小儿蜗后听觉神经损害的临床与听力学特征及定位

目的 探讨包含了听神经病在内的ABR严重异常、DPOAE正常为特征的蜗后听觉神经功能障碍小儿的临床与听力学特征及其可能的病损部位.方法 选取2002至2006年听力专科中ABR严重异常、DPOAE正常,排除中耳传导功能异常的患儿86例(165耳),年龄8 d～7岁,平均1岁1个月,入选为本研究对象.选择ABR严重异常、DPOAE异常、排除中耳病变的听功能障碍26例(29耳)患儿作为蜗性病变对照组,选择健康同龄儿童86例(166耳)作为正常对照组,比较蜗后病变、蜗性病变、正常听力3组间ABR波Ⅰ、波Ⅲ、波Ⅴ潜伏期和振幅,以及Ⅰ～Ⅲ波间期等参数的异同.所有数据采用SPSS11.0统计软件包进行t检验.结果 86例蜗后听神经损害患儿中,51例(59.3%)的病例新生儿期有高胆红素血症史,其中40例血中间接胆红素水平达重度标准,11例为轻中度;在首次就诊的原因中,主诉运动障碍者40例(46.5%),听力言语障碍者10例(11.6%);在伴随的疾病中,32例(37.2%)确诊伴随有脑性瘫痪.在86例165耳蜗后听觉神经功能障碍患耳中,103耳最大强度声刺激(103 dB)ABR无波分化,27耳仅见波Ⅰ分化,19耳仅见波Ⅴ分化,13耳见波Ⅰ+Ⅲ分化,3耳见波Ⅰ+Ⅴ分化.仅见波Ⅰ分化耳,其波Ⅰ潜伏期较正常听力耳延长,振幅较正常听力耳低矮(t值分别为-6.75和2.58,P值均<0.05);有波Ⅰ+Ⅲ分化耳,波Ⅰ潜伏期和振幅与正常听力耳差异无统计学意义,波Ⅲ潜伏期则较正常听力耳延长,振幅较正常听力耳低矮(t值分别为-2.77和3.63,P值均<0.05),Ⅰ～Ⅲ波间期较正常听力耳Ⅰ～Ⅲ波间期延长(t=-2.99,P<0.05).结论 在蜗后听觉神经功能损害类型中,最常见的类型为ABR从波Ⅰ开始就严重异常,即听神经病,其病变主要在第Ⅷ颅神经听支;仅见波Ⅰ分化耳,其病变部位主要在第Ⅷ颅神经听支以后;ABR有波Ⅰ+波Ⅲ分化耳,主要病变部位在波Ⅲ的发源神经核团,即上橄榄核以后的听觉神经通路.振幅低矮的波Ⅴ不是听神经病独有的特征.高胆红素血症导致的蜗后听觉神经系统病变的病例中,其受侵害部位的先后次序可能为大脑皮层、腩干听觉神经核团、第Ⅷ对颅神经听支.     

经鼻持续正压通气对OSAHS患者ABR的影响

目的　研究经鼻持续正压通气(continuouspositiveairwaypressurethroughthenares,nCPAP)治疗前后阻塞性睡眠呼吸暂停低通气综合征(obstructivesleepapnea/hypopneasyndrom ,OSAHS)患者听性脑干反应(ABR)各波潜伏期及波间期的变化,探讨OSAHS患者脑干电生理变化的解剖学及病理生理学基础。方法　对4 5例( 90耳)OSAHS患者及16例( 32耳)正常对照者行ABR测试及多导睡眠监测(polysomnography ,PSG) ,对其中34例( 6 8耳)OSAHS患者行nCPAP治疗前后ABR测试对比。结果　OSAHS患者的波Ⅲ、Ⅴ潜伏期及Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ波间期比正常对照组明显延长(P <0 .0 5 )。nCPAP治疗后波Ⅲ潜伏期较治疗前缩短,Ⅰ-Ⅲ波间期较治疗前缩短,Ⅲ-Ⅴ波间期较治疗前延长;nCPAP治疗后OSAHS患者呼吸紊乱指数及减血氧次数较治疗前明显下降(P <0 .0 5 )。结论　OS AHS患者的脑干听觉传导通路受损,与其高碳酸-低氧血症有密切关系。nCPAP治疗可以改善脑干听觉传导功能。     

听力正常孤独症谱系障碍儿童的听性脑干反应波形特征分析

目的 探究听力正常孤独症谱系障碍(autism spectrum disorder, ASD)儿童的听性脑干反应(ABR)特征及各波潜伏期和波间期与ASD严重程度分级的关系。方法 (1)将55例(110耳)听力正常ASD儿童和月龄、性别相匹配的55例(110耳)典型发育(typical development, TD)儿童,按月龄分为≤24月龄(22耳)、25～36月龄(40耳)、37～48月龄(28耳)及>48月龄(20耳)四个亚组。比较听力正常ASD儿童与TD儿童的ABR潜伏期和波间期是否存在差异。(2)根据第五版精神障碍诊断与统计手册(DSM-V)将ASD儿童按照严重程度分级,探究听力正常ASD儿童ABR各波潜伏期和波间期与其严重程度分级是否相关。结果 (1)≤24月龄时,ASD与TD儿童ABR各波潜伏期及波间期差异均无统计学意义(P>0.05);(2)25～36月龄时,与TD儿童相比,听力正常ASD儿童波Ⅲ潜伏期及Ⅰ-Ⅲ、Ⅰ-Ⅴ波间期显著延长;37～48月龄时波Ⅲ、Ⅴ潜伏期及Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ波间期显著延长;>48月龄时波Ⅴ潜伏期及Ⅲ-Ⅴ、Ⅰ-Ⅴ波间期显著...     

正常青年女性月经周期ABR变化观察

目的 观察正常青年女性月经周期听性脑干反应各参数变化情况。方法 采用日本三荣7S11-A型信号处理机，对20名正常女性月经前期、行经期、月经中期与对照组之间听性脑干反应波Ⅰ、Ⅲ、Ⅴ潜伏期及Ⅰ—Ⅴ波间期进行分析。结果 女性月经前期、行经期、月经中期与男性对照组之间听性脑干反应波Ⅰ、Ⅲ、Ⅴ潜伏期及Ⅰ—Ⅴ波间期差异均有统计学意义，女性ABR波Ⅰ、Ⅲ、Ⅴ潜伏期在月经前期比行经期和中期分别缩短。结论 女性月经周期内分泌的变化可以导致ABRⅢ、Ⅴ波潜伏期及Ⅰ—Ⅴ波间期的变化。     

3～4月龄及5～6月龄婴儿听性脑干反应的正常值分析

目的观察正常婴儿听性脑干反应(ABR)潜伏期及阈值正常值范围,为早期干预治疗提供依据。方法应用美国ICS CHARTR诱发电位仪对40例(80耳)听力正常的婴儿和20例听力正常成人进行ABR检测,根据年龄分为A组(3~4月龄)、B组(5~6月龄)、对照组。建立不同月龄婴儿ABR正常值范围,讨论性别、耳别、月龄对测试结果的影响及阈值测定的临床应用。结果80dB nHL短声刺激下,A组A easeBR波Ⅰ、Ⅲ、Ⅴ潜伏期的正常值范围分别是:(1.52±0.19)m s、(4.20±0.20)m s、(6.34±0.26)m s;B组ABR波Ⅰ、Ⅲ、Ⅴ潜伏期的正常值范围分别是:(1.50±0.09)m s、(4.05±0.16)m s、(6.16±0.25)m s;对照组ABR波Ⅰ、Ⅲ、Ⅴ潜伏期的正常值范围分别是:(1.43±0.10)m s、(3.63±0.15)m s、(5.50±0.16)m s。随着月龄的增长,婴儿各波的潜伏期(PL)和波间期(IPL)均缩短;但6月龄时仍未达成人水平。A、B两组各波的潜伏期及波间期与对照组比较差异均有统计学意义(P0.05);A组与B组比较Ⅲ、Ⅴ波潜伏期及Ⅰ-Ⅲ、Ⅰ-Ⅴ波间期差异具有统计学意义(P0.05)。女婴潜伏期和波间期短于男婴(A组内Ⅰ-Ⅲ波间期除外),A组内男女间Ⅴ波潜伏期差异具有统计学意义(P0.05);B组内男女Ⅲ、Ⅴ波潜伏期及Ⅰ-Ⅴ波间期差异有统计学意义(P0.05);各组内左右耳差异无统计学意义(P0.05)。各月龄组及正常成人ABR反应阈差异无统计学意义。结论建立不同月龄婴儿ABR潜伏期及阈值正常值标准,为听损伤的早期诊断和随访监测提供可靠依据。     

分泌性中耳炎患儿听性脑干反应的应用及特征

目的 通过比较分泌性中耳炎(otitis media with effusion, OME)患儿鼓膜置管术前、后听性脑干反应(auditory brainstem response, ABR)的变化,探讨ABR测试在儿童分泌性中耳炎诊治中的临床应用价值.方法 对50例(100耳)分泌性中耳炎患儿行鼓膜置管术前进行ABR测试,其中有30例(60耳) 术后再次行ABR测试,并与50例(100耳)正常对照组儿童进行比较;另外将该30例(60耳)患儿根据鼓室分泌物黏稠度分两组,分泌物黏稠组16例(32耳),分泌物稀薄组14例(28耳),将两组ABR波Ⅴ阈值结果进行比较.结果 50例(100耳)分泌性中耳炎患儿术前ABR波Ⅴ阈值及波Ⅰ潜伏期均正常者占13%,漏诊率为13%;波Ⅴ阈值正常占41%,轻度异常52%,中度异常7%;波Ⅰ潜伏期正常19%,72%波Ⅰ潜伏期延长,9%出现波Ⅰ缺失.术前OME组患儿的ABR波Ⅰ、Ⅲ、Ⅴ各波潜伏期比正常儿童延长,阈值升高,差异有显著统计学意义(P＜0.01).Ⅰ-Ⅲ、Ⅰ-Ⅴ波间期缩短,与正常组比较差异有显著统计学意义(P＜0.01).术后ABR波Ⅴ阈值及波Ⅰ潜伏期均正常者占46.7%;波Ⅴ阈值正常占70.5%,轻度异常29.5%;波Ⅰ引出率100%,潜伏期正常占50.2%;OME组中术前、术后ABR各波潜伏期、波Ⅴ阈值比较差异有显著统计学意义(P＜0.01),各波波间期比较无差异,术后听力有明显改善,但与正常组比较部分患儿波Ⅴ阈值仍高,波Ⅰ、Ⅲ潜伏期仍延长,Ⅰ-Ⅲ、Ⅰ-Ⅴ波间期缩短(P＜0.05);分泌物黏稠组波Ⅴ阈值较稀薄组高.结论 单用ABR作为诊断OME的依据是有欠缺的,但大部分患儿可以通过该检查进行听力损失的评估,以了解鼓膜置管术后的听力状况及恢复程度.     

非镇静听性脑干反应检测的有效性研究

目的探讨非镇静听性脑干反应(ABR)检测的有效性,为其临床应用提供参考。方法以30例(60耳)听力正常人(0.5~2 kHz气导平均听阈15.7±4.1 dB HL)为正常组,10例(20耳)感音神经性聋患者(0.5~2 kHz气导平均听阈35.7±8.4 dB HL)为病例组,均进行非镇静ABR测试和镇静ABR测试,比较两种ABR的潜伏期、波间期及反应阈。结果①正常组非镇静ABR波Ⅰ、Ⅲ、Ⅴ潜伏期分别为1.78±0.25、3.96±0.18、6.10±0.33 ms,镇静ABR波Ⅰ、Ⅲ、Ⅴ潜伏期分别为1.62±0.18、3.76±0.20、5.78±0.45 ms,二者比较差异无统计学意义(P>0.05);非镇静ABR各波波间期(Ⅰ-Ⅲ1.98±0.32 ms,Ⅲ-Ⅴ2.13±0.37 ms,Ⅰ-Ⅴ4.05±0.08 ms)与镇静ABR各波波间期(Ⅰ-Ⅲ2.10±0.02 ms,Ⅲ-Ⅴ1.98±0.25 ms,Ⅰ-Ⅴ4.02±0.18 ms)比较,差异无统计学意义(P>0.05)。②病例组非镇静ABR波Ⅰ、Ⅲ、Ⅴ波潜伏期分别为1.71±0.29、4.06±0.08、5.90±0.18 ms,镇静ABR波Ⅰ、Ⅲ、Ⅴ潜伏期分别为1.72±0.14 ms、3.76±0.25 ms、5.77±0.59 ms,二者比较差异无统计学意义(P>0.05);非镇静ABR各波波间期(Ⅰ-Ⅲ2.18±0.47 ms,Ⅲ-Ⅴ2.03±0.27 ms,Ⅰ-Ⅴ4.15±0.58 ms)与镇静ABR各波波间期(Ⅰ-Ⅲ2.00±0.10 ms,Ⅲ-Ⅴ1.98±0.39 ms,Ⅰ-Ⅴ4.12±0.38 ms)比较,差异无统计学意义(P>0.05)。③两组非镇静ABR与镇静ABR反应阈差异无统计学意义(P>0.05)。结论非镇静ABR测试结果与镇静ABR无差异,且波形分化好,易辨别,可方便、有效的应用于临床。     

听阈正常耳鸣患者听性脑干反应检测的特点及临床意义

目的研究听阈正常耳鸣患者听性脑干反应(auditory brainstem response,ABR)、畸变产物耳声发射(dis-tortion product evoked otoacoustic emissions, DPOAE)客观测试结果的特点,探讨ABR检测在耳鸣中的意义。方法对24例听力正常单侧耳鸣为主诉的患者进行纯音听阈、DPOAE和ABR检测,对比耳鸣侧和健侧的听阈、DPOAE各频率检出率及幅值和ABR各波波幅及潜伏期结果,进行统计分析。结果 24例患者双侧纯音听阈全部≤25dBHL,双侧无显著差异;DPOAE各频率检出率及幅值双侧无显著性差异;ABR结果中Ⅰ波波幅在耳鸣侧较健侧降低(t=-2.681,P<0.05),而Ⅲ、Ⅴ波波幅双侧无显著性差异,各波幅比双侧无显著性差异;Ⅰ、Ⅲ、Ⅴ各波潜伏期及波间期双侧无显著性差异。结论 ABR中Ⅰ波波幅下降代表听阈正常的耳鸣患者可能已经存在耳蜗早期变化,对耳鸣早期临床诊断有重要意义。     

骨导ABR测试信号经气放射对结果的影响

为了解骨导听性脑干反应(ABR)测试中骨导振荡器测试信号经气放射对结果的影响,本组用Dantec-Evolution诱发电位系统测试了正常听力年青人20名38耳和传导性聋13例21耳的骨导ABR.两组结果比较,在较高刺激强度正常组有较大的刺激伪迹,对Ⅰ波干扰较大.两组反应阈、Ⅰ、Ⅲ和Ⅴ波潜伏期、Ⅰ-Ⅲ和Ⅲ-Ⅴ波间期无显著差异,但Ⅰ-Ⅴ波间期的差异有统计学意义.这是由于正常组骨导振荡器经气放射的刺激伪迹对波Ⅰ的影响使Ⅰ-Ⅴ波间期缩短.本结果提示在用骨导ABR确定反应阈时可不考虑这个影响,但在用于蜗后病变定位诊断时要考虑经气放射的影响问题,     

中耳功能异常婴儿听性脑干反应特点及应用

目的探讨中耳功能异常婴儿的听性脑干反应(ABR)特点及临床应用价值。方法分析比较85例(170耳)中耳功能异常、ABR反应阈≤60dB nHL的婴儿(A组)和83例(166耳)中耳功能正常、ABR反应阈40～60dB HL的婴儿(B组)以及41例(82耳)正常婴儿(C组)的ABR波Ⅰ、Ⅲ、Ⅴ潜伏期、波间期和波Ⅴ反应阈值。结果 A组中24耳(14.11%)为ABR反应阈≤30dB nHL、73耳(42.94%)为40dB nHL、54耳(31.76%)为50dBnHL、19耳(11.18%)为60dB nHL;B组中83耳(50%)ABR反应阈为40dB nHL、52耳(31.33%)为50dB nHL、31耳(18.67%)为60dB nHL;C组婴儿ABR反应阈均≤30dB nHL。刺激声为80dB nHL时三组间波Ⅰ、Ⅲ、Ⅴ潜伏期的关系分别为:A组波Ⅰ、Ⅲ、Ⅴ潜伏期明显长于B组和C组(P<0.01),而Ⅰ-Ⅲ、Ⅰ-Ⅴ波间期则较B组和C组短(P<0.01),Ⅲ-Ⅴ波间期则与B组和C组差异无统计学意义(P>0.05);B组各波潜伏期、波间期与C组比较差异均无统计学意义(P>0.05)。三组中反应阈相同者波潜伏期比较:A组波Ⅰ、Ⅲ、Ⅴ潜伏期仍明显长于B组和C组(P<0.05)。结论婴儿中耳功能异常时大部分ABR反应阈升高,以轻中度异常为主,均有波Ⅰ潜伏期延长;波Ⅰ潜伏期明显延长对判断婴儿中耳功能异常有意义。     

Audiological assessment in Ramsay Hunt syndrome.

Ramsay Hunt syndrome is known to cause symptoms and signs of vestibulocochlear dysfunction, including sensorineural hearing loss. The present study investigates the audiological features of a group of 15 patients with this syndrome. A complete otolaryngological, neurologic, and audiological workup was performed in every patient, including auditory brain stem response measurements and recording of transiently evoked otoacoustic emissions. In most patients, some degree of hearing loss was evident, and abnormal latencies and interpeak latencies of the auditory brain stem response, or even absence of the waves, were observed. Transiently evoked otoacoustic emissions were present in only 6 cases, and caloric tests showed unilateral weakness in the majority of the patients. In all of the performed tests, abnormalities were present only on the affected side. The audiological data suggested cochlear or retrocochlear involvement or involvement at more than one site along the auditory pathway.     

Auditory brain stem response throughout the menstrual cycle

A prospective study was performed to evaluate the changes in the auditory brain stem response (ABR) that occur in healthy premenopausal women throughout the menstrual cycle. Ninety-four women with ovulatory menstrual cycles underwent ABR testing by auditory evoked potentials for wave I, III, and V latencies and for interpeak I-III, I-V, and III-V intervals during the follicular, periovular, and luteal phases of the menstrual cycle. The wave latencies and the interpeak intervals showed shorter values during the periovular phase than during the luteal phase (p < .05) and shorter values during the follicular phase for wave I (p < .05) and interpeak interval I-V (p < .05). The ABR seems to be influenced by the variations of ovarian steroids that occur during the menstrual cycle.     

Electrocochleography and brain-stem potentials in Ramsay Hunt syndrome

Audiometric investigations and electrophysiologic recordings of cochlear and brain-stem auditory evoked potentials (BAEPs) were performed in 13 patients to elucidate further the type of hearing disorders in Ramsay Hunt syndrome. Transtympanic electrocochleography showed no enhancement of summating potential and did not suggest secondary endolymphatic hydrops. The recording of BAEPs was clearly abnormal in several of the 13 patients. The striking feature of the abnormalities in these patients was the prolongation of the latencies of waves III and V with the preservation of wave I, which clearly suggests retrocochlear involvement. In all the patients tested, abnormalities of the BAEPs were present only on the affected side. It is possible, on the basis of BAEP findings, to suggest that in Ramsay Hunt syndrome both cochlear and retrocochlear involvement may occur.     

Auditory brainstem response in pediatric migraine: during the attack and asymptomatic period

OBJECTIVE: The aim of this study was to evaluate the hearing parameters of children with migraine during ictal and interictal period. METHOD: 16 pediatric patients with migraine and normal otolaryngologic examination were evaluated. Hearing parameters were assessed with auditory brainstem response (ABR) testing between and during the migraine attacks. Binaural absolute latencies of waves I, III and V, interpeak latencies I-III, III-V and I-V of ABR in response to 80 dB nHL clicks were calculated. Initial findings were compared with those of 20 healthy volunteers. RESULTS: Peak latencies of wave V and interpeak latencies of I-V were prolonged during the attack in migraineurs on the left. The side of latency elongation was not affected by the side of headache. When these parameters were separately compared for gender, they were prolonged in boys during the attack in migraineurs; however in girls, while there was statistically significant difference at interpeak latencies of I-V, no significant difference was noted at peak latencies of wave V. CONCLUSIONS: ABR waves did not exceed clinical norms in migraine patients in headache-free period. But, important effects on sensorineural hearing parameters were detected during the attack. Our results indicated a transient impairment of the auditory brainstem function during the headache in pediatric migraine patients.     

Effect of hearing loss of cochlear origin on the auditory brain stem response.

Auditory brain stem response (ABR) testing is widely used to detect lesions of the auditory neural pathways. The ABR waves depend not only on the integrity of the neural pathways, but also on the condition of the cochlea. To properly interpret the ABR response, it is necessary to understand the effects of cochlear hearing loss on the ABR wave latencies. We studied two populations of subjects with cochlear hearing loss: one with varying degrees of high-frequency hearing loss and the other with varying degrees of flat configuration hearing loss. The degree of cochlear hearing loss was quantified in several different ways and subjected to one linear and three nonlinear regression analyses to test for accuracy in predicting ABR wave latencies and interpeak intervals (waves I, III, V, I-V, I-III, and III-V) for three click intensities. Hearing loss levels from 2 to 6 kHz, in particular 4 kHz, were superior to other audiometric test frequencies as predictors of ABR wave latencies for the group with the high-frequency losses. No particular characterization was found to be superior for the flat hearing loss configurations. From these results, modeled predictions of wave latencies as a function of degree and configuration of hearing loss were made. The modeled predictions are then used to suggest guidelines for interpretations of ABR results where hearing impaired patients are involved.     

Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma--a prospective study.

A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway.     

Auditory brainstem responses to tonal stimuli in young and aging rats

The auditory brain stem response (ABR) was studied in young adult and aged rats using 3,8 and 40 kHz tone pips. The expected inverse relationship between frequency and latency was observed in the younger group for waves I, II and III, while the response to the highest frequency stimulus had the longest latency at wave V. Absolute latencies for waves I through V each showed age-related increments with more pronounced changes occurring to 3 and 40 kHz stimuli than to the frequency of maximum sensitivity (8 kHz). Threshold increases with age for the highest frequency approximately doubled those for the lower frequencies. Examination of interpeak intervals (IPI) I-III, III-V and I-V revealed aging effects. The largest IPI I-V increment occurred to 3 kHz stimulation which reflects changes at both I-III and III-V sub-intervals. These results demonstrate electrophysiological correlates of aging due to transformations in the peripheral auditory system coupled with alterations in brainstem auditory pathways.     

Auditory brainstem response differences in diabetic and non-diabetic veterans

A number of studies have found statistically significant delays in auditory brainstem latencies of patients with diabetes compared with non-diabetic controls. However, the mechanisms ascribed as responsible for the latency differences between diabetic and non-diabetic patients vary among studies, and the latency differences, while significant, are small. In this 5-year prospective study, auditory brainstem response testing was conducted with 416 non-diabetic and 375 diabetic veterans from the Portland Veterans Affairs Medical Center as part of a larger study. Patients with diabetes had significantly delayed latencies of Wave III and V in the right ear and significantly prolonged interpeak I-III and I-V latencies in both ears. Stimulus polarity difference yielded slightly different results. None of the diabetes-related clinical characteristics were associated with the latency differences between the subject groups after accounting for hearing loss and age. Effect size was calculated and clinical significance of these differences is discussed.     

Auditory findings and electrophysiologics in individuals with G/BBB syndrome

The G/BBB syndrome is a rare condition characterized by hypertelorism, cleft lip and palate, and hypospadias. No studies were found on the hearing of individuals with this syndrome.AimTo investigate the auditory function in patients with G/BBB syndrome, such as the occurrence of hearing loss, and central and peripheral auditory nerve conduction.MethodsFourteen male patients aged 7-34 years with the G/BBB syndrome were assessed by otoscopy, audiometry, tympanometry and evoked auditory brainstem response (ABR). Model: A retrospective clinical series study.ResultsAudiometric thresholds were normal in 12 (66.7%) of the sample and altered in two (33.3%), one with conductive and one with sensorineural loss. ABR resuts were: all patients had normal absolute wave I latencies; absolute wave III and V latencies were increased in two and six patients, respectively; interpeak latencies I-III, IV and V interpeak latencies were increased in four, three and eight patients respectively.ConclusionHearing loss can occur in the G/BBB syndrome. There is evidence of central auditory pathway involvement in the brainstem. Imaging studies are needed to clarify the clinical findings.