Contralateral suppression of otoacoustic emissions in a clinical sample of children with auditory processing disorder

Objective: The suppression of evoked otoacoustic emissions (EOAE) may serve as a clinical tool to evaluate the medial olivocochlear (MOC) reflex, which is thought to aid speech discrimination (particularly in noise) by selectively inhibiting cochlear amplification. The present study aimed to determine if contralateral transient evoked otoacoustic emission (TEOAE) suppression was present in a clinical sample of children with listening difficulties with and without auditory processing disorder (APD).

Design: A three-group, repeated measure design was used.

Study sample: Forty three children aged 8–14?years underwent an auditory processing assessment and were divided into three groups: children with reported listening difficulties with APD, children with reported listening difficulties without APD, and children with normal hearing. APD was defined as per British Society of Audiology.

Results: TEOAE suppression was present in all three participant groups. No significant group, age or ear effects were observed for TEOAE suppression in dB or as a normalised index.

Conclusion: Contralateral TEOAE suppression method could not be used as a clinical tool to identify APD in this study’s participating children and did not support the hypothesised link between reduced MOC function and general listening difficulties in background noise in children with or without APD.     

学习困难儿童视听知觉特征与智力结构的关系探讨

目的：阐明Illinois心理语言测试与智力及Berry视觉一运动测试之间的交互关系。方法：对59名学习困难儿童进行韦氏智力测验、Illinois心理语言测试及Beny单项神经心理测试。结果：Illinois心理语言测试除听觉理解外，均与Berry视-动测验呈显著性正相关；除词汇表达外，均与韦氏测验的空间因子正相关；听觉理解、视觉组合与韦氏总智商、操作智商密切相关；语法组合、视觉联合及手势表达与概念因子正相关。表象和自动化水平有赖于视听知觉的整合。学习困难儿童的词汇表达、视觉记忆相对较低。结论：心理语言测试与智力测试不是测量同一种特质，认知水平与一般能力的空间因子密切相关．知觉的某些分测最与总智商有关，并与视觉一运动测量正相关。     

听性脑干反应与40Hz听觉相关电位综合评估听觉阈值

目的 探索应用听性脑干反应(auditory brain stem response,ABR)和40Hz听觉相关电位(40Hz auditory event related potential,40Hz AERP)来客观评估听阈的最佳方法.方法 对120例受试者分别测出其平均听阈和ABR阈值、40Hz AERP阈值,共获得资料可靠完整的86耳用于实验分析.将86耳根据听力曲线的类型分为下降型29耳、上升型20耳和水平型37耳三种.用SPSS软件分别对3组数据进行统计学处理,并进行多元回归分析,建立三种数学模型,并进行简化和检验.最后另选10例新的受试者对得到的公式进行均方差可靠性检验.结果 3组平均听阈与ABR阈值和40Hz AERP阈值具有显著线性相关性(r2=0.932,0.944,0.934).建立的三种模型分别为:水平型,平均听阈=ABR阈值;下降型,平均听阈=1/3(40HzAERP) 2/3ABR;上升型,平均听阈=2/3(40HzAERP) 1/3ABR.均方差检验显示公式法优于ABR法.结论 利用ABR阈值和40Hz AERP阈值通过三种回归方程较单纯应用ABR阈值能够更准确的估计受试者的平均听阈,可以尝试用于评估婴幼儿及不能主动配合的受试者的听阈.     

鼓索神经对听骨链重建术中纯音听阈测试结果的比较

目的：论证鼓索神经对听骨链重建的作用。方法：141例（154耳）患者分成3组：①鼓索神经弹压组（索弹组）35例（41耳）。鼓膜穿孔,鼓索尚存,臼柱即PORP或枪柱即TORP都在听骨外侧横行磨一细槽,嵌入鼓索神经,使鼓索神经能稳定弹压听骨,不使其移位。②残余鼓膜弹压组（膜弹组）67例（72耳）。用鼓膜弹压听骨。③无弹压组（无弹组）39例（41耳）。3组分别进行术前、术后气骨导差（ABG）自身配对S-t检验,并作术后ABG差值的两两对比和S-t检验。结果：显效、有效、无效率索弹组分别为：29．3％,51．2％,19．5％;膜弹组分别为：22．2％,50．0％,27．8％;无弹组分别为：19．5％,36．6％,43．9％;与无弹组比较,均P〈0．01。索弹组和膜弹组的术前、后ABG差值分别与无弹组比较,均P〈0．05。索弹组1耳术后有暂时味觉减退,1耳有迟发性轻度面瘫,均2周内自愈。结论：索弹听骨能使听骨稳定,获得良好的听力改善,不必二期手术;也不产生味觉及面神经功能障碍。     

An atlas of glycine- and GABA-like immunoreactivity and colocalization in the cochlear nuclear complex of the guinea pig

Summary The distribution and colocalization of -aminobutyric acid (GABA)- and glycine-like immunoreactivity in the cochlear nuclear complex of the guinea pig have been studied to produce a light microscopic atlas. The method used was based on post-embedding immunocytochemistry in pairs of 0.5-m-thick plastic sections treated with polyclonal antibodies against conjugated GABA and glycine respectively. Immunoreactive cells, presumably short axon neurones, predominated in the dorsal cochlear nucleus, with mostly single-GABA-labelled cells in the superficial layer, double-labelled in the middle, and single-glycine-labelled in the deep layers. A few large single-glycine-labelled cells, interpreted as commissural neurons, occurred in the ventral nucleus. Scattered double-labelled cells, probably Golgi cells, were seen in the granule cell domain. Immunolabelled puncta of all three staining categories occurred in large numbers throughout the complex, apposed to somata and in the neuropil, showing a differential distribution onto different types of neuron. Three immunolabelled tracts were noted: the tuberculoventral tract, the commissural acoustic stria, and the trapezoidal descending fibres. Most of the fibres in these tracts were single-labelled for glycine, although in the last mentioned tract single-GABA- and double-labelled fibres were also found. Some of the immunolabelled cell types described here are proposed as the origins of the similarly labelled puncta and fibres on the basis of known intrinsic connections.Abbreviations 1-4 DCN layers 1 to 4 - as acoustic stria - AVCN anteroventral cochlear nucleus - C caudal - cap cap area - cas commissural acoustic stria - cnr cochlear nerve root - co commissural cell - CRVCN central region of the VCN - cw cartwheel cell - CZ confluence zone - d dendrite - D dorsal - das dorsal acoustic stria - DCN dorsal cochlear nucleus - df descending fibres - ep ependyma - flocc flocculus - g glial cell - GABA -aminobutyric acid - GLY glycine - gi giant cell - gl/gla globular cell/area - Go Golgi cell - gr granule cell - ias intermediate acoustic stria - icp inferior cerebellar peduncle - lam granule cell lamina - mp/mpa multipolar cell/area - oc/oca octopus cell/area - PVCN posteroventral cochlear nucleus - py pyramidal cell - R rostral - sgl superficial granule cell layer - spcg subpeduncular corner of granule cells - sph/spha spherical cell/area - st stellate cell - tb trapezoid body - tv tuberculoventral cell - TVT tuberculoventral tract - V ventral - VCN ventral cochlear nucleus - vn vestibular nerve     

Integration of multiple sensory modalities in cat cortex

Summary The results of this study show that the different receptive fields of multisensory neurons in the cortex of the cat anterior ectosylvian sulcus (AES) were in spatial register, and it is this register that determined the manner in which these neurons integrated multiple sensory stimuli. The functional properties of multisensory neurons in AES cortex bore fundamental similarities to those in other cortical and subcortical structures. These constancies in the principles of multisensory integration are likely to provide a basis for spatial coherence in information processing throughout the nervous system.     

Rhythmic expression of per1 in the dentate gyrus is suppressed by corticosterone: implications for neurogenesis

When an acoustic stimulus that is sufficiently intense to elicit a startle response is delivered in conjunction with the "go" signal in a simple reaction time (RT) task, RT is greatly reduced. It has been suggested that this effect is due to the startle interacting with voluntary response channels to directly trigger the pre-programmed action. Alternatively, it may be that the startling stimulus simply increases activation along the sensory and motor pathways allowing for faster stimulus-response processing. In the present study a startling acoustic stimulus (SAS) was presented in addition to a visual or an auditory imperative stimulus (IS) in a simple RT task. Results showed that the pre-programmed response was initiated much faster when participants were startled. However, while differences in RT due to IS modality were observed in control trials, this difference was absent for startle trials. This result indicates that the SAS does not simply speed processing along the normal stimulus-response channels, but acts to release the pre-planned movement via a separate, faster neural pathway.     

Limitation of Conventional Audiometry in Identifying Hidden Hearing Loss in Acute Noise Exposure

PurposeThe concept of hidden hearing loss can explain the discrepancy between a listener''s perception of hearing ability and hearing evaluation using pure tone audiograms. This study investigated the utility of the suprathreshold auditory brainstem response (ABR) for the evaluation of hidden hearing loss in noise-exposed ear with normal audiograms.Materials and MethodsA total of 15 patients (24 ears) with normal auditory thresholds and normal distortion product otoacoustic emissions were included in a retrospective analysis of medical records of 80 patients presenting with histories of acute noise exposure. The control group included 12 subjects (24 ears) with normal audiograms and no history of noise exposure. Pure tone audiometry and suprathreshold ABR testing at 90 dB peSPL were performed. The amplitudes and latencies of ABR waves I and V were compared between the noise-exposed and control groups.ResultsWe found no significant difference in the wave I or V amplitude, or the wave I/V ratio, between the two groups. The latencies of ABR wave I, V, and I-V interpeak interval were compared, and no significant intergroup difference was observed.ConclusionThe results suggest that either hidden hearing loss may not be significant in this cohort of patients with acute noise exposure history, or the possible damage by noise exposure is not reflected in the ABRs. Further studies are needed to inquire about the role of ABR in identification of hidden hearing loss.