Diagnosis Of Acoustic Neuroma Research Articles

Translabyrinthine approach in acoustic neuroma surgery – case report

Introduction. Acoustic neuroma is a benign tumor that arises from the glial Schwann sheath junction of the vestibulocochlear nerve. It has an incidence of 1:100000 population. Despite the fact that this is a rare tumor, it accounts for approximately 6% of all intracranial tumors and 80% of tumors localized in cerebellopontine angle. Treatment of acoustic neuroma is represented by “Wait and Scan” monitoring, radiologic and surgical treatment. The latter remains the primary treatment for acoustic neuroma and consists of 3 main approaches: retrosigmoid approach, middle cranial fossa approach and translabyrinthine approach. Until now, in our country, acoustic neuroma surgery was done only by retrosigmoid approach. Case presentation. The first translabirinthine surgery for acoustic neuroma in our country was done on 09.12.2021 on a 60-year-old patient who, during preparation for cochlear implant surgery, was accidentally diagnosed with 3rd grade right acoustic neuroma, according to Koos classification. Patient had cophosis on the right ear and moderate hearing loss in the left ear. During the surgery, a gross total resection of the tumor was accomplished. The patient was discharged from the medical institution on 20.12.2021 in a satisfactory condition. Magnetic resonance imaging performed 3 months and 1 year after the surgery showed no complications or tumor remnants. Conclusion. The current report, which describes an accidental diagnosis of acoustic neuroma during preparation for a cochlear implantation surgery, resulted in acoustic neuroma surgery through the translabyrinthine approach. This serves as an eloquent example of why it is necessary to perform initially a magnetic resonance examination in cases of sensorineural hearing loss or tinnitus. The translabyrinthine approach in acoustic neuroma surgery allows for the removal of tumors of any size without affecting the brain, especially the cerebellum. In our case, where the patient had cophosis on the side of the tumor, this was the most appropriate surgical approach.

Changes of video head impulse test before and after translabyrinthectomy in patients with acoustic neuroma.

Acoustic neuroma (AN) is a benign tumor that usually affects a patient's hearing and balance function. For the screening and diagnosis of AN, the traditional approach mainly relies on audiological examination and magnetic resonance imaging (MRI), often ignoring the importance of vestibular function assessment in the affected area. As an emerging method of vestibular function detection, video head impulse test (vHIT) has been widely used in clinic, but research on its use in AN diagnosis is relatively limited. This study aims to explore the value of vHIT in the diagnosis of AN, vestibular dysfunction assessment, and postoperative compensation establishment in unilateral AN patients undergoing unilateral AN resection through labyrinthine approach. This retrospective study was conducted on 27 AN patients who underwent unilateral AN resection via labyrinthine approach from October 2020 to March 2022 in the Department of Otolaryngology-Head and Neck Surgery, the Second Xiangya Hospital, Central South University. vHIT was performed 1 week before surgery to assess vestibular function, pure tone audiometry (PTA) was used to assess hearing level, and ear MRI was used to assess tumor size. Follow-up vHIT was conducted at 1 week, 1 month, 6 months, and 1 year post-surgery. The correlation of vHIT with hearing and tumor size was analyzed. Preoperative vHIT showed that the posterior semicircular canal on the affected side was the most common semicircular canal with reduced vestibulo-ocular reflex (VOR) gain. There was a correlation between the VOR gain of vHIT on the affected side and the hearing level (r=-0.47, P<0.05) or tumor size (r=-0.54, P<0.01). The results of vHIT on the affected side showed that the hearing level and mean VOR gain of the anterior semicircular canal increased slightly with time, and the amplitude and saccade percentage of the dominant saccades of the 3 semicircular canals increased, while the latency time decreased, with the most obvious changes occurring 1 week post-surgery. vHIT can effectively monitor the changes of vestibular function in AN patients before and after surgery and has application value in assisting the diagnosis of vestibular dysfunction in AN patients.

Clinical Characteristics and Corticosteroid Responses of Acoustic Neuroma Treated as Idiopathic Sudden Sensorineural Hearing Loss.

Few investigations have been conducted on the clinical characteristics of the differential diagnosis of acoustic neuroma with acute sensorineural hearing loss and idiopathic sudden sensorineural hearing loss. The aim of the study was to investigate the clinical characteristics of the differential diagnoses between acoustic neuroma and idiopathic sudden sensorineural hearing loss. The medical records of patients with acute sensorineural hearing loss (142 ears), including acoustic neuroma (19 ears) and idiopathic sudden sensorineural hearing loss (123 ears), who underwent audiometric and hematologic examinations and received systemic corticosteroid treatment, were retrospectively reviewed. Hematological examination revealed that the erythrocyte sedimentation rate and fibrinogen values were significantly higher in the idiopathic sudden sensorineural hearing loss group compared to the acoustic neuroma group. Although all patients received corticosteroid treatment, hearing thresholds at the initial examination and 3 months after corticosteroid treatment were significantly higher in the idiopathic sudden sensorineural hearing loss group compared to the acoustic neuroma group at all frequencies. However, hearing recovery was worse in the acoustic neuroma group compared to the idiopathic sudden sensorineural hearing loss group. Furthermore, speech discrimination and short increment sensitivity index tests were not significantly different between the acoustic neuroma and idiopathic sudden sensorineural hearing loss groups. This is the first study to reveal that speech discrimination and short increment sensitivity index tests are not useful for the differential diagnoses between acoustic neuroma and idiopathic sudden sensorineural hearing loss, whereas erythrocyte sedimentation rate and fibrinogen, blood biomarkers of inflammation and blood viscosity, would be considered valuable. Furthermore, acoustic neuroma should be considered in cases where acute sensorineural hearing loss did not recover after corticosteroid treatment, although the initial hearing loss was mild.

Clinical characteristics of acoustic neuroma patients with normal hearing

Objective:To analyze the clinical characteristics of unilateral acoustic neuroma（AN） with normal hearing, so as to provide evidence for early identification AN. Methods:Clinical datas from 73 patients of unilateral AN with normal hearing of Otorhinolaryngology Head and Neck Surgery of Beijing Tiantan Hospital affiliated of Capital Medical University from August 2019 to April 2022 admitted to department were retrospectively analyzed. All patients underwent pure tone audiometry（PTA）, speech discrimination score（SDS）, auditory brainstem response（ABR）, distortion product otoacoustic emission（DPOAE） and head enhanced MRI. Results:The incidence of normal hearing among patients with AN was 10.7%. Male∶female=1∶2.2; the mean age of the patients was（37.3±9.4） years; the mean tumor size was（24.2±11.2） mm. Tinnitus was the most common reason for visit; the patients who had headache and dizziness had larger tumors. Surgery was the main treatment, and the patients who underwent surgery had larger tumors than those of follow-up. Heterogeneous tumors were the most common type of MRI, homogeneous tumors were smaller than heterogeneous and cystic tumors. The sensitivity of ABR in the diagnosis of AN with normal hearing was 95.9%, and that of ≥20 mm tumors was 100%; prolonged Ⅴ-waves were the most common, patients with Ⅴ-wave deletion had larger tumors than those with normal or prolonged Ⅴ-waves. Patients who had the longer the Ⅴ-wave and the longer difference between Ⅰ-Ⅴ wave had larger tumors. DPOAE was not elicited at full frequency in 11 patients. There was no statistically significant difference in age among patients with different symptoms, treatments, types of MRI, ABR and DPOAE. Conclusion:AN of normal hearing was most common in 30-39 years old women. Patients had different symptoms, phenotypes of MRI and ABR. Patients with normal hearing who had tinnitus, dizziness, headache, facial paraesthesia, and recovery after sudden haring loss can be further examination of ABR and DPOAE for early identification AN. The sensitivity of ABR in diagnosis of hearing normal AN was 95.9%, and the abnormal type of Ⅴ-wave is related to tumor size.

Cerebellar Hemangiopericytoma: A Case Report and Literature Review

Background: Haemangiopericytoma (HPC) is a rare mesenchymal tumour. It was first described in 1942 by A.P. Stout and M. Murray. It represents less than 1% of intracranial tumours. Its location in the cerebellopontine angle and its appearance on CT or MRI can be misleading and lead to a false diagnosis of acoustic neuroma or meningioma. Hemangiopericytoma is characterised by its malignant potential, high rate of recurrence and distant metastases, justifying wide surgical removal and additional radiotherapy.

The application value of video head impulse test, caloric test and dizziness handicap inventory in the diagnosis of acoustic neuroma

Objective:To explore the application value of video head impulse test（vHIT）, caloric test（CT） and the dizziness handicap inventory（DHI） in the diagnosis of acoustic neuroma（AN）, to analyze the correlation between vHIT and CT, and to determine the correlationsof tumor size, vHIT, CT and DHI score. Methods:The clinical data of 24 patients with AN who underwent surgery in our department from January 2019 to January 2022 were analyzed retrospectively, including craniocerebral MRI, vHIT, caloric test and DHI score. All the data were statistically analyzed by GraphPadPrism9.0. Results:There was a significant negative correlation between the UW value of CT and the vestibular eye reflex gain of vHIT（P<0.01, r=-0.62）. The tumor size was significantly correlated with the increase of UW value of CT（P<0.01, r=0.69）, and with the decrease of vestibulo-ocular reflex gain of vHIT（P<0.01, r=-0.53）. The average Dizziness Handicap Inventory score was 8.9±16.2, which was not correlated with tumor size（P>0.05）. Conclusion:Both vHIT and CT can effectively evaluate the vestibular function of patients with AN（and they are complementary）, and they are related to the size of the tumor and have certain value in the diagnosis of acoustic neuroma.

Diagnosis of Acoustic Neuroma through Telemedicine

A 65-year-old male individual presented to an electronic urban primary health center with complaints of impaired hearing in the left ear, loss of sensations on the left side of the face, loss of sensation of taste of the left side of the tongue, and tingling and numbness of the left side of the face for 2 months. He had a history of diabetes for 8 years and hypertension for 5 years and on regular medication. The patient was completely evaluated by the medical officer and referred to a general medicine doctor for teleconsultation. The general medicine specialist had clinical evaluation, and after detailed discussion with the medical officer, he was referred to a neurosurgeon for further evaluation and management to Guntur Medical College. He had evaluated the client and recommended magnetic resonance imaging scans, and imaging revealed an extra-axial cerebellopontine angle solid mass lesion of size 3 cm × 2 cm with cystic component, arising from the left internal auditory canal causing mass effect on the middle cerebellar peduncle, suggestive of left acoustic neuroma without mass effect. He had specialized radiation therapy of 30 fractions of 25 gray in 5 cycles from July 20 to August 5, 2019, currently on regular medication for diabetes and hypertension and Vitamin B12 supplements, and follow-up scheduled in July 2020.

Signs and Symptoms of Acoustic Neuroma at Initial Presentation: An Exploratory Analysis.

IntroductionThe objective of this study was to describe the most common clinical features associated with an acoustic neuroma diagnosis and to identify those features associated with larger tumour size at initial diagnosis.MethodsThe clinical information of 945 consecutive patients diagnosed with acoustic neuroma at a single centre between 1992 and 2015 was analysed. Clinical features were examined and the relationship between these features and tumour size (>2.5 cm) was analysed using descriptive statistics and logistic regression analysis. Statistical analysis was performed in R version 3.1.1.ResultsThe most common presenting symptom was a unilateral hearing loss in 752 patients (80%), with a progressive pattern in 90% of these cases. The second most common presenting symptom was unilateral tinnitus, accounting for 6.3%, while ataxia, vertigo and headache accounted for 3.8%, 3.4% and 2%, respectively. The diagnosis of acoustic neuroma was an incidental finding in 20 patients (2.1%). Temporal analysis demonstrated a downward trend in the number of patients presenting with hearing loss and an increased proportion of patients presenting with other symptoms. On multivariate analysis, larger tumour size was associated with abnormal tandem gait (odds ratio 8.9, p=0.02), subjective facial weakness (odds ratio 5.3, p< 0.001), abnormal facial sensation on examination (odds ratio 3.0, p=0.03) and headache (odds ratio 2.6, p< 0.001).ConclusionThe majority of patients with acoustic neuroma present with the classic, progressive, unilateral hearing loss. However, the pattern of presentation in acoustic neuroma patients is changing. Features in the history indicative of a larger tumour are headaches and subjective facial weakness, whilst concerning features on examination are abnormal tandem gait and altered facial sensation.

STEREOTAKTİK RADYOTERAPİNİN AKUSTİK NÖRİNOMA HASTALARI ÜZERİNE ETKİSİ

Aim: Treatment options for acoustic neuroma are; microsurgery, stereotactic radiotherapy and the use of these two options together. In this study, after treatment quality of life and changes in the tumor size,hearing level of patientswhom were applied stereotactic radiotherapy due to acoustic neuroma in our clinic were evaluated.. Material and Methods: In our clinic, between September 2009 and May 2016 22 patients who had acoustic neuroma smaller than 3 centimeter were evaluated retrospectively. The patients underwent stereotactic radiotherapy with a dose of 12 Gray. Size was measured before and after treatment with magnetic resonance and hearing level and speech discriminations were calculated with audiogram.Their quality of life was evaluated with SF-36 Quality of Life Assessment Scale after treatment. Results: In both of these patients groups with acoustic neuroma whose tumor is located at only internal auditory canal or at cerebellopontine angle and internal auditory canal; it was showed that stereotactic radiotherapy can cause hearing loss and decrease in speech discrimination scores but this difference is not statistically significant (P>0.05). In recent follow-up magnetic resonance imaging was taken and in 12 of these patients; sizes of the acoustic neuroma was stabil and on the other hand in 2 of the patients there was a progression and in 8 of the patients there was a regression. In the evaluation of Quality of Life Assessment Scale; most decrease was found in vitality scores. Conclusion: Stereotactic radiotherapy can be used with hearing function, changes of tumor size and low morbidity in quality of life in patients with diagnosis of acoustic neuroma under 3 centimeter.

Predictive factors of acoustic neuroma growth

&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Background:&lt;/span&gt;&lt;/strong&gt;Since the use of magnetic resonance imaging (MRI) as the gold standard for acoustic neuroma diagnosis, the size of the majority of newly diagnosed acoustic neuromas has decreased. Management strategy is challenging, especially in young patients with small tumors. Therefore, prognostic factors for tumor growth may facilitate physicians to optimize treatment choice.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Methods:&lt;/span&gt;&lt;/strong&gt;Patients diagnosed with acoustic neuromas were recruited in this study. Gender, age, side, presence of hearing loss, tinnitus, vertigo, unsteadiness, other symptoms, hearing level in the affected ear and tumor growth at the first follow up MRI were recorded. Two primary endpoints were set: overall acoustic neuroma (AN) growth and growth correlated to treatment plan change (clinically significant growth). Multivariate and survival analysis were conducted to this end. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Results:&lt;/span&gt;&lt;/strong&gt;85 patients were finally included in the study. The most prevalent presenting symptoms were hearing loss (76%), tinnitus (56%) and unsteadiness (46%). The tumour grew in size in less than 50% of the cases during the observation period. Clinically significant growth was observed in 27% of the cases. Mean initial diameter was 10.41mm and mean final follow-up diameter (diameter at the end of the observation period) 12.73 mm. Following binary logistic regression analysis, tumour growth during the initial follow up visit was found to be correlated in a statistically significant level to overall tumour growth (p-value 0.023). Regarding clinically significant growth, three factors were found to be statistically significant: growth at the initial visit (p-value 0.02), initial diameter (p-value 0.045) and existence of unsteadiness at diagnosis (p-value 0.02).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Conclusions:&lt;/span&gt;&lt;/strong&gt;Acoustic neuroma overall growth is not identical to clinically significant growth. Growth at first visit is a significant prognostic factor and intervention potential should be considered under this perspective.&lt;/p&gt;

Application of auditory brainstem response and pure tone audiometry in early diagnosis of acoustic neuroma

Objective To investigate the clinical application value of using auditory brainstem response and pure tone audiometry for early diagnosis of acoustic neuroma. Methods The clinical data, the results of pure tone audiometry, auditory brainstem response, and enhanced MRI in 111 patients with acoustic neuroma were analyzed retrospectively. Linear regression analysis was used to analyze the correlation between the mean value of pure tone audiometry and the neuroma volume or course of disease. Chi-squared test was used to analyze the whether there were differences in the different neuroma volumes on the incidence of abnormal auditory brainstem response. Results Acoustic neuroma caused sensorineural deafness. There was a significant correlation between the mean value of pure tone audiometry and the course of disease (P=0.000). The sensitivity and specificity of auditory brainstem response for the diagnosis of acoustic neuroma were 98.2% and 93.6% respectively. The maximum diameters of neuromas were divided into 2 groups: >3 cm or ≤3 cm. There were significant differences on the abnormal incidence of the Ⅲ to Ⅴ wave intervals of the ipsilateral and contralateral ears (P=0.038 and 0.045 respectively). Conclusion Auditory brainstem response in combination with pure tone audiometry is the effective method for early diagnosis of acoustic neuroma. Key words: Neuroma, acoustic; Audiometry, pure-tone; Auditory threshold; Evoked potentials, auditory, brain stem; Diagnosis

Hearing in Static Unilateral Vestibular Schwannoma Declines More Than in the Contralateral Ear

To determine the effect of static vestibular schwannomas on hearing. Retrospective review of audiometric measures in 15 patients with documented nongrowth of internal auditory canal and cerebellopontine angle enhancing masses. Data from patients seen in an ambulatory tertiary care setting between the years of 2002 and 2012 with a diagnosis of acoustic neuroma or vestibular schwannoma were reviewed. Exclusion criteria included preexisting otologic disease, prior therapy for the schwannoma, and tumor growth. Radiology reports were reviewed to ensure nongrowth and were confirmed by taking magnetic resonance imaging (MRI) measurements ourselves. Audiologic measurements included pure tone average, enhanced pure tone average (average of .5, 1, 2, and 4 KHz thresholds), 4 KHz threshold, 8 KHz threshold, and speech discrimination. The data were analyzed using mixed effect model with unstructured variance-covariance structure. Difference in audiometric measures between ears significantly (P<.05) increased for all measures except 8 KHz. Spontaneous decline in hearing relative to time is exaggerated in the affected ear despite no vestibular schwannoma growth. This finding can be useful for patient counseling and treatment decision making.

Magnetic resonance imaging findings in children with tinnitus.

Tinnitus in adults is generally investigated by contrast-enhanced magnetic resonance imaging (MRI) to rule out the diagnosis of acoustic neuroma. Acoustic neuroma is rare in children and, therefore, the role of MRI in children with tinnitus is unclear. This study was undertaken to determine the value of MRI in the investigation of tinnitus in children. Retrospective study of children younger than 18 years who underwent MRI for the investigation of tinnitus over a 10-year period. Sixty-five patients were identified, but there were only 34 who had also undergone audiologic assessment. Among the 25 patients with normal audiology, MRI abnormalities were present in 9, but these were all thought to be nonspecific. Nine patients had abnormal audiograms and the MRI was abnormal in 4 of these cases, which included 3 children who were found to have multiple sclerosis. Magnetic resonance imaging would appear to be mandatory in the investigation of tinnitus in children who are found to have sensorineural hearing loss, particularly to rule out the diagnosis of multiple sclerosis. Although our study does not support the routine use of MRI in children with normal audiology, the numbers in our series are too small for a conclusive recommendation.

Heyrnartaugaslíðursæxli á Íslandi í 30 ár (1979-2009)

Acoustic neuroma (AN) is a tumor of the 8th cranial nerve. The goal of this study was to find the incidence of AN in Iceland from 1979 - 2009 as well as investigate other epidemiological factors. The group of patients with the AN diagnosis was gathered retrospectively through medical records. We looked at several epidemiological factors including age and symptoms at diagnosis, and the treatment chosen for each individual. The incidence rate of AN in Iceland is 1.24/100,000. About 10% of diagnosed tumors were found incidentally. Most of those were found in the last 10 years of the investigation and in that period fewer large and giant tumors at diagnosis. Present complaints of patients at diagnosis were hearing loss (69%), dysequilibrium/dizziness (47%) and tinnitus (43%). Treatments were surgery (n=47), observation (n=30) and gamma knife radiosurgery (n=16). We had information concerning postoperative hearing loss and facial paralysis in 39 patients who underwent surgery. Loss of hearing postoperatively occurred in 69% (n=27) and 44% (n=17) had facial paralysis. For an average of 3.5 years, 17% of tumors followed by imaging grew. The incidence of AN is similar to that in Europe and is increasing. More tumors are found incidentally. Small tumors can be followed by regular imaging, at least for the short term. Larger tumors are treated by surgery or gamma knife radiosurgery. A high percentage of patients receiving surgery lost their hearing postoperatively.

청신경종양에서 나타나는 청성뇌간반응 잠복기의 진단적 가치

Background and Objectives: It is important to rule out acoustic neuroma when treating patients who have tinnitus or monaural hearing loss. The most accurate diagnostic tool is MRI but due to high costs, auditoiy brainstem response (ABR) latency is often used. The aim of this study is to confirm the diagnostic value of ABR latency in acoustic neuroma. Patients and Methods: The medical records of 20 patients who were diagnosed acoustic neuroma in MRI and evaluated with pure tone audiometry, speech audiometry and ABR were retrospectively reviewed from January, 2003 to January, 2010. Tumor size and hearing classification system of 2003 Consensus Meeting was used. Using I-V interpeak latency (IPL) and I-V interlatency difference (ILD) , we identified the diagnostic value of ABR latency in diagnosing acoustic neuroma. Results: Among 20 patients, there were 2 cases of intra-meatal tumor, 2 cases of grade 1, 6 cases of grade 2, 6 cases of grade 3, 2 cases of grade 4 and 2 cases of grade 5 according to the acoustic neuroma classification system of 2003 Consensus Meeting. There were 9 cases with no wave in ABR. 4 cases showed over 4.4 msec in I-V IPL and 6 cases showed over 0.2 msec in I-V ILD. There were 3 cases that showed over 4.4 msec in I-V IPL and over 0.2 msec in I-V ILD. Therefore, there were 16 cases that showed abnormal reactions to ABR among acoustic neuroma patients, false negative rate was founded to 20%. Conclusion: The smaller tumor size, the better prognosis in treating tumor and preserving hearing and facial nerve function, so that early diagnosis of acoustic neuroma is important. Because false negative rate of ABR was 20% in this study, using ABR as screening test of acoustic neuroma needs attention. (J Clinical Otolaryngol 2010; 21:46–49)

The role of magnetic resonance imaging in the identification of suspected acoustic neuroma: a systematic review of clinical and cost effectiveness and natural history

To evaluate the clinical effectiveness and cost-effectiveness of a range of diagnostic strategies for investigating patients with unilateral hearing loss and/or tinnitus, with a view to confirming or eliminating a diagnosis of acoustic neuroma, and to describe the natural history of acoustic neuroma. Major electronic databases were searched from January 1980 to August 2008. Selected studies were assessed and subjected to data extraction and quality assessment using standard methods. Studies comparing auditory brainstem response (ABR) with magnetic resonance (MR) imaging were highly heterogeneous. ABR has high sensitivity compared with MR imaging for acoustic neuromas greater than 1 cm in size but not for smaller neuromas. The sensitivities of T2-weighted (T2W) and T2-star-weighted (T2*W) imaging strategies compared with gadolinium-enhanced T1-weighted (GdT1W) MR imaging (gold standard) were high and relatively homogeneous. The specificity of T2W and T2*W studies ranged from 90% to 100% and from 86% to 99% respectively. The review of cost-effectiveness showed that GdT1W MR imaging immediately or in conjunction with ABR appears to be more cost-effective than 'traditional' protocols; ABR/GdT1W MR imaging protocols were more cost-effective than going directly to GdT1W MR imaging. Non-contrast-enhanced MR imaging was found to be a more cost-effective test for acoustic neuroma than GdT1W MR imaging. The incidence of acoustic neuroma has increased over the last 30 years, with the median age at diagnosis remaining at 55 years. Most patients present with insidious symptoms of unilateral hearing impairment, tinnitus and/or vertigo. The pattern and rate of growth of acoustic neuroma are highly variable and currently unpredictable. At least 50% of tumours do not grow, at least for some years after diagnosis. Some studies have found large initial size to be a determinant of later growth, with the opposite also being reported. The mean growth rate for all tumours varies between 1 and 2 mm/year, with a rate of 2-4 mm/year for only those that grow; however, there are cases with significant regression (5%) or exceptional growth (which may exceed 18 mm/year). The majority of the evidence reviewed was poorly reported and there is therefore an inherent risk of bias. Given the recent improvement in resolution and reduction in cost of MR imaging, ABR can no longer be considered appropriate as the primary test used to screen for acoustic neuroma. T2W or T2*W sequences enable accurate evaluation of the VIIIth and VIIth cranial nerves within the cerebellopontine angle and internal auditory canal as well as evaluation of the cochlea and labyrinth, and inclusion of GdT1W sequences is unlikely to contribute information that would alter patient management in the screening population. The quality of the imaging chain and experience of the reporting radiologist are key factors determining the efficacy of a non-contrast screening strategy. Based on a cost-effectiveness model developed to reflect UK practice it was concluded that a diagnostic algorithm that deploys non-contrast MR imaging as an initial imaging screen in the investigation of acoustic neuroma is less costly than and likely to be as effective as available contrast MR imaging.

聴神経腫瘍の取り扱い―耳鼻科医としての対応―

It has become possible to make a diagnosis of small acoustic neuroma localized within the internal auditory meatus in the presence of normal or mild hearing impairment. From the viewpoint of functional preservation, it is deemed that a turning point has come in terms of the neurotologist's role in the management of patients with acoustic neuroma, especially in cases with small tumors. As a neurotologist, one is expected to locate the tumor while it is small, and follow the time-course of the tumor's growth and cochleo-vestibular symptoms, and then adopt the most beneficial treatment policy for the patient among the three treatment options of surgery, gamma-knife application, and follow up. To determine the optimal policy, one should take into consideration one's own experience, as well as the patient's social and familial background on an individual basis. When considering hearing preservation surgery, a middle cranial fossa approach could be the most promising and desirable. Some important check points for making a diagnosis of acoustic neuroma are also presented.

Acoustic Neuroma in a Private Neurotology Practice: Trends in Demographics and Practice Patterns

To determine whether changes in demographics and management of patients with acoustic neuromas occurred between the years 1990 and 2005. Retrospective chart review. Charts of all 614 patients with a diagnosis of acoustic neuroma, excluding neurofibromatosis-2, from 1990 through 2005 were reviewed. Age at diagnosis, tumor size, hearing, and initial therapy (observation, stereotactic radiation, or surgical excision) were obtained. Patients were grouped by time period (1990-1994, 1995-2000, 2001-2005). Mean age at diagnosis increased slightly from the middle period (53.4 yr) to the most recent (56.9 yr) (P < or = .025). The proportion of patients 65 years or older increased from 21% to 29% to 32%, respectively, but the change was not significant. Average tumor size decreased from 1.7 cm initially to 1.4 cm most recently (P < or = .039). There were no significant changes in hearing. Although surgical excision remains our most common treatment (58.5% in 2001-2005), it is becoming less frequent (>80% in earlier periods) (P < or = .001). Observation with serial imaging was recommended in 37.3% in 2001 to 2005 as compared with 18.3% and 11.6% in the previous two time periods (P < or = .001). These changes in initial treatment choices occurred for all age groups and primarily for small tumors. Use of radiation has increased only slightly, to 4.2% in the recent period. : Patients with acoustic neuroma are presenting with increased age and smaller tumors compared with 16 years ago. However, these changes cannot totally account for the large change in treatment trends. Technology and demographics are influential in these changes, but other difficult to measure forces, such as patient influence and patient use of the Internet, are also factors.

Carcinomatous Meningitis Appearing as Acoustic Neuromas

For acoustic neuromas, stereotactic radiotherapy (radiosurgery or stereotactic fractionated radiotherapy) has been established as an important alternative to microsurgery. In most cases initial symptoms are slow progression of unilateral hearing loss, tinnitus or vertigo or acute hearing loss with vertigo. MRI scan shows a contrast-enhancing tumor within the inner auditory channel. If the patient undergoes primary radiotherapy, diagnosis is usually not verified histologically. Therefore, careful evaluation of the medical history is mandatory despite a typical appearance on the MRI scan. If medical history does not match with acoustic neuroma, further diagnostics are necessary to rule out infectious disease or carcinomatous meningitis. Two patients with hearing loss, vertigo and the diagnosis of acoustic neuromas by MRI scan were referred for radiotherapy. In both cases the symptoms progressed very rapidly, not typical of acoustic neuromas, and in both patients repeated liquor puncture finally revealed carcinomatous meningitis. One patient died during therapy; in the second patient intrathecal chemotherapy and additional radiotherapy of the skull base led to partial remission continuing for several months. Before primary radiotherapy of small intrameatal lesions diagnosis must be reassessed carefully. This is especially true for bilateral lesions suspicious for acoustic neuromas and rapid progression and persistence of clinical symptoms where carcinomatous meningitis has to be taken into account.

Non-invasive acoustic neuroma treatment via Gamma Knife stereotactic radiosurgery

Non-invasive acoustic neuroma treatment via Gamma Knife stereotactic radiosurgery