frequency of AN/AD within UNHS was found to be 0.044%. Seven of the 10 babies with AN/AD had hyperbilirubinemia as a risk factor, which is a high rate to be emphasized. On the other hand, the retrospective investigation of children diagnosed with AN/AD in the same audiology department between 1999 and 2005 (i.e. before the implementation of UNHS) revealed only 7 children, with an average diagnostic age of 34 months.
After implementing the UNHS, the incidence of AN/AD in the audiology department increased from 1.16 to 4.13. Furthermore, the age of diagnosis of AN/AD decreased from 34 months to 5.7 months. This study shows that AN/AD, when screened, is a comparatively common disorder in the population of hearing-impaired infants. While newborn hearing screening provides early detection of babies with hearing loss, it also helps to differentiate AN/AD cases when the screening is performed with both a-ABR and automated oto-acoustic emission (a-OAE) tests. Thus, the routine combined use of a-ABR and a-OAE tests in UNHS programs, especially for the high-risk infants, can provide better detection of newborns with AN/AD. Furthermore, hyperbilirubinemia is merely an association and maybe etiologically linked.
听觉神经病/听觉失同步（AN/AD）已成为一种被广泛认可的临床病症。在新生儿听力普遍筛查（UNHS）中联合使用耳声发射（OAE）和听觉脑干反应（ABR）测试，使得这种病症易于识别。尽管我们现在能够可靠地诊断AN/AD，但对其流行病学、病因，尤其是发病率知之甚少。本研究的主要目的是确定土耳其安纳托利亚西部地区AN/AD的发病率。次要目的是比较多库兹艾吕尔大学医院听力科实施UNHS前后AN/AD的检出率。
2005年至2007年间，在23786名接受自动瞬态诱发耳声发射（a-CEOAE）和自动听觉脑干反应（a-ABR）筛查的新生儿中，有2236名被转诊至我科。对所有转诊的新生儿都进行了所有必要的听力学检查。其中，ABR测试结果异常或缺失且OAE正常的婴儿被视为患有AN/AD。这些婴儿接受了额外的诊断性听力学检查。此外，还对我科实施UNHS前后被诊断为AN/AD的儿童发病率进行了比较。
在转诊的新生儿中，65名婴儿的ABR测试结果异常或缺失。这65名听力受损的新生儿中，有10名（平均诊断年龄：5.7个月）的电生理测试结果符合AN/AD。这65名听力损失儿童中AN/AD的发病率为(15.38%)。此外，在UNHS中AN/AD的发病率为(0.044%)。10名患有AN/AD的婴儿中有7名有高胆红素血症这一危险因素，这一比例很高，值得关注。另一方面，对1999年至2005年（即实施UNHS之前）同一听力科诊断为AN/AD的儿童进行回顾性调查发现，只有7名儿童，平均诊断年龄为34个月。
实施UNHS后，听力科AN/AD的发病率从(1.16)上升至(4.13)。此外，AN/AD的诊断年龄从34个月降至5.7个月。本研究表明，AN/AD在听力受损婴儿群体中经筛查是一种相对常见的病症。新生儿听力筛查不仅能早期发现听力损失的婴儿，在同时使用a-ABR和自动耳声发射（a-OAE）测试进行筛查时，还有助于鉴别AN/AD病例。因此，在UNHS项目中常规联合使用a-ABR和a-OAE测试，尤其是对高危婴儿，可以更好地检测出患有AN/AD的新生儿。此外，高胆红素血症只是一种关联，可能在病因上存在联系。
