Rapid Increase in Neural Conduction Time in the Adult Human Auditory Brainstem Following Sudden Unilateral Deafness

Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.     

Dorsal suspension for Morton’s neuroma: A comparison with neurectomy

BackgroundThe purpose of this study was to investigate and compare the clinical outcomes of dorsal suspension with those of neurectomy for the treatment of Morton’s neuroma.MethodsWe conducted a retrospective study of dorsal suspension and neurectomy group. The dorsal suspension was performed by dorsal transposition of neuroma over the dorsal transverse ligament after neurolysis. The visual analog scale (VAS), the Foot and Ankle Ability Measure (FAAM), postoperative satisfaction, and complications were evaluated.ResultsBoth groups reported significant pain relief, and there were no significant differences between the groups with respect to postoperative pain. The postoperative FAAM outcomes showed no significant between-group differences. Satisfaction analysis showed ‘excellent’ and ‘good’ results in the dorsal suspension and neurectomy groups (95% and 77.7%, respectively). Complications of numbness and paresthesia reported in the dorsal suspension group (5% and 5%, respectively) were significantly fewer than those of neurectomy group (61.1% and 33.3%, respectively) (both, p < .05).ConclusionsWith its favorable results, dorsal suspension can be another operative option for the treatment of Morton’s neuroma.Level of Evidence: Level III, retrospective comparative case series.     

听神经瘤术中耳蜗电图监测与听力保护

目的：评价耳蜗神经电位活动直接监护在听神经瘤手术中对保护听力的作用。方法：听神经瘤手术中施行耳蜗电图监护。结果：１６例听神经瘤手术中施行耳蜗电图监护者，术后听力保留５例（３１％），其中４例为有效听力保留。肿瘤在２厘米以下者听力保留为３８％（５／１３）。结论：听神经瘤手术过程中采用耳蜗电图监护，能敏感地反应即时的听神经功能状况，给术者及时的反馈信息，有助于听力保护     

Acoustic rhinometry in pre-school children

Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34±0.06 cm², 0.35±0.08 cm² and 1.37±0.48 cm² respectively. The average minimal cross-sectional area was 0.29±0.06 cm². The minimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal tubinates in 21 of the 35 children. As would be expected, the cross-sectional areas at different sites of the nasal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm² per year, the nasopharyngeal cross-sectional area increased by 0.20 cm² per year. No significant differences were found between boys and girls. Measurements of the posterior nasal and nasopharyngeal cross-sectional areas were unreliable, whenever the minimal cross-sectional area was less than 0.2 cm². Furthermore, assessment of the nasopharynx may be difficult because of involuntary movements of the soft palate.     

The value of the acoustic analysis of pathological infant cry and breathing noise in everyday practice

During a period of twenty years [1969-1988] the author has observed 614 cases of congenital malformations and noninflammatory diseases of the larynx in infants and young children, Budapest. He summarizes the most characteristic symptoms of laryngeal pathology in infants, and discusses the diagnostic possibilities. Among the latter, spectrographic analyses complemented by auditory evaluation of pathological cry and different breathing noises play an important role. Based on his investigation author differentiates 20 kinds of pathological crying sounds and 4 basic forms of stridor. He describes the acoustic attributes of different pathological sound phenomena and summarizes characteristic voice changes.     

富含血管的听神经瘤

目的探讨富含血管的听神经瘤的手术治疗。方法复习20年（1975—1995）手术治疗单侧听神经瘤90例，其中4例为富含血管的听神经瘤（HAT），与86例非富含血管的听神经瘤（NHAT），做回顾性分析，据临床表现、放射学检查、手术所见做比较。结果HAT较NHAT年轻（28±10与54±17岁）（P〈0．01），MRI显示HAT为实质性，无肿瘤囊变，多数较NHAT为大（P〈0．05）；MRI示HAT有多个代表较大引流静脉的流空效应；经皮股动脉、椎动脉造影显示HAT有广泛的肿瘤着色及早期引流静脉的充盈，并证实由椎基动脉供血。过去文献报道认为以分期手术为宜。作者在控制性低血压麻醉下，成功地完成了4例HAT的切除术，未输血，术后无明显伤残。结论HAT是一种实质性大型肿瘤，出现于青年期，血管造影能够提供特征性发现。MRI能显示肿瘤表面的流空效应而确诊。采用控制性低血压麻醉有望能一期全切除肿瘤。     

近端/远端复合肌肉动作电位振幅比率在术后面神经功能评估上的价值

目的 探讨近端/远端复合肌肉动作电位振幅比率在术后面神经肿瘤侵犯段功能评估上的价值和对早期面神经修复的指导意义。方法 比较术末面神经近端/远端复合肌肉动作电位振幅比率和术后2周、6个月患侧面神经功能的H-B分级之间的关系。结果 术后6个月面神经H-B分级恢复到Ⅰ-Ⅱ级者,术末近端/远端复合肌肉动作电位振幅比率均>0.3。结论 术末面神经近端/远端复合肌肉动作电位振幅比率是判断术后面神经远期功能,特别是肿瘤侵犯段功能的重要指标,为术中直接修复面神经提供了指导依据。     

两种MRI序列对听神经瘤成象的比较与评价

为选择中等场强的ＭＲＩ听神经瘤成像最佳序列。收集手术和病理证实的听神经瘤１３５例，分析序列Ⅰ、Ⅱ对内听道中心层面、三叉神经显示率及ＭＲ征象的显示情况。结果：序列Ｉ择内听道中心层面及三叉神经的显示均优于序列Ⅱ，序列Ⅱ在显示肿瘤内囊变、出血、不肿优于序列Ｉ；对肿瘤钙化、肿瘤血管、脑干移位的观察，两者相仿。结果显示：序列Ｉ在中等场经下作为听神经瘤成像的首选序列，并中运用到小脑角区ＭＲＩ成像。