Causation of Permanent Unilateral and Mild Bilateral Hearing Loss in Children

Abstract

kHz) in 1 or both ears with air-bone gaps at 3.0 and 4.0 kHz no greater than 10 dB. On average, children with these losses have high academic failure rates as compared with those of their normal hearing peers. 1,3,6 The psychoeducational and psychosocial implications of UHL and MBHL are reviewed earlier in this issue by Tharpe.8 Despite considerable interest in the effects of these losses on child development, little attention has been paid to the underlying etiologies. In fact, contemporary reports of causes of UHL are no more illuminating than reports from the 1960s through the 1980s-before newborn hearing screening. That is, early reports indicated that between 35% and 65% of children with UHL had unknown etiologies. 1,9,10 More recently, in reports from the 1990s, unknown etiology was again reported to account for approximately 35% to 60% of cases of UHL.11,12 This is indeed surprising given the recent completion of the sequencing of the human genome and other medical advances that have improved our ability to identify genetic, metabolic, and viral causes of hearing loss in infancy. The most commonly reported known etiologies of UHL include viral complications (approximately 25%), 1,9,10,17 meningitis (approximately 15%), 1,9,10 head trauma (approximately 8% to 12%), 1,12 prenatal or perinatal disorders (12%), 4 and genetic disorders. U nilateral (UHL) and mild bilateral (MBHL) permanent hearing loss have long been implicated for putting children at risk for academic difficulty.1-7 For purposes of this article, the term "mild" bilateral hearing loss may include what are often termed "minimal" degrees of loss. Bess et al 6 defined minimal degrees of hearing loss as (1) unilateral sensorineural hearing loss, defined as average airconduction thresholds (0.5, 1.0, 2.0 kHz) 20 dB HL or more in the impaired ear and an average air-bone gap no greater than 10 dB at 1.0, 2.0, and 4.0 kHz and average air-conduction thresholds in the normal hearing ear of 15 dB HL or less; (2) bilateral sensorineural hearing loss, defined as average pure-tone thresholds between 20 and 40 dB HL bilaterally with average air-bone gaps no greater than 10 dB at frequencies 1.0, 2.0, and 4.0 kHz; and (3) highfrequency sensorineural hearing loss defined as airconduction thresholds greater than 25 dB HL at 2 or more frequencies above 2 kHz (ie, 3.0, 4.0, 6.0, or 8.0Children with permanent unilateral or mild bilateral hearing loss have been a focus of concern by audiologists, educators, and physicians for at least 2 decades. These children are known to be at risk for psychoeducational difficulties. However, despite this concern, little has been learned about the causative factors of these hearing losses and how those factors might be contributing to child development. This review of known causes of permanent unilateral and mild bilateral hearing loss in children is meant to draw attention to the importance of the search for etiologic factors. That is, the identification of the hearing loss should not signal the end of the diagnostic process but...

Adolescent development of psychosis as an outcome of hearing impairment: a 10-year longitudinal study

“…Since complete deafness was an exclusion criterion for EDSP study participation at baseline, the impairment assessed referred to a period of transient or permanent severe HI. The most common causes of severe hearing loss that may temporarily or permanently affect young people include syndromal or non-syndromal genetic disorders, prenatal and perinatal infections and noise exposure (for reviews, see Olusanya & Newton, 2007 ;Tharpe & Sladen, 2008).…”

“…Numerous conditions in young people may affect hearing acuity, resulting in transient or permanent impairment (for reviews, see Olusanya & Newton, 2007 ;Tharpe & Sladen, 2008). Causes of HI in young people that may also have an impact on the risk for psychotic experiences include birth trauma (Herrgard et al 1995) and prenatal and postnatal exposure to infections (Dalman et al 2008 ;Zammit et al 2009).…”

Perda auditiva unilateral em crianças: avaliação fonológica e do vocabulário

“…Thus, UHL may be a risk factor for children's language development and academic achievement, since they might present difficulties in daily communication and hearing situations (6) . Studies have shown that 1/3 of children with permanent unilateral hearing loss present language and learning delays (7,8,9) . A study conducted at the Colorado Home Intervention Program (10) noticed that nearly 33% of its subjects presented language development below the expected for their age groups.…”

An approach to unilateral hearing loss

“…En sık görülen nedenler arasında viral enfeksiyonlar (yaklaşık %25), menenjit (%15), iç kulak yokluğundan geniş vestibüler aquaduktus sendromuna kadar değişen iç kulak anomalileri, işitme siniri yokluğu, kafa travması, ototoksik ilaç kullanımı, tümörler, ani işitme kaybı ve işitsel nöropati sayılabilir. [12] Doğuştan işitme kayıpları açısından önemli olan risk faktörleri tek taraflı işitme kayıpları için de araş-tırılmıştır. Buna göre yenidoğan döneminde tek taraflı işitme kaybı tanısı konulan bebeklerin %30'unda risk faktörü bulunmuştur ve en sık bulunan risk kraniyofasiyal anomalilerdir.…”

“…Bakteriyel menenjit ise farklı çalışmalarda %4-30 oranında bildirilmiştir. [12,16] Ani işitme kaybı çoğunlukla tek taraflı olarak görü-lür. Olguların ancak %2 kadarı iki taraflıdır.…”