The prevalence of vestibular schwannoma among patients treated as sudden sensorineural hearing loss

Objective

To assess the prevalence of vestibular schwannoma (VS) in patients with sudden sensorineural hearing loss (SSNHL).

A cochlear schwannoma presenting with sudden hearing loss

A cochlear schwannoma is a rare tumor that arises from the cochlear nerve. Clinically, a cochlear schwannoma mimics the clinical features of sudden deafness or Meniere's disease. We report a case of cochlear schwannoma that presented with sudden hearing loss, which was diagnosed with gadolinium-enhanced magnetic resonance imaging and removed using a transotic approach.     

一例神经纤维瘤患者植入人工耳蜗的效果观察

目的：探讨神经纤维瘤听力下降患者人工耳蜗植入手术可行性及疗效。方法对一例多发性神经纤维瘤伽马刀术后患者带瘤行CS-10A人工耳蜗植入,术前和术后3个月分别进行裸耳/助听听阈评估、单音节和双音节言语识别测试。结果患者术前右侧重度、左侧极重度感音神经性聋,术前言语识别率左耳最大声输出患者无反应,右耳最大单音节词言语识别率为12%,双耳双音节词言语识别率均为0%。听觉行为分级量表为2级。患者右侧成功植入人工耳蜗。术后3个月助听后声场评估右耳（人工耳蜗植入耳）平均听力42.5 dB HL,单音节词最大言语识别率为64%,双音节词最大言语识别率为47%,听觉行为分级量表为7级。结论在影像学证明听神经完整的情况下,神经纤维瘤伽马刀术后重度聋患者可植入人工耳蜗,以提升听力水平。     

Stereotactic radiotherapy in three weekly fractions for the management of vestibular schwannomas

Purpose

This study evaluates the rates of tumor control, hearing preservation and cranial nerve toxicity with the use of CyberKnife stereotactic radiotherapy consisting of 2100?cGy to the 80% isodose line delivered in three weekly fractions to treat vestibular schwannomas.

Balance sensory organization in children with profound hearing loss and cochlear implants

OBJECTIVES: (1) To determine the feasibility of the use of a modified postural control test under altered sensory conditions in children over 8 years of age, and (2) to assess how deaf children use sensory information for postural control when they have normal or abnormal vestibular responses, and if hearing input from a unilateral cochlear implant, changes their postural behavior. PATIENTS: We selected 36 children, 8 to 11 years of age, with congenital or early-acquired profound sensorineural hearing loss, 13 of them with unilateral cochlear implantation and 22 normal-hearing children. METHODS: The Postural Control (PC) test consists of a force platform with 2 stimulation paradigm conditions: (1) standing on the platform with opened eyes; (2) standing on foam placed on the force platform with closed eyes. Implanted children were tested with the implant turn on and turn off in this condition, in order to evaluate eventual change in the postural control parameters when they have hearing habilitation. The body center of pressure distribution area (COP) and the body sway velocity (SV) were the parameter to evaluate the postural control. RESULTS: Deaf children were classified into two groups according with the vestibular responses: group A (n=28) Children with normal vestibular rotary responses; group B (n=8) children with hypoactive responses. Children in group A had diagnoses of syndromic and non-syndromic hereditary deafness, and children in group B had inner ear malformations, post-meningitis deafness, and one child had non-syndromic hereditary deafness with hypoactive vestibular response. In condition 1, when vestibular, somatosensory and visual information were enabled, the COP and SV values did not show any statistically significant differences between groups A, B and control. In condition 2, when visual information was removed and the somatosensory input strongly modified by standing on the foam, group B showed significant higher COP and SV values than groups A and control (p<0.05). In addition, the scalograms by wavelets of children in group B had higher amplitudes increasing the sway frequencies contents up to 3 Hz, not allowing them to maintain the up right stance in similar stimulation than in condition. Implanted children of the group A and B with the implant turn on, in the condition 2, did not show any significant difference in the SV, comparing when they had the implanted turn off. Group A p=0.395 and group B p=0.465 (Wilcoxon ranked test). CONCLUSION: These findings allow us to confirm that this postural test can be performed in children over 8 years old. Also our results suggest that deaf children with associated hypoactive vestibular responses included in our study, despite the etiology of the deafness, primarily use visual and somatosensory information to maintain their postural control. Hearing habilitation with a unilateral cochlear implant has no effect on the observed sensory organization strategy.     

Outcomes of cochlear implantation in patients with neurofibromatosis type 2

In neurofibromatosis type 2 (NF2) bilateral vestibular schwannomas (VS) or their treatment usually results in bilateral hearing loss. Cochlear implantation (CI) was traditionally not used in these patients due to concern that retrocochlear disease would render the implant ineffective. This paper describes the auditory outcomes of CI in 13 patients with NF2 and includes patients with untreated VS and patients undergoing VS removal with cochlear nerve preservation. The non-user rate was 7.7%. Of the active users, median CUNY score was 98%, median BKB score in quiet was 90% and median BKB score in noise was 68%. CI is a viable option in selected patients with NF2.     

Progressive familial hearing loss in Muckle-Wells syndrome

Conclusion. The tumor size of acoustic neuroma correlates with cochleovestibular deficits. Those tumors with global frequency hearing loss, bilateral gaze nystagmus, or absent caloric and VEMP responses may indicate a tumor size >2.5 cm. Objective. This study aimed to investigate the correlation between cochleovestibular deficits and the size of acoustic neuroma. Patients and methods. A total of 44 patients with acoustic neuroma were enrolled in this study. Pure tone audiometry, electronystagmography, caloric test, vestibular evoked myogenic potential (VEMP) test, and MRI were conducted. Results. There is a trend of correlation between tumor size and audiographic configuration, with small-sized tumor in normal and rising types, medium-sized tumor in mid- and high-frequency hearing loss, and large-sized tumor in flat and deafness types. Five patients with bilateral gaze nystagmus had significantly larger tumor size than those without nystagmus. When 1 and 0 are used to represent abnormal and normal responses, respectively, the relationship between tumor size and vestibular function can be expressed as: tumor size (cm)=1.43 (caloric response)+1.35 (VEMP response), indicating that the estimated tumor size for those with abnormal caloric or VEMP responses increased by 1.43 or 1.35 cm, respectively.     

Neurofibromatosis 2: hearing restoration options

Neurofibromatosis 2 (NF2) is an autosomal dominant disease in which hearing loss is predominant. Auditory restoration is possible using cochlear implants (CI) or auditory brainstem implant (ABI).ObjectiveTo assess the auditory results of CI and ABI in NF2 patients and review the literature.MethodsFour NF2 patients were prospectively evaluated. They were submitted to tumor resection followed by ipsilateral CI or ABI depending on cochlear nerve preservation. Long term auditory results were described for CI (12 months) and ABI (48 months).ResultsAll patients achieved auditory perception improvements in their hearing thresholds. The CI patient does not recognize vowels or sentences. The 3 ABI patients discriminate 70% of vowels and 86% in the 4-choice test. One of them does not recognize sentences. The other two recognize 100% of closed sentences and 10% and 20% of open sentences.ConclusionThe choice of implant type to restore hearing to NF2 patients will relay on anatomical and functional cochlear nerve preservation during tumor resection surgery. Although our experience was different, the literature shows that if this condition is achieved, CI will offer better auditory results. If not, ABI is recommended.     

神经纤维瘤病Ⅱ型基因型与表型研究现况

神经纤维瘤病Ⅱ型(Neurofibromatosis Type 2,NF2)是一种常染色体显性肿瘤易感性综合征,典型临床表现为单侧或双侧听力下降,耳鸣和平衡障碍。前庭神经鞘瘤为该病特征,约95%患者出现双侧前庭神经鞘瘤,许多NF2患者也患有其他组织学上表现为良性的中枢神经系统肿瘤,如脑膜瘤和脊柱内室管膜瘤。该病是由22号染色体上NF2基因的遗传性突变或新发突变引起的。患者面临听力丧失,反复手术切除颅内和脊柱肿瘤,重要功能丧失以及预期寿命缩短。基于基因型与表型相关性研究,早期精准评估患者病情,为患者选择合适干预手段,提供预后相关依据具有重大意义。该篇归纳了NF2基因型与表型相关性研究中的主要进展。     

‘Compassionate use’ protocol for auditory brainstem implantation in neurofibromatosis type 2: Early House Ear Institute experience

Objective: To report the preliminary outcomes of auditory brainstem implantation (ABI) under a compassionate use protocol for two ABI devices that are not approved by the US Food and Drug Administration.

Methods: A retrospective review was performed of neurofibromatosis type 2 (NF2) patients who underwent microsurgery for vestibular schwannoma (VS) and placement of either the Cochlear ABI541 or Med-El Synchrony ABIs. Peri-operative and device- related complications were reviewed. Audiometric performance was also evaluated.

Results: Seven patients received either the Cochlear ABI541 (6) or the Med-El Synchrony ABI (1) after the resection of VS. No device or patient-related complications occurred to date. Surgical times and early audiological performance are similar to our previous experience with the Cochlear ABI24 device.

Conclusions: Early experience with the Cochlear ABI541 and Med-El Synchrony ABI devices under a compassionate use protocol suggest that both devices are safe with comparable utility to the Cochlear ABI24 device.     

神经纤维瘤病Ⅱ型误诊为双侧视网膜母细胞瘤一例

1临床资料患者,女,15岁。主因“左眼视力下降伴外斜视12年余”于2018年12月入住解放军总医院第一医学中心神经外科。患儿于2005年开始无明显诱因出现左眼视力下降伴外斜视,当时未予相关检查及治疗。上述症状持续缓慢加重,于2008年至某院眼科就诊行相关检查示:“双侧视网膜母细胞瘤、左眼球内占位、右侧视网膜前膜”,并行“双眼底肿物激光封闭术”,术后未行放化疗,治疗后患者左眼视力明显下降,仅存光感。2016年患者突然出现左侧周围性面瘫,左面部电极样疼痛,未予检查及治疗。2018年至某院眼科行检查示:“左眼白内障”,并行“左眼晶状体超声乳化吸除术”。     

Cochlear microphonics for hearing preservation in vestibular schwannoma surgery

OBJECTIVES: To determine whether cochlear function is beneficial in decision-making concerning the selection of hearing preservation surgery for vestibular schwannoma. STUDY DESIGN: Retrospective review of 44 patients undergoing tumor resection with a middle fossa approach. METHODS: Cochlear microphonics in electrocochleography together with tumor size, pure-tone average (PTA), speech discrimination score (SDS), auditory brainstem response (ABR), and compound action potentials were examined. As acoustic stimuli, short tone-bursts with frequencies of 0.5, 1, and 2 kHz were employed to measure cochlear microphonics and a click was used to obtain compound action potentials. We determined detection thresholds of cochlear microphonics and action potentials. RESULTS: The overall rate of preservation of serviceable hearing was 59.1% (26/44). There were significant differences between patients with and without serviceable postoperative hearing in PTA, SDS, finding of ABR, compound action potential detection threshold, and mean cochlear microphonic detection threshold (at 0.5, 1, and 2 kHz). However, tumor size was unrelated to hearing outcome. Serviceable hearing was preserved in 23 (76.7%) of 30 patients, with a mean cochlear microphonic detection threshold of 40 dB nHL or less, suggesting normal or slightly impaired cochlear function. Hearing recovery was recognized in three patients, who also had a mean cochlear microphonic detection threshold of 40 dB nHL or less. Of the three patients, two had lower cochlear microphonic detection thresholds than audiometric thresholds, demonstrating the existence of a retrocochlear component in their hearing loss. CONCLUSIONS: The cochlear microphonic detection threshold predicts not only hearing preservation but also hearing improvement in patients with vestibular schwannomas.