Recovery from repeated sudden hearing loss with corticosteroid use in the presence of an acoustic neuroma.

Sensorineural hearing loss of sudden onset may be the presenting symptom in up to 14% of patients with acoustic neuroma. We present the first reported case of sudden hearing loss in an only hearing ear with recovery to normal levels after steroid therapy on four separate occasions. Evaluation revealed a 1.5-cm acoustic neuroma. After middle cranial fossa decompression, a fifth episode with recovery after steroid use was documented. A review of the recent literature is presented, emphasizing the possible causation of sudden sensorineural hearing loss with recovery to normal in patients with acoustic neuroma. Modalities of therapy for the dilemma of the acoustic neuroma in an only hearing ear are discussed, including surgery, radiotherapy, and chemotherapy. An aggressive approach to the evaluation of the cause of sudden hearing loss is suggested.     

Acoustic neuroma presenting with sudden and fluctuating hearing loss--a case report

A case of acoustic neuroma presenting with sudden and fluctuating hearing loss is reported. The patient was a 38-year-old Japanese woman who noticed a sudden onset of hearing loss and tinnitus in the right ear. With a provisional diagnosis of sudden deafness, she was subjected to conservative therapy, including steroid hormone. The hearing started to recover and reached a normal level 2 months after the treatment. Meanwhile, the results of an ABR and plain skull X-rays aroused a suspicion of acoustic neuroma. She was operated on via a middle cranial fossa approach and an acoustic neuroma occupying the internal auditory meatus was removed.     

Sudden hearing loss induced by acoustic neuroma: Significance of small tumors

In our series of 111 patients operated on for acoustic neuroma from 1972 to 1990, 21 (18.9%) had sudden hearing loss. The 21 tumors involved were comprised of 9 small, 5 medium, and 7 large tumors. Emphasis is placed on the fact that even a small tumor has the potential to produce sudden hearing loss (SHL) and that the possibility of seeing patients with SHL is increasing thanks to advances in imaging diagnosis. Recognition of SHL as an initial symptom of acoustic tumor is considered essential to detect small acoustic neuroma.     

Pre- and post-operative brainstem responses in a case of acoustic neuroma, sparing the VIII nerve.

A case is reported of a patient with an acoustic neuroma presenting with a 2 month history of tinnitus and a 25dB hearing loss with evidence of recruitment. The neuroma was removed via a posterior fossa approach with preservation of hearing. Preoperative and postoperative brainstem electric response (BSER) studies are compared. The preoperative results demonstrated a marked reduction in amplitude and increase in latency on the affected side which returned to normal after removal of the neuroma.     

Pre- and post-operative brainstem responses in a case of acoustic neuroma,sparing the VIII nerve

A case is reported of a patient with an acoustic neuroma presenting with a 2 month history of tinnitus and a 25dB hearing loss with evidence of recruitment. The neuroma was removed via a postefior fossa approach with preservation of hearing. Preoperative and postoperative brainstem electric response (BSER) studies are compared. The preoperative results demonstrated a marked reduction in amplitude and increase in latency on the affected side which retunred to normal after removal of the neuroma.     

Differenzialdiagnosen einer beidseitigen akuten Hörminderung bei einem Patienten mit metastasierendem Bronchialkarzinom

The first symptom of an acoustic neuroma in about 50% of the patients is hearing loss, which occurs suddenly in about 5-10% of cases. Acute progressive hearing loss is associated with a broad spectrum of differential diagnoses. Cerebellar and hepatic metastases from a bronchial carcinoma were previously diagnosed in the case presented here, and the most probable causes of the progressive hearing loss, e.g. idiopathic sudden deafness, infection and tumor-associated factors, were considered and diagnostically analyzed. The discussion ultimately focused on the clinical and radiological signs of bilateral acoustic neuroma. The patient's history and clinical findings yielded no indication of neurofibromatosis (type 1/2). Nevertheless, the constellation of findings suggests that the bilateral hearing loss was caused by a bilateral acoustic neuroma.     

Sudden hearing loss as a presenting symptom of acoustic neuroma.

PURPOSE: Retrocochlear pathological findings may be suggested by findings on the brainstem response and acoustic sensorineural reflex (AR) tests. We describe the incidence of acoustic neuroma presenting as sudden hearing loss (SHL) and the effectiveness of the discrimination (DISC) test, the brainstem-evoked response, and AR test in predicting acoustic neuroma in patients with SHL. METHODS: We retrospectively reviewed the charts of all adult patients who presented to our center with sensorineural SHL between 1989 and 1995. Two groups were defined: those with cerebellopontine angle (CPA) tumor and those with negative imaging findings. Results of the brainstem-evoked response, AR, and DISC tests were compared. RESULTS: Forty patients were admitted with sensorineural SHL, of whom 19 (47.5%) had a CPA tumor. The latter group showed a significantly lower mean age and better results for the low frequencies on pure tone audiometry, as well as better brainstem-evoked response test results than the patients with negative imaging findings. There was also a significant difference between the groups for both the affected and unaffected ears on the discrimination test. CONCLUSION: Acoustic tumors may be a more common cause of sudden sensorineural hearing loss than previously suspected. The DISC test is a useful screening tool for acoustic tumor, whereas the brainstem-evoked response test shows poorer results in affected patients with sensorineural hearing loss than in other subgroups with different signs of acoustic neuroma. We recommend that young patients presenting with mild SHL who have normal results on the AR and brainstem-evoked response tests undergo magnetic resonance imaging to rule out CPA tumor.     

Disociación clínica-tamaño tumoral en el neurinoma del acústico: ¿realidad o problema de medida?

IntroductionIn this study we have analyzed (i) the audiometric frequencies more often affected in acoustic neuroma (AN), (ii) the percentage of patients presenting normal hearing and those with sudden hearing loss, (iii) if there is a correlation between tumor size and hearing loss, and (iv) the relationship between clinical and radiological parameters and audiological data.Methods and MaterialRetrospective study of 81 patients undergoing surgical removal of a sporadic AN.ResultsThe highest threshold in the tumor´s ear was found at 8000 Hz, and the highest interaural difference at 4000 Hz. The percentage of patients presenting normal hearing and sudden hearing loss was 2.5% and 9%, respectively. No significant association was found between tumor size and hearing loss, preoperative facial palsy or Vth cranial nerve deficit. There was a significant association between the degree of hearing loss and Vth cranial nerve deficit, and between hearing loss and preoperative facial palsy.ConclusionsThe association between hearing loss and Vth cranial nerve deficit, and between hearing loss and preoperative facial palsy is independent the size of the tumour.     

Coexistence of acoustic neuroma and pineal region tumor in patient with sudden deafness

INTRODUCTION: Acoustic neuroma usually presents as an unilateral tumor, seldom - bilateral and rarely in coexistence with other central nervous system neoplasms. The following paper reports such a case of a 21-year-old male patient presented with sudden deafness in left ear accompanied with tinnitus and vertigo. Symptoms started 4 weeks prior hospitalization. Their aggravation has been observed 7 days before admission to the hospital. Audiometry revealed moderate sensorineural hearing loss in left ear (for low and middle frequencies), brainstem auditory evoked potentials were absent on the left side and ENG examination showed left peripheral vestibular impairment. Initially patient received i.v. vasodilatators showing 20-25 dB improvement in low frequencies after 3 days of treatment. MRI study revealed in the left internal acoustic meatus mass (7 x 7 x 14 mm) suggesting acoustic neuroma and an oval mass (7 x 9 x 14 mm) in the pineal gland presenting radiological features of pinealoma. Patient has been qualified for neurosurgical treatment. Acoustic neuroma has been removed by suboccipital approach and pinealoma has been left for further observation as it was found incidentally. Histopathological examination confirmed diagnosis of left VIII nerve schwannoma. The left facial palsy (House-Brackmann III/IV grade) and profound hearing loss appeared after surgery. The postoperative course shows no evidence of acoustic neuroma recurrence.     

Hearing recovery following suboccipital excision of acoustic neuroma

Improvement of hearing after excision of an acoustic neuroma has been observed infrequently. We present a case of dramatic recovery of hearing in a patient with a 1-cm acoustic neuroma whose pure-tone thresholds and speech discrimination had profoundly deteriorated while she awaited surgical therapy. Postoperatively, her hearing in the affected ear is equal to that in her other ear, and her speech discrimination exceeds that of her best preoperative audiogram. Issues related to hearing preservation and improvement after acoustic tumor surgery are discussed.     

Unilateral acoustic neuroma in childhood

Three cases of unilateral acoustic neuroma in childhood that are associated with neither neurofibromatosis type 1 nor type 2 were reported. All three cases had a hearing disorder as an initial symptom. Two of them had a large neuroma and had considerable abnormal findings in neurootological examinations, and one case with an intracanalicular tumor showed a unilateral progressive sensorineural hearing loss that had no response to steroid administration. Surgical removal of the tumor was carried out for these cases. Different approaches were used in each case; suboccipital approach, one-stage suboccipital and middle fossa approach, and middle fossa approach. Although the facial nerve functions were fairly well maintained, hearing preservation could not be attained in all. Papers dealing with this tumor were reviewed, and certain characteristics of cases with acoustic neuroma in childhood were discussed.     

Otosclerosis masking coexistent acoustic neuroma

The coexistence of an acoustic neuroma with otosclerosis can prove to be a great diagnostic dilemma. In such cases, the diagnosis of acoustic neuroma is usually delayed while more common causes of sensorineural hearing loss associated with otosclerosis or its surgery are considered. Any asymmetric progression of a sensorineural loss or shift in discrimination after stapes surgery, whether sudden or gradual, should provoke suspicion of a second pathologic process. These include perilymph fistula, labyrinthine otosclerosis or ischemia, and acoustic neuroma. The use of auditory brainstem response and acoustic reflex testing and various imaging techniques is essential for accurate diagnosis. This paper includes two cases that demonstrate this dual pathology, bringing the total to 15 such cases reported in the literature. The purposes of this paper are to alert the clinician to the diagnostic problem of acoustic neuroma coexisting with otosclerosis and to propose a means of evaluating these patients.     

听神经瘤误诊分析

对经耳鼻咽喉科首诊，最终由神经外科手术全切或部分切除的经病理证实的７２例听神经瘤进行早期误诊分析，误诊时间平均５．５年，误诊病种为神经性耳聋、突发性耳聋、神经性耳鸣、颈椎病、鼻咽癌等。文中重点讨论了误诊原因。     

Acute inner ear deafness]

Sudden inner ear hearing loss initially might suggest a psychogenic disorder of hearing, particularly when it is bilateral and simultaneous. The differential diagnosis includes disseminated encephalitis, syphilitic labyrinthitis and Cogan's syndrome. The history and cause of acute bilateral deafness in meningitis are easy to recognise. Furthermore, unilateral acute inner ear deafness should not be regarded as idiopathic without further consideration. A acoustic neuroma is a possible cause even of a low-tone hearing loss. More controversial is rupture of the round window membrane as a cause of sudden deafness. The deafness after epidemic parotitis obviously leads to a total unilateral hearing loss in every case. Even labyrinthine apoplexy with loss of hearing and vestibular function can be caused by a tumour of the cerebellopontine angle. Idiopathic sudden deafness should be defined as an acute sensory hearing loss whose anatomical basis in an acute vascular endolymphatic hydrops of unknown cause. The sudden deafness affects only one ear; tinnitus and brief vertigo can be accompanying symptoms. A sudden hearing disorder due to other causes should be distinguished from idiopathic lesions.     

Safety and clinical performance of acoustic reflex tests

OBJECTIVE: Safety and effectiveness of acoustic reflex tests are important issues because these tests are widely applied to screen for retrocochlear pathology. Previous studies have reported moderately high sensitivity and specificity for detection of acoustic neuroma. However, there have been reports of possible iatrogenic hearing loss resulting from acoustic reflex threshold (ART) and decay (ARD) tests. This study assessed safety and clinical performance of ART tests for detection of acoustic neuroma. DESIGN: We report a case in which ARD testing resulted in a significant bilateral permanent threshold shift. This case was the impetus for us to investigate the clinical utility of ART and ARD tests. We analyzed sensitivity and specificity of ART, as well as asymmetry in pure-tone thresholds (PTT) for detection of acoustic neuroma in 56 tumor and 108 non-tumor ears. RESULTS AND CONCLUSIONS: Sensitivity and specificity were higher for PTT asymmetry than for ART. Ipsilateral ART at 1000 Hz had poor sensitivity and specificity for detection of acoustic neuroma, and involves some potential risk to residual hearing for presentation levels higher than 115 dB SPL. Approximately half of the acoustic neuroma group had ipsilateral ARTs that would require administration of ARD tests at levels exceeding 115 dB SPL. Therefore, we conclude that PTT asymmetry is a more effective test for detection of acoustic neuroma, and involves no risk to residual hearing. Future studies of contralateral reflex threshold and ARD in combination with PTT asymmetry are recommended.     

Conservative management of unilateral acoustic neuromas

OBJECTIVE: The aim of this study was to analyze the natural course of unilateral acoustic neuromas and to evaluate the advantages and disadvantages of an initial conservative approach. METHODS: Between 1989 and 1994, 74 consecutive patients with the diagnosis of unilateral acoustic neuroma were evaluated at the Department of Otorhinolaryngology, University of Zurich. Their charts and magnetic resonance imaging scans were retrospectively analyzed regarding duration and type of symptoms, initial tumor size, tumor growth pattern, and audiometric data. RESULTS: Of the 74 tumors, 68.9% (51/74) did not grow during a mean follow-up of 35 months. Eight (16%) of these tumors had radiologically documented tumor regression. Twenty-three tumors did grow, 16 of them (70%) with a growth rate of <2 mm/year. There was a statistically significant correlation between the first-year and the total growth rate, indicating that the tumor's behavior in the first year is highly predictive of its subsequent growth pattern. Patients with progressive hearing loss as a first symptom had a significantly lower tumor growth than those presenting with tinnitus, sudden hearing loss, or dizziness. Patients with tumor growth showed a greater tendency for hearing loss, although this trend was significant only for isolated frequencies. In 12% of the cases (9/74), the initial conservative approach had to be abandoned in favor of surgery. CONCLUSION: Watchful expectation can be regarded as a safe approach for selected cases of acoustic neuromas. Surgery or irradiation is indicated in patients with proven growth of their tumors.     

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。     

Acoustic neuromas presenting as sudden deafness

Caution is required in diagnosing even apparently "obvious" causes of hearing loss. A patient is described who came to medical attention through referral from a lawyer for sudden deafness allegedly caused by exposure to noise in an industrial setting. Thorough evaluation revealed an acoustic neuroma. Review of the literature suggests that presentation of acoustic neuromas as sudden deafness is more common than generally recognized. Clinicians must be alert to this possibility and diligent in their evaluation of any unilateral ear symptoms.     

Present state of early neurotological diagnosis of acoustic neuroma

The incidence of cases of acoustic neuroma that are manifested as sudden deafness or progressive sensorineural hearing loss was investigated. The findings of the stapedius reflex test, the auditory brain stem response test and the caloric test were analyzed, and the procedure for the diagnosis of acoustic neuroma was discussed.     

Hearing impairment in patients with acoustic neuroma—analysis by electrocochleography

Objective: In patients with acoustic neuroma, the site and severity of hearing impairment are important in discussing surgical approaches. Since the effectiveness of conventional auditory psychological testing is limited, we studied objectively hearing impairment of the cochlea and the cochlear nerve due to the tumor. Methods: Electrocochleography (ECochG) was carried out in 21 patients with acoustic neuroma. Cochlear microphonic potential (CM) and action potential (AP) in ECochG evoked with clicks and short tone bursts were recorded through a transtympanic needle electrode technique. Cochlear function was studied using the detection thresholds of CM, and cochlear nerve involvement was analyzed by differences between AP and CM detection thresholds. Results: The 1 kHz CM detection threshold was elevated in 17 (81.0%) of 21 patients indicating cochlear impairment. Of seven patients with normal hearing or mild sensorineural hearing loss in pure tone audiometry, three had a slightly elevated CM detection threshold. Of five patients with pronounced pure tone levels, four showed a CM response and were thought to have mild cochlear dysfunction. Cochlear nerve impairment was confirmed in three of four patients with well-developed CM based on elevated AP detection thresholds. Three patients had CM response but no AP response, suggesting severe cochlear nerve impairment. Conclusion: Disorders of the cochlea and the cochlear nerve can be evaluated with ECochG AP and CM measurement. The findings of ECochG are thought to be important information to judge hearing prognosis, thereby enhancing its clinical utility.