听力正常儿童 chirp 声与 click 声听性脑干反应特征比较

目的：比较听力正常儿童chirp声与click声听性脑干反应的特征。方法选择97例（194耳）听力正常儿童,分别采用 CE－chirp 和 click 刺激声进行 ABR 检测,比较两种 ABR 波形辨认率,波Ⅲ、V 潜伏期,波 V反应阈及不同刺激声强度下波 V 的振幅及检测时间。结果chirp－ABR 波Ⅰ辨认率（36％）明显低于 click－ABR （100％）,chirp－ABR 与 click－ABR 波 V 反应阈值差异无统计学意义（P＞0．05）,在刺激声强度为80 dB nHL 时, chirp－ABR 波Ⅲ、V 潜伏期比 click－ABR 短,差异有统计学意义（P＜0．05）,且两种刺激声 ABR 波 V 振幅差异无统计学意义（P＞0．05）;在刺激声强度为50 dB nHL 时,chirp－ABR 波 V 振幅较 click－ABR 明显增大,差异有统计学意义（P＜0．05）;在刺激声强度分别为80、50 dB nHL 时,chirp－ABR 波 V 振幅差异无统计学意义（P＞0．05）;chirp－ABR 较 click－ABR 检测时间短,差异有统计学意义（P＜0．05）。结论与 click－ABR 相比,chirp－ABR 的反应幅度高,潜伏期短,检测时间短,用于儿童听力检测具有明显优势。     

健听青年短音ABR和倍频程CE-Chirp? ABR的V波特性分析

目的：观察健听青年人短音ABR和倍频程CE-Chirp? ABR的V波潜伏期和振幅差异,探讨倍频程CE-Chirp?? ABR的临床应用价值。方法选择听力正常青年人20例,分别行双耳短音ABR和倍频程CE-Chirp? ABR测试,记录Ⅴ波潜伏期和振幅,并用析因设计方法进行统计。结果在20、40、60、80 dB nHL刺激强度下,倍频程CE-Chirp? ABR的Ⅴ波潜伏期明显缩短,与短音ABR相比具有统计学差异（P＜0.05）;在20、40、60 dB nHL刺激强度下,倍频程CE-Chirp?ABR的Ⅴ波振幅明显高于短音ABR,差异具有统计学意义（P＜0.05）,而在80 dB nHL刺激强度下两者Ⅴ波振幅无统计学差异（P＞0.05）。结论听力正常青年人倍频程CE-Chirp? ABR V波潜伏期短于短音ABR,且倍频程CE-Chirp? ABR中低刺激强度下Ⅴ波振幅明显高于短音ABR,更有利于V波判断,但其V波潜伏期的规律性较短音ABR差,在不同个体间差异较大。     

分泌性中耳炎儿童Chirp声与短声诱发听性脑干反应的对比研究

目的探讨分泌性中耳炎(otitis media with effusion,OME)儿童Chirp声诱发的听性脑干反应(auditory brainstem response,ABR)的特征。方法以16例(24耳)8个月~4.6岁OME患儿为研究对象,分别进行Chirp-ABR及click声诱发的ABR(click-ABR)检测,对结果进行自身配对t检验,比较Chirp-ABR和click-ABR各波潜伏期、波间期及反应阈。结果在80 dB nHL刺激声强度时,Chirp-ABR波I、III潜伏期均较click-ABR延长,差异有统计学意义(P<0.05),波V潜伏期较click-ABR延长,但差异无统计学意义(P>0.05)。Chirp-ABR I-III、III-V、I-V波间期均较click-ABR缩短,但差异无统计学意义(P>0.05);波V振幅增高,差异有统计学意义(P<0.05)。Chirp-ABR和click-ABR波V反应阈均值相等,且均升高,差异无明显统计学意义(P>0.05),但在反应阈刺激声强度时Chirp-ABR波V潜伏期较click-ABR延长(P<0.05)。结论本组分泌性中耳炎儿童80 dB nHL刺激声强度时,与click-ABR比较,Chirp-ABR波I、III潜伏期延长,波V振幅升高,反应阈强度时波V潜伏期延长。     

短纯音诱发的听性脑干反应测试中声诱发短潜伏期负反应研究

目的 总结在有听力损失儿童中行短纯音诱发的听性脑干反应(tbABR)测试时记录到的声诱发短潜伏期负反应(acoustically short latency negative response,ASNR)的特点.方法 在有听力损失的0～6岁儿童中应用SmartEP听觉诱发电位仪记录短声和短纯音ABR的反应阈,在记录到ASNR的受试者中分析其反应阈和潜伏期.结果 在所有80受试耳中共7耳(8.75%)在cABR测试中引出ASNR,40耳(50%)在tbABR测试中引出ASNR,其中1 kHz引出率最高(37耳,46.25%),2 kHz次之(25耳,31.25%).引出ASNR者ABR波V反应阈最低65 dB nHL,ASNR反应阈最低80 dB nHL.0.5、1、2和4 kHz短纯音诱发的ASNR潜伏期分别为6～8、5～7、3～5、3～4 ms.随刺激强度的增加,其潜伏期缩短.结论 有听力损失的儿童tbABR测试中可以记录到AS-NR,但不影响以波V反应阈评估听力.     

短声与短纯音ABR波V阈值的相关性比较

目的研究分别用短声与短纯音作为刺激声的听觉脑干诱发电位（auditory braistem response，ABR）波V阈值测试结果的相关性，以探讨短纯音ABR的临床应用价值。方法分别用短声和短纯音ABR对患者进行波V阈值的测试。结果测试的31耳中，短声与短纯音ABR500Hz～4000Hz的波V阈值的相关系数分别为：0．480、0．583．0．752和0．811。P值均为0。结论短声和短纯音ABR波V阈之间有相关性。其中，2000～4000Hz的相关性优于500～1000Hz；当听力损失大于70dBnHL时的500～1000Hz的相关性好于听力损失小于70dBnHL的时候。提示当短声ABR波V阈值大于70dBnHL时同样可以预测0．5kHz、1kHz短纯音ABR波V阈值。     

极重度听损大前庭水管综合征婴幼儿患者ABR和ASSR结果分析

目的通过对极重度听力损失的大前庭水管综合征婴幼儿进行听性脑干反应（ABR）和多频稳态反应（ASSR）测试,探讨其ABR检查过程中出现的声诱发短潜伏期负向波（acoustically evoked short latency negative response,ASNR）及其ASSR特点。方法回顾性研究22例（42耳）极重度听力损失的大前庭水管综合征（LVAS）婴幼儿,另选择28例（56耳）极重度听力损失的非LVAS的感音神经性耳聋婴幼儿作为对照组,研究其ABR及ASSR相关性。结果①LVAS婴幼儿组ABR测试中,36耳（85．7％）记录到AsNR,在109．6 dB nHL刺激强度引出的ASNR平均潜伏期在3．04±0．22msT对照组中婴幼儿无一例记录到ASNR。②LVAS婴幼儿组ASSRNI]试在250、500和1000Hz引出率明显高于对照组,两组间差异有统计学意义（P〈0．01）。结论相比于普通的极重度感音神经性耳聋患儿,极重度听损LVAS患儿进行听力学检查时,ABR容易出现ASNR负向波,ASSR测试结果显示较高的中低频的电位反应引出率,此结果可用于临床辅助诊断大前庭水管综合征。     

婴幼儿短纯音与短声诱发的听性脑干反应初探

目的分析婴幼儿短纯音诱发的听性脑千反应（tone burst click auditory brain stem response, TB-ABR）与短声诱发的听性脑千反应（click auditory brain stem response, C-ABR）阈值的相关性,以探讨TB—ABR在婴幼儿客观听力评估中的临床应用价值。方法对2007年1月-2009年1月,新生儿听力筛查通过且C—ABR阈值正常者27例（54耳）,以短纯音为刺激声,进行ABR波V反应阈值及潜伏期测试,并与C-ABR作差异与相关性分析。结果本组27例（54耳）婴幼儿中完成4个频率TB-ABR测试的共27例（54耳）,0．5、1、2、4kHz TB—ABR波V反应阈值分别为（40．0±11．6）dBnHL、（36．7±9．0）dBnHL、（27.2±6．7）dBnHL和（25．9±6．3）dB nHL,明显高于C-ABR阈值（17．8±6．4）dBnHL（P〈0．05）,TB-ABR波V反应阑值随着刺激声频率的升高而下降,潜伏期随着刺激声频率的升高而缩短。0．5、1、2及4kHz1BABR反应阈与GABR反应阈的线性相关系数分别为0.53、0．60、0.67、0．72,存在直线正相关关系（P〈0．01）。结论婴幼儿TB-ABR和C-ABR反应阈之间存在相关性,且高频相关性优于低频,TB-ABR可作为一种具有频率特异性的婴幼儿客观听力评估方法。     

听力正常者交替短声诱发的耳蜗电图特征

目的 分析听力正常者交替短声诱发的耳蜗电图(ECochG)特征,为耳蜗电图的临床应用提供参照.方法 对听力正常者38人(49耳)行耳蜗电图检查.使用Nicolet Bravo诱发电位系统,用交替短声作为刺激信号.每只测试耳的起始测试强度为100 dB nHL,以10 dB为步距逐渐降低强度,直至无法引出CAP.观测各强度下CAP的潜伏期和幅度、CAP阈值以及高强度(90 dB nHL)下SP/CAP幅度比值.绘制CAP的输入-输出曲线.结果 49耳均引出良好ECochG波形,平均引出反应阈为28.37±6.81 dB nHL.CAP峰潜伏期随刺激强度降低而延长.高强度下-SP与CAP幅度比为0.27±0.14.CAP幅度的I/0曲线呈明显的低、高两个强度段,在60 dBnHL附近存在明显的拐点.结论 听力正常者耳蜗电图可作为临床诊断的参照依据.CAP的I/0曲线及-SP/CAP幅度比可提供耳蜗病变的诊断信息.CAP的潜伏期和阈值可反应耳蜗内、外毛细胞的功能.     

正常青年人气骨导听性脑干反应的比较研究

目的 比较气、骨导听性脑干反应（ABR）测试结果的差异，为骨导听性脑干反应的临床应用提供参考依据。方法 利用Nicolet spirit诱发电位仪，TDH－39P和Radioear B-71换能器，对一组听力正常青年人（男31耳，女30耳）进行短声气，骨导测试。结果 在阈值及阈上强度下，骨导ABR波形与气导类似，但各波引出率较气导低。听力正常青年男女之骨导短声ABR阈值间无差异（P＞0．05）；阈上60dB三声刺激下Ⅰ、Ⅲ、Ⅴ波潜伏期及Ⅰ-Ⅴ波间期亦无差异（P＞0．05）。骨导短声ABR与气导短声ABR比较显示：前者阈值高于后者（P＜0．01），两者间呈显著的正相关（r=0.7740)；短声阈上60dB强度刺激下，前者Ⅰ、Ⅲ、Ⅴ波潜伏期均大于后者（P＜0．01），但两者Ⅰ-Ⅲ，Ⅲ-Ⅴ，Ⅰ-Ⅴ波间期无差异（P＞0．05）。结论 骨导听性脑干反应测试的应用具有一定的局限性，但对部份不适于气导ABR检测的患者，仍有其临床使用价值。     

轻度感音神经性听力损失婴儿骨导ABR检测结果分析

目的探讨骨导听性脑干反应(ABR)检测在婴儿轻度感音神经性听力损失诊断中的价值。方法分别对30例(52耳)轻度感音神经性听力损失婴儿(患儿组)和30例(60耳)听力正常婴儿(正常组)行骨、气导ABR检测,并对两组结果进行分析比较。结果从40 dB nHL刺激强度开始,随着刺激强度下降,患儿组骨导ABR波V引出率逐渐下降;在40 dB nHL刺激强度下,患儿组骨导ABR波Ⅰ、Ⅲ、Ⅴ潜伏期较正常组稍延长,但差异无显著统计学意义(P>0.05)。患儿组骨、气导ABR反应阈均较正常组显著升高(P<0.05),但两组骨气导反应阈差值无明显差异(P>0.05)。结论骨导ABR检测对轻度感音神经性听力损失婴幼儿听力损失性质的鉴别诊断和评估具有重要的临床参考价值。     

One‐stop neck lump clinic: phase 2 of audit. How are we doing?

One‐stop neck lump clinic: phase 2 of audit. How are we doing? Regular monitoring and audit of a service are integral to ensuring maintenance of efficiency and standards. This is particularly important where the quality of the service is operator dependent, as is the case in the clinical diagnosis of neck lumps and fine needle aspiration cytology. The one‐stop neck lump clinic has now been running in the department for more than 20 months. A previous article described the results of the first phase audit carried out at 6 months and had identified a waiting time to be seen that was longer than that recommended by the British Association of Otorhinolaryngologists, Head and Neck Surgeons. Measures were implemented to reduce this waiting time and a second audit was carried out after another 10 months with the aims of assessing if modification of the means of referral reduces waiting time and if the outcomes of clinical performance in phase 1 could be maintained or improved. We discuss the results of phase 2 in the audit spiral.     

A Decrease in Maxillary Sinus Pressure,as Seen in Upper Airway Allergy or Infection,Results in an Increase in Upper Airway Nitric Oxide Levels

The paranasal sinuses are connected to the nasal cavity via small osties. Ostial occlusion, caused by mucosal swelling, will result in a slowly increasing negative pressure inside the sinus cavity. In parallel, the oxygen content in the sinus will decrease, resulting in the development of relative hypoxia. Hypoxia is a powerful inducer of nitric oxide (NO) synthase, and inducible NO synthase has been shown to be present in considerable amounts in the upper airways, including the sinuses. The present study was designed to investigate whether a reduction in sinus pressure would affect upper airway NO production. Thirteen healthy volunteers were investigated. A pressure chamber was used to lower the ambient pressure to-4.9 kPa. NO was sampled from one nostril or via a drainage tube inserted into the maxillary sinus before, during and after the hypobaric exposure. When the pressure was decreased, NO levels increased from 256 &#45 15 to 316 &#45 19 ppb ( n =13, p <0.001). The NO levels remained elevated (282 &#45 21 ppb; p <0.05) when measurements were repeated 20 min after leaving the chamber. The nasal airway resistance (V2 tot ) also increased as a result of the chamber session (from 16 &#45 2° before to 21 &#45 3° after; p <0.05). An increase in NO levels was also found when the experiments were repeated with NO sampled directly from the maxillary sinus (225 &#45 6 before and 265 &#45 9 ppb after; n =6, p <0.001). For control purposes the nasal analyses were repeated again, this time under hyperbaric conditions (+4.9 kPa). This resulted in a slight decrease in the NO levels (from 273 &#45 22 to 241 &#45 17 ppb; n =10, p <0.001), but there was no change in the nasal airway resistance. We conclude that a reduction in sinus pressure, as seen in upper airway allergy or infection, may result in an increase in upper airway NO production.     

Physiologische Grundlagen einer Hörprothese

Zusammenfassung Im Bemühen, eine Hörprothese zu entwickeln, die ein Sprachverständnis erlaubt, erscheint es zumindest fürs erste am zweckmäßigsten, durch künstliche elektrische Reizung des Hörnerven die natürlichen Verhältnissen so gut als möglich zu imitieren. Der normale Hörnerv enthält etwa 30000 Nervenfasern, die sich qualitativ gleich, quantitativ jedoch unterschiedlich verhalten, wobei über die Eigenschaften der von den ÄHZ kommenden Spiralfasern im Augenblick sichere Aussagen nicht möglich sind (siehe 2.3). Die quantitativen Unterschiede zwischen den einzelnen Hörnervenfasern beziehen sich auf deren Frequenzabstimmung, Frequenzselektivität, Schwellen, Intensitätsfunktionen und — wichtig insbesondere für das Vorhaben einer künstlichen elektrischen Reizung — in Zeitunterschieden in den Aktivitätsmustern, die durch Laufzeitunterschiede auf der Basilarmembran bedingt sind (2.3). Diese Zeitunterschiede in der Aktivität einzelner Fasern liegen im Bereich mehrerer ms (2.3.6; 2.3.7). Die durch Schallreize im normalen Hörnerven ausgelösten Aktionspotentiale haben überdies einen probabilistischen Charakter, d. h. ihr Auftreten ist keineswegs streng determiniert. Es versteht sich von selbst, daß man bei künstlicher, elektrischer Reizung nicht alle verbliebenen Nervenfasern selektiv reizen kann. Somit wird eine Reizelektrode immer eine Gruppe von Nervenfasern erregen müssen. Bei jeder denkbaren elektrischen Reizung wären alle Fasern im Reizbereich einer Elektrode synchron und streng deterministisch aktiviert, was einen außerordentlich ernstzunehmenden Unterschied zu natürlichen Verhältnissen darstellt (3.2).Um die Zahl der zum Sprachverständnis mindestens notwendigen Reizkanäle abzuschätzen, wird man, in Ermangelung anderer experimenteller Daten, von psychoakustischen Untersuchungen an Normalhörenden auszugehen haben. Diese haben gezeigt, daß das Gehör neben einer außerordentlichen Fähigkeit verschiedene Tonhöhen zu unterscheiden, andererseits die Fähigkeit besitzt, bestimmte Frequenzgebiete zu sogenannten Frequenzgruppen zu integrieren. Die in eine solche Frequenzgruppe fallende Schallenergie wird zu einem einheitlichen Höreindruck verarbeitet. Es scheint also sinnvoll, die für einen Prothesenbau notwendige Zusammenfassung von Gruppen von Fasern des Hörnerven in verschiedene Reizkanäle entsprechend diesen Frequenzgruppen vorzunehmen (3.1). Demnach müßte der Sprachbereich in 15 Reizkanäle aufgeteilt werden, was wiederum, wenn man in der Cochlea reizen will, 1,2 mm Abstand von Kanal zu Kanal erlauben würde. Dabei müßte der Reizerfolg sauber auf die einzelnen Kanäle beschränkt bleiben, d.h. eine optimale Kanaltrennung erreicht werden. In Anbetracht der groben Abweichungen der neuronalen Aktivität vom normalen Verhalten, die bei künstlicher, elektrischer Reizung unvermeidlich sind, ist freilich unsicher, ob die angegebene Zahl ausreichen würde. Andererseits ist es in Anbetracht der zu erwartenden Stromverteilung im Sprachbereich kaum vorstellbar, mehr als die angegebene Zahl von Kanälen realisieren zu können.Was die Kodierung der Schallparameter innerhalb eines Elektrodenkanals betrifft, wird vorgeschlagen, die Frequenzkodierung nach dem Ortsprinzip optimal auszunutzen, und im Hinblick auf die Periodizitätsanalyse und die Lautheitskodierung sich soweit als möglich den natürlichen Verhältnissen anzunähern (3.3). Dabei wären Laufzeitunterschiede zwischen den Kanälen und der probabilistische Charakter der neuronalen Entladungen soweit als möglich einzuführen, um die Dominanz eines periodicity pitch zu vermeiden.Eine für Sprachverständnis ausreichende Prothese ist auch nur denkbar, wenn eine Prothese die zur Sprachübertragung notwendige Übertragungskapazität besitzt. Ergebnisse der Kanal-Vocoder-Technik zeigen, daß Sprache noch mit 1500 bit/s befriedigend übertragen werden kann. Eine Abschätzung der möglichen Leistungsfähigkeit einer 15-kanaligen Prothese (3.4), basierend auf der Zahl der möglichen unterscheidbaren Unterschiedsstufen der Hörempfindung, ergibt, daß diese Übertragungskapazität knapp erreicht werden könnte. Allerdings ist damit noch nicht gesagt, daß das Zentralnervensystem die angebotene Information auch im Sinne einer Phonemanalyse auswertet und damit für ein Sprachverständnis maximal ausschöpft. Nur für diesen Fall wäre ein Sprachverständnis zu erwarten.Als Reizort erscheint in erster Linie die Cochlea (5.1) geeignet. Für den Fall einer Degeneration der primären afferenten Fasern des Hörnerven ist aufgrund physiologischer Überlegungen auch der Nucleus cochlearis ventralis (5.5) interessant, allerdings würde so nur der ventrale Anteil der Hörbahn stimuliert. Doch besitzen auch andere Reizorte spezifische Vorteile (5.2–5.4).Theoretische Überlegungen (6.1) und experimentelle Messungen an implantierten Elektrodensätzen (6.3) zeigen, daß die Forderung der Kanaltrennung nur schwer zu erreichen sein wird. Deswegen wird der dynamische Bereich (im Hinblick auf Veränderung des Reizstromes) eines nach den obigen Kriterien konstruierten Reizkanals auf maximal 3 dB zu beschränken sein, so daß Erregungsausbreitung auf weitere Bereiche der Cochlea durch Ansteuerung von mehreren Reizkanälen zu imitieren wäre.Die Chancen, eine Prothese zu verwirklichen, die befriedigendes Sprachverständnis auf der Basis einer quasinatürlichen Reizung des Hörnerven erlaubt, wird von uns in Anbetracht der geschilderten mannigfaltigen Schwierigkeiten als sehr niedrig angesehen. In Anbetracht des großen Nutzens, der andererseits eventuell resultieren könnte, halten wir die Erforschung des Problems jedoch für angebracht.Es wird von uns vorgeschlagen, auch zu untersuchen, ob sich für eine prothetische Versorgung vorverarbeitete Sprache besser eignet (7.). Für Prothesen, die ein Sprachverständnis nicht anstreben, halten wir eine Implantation in die Cochlea für überflüssig. Hier erscheint uns die Implantation von Reizelektroden am runden Fenster (Douek et al., 1977; Fourcin et al., 1978; s. a. 1. und 7.) wegen des geringeren Risikos der überlegenere Weg.Die zitierten eigenen Arbeiten der Autoren wurden mit Unterstützung der DFG durchgeführt (DFG-K1 219).     

The expression of vascular endothelial growth factor (VEGF) and VEGF‐C in early laryngeal cancer: relationship with radioresistance

The expression of vascular endothelial growth factor (VEGF) and VEGF‐C in early laryngeal cancer: relationship with radioresistance Angiogenesis is essential for tumour growth and invasion. Vascular endothelial growth factor (VEGF) is a prime mediator of tumour angiogenesis. VEGF‐C is a closely related protein that effects lymphatic endothelial cells and may be important in the process of lymphatic metastasis. The purpose of this study was to evaluate the expression of these cytokines in patients with T1 and T2a glottic, squamous cell carcinoma, in comparison with normal epithelial control tissue, to ascertain any association with radioresistance. Twenty‐two tumours treated by radiotherapy (13 radiosensitive, nine radioresistant) and seven normal control tissues were studied. The minimum follow‐up was 2 years after radiotherapy. Expression of VEGF and VEGF‐C was evaluated by immunohistochemistry of formalin‐fixed, paraffin‐embedded biopsy specimens. Analysis was carried out using a quantitative computer image analyser. Both VEGF and VEGF‐C were detectable in tumour and normal control specimens. There was increased expression in tumour specimens of both VEGF (P = 0.03) and VEGF‐C (P < 0.001). In addition, the expression of VEGF‐C was associated with tumours of higher histological grade (P = 0.021). There was, however, no difference in VEGF and VEGF‐C expression between radioresistant and radiosensitive tumours. The expression of VEGF and VEGF‐C is increased in early laryngeal squamous cell carcinoma (SCC). However, measuring the expression of these proteins cannot predict radioresistance in this tumour group.     

Treatment of Maxillary Sinus Carcinoma: Clinical Results Using the Kitasato Modality

The conventional therapeutic regimen for maxillary sinus carcinoma consists of dissection of the maxilla, full-dose irradiation and extensive chemotherapy. However, the results obtained with this treatment are often poor. Even when patients recover, their quality of life is significantly reduced as a result of deformity of facial structures and swallowing and articulation dysfunctions. A retrospective analysis of 68 patients with maxillary sinus carcinoma treated with the Kitasato modality between 1975 and 1999 was conducted. All patients underwent pergingival maxillary sinus surgery combined with pre- and postoperative irradiation therapy with standardized total doses of 16 Gy; the postoperative irradiation was given in combination with regional intra-arterial infusion chemotherapy administered via the superficial temporal artery. All visible tumor lesions were removed where possible in order to preserve or facilitate cellular immunity after surgery. The cumulative 5-year survival rates were 85.7% for Stage II patients, 88.1% for Stage III, 76.6% for Stage IVA and 75.0% for Stage IVB.     

Limited Surgery for Cancer of the Larynx and Hypopharynx: Options and Consequences

We reviewed surgical options for laryngeal preservation (limited surgery) in laryngeal and hypopharyngeal cancers and the consequences of the options. Of 44 patients with laryngeal cancer, 11 (25%) received limited surgery and 33 (75%) received total laryngectomy. The survival rates were 91% for the limited surgery group and 73% for the total (radical) surgery group. Of 31 patients with hypopharyngeal cancer, 7 (23%) received limited surgery and 24 (77%) received total laryngopharyngectomy. The survival rates were 53% for the limited surgery group and 40% for the total (radical) surgery group. The survival rates associated with limited surgery were thus better than those for total (radical) surgery for cancers of both the larynx and hypopharynx. This was attributed to the limited surgery group comprising well-selected patients with confined lesions. Organ preservation surgery should be technically simple, reliable in terms of its functional impact and, above all, should not jeopardize the patient's survival. Supracricoid subtotal laryngectomy with cricohyoidoepiglottopexy or cricohyoido-pexy has great potential for laryngeal preservation and will become the major limited surgery modality for treating cancer of the larynx. Limited surgery, however, needs to be performed with great care and is indicated only for very well-selected patients with cancer of the hypopharynx.     

Cervical Reflex Induced by Click Stimuli in Cats

We studied click-evoked potentials in the anterior horn of the spinal cord in 17 cats. A concentric needle electrode was inserted into the anterior horn of the spinal cord at levels C3-C6. Potentials evoked with 105 dB SPL clicks were recorded with a peak latency of 4.89-5.10 ms only at the C3 level. These responses were observed 45-60 dB SPL above the auditory brainstem response (ABR) threshold, and no potentials were evoked by stimulation of the contralateral ear. Average was performed 100 times with changes in stimulation frequency of 1-20 Hz. The amplitude of the potentials decreased with increasing stimulus frequency, but there were no changes in ABRs. The responses disappeared after destruction of the medial vestibulospinal tract at the obex level, but ABRs were still recorded. The spinal nucleus of the accessory nerves was located in the anterior horn of the spinal cord at levels C1-C6, and the sternocleidomastoid muscle motoneurons were found at levels C1-C3. The click-evoked potentials recorded in this study reflect responses of the spinal nucleus of accessory nerves through the vestibulospinal tract to click stimulation. The responses have the same characteristics as vestibular-evoked myogenic potentials that can be recorded using surface electrodes over the sternocleidomastoid muscles of humans.     

Tongue Base Reduction with Temperature-controlled Radiofrequency Volumetric Tissue Reduction for Treatment of Obstructive Sleep Apnea Syndrome

In recent years a considerable effort has been made to establish the use of different surgical techniques for the treatment of obstructive sleep apnea syndrome (OSAS). Nevertheless, treatment of hypopharyngeal obstruction due to tongue base hypertrophy remains in many ways an unsolved problem. The aim of this study was to evaluate the safety and efficacy of tongue base reduction with temperature-controlled radiofrequency volumetric tissue reduction in the treatment of OSAS. Twenty patients with OSAS and tongue base hypertrophy were treated with radiofrequency tissue ablation. An intensified treatment protocol was used, delivering 2,800 J per treatment session under local anesthesia. Two nights of polysomnography testing were performed before and after treatment. Daytime sleepiness, snoring and postoperative morbidity were assessed using questionnaires. Mean respiratory disturbance index (RDI) was reduced from 32.1 to 24.9/h after a mean of 3.4 treatment sessions. Six patients (33%) were cured after the procedure (reduction in RDI of &#83 50% and a postoperative RDI of <15/h) and ten (55%) showed an improvement of >20% in their RDI. Daytime sleepiness and snoring improved significantly. Peri- and postoperative morbidity was low; one severe complication occurred (tongue base abscess). We were able to achieve similar cure and responder rates to those reported in a recently published pilot study but with a reduced number of treatment sessions. We believe that this technique may improve patient acceptance and have beneficial cost implications.     

Cochlear Function in Ears with Immunomediated Inner Ear Disorder

The aim of the present study was to evaluate the performance of ears with inner ear disorder, responsive to immunosuppressive drugs, in advanced tests designed to assess primary cochlear functions (temporal integration, frequency selectivity, cochlear mechanics). The results of this study suggest that immunomediated inner ear disease results, in the acute clinical stage, in the development of endolymphatic hydrops, which increases the stiffness of the vibrating structures within the inner ear and causes dysfunctions of the outer hair cells. Our patients presented with upsloping or flat sensorineural hearing loss, absence of evoked otoacoustic emissions and distortion-product otoacoustic evoked emissions and abnormal temporal integration, frequency selectivity and cochlear mechanics. Following immunosuppressive treatment, hydrops recovered, hearing subsequently returned to normal, the audiometric curve became flat at low-to-middle frequencies and primary cochlear function tended to normalize. This study seems to support the usefulness of testing primary cochlear functions in order to monitor the clinical course of immunomediated inner ear disorders.     

Bacterial Interference Between Pathogens in Otitis Media and Alpha-Haemolytic Streptococci Analysed in an In Vitro Model

Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alphahaemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the interference activity studied using agar overlay methods. We found that non-typeable Haemophilus influenzae (NTHI) and Moraxella catarrhalis are readily inhibited by AHS in broth. Streptococcus pneumoniae was more bacteriostatically inhibited. If two OM pathogens were inoculated simultaneously, an isolate of AHS with poor inhibitory activity was not able to inhibit the growth, in contrast to an isolate of AHS with good inhibitory activity. The initial amount of AHS inoculated with M. catarrhalis seemed to play a decisive role with respect to the inhibitory activity. M. catarrhalis developed reduced susceptibility against AHS both in vivo and in vitro . In vivo studies showed that children with secretory otitis media had fewer isolates of AHS in their nasopharynx with the ability to inhibit all the test pathogens than healthy children ( p < 0.001). Although the factor(s) responsible for the inhibitory activity have thus far not been defined, we could exclude low pH and nutrition depletion as the inhibitory mechanism of AHS with good inhibitory activity.