Audit of regional screening guidelines for vestibular schwannoma

Predictors of Abnormal MRI Findings in Patients with Asymmetrical Sensorineural Hearing Loss

OBJECTIVE

This study aimed to determine the predictive factors of abnormal MRI findings in patients with asymmetrical sensorineural hearing loss (ASNHL).

STUDY DESIGN

A retrospective review of medical records.

SETTING

A tertiary care hospital.

METHODS

Patients with asymmetries of ≥10 dB in at least 1 frequency, who underwent an MRI study of the temporal bone or brain during 2019-2021, were included. Age, sex, clinical symptoms, past medical history, and audiometric parameters, including pure tone thresholds, speech reception thresholds, and speech discrimination scores, were retrieved from the electronic database. The MRI findings reported by radiologists were reviewed and extracted.

RESULTS

Of 390 patients, 50 (12.8%) patients had relevant abnormal MRI findings that could explain ASNHL. The most prevalent abnormal MRI finding was an internal acoustic canal (IAC) or cerebellopontine angle (CPA) tumor (n = 38; 76.0%), with other notable abnormalities including labyrinthitis, stroke, mucocele, and epidermoid. Multiple logistic regression analysis highlighted that hearing asymmetry of 15 dB at 1000 Hz (OR = 4.8; 95% CI 2.2-10.5) was a significant variable. The proposed predictor demonstrated 84% sensitivity and 48% specificity in detecting abnormal MRI findings.

CONCLUSION

A hearing asymmetry of 15 dB at 1000 Hz was an important clinical predictor of abnormal MRI findings in patients with ASNHL. This finding has the potential to serve as a referral guide for further MRI investigations.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 2024.

MRI Screening in Vestibular Schwannoma: A Deep Learning-based Analysis of Clinical and Audiometric Data

Objective

To find a more objective method of assessing which patients should be screened for a vestibular schwannoma (VS) with magnetic resonance imaging (MRI) using a deep-learning algorithm to assess clinical and audiometric data.

Materials and Methods

Clinical and audiometric data were collected for 592 patients who received an audiogram between January 2015 and 2020 at Duke University Health Center with and without VS confirmed by MRI. These data were analyzed using a deep learning-based analysis to determine if the need for MRI screening could be assessed more objectively with adequate sensitivity and specificity.

Results

Patients with VS showed slightly elevated, but not statistically significant, mean thresholds compared to those without. Tinnitus, gradual hearing loss, and aural fullness were more common in patients with VS. Of these, only the presence of tinnitus was statistically significant. Several machine learning algorithms were used to incorporate and model the collected clinical and audiometric data, but none were able to distinguish ears with and without confirmed VS. When tumor size was taken into account the analysis was still unable to distinguish a difference.

Conclusions

Using audiometric and clinical data, deep learning-based analyses failed to produce an adequately sensitive and specific model for the detection of patients with VS. This suggests that a specific pattern of audiometric asymmetry and clinical symptoms may not necessarily be predictive of the presence/absence of VS to a level that clinicians would be comfortable forgoing an MRI.

The Diagnostic Accuracy of Pure-Tone Audiometry Screening Protocols for Vestibular Schwannoma in Patients with Asymmetrical Hearing Loss-A Systematic Review and Meta-Analysis

(1) Background: Magnetic resonance imaging (MRI) is the gold standard investigation for all patients who present with asymmetrical hearing loss (AHL) and a high index of suspicion for vestibular schwannoma (VS). However, pure-tone audiometry (PTA) is an investigation that can be used for the screening of these patients in order to reduce the costs. The aim of this systematic review and meta-analysis was to evaluate the diagnostic accuracy of different PTA protocols for VS in patients with ASHL, when compared with MRI; (2) Methods: Medline, Embase, and Cochrane databases were used to find relevant studies. All prospective and retrospective observational studies that evaluated the accuracy of PTA protocols for the screening of VS were assessed, according to the international guidelines; (3) Results: We analyzed seven studies (4369 patients) of poor-to-moderate quality. Their pooled sensitivity was good (0.73-0.93), but their specificity was low (0.31-0.60). All protocols were located in the right lower quadrant on the likelihood scattergram, and the post-test probabilities for positive and negative diagnosis of these protocols were extremely low; (4) Conclusions: PTA protocols cannot be used for a proper screening or diagnosis of vestibular schwannoma despite their good sensibility, and MRI remains the gold standard for this purpose.

Evaluation of pure-tone audiometric protocols in vestibular schwannoma screening

The objective was to evaluate the pure-tone audiogram-based screening protocols in VS diagnostics. We retrospectively analyzed presenting symptoms, pure tone audiometry and MRI finding from 246 VS patients and 442 controls were collected to test screening protocols (AAO-HNS, AMCLASS-A/B, Charing Cross, Cueva, DOH, Nashville, Oxford, Rule3000, Schlauch, Seattle, Sunderland) for sensitivity and specificity. Results were pooled with data from five other studies, and analysis of sensitivity, specificity and positive likelihood ratio (LR+) for each protocol was performed. Our results show that protocols with significantly higher sensitivity (AMCLASS-A/B, Nashville) show also significantly lowest specificity, and tend to have low association (positive likelihood ratio, LR+) to the VS. The highest LR+ was found for protocols AAO-HNS, Rule3000 and Seattle. In conclusions, knowing their properties, screening protocols are simple decision-making tools in VS diagnostic. To use the advantage of the highest sensitivity, protocols AMCLASS-A + B or Nashville can be of choice. For more reasonable approach, applying the protocols with high LR+ (AAO-HNS, Rule3000, Seattle) may reduce the overall number of MRI scans at expense of only few primarily undiagnosed VS.

Asymmetric sensorineural hearing loss and vestibular schwannoma: when to image?

PURPOSE OF REVIEW

We review the literature on the use of audiometric protocols in the guidance of when to obtain MRI for detection of vestibular schwannoma. This discussion will focus on the sensitivity, specificity, and cost-effective analysis of audiometric criteria of asymmetric sensorineural hearing loss (ASNHL) when used to decide when MRI scans should be performed.

RECENT FINDINGS

The sensitivity for detecting vestibular schwannomas when invoking published audiometric protocols for triggering MRI acquisition in ASNHL ranged from 50 to 100%. Specificity of these protocols ranged from 23 to 83%. Such audiometric protocols are efficient, achieving sensitivity and specificity at these rates while reducing the screening rate to 18 to 35%. The reduced procurement of MRI while using such audiometric protocols is associated with annual cost savings of between 23 and 82%. While no definitive recommendations can be made from this review, some audiometric protocols offer a better balance of sensitivity and specificity than others.

SUMMARY

Audiometric protocols for triggering MRI acquisition in ASNHL for evaluation of vestibular schwannoma can be both sensitive and specific. These are competitive measures, and so no protocol is both 100% sensitive and specific. Such protocols become less effective in populations with increased incidence of noise-induced hearing loss. Invocation of such audiometric protocols can considerably reduce the annual cost of MRI evaluation for vestibular schwannomas.

Audiologist-led screening of acoustic neuromas in patients with asymmetrical sensorineural hearing loss and/or unilateral tinnitus: our experience in 1126 patients

OBJECTIVE

To determine whether patients within an otolaryngology department presenting with asymmetrical sensorineural hearing loss and/or unilateral tinnitus can be safely and cost-efficiently screened for acoustic neuroma by audiologists as a first or only point of contact.

METHODS

A prospective case series and cost analysis were conducted at a tertiary referral centre. Between April 2013 and March 2017, 1126 adult patients presented to the audiology department with asymmetrical sensorineural hearing loss and/or unilateral tinnitus. All were screened for acoustic neuroma with magnetic resonance imaging, based on pre-determined criteria. The main outcome measure was the presence of acoustic neuroma or other pathology on magnetic resonance imaging.

RESULTS

Twenty-five patients (2.22 per cent) were found to have an acoustic neuroma (size range: 3-20 mm) and were referred to the otolaryngologist for further assessment. The remaining patients were appropriately managed and discharged by the audiologists without ENT input. This resulted in an overall cost saving of £164 850.

CONCLUSION

Patients with asymmetrical sensorineural hearing loss and/or unilateral tinnitus can be safely screened for acoustic neuroma and independently managed by audiologists as a first or only point of contact, resulting in considerable departmental cost savings.

Diagnostics and therapy of sudden hearing loss

This article reviews recent aspects of diagnostics, differential diagnostics, and evidence in systemic and local therapy of idiopathic sudden sensorineural hearing loss (ISSHL). Since a number of disorders can be accompanied by sudden hearing loss, a meaningful and targeted diagnostic strategy is of utmost importance. An important differential diagnosis of sudden hearing loss are intralabyrinthine schwannomas (ILS). The incidence of ILS is probably significantly underestimated. This may be due to the lack of awareness or lack of explicit search for an intralabyrinthine tumor on MRI or an inappropriate MRI technique for the evaluation of sudden hearing loss ("head MRI" instead of "temporal bone MRI" with too high slice thicknesses). Therefore, the request to the radiologist should specifically include the question for (or exclusion of) an ILS. With special MRI techniques, it is possibly today to visualize an endolymphatic hydrops. The evidence in the therapy of ISSHL is - with respect to the quality and not quantity of studies - unsatisfying. The value of systemically (low dose) or intratympanically applied corticosteroids in the primary treatment of ISSHL is still unclear. In order to investigate the efficacy and safety of high dose corticosteroids as primary therapy for ISSHL, a national, multicenter, three-armed, randomized, triple-blind controlled clinical trial is currently performed in Germany (http://hodokort-studie.hno.org/). After insufficient recovery of the threshold with systemic therapy of ISSHL, intratympanic corticosteroid therapy appears to be associated with a significantly higher chance of an improved hearing threshold than no therapy or placebo. Both, hearing gain and final hearing threshold, however, appear to be independent from the onset of secondary therapy. Based on currently available data from clinical studies, no recommendation can be made with respect to the type of corticosteroid and specifics of the intratympanic application protocol.

Incidental findings on magnetic resonance imaging of the internal auditory meatus performed to investigate audiovestibular symptoms

OBJECTIVE

To determine the frequency of incidental findings found on magnetic resonance imaging scans of the internal auditory meatus performed to investigate audiovestibular symptoms, and to determine how to best manage these when found.

METHOD

A retrospective review was conducted of internal auditory meatus magnetic resonance imaging scans during a three-month period in the radiology department at a UK district general hospital.

RESULTS

A total of 109 scans were reviewed. Of these, 92.7 per cent showed no retrocochlear pathology, 0.9 per cent showed vestibular schwannoma, 6.4 per cent revealed vascular loops, and 2.8 per cent showed incidental findings that warranted further action and investigation. Of the scans, 40.4 per cent showed other incidental pathologies such as age-related ischaemic changes, and sinus disease that required no further intervention. Of the magnetic resonance imaging scans reviewed, 49.5 per cent were entirely normal.

CONCLUSION

Almost half of the scans investigating audiovestibular symptoms showed incidental findings. Otolaryngologists should have an understanding of the significance of the most commonly encountered incidental findings, and should counsel patients appropriately and refer them onward when necessary.

Evaluation of Magnetic Resonance Imaging Diagnostic Approaches for Vestibular Schwannoma Based on Hearing Threshold Differences Between Ears: Added Value of Auditory Brainstem Responses

OBJECTIVE

This study investigates the most appropriate audiometric criterion in deciding which patients with asymmetric hearing loss should be referred to MRI to exclude a lesion in the cerebellopontine angle (CPA). Careful selection of patients could improve resource utilization while preventing unnecessary investigations with accompanying burden and costs.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Of all the patients who were referred to our clinic between 1997 and 2012, the records were reviewed of those who underwent pure-tone audiometry, auditory brainstem response (ABR) testing, and had a Gadolinium-enhanced MRI of the CPA.

INTERVENTION

Regarding interaural pure-tone threshold differences at single or multiple (averaged) frequencies, we assigned multiple possible cut-off values (dB) defining an aberrant result, suggestive for CPA lesions. Results were compared with MRI to calculate sensitivity and specificity for every cut-off value. These were visualized as ROC curves enabling qualitative comparison. Added value of ABR was assessed as well.

MAIN OUTCOME MEASURES

Sensitivity and specificity of various criteria to decide which patients with asymmetric hearing loss to send to MRI to exclude a CPA lesion.

RESULTS

In total, 1016 records were reviewed. Two hundred ninety-four subjects (29%) were diagnosed with a CPA lesion on MRI. Sensitivity and specificity for audiometry results differed greatly depending on the predefined cut-off value for hearing threshold difference (40-95% sensitivity and 20-90% specificity). Best ROC curves were obtained when threshold differences at two or three higher frequencies were averaged. Adding results of ABR to the threshold criterion yielded a slightly better ROC curve, although sensitivity decreased.

CONCLUSIONS

The best criterion to decide which patient with asymmetric hearing loss should be referred to MRI is based on the average bone conduction threshold difference at multiple (two or three) higher frequencies. The extent of the average threshold difference between ears that is used as a cutoff will mainly depend on treatment modality and (eventually) on resource costs and on the burden of Gadolinium-enhanced magnetic resonance imaging. Results of ABR can have little added value when only patients with a unilateral abnormal ABR at the worse hearing ear are referred to MRI. However, a lower sensitivity must then be accepted.

Cost analysis of vestibular schwannoma screening with contrast-enhanced magnetic resonance imaging in patients with asymmetrical hearing loss

BACKGROUND

Vestibular schwannomas are a rare cause of asymmetrical hearing loss, and routine screening with magnetic resonance imaging can be costly. This paper reports results on vestibular schwannoma screening at our institution and compares the cost of screening to a utility of hearing benefit.

METHOD

All screening examinations with magnetic resonance imaging performed for asymmetrical hearing loss between 2006 and 2011 were retrospectively reviewed. The cost per new vestibular schwannoma diagnosis was calculated. The cost per patient for those who benefitted from intervention was estimated based on rates of hearing preservation reported in the literature.

RESULTS

Forty-five (4.3 per cent) of 1050 screening examinations with magnetic resonance imaging performed for asymmetrical hearing loss were positive for vestibular schwannoma, and the cost per new diagnosis was $11,436. The estimated screening cost per patient for those who benefitted from surgery or radiation was $147,030, while US federal compensation for unilateral hearing loss was $44,888.

CONCLUSION

Although we achieved a lower screening cost per new diagnosis than reported in the current literature, there remains disparity between the screening cost per benefitted patient and the 'benefit' of hearing.

Incidence of vestibular schwannoma and incidental findings on the magnetic resonance imaging and computed tomography scans of patients from a direct referral audiology clinic

OBJECTIVE

To identify the incidence of vestibular schwannoma amongst patients referred from a direct referral audiology clinic, and also the number of incidental findings, as seen on magnetic resonance imaging or computed tomography scans.

METHOD

Prospective data collection for patients referred from a direct referral audiology clinic due to audiological evidence of asymmetrical hearing loss. The audiograms, magnetic resonance imaging and computed tomography scans of patients with diagnosed vestibular schwannoma were subsequently reviewed.

RESULTS

A total of 4100 patients were seen during the study period, with 396 scans performed. Six (1.5 per cent) patients had vestibular schwannoma, while 12 (3 per cent) had significant incidental findings.

CONCLUSION

Patients referred from the direct referral audiology clinic had a low incidence of vestibular schwannoma detection. Their detection rate for significant incidental findings was similar to previous reports. If the current protocol had not been in place, over 300 patients would have been needlessly added to the ENT clinic list. Thus, general practitioner referral to direct referral audiology clinics provides a cost-effective way of managing asymmetrical sensorineural hearing loss in older patients. The number of such clinics could be expanded.

Three-Year Ear, Nose, and Throat Cross-sectional Analysis of Audiometric Protocols for Magnetic Resonance Imaging Screening of Acoustic Tumors

Objectives. (1) Evaluate audiometric protocols and recommend protocols with best sensitivity and specificity for magnetic resonance imaging (MRI) screening of acoustic tumors; (2) determine clinical risks (false negative) of missing acoustic tumors and potential wastes in screening (false positive) nonacoustic tumors or radiologically “normal” cases; and (3) identify the decibel difference and range of frequencies compared by the best-performing protocols.

Study Design. Cross-sectional study with chart review.

Setting. Ear, nose, and throat (ENT); audiology; and radiology departments in a tertiary-care hospital.

Subjects and Methods. Three-year cohort (2006-2009) of 1751 ENT patients underwent MRI screening and pure-tone audiometry indicating sensorineural hearing loss. Audiometric protocols were ranked by highest sensitivity to acoustic tumors, specificity A to nonacoustic tumors, and specificity B to “radiologically normal” cases.

Results. No audiometric protocols achieved 100% sensitivity or specificity rates. Only 2 protocols achieved ≥90% sensitivity: the AMCLASS-A-Urben protocol (93.16%) and the Mangham protocol (91.58%). Eleven of 15 protocols for specificity A and 12 of 15 protocols for specificity B achieved ≥50%. Clinical risks ranged from 6.84% to 18.95%, whereas potential wastes ranged from 33.56% to 68.37% for specificity A and 31.76% to 66.86% for specificity B. Interaural difference parameters indicating highest mean sensitivity were on the order of ≥10 dB, ≥15 dB, and ≥20 dB. For frequency comparison parameters, “2 or more adjacent frequency” and “single-frequency” comparison indicated higher mean sensitivity than the “averaged multifrequency” comparison. Mean specificity showed an opposite pattern.

Conclusions. For optimum sensitivity, the Mangham protocol is preferred (sensitivity, 91.58%; specificity A, 44.23%; specificity B, 44.91%), which proposes a ≥10-dB interaural difference, averaging 1 to 8 kHz. For optimum specificity, the American Academy of Otolaryngology–Head and Neck Surgery protocol is preferred (sensitivity, 87.37%; specificity A, 65.38%; specificity B, 66.04%), which proposes ≥15 dB between ears, averaging 0.5 to 3 kHz.

Magnetic resonance imaging screening in acoustic neuroma

OBJECTIVES

Magnetic resonance imaging (MRI) is the definitive investigation for detection of an acoustic neuroma. It is however an expensive resource, and pick-up rate of a tumor can be as low as 1% of all patients scanned. This study aims to examine referral patterns for MRI screening for patients presenting with asymmetrical sensorineural hearing loss (ASHL). A second aim was to suggest appropriate screening criteria.

METHOD

All 132 MRI scans performed for ASHL in the year 2005 were reviewed retrospectively along with their case records and audiograms. In addition, MRI scans and case records were reviewed for the last 30 patients diagnosed with acoustic neuromas. Information was analyzed using 2 published protocols and additional frequency-specific defined criteria.

RESULTS

Two acoustic neuromas were picked up out of 132 scans performed. Of the scans performed for ASHL, a third did not fit with any of the published criteria. Of the 30 positive scans for a tumor, the patients/audiograms revealed that 10% did not fit the published criteria despite the patients having no other audiovestibular symptoms.

CONCLUSIONS

There appears to be no universally accepted guidelines on screening in ASHL with clinical acumen being used by most ENT consultants in this region. Applying protocols may reduce the amount of scans performed, but up to 10% of tumors may be missed by this approach.

Vestibular schwannoma: when to look for it?

OBJECTIVES

(1) To compare audiometric parameters in patients with vestibular schwannoma and in those with asymmetric hearing loss from other causes; and (2) to assess proposed screening criteria by comparing published protocols.

METHODS

Audiometric data from 199 vestibular schwannoma patients and 225 non-tumour patients were compared. Eight screening protocols were tested on these 424 patients.

RESULTS

Vestibular schwannoma and non-tumour patients with little or no hearing loss in the unaffected ear were inseparable; however, vestibular schwannoma patients with hearing loss in the unaffected ear had greater audiometric asymmetry, compared with non-tumour patients with the same pattern of hearing loss. The sensitivity of screening protocols varied from 73 to 100 per cent; parallelism was observed between sensitivity and screening rate.

CONCLUSION

As regards vestibular schwannoma screening protocols, the best compromise between sensitivity and screening rate was offered by a criterion comprising either: (1) > or =20 dB asymmetry at two neighbouring frequencies, or unilateral tinnitus, or (2) > or =15 dB asymmetry at two frequencies between 2 and 8 kHz.

Asymmetric hearing loss: rule 3,000 for screening vestibular schwannoma

OBJECTIVE

To assess the diagnostic yield of audiograms associated to electronystagmography (ENG) for screening vestibular schwannomas (VSs), to determine what definition of asymmetric sensorineural hearing loss (ASNHL) fits best for the diagnosis of VS, and to determine if cochleovestibular symptoms and atherosclerotic potential risk factors play a role in the VS screening.

STUDY DESIGN

Retrospective chart review in a tertiary care center.

METHODS

One hundred twenty-two patients were included in the study and divided into 2 groups: 1) patients presenting a VS (n = 74) and 2) patients without VS (n = 48). They had received an audiometry assessment, an ENG, and a posterior fossa magnetic resonance imaging (MRI). In addition, a variety of risk factors and clinical data were collected. Mean hearing threshold by frequency, mean asymmetries by frequency, speech discrimination score (SDS), ENG results, and presence or absence of vertigo are studied. Cochleovestibular symptoms and atherosclerotic potential risk factors were collected. Characteristics were studied with analysis of variance, chi2 test, or a paired t test. A receiver operating characteristic curve was obtained. A logistic regression with a step-wise selection based on the likelihood ratio was used to identify the best subgroup of predictors of the VS.

RESULTS

The most revealing data were the mean ASNHL at 3,000 Hz (p < 0.001), the interaural SDS asymmetry (p < 0.001), the vestibular deficit (p < 0.049), and the absence of vertigo (p < 0.001). The ASNHL at 3,000 Hz was the most representative value of all the frequencies and for the SDS asymmetry. Interaural difference of 15 dB or more at 3,000 Hz is sufficient to consider hearing loss as asymmetric. When the cutoff for a positive test was placed at 50% probability, the receiver operating characteristic curve shows a sensitivity of 73%. The grade of the tumor was also related with the degree of ASNHL at 3,000 Hz. Caloric test does not predict the localization or the grade of the VS. Tinnitus and atherosclerotic potential risk factors were not considered significantly linked with VS.

CONCLUSION

To reduce the number of negative MRI performed in the investigation of an ASNHL, we propose the "rule 3,000," ASNHL of 15 dB or more at the 3,000-Hz frequency. In this case, an investigation with MRI is crucial. If this ASNHL is less than 15 dB, we recommend a biannual audiometric follow-up.

Screening patients with sensorineural hearing loss for vestibular schwannoma using a Bayesian classifier

OBJECTIVES

Selecting patients with asymmetrical sensorineural hearing loss for further investigation continues to pose clinical and medicolegal challenges, given the disparity between the number of symptomatic patients, and the low incidence of vestibular schwannoma as the underlying cause. We developed and validated a diagnostic model using a generalisation of neural networks, for detecting vestibular schwannomas from clinical and audiological data, and compared its performance with six previously published clinical and audiological decision-support screening protocols.

DESIGN

Probabilistic complex data classification using a neural network generalization.

SETTINGS

Tertiary referral lateral skull base and a computational neuroscience unit.

PARTICIPANTS

Clinical and audiometric details of 129 patients with, and as many age and sex-matched patients without vestibular schwannomas, as determined with magnetic resonance imaging.

MAIN OUTCOME MEASURES

The ability to diagnose a patient as having or not having vestibular schwannoma.

RESULTS

A Gaussian Process Ordinal Regression Classifier was trained and cross-validated to classify cases as 'with' or 'without' vestibular schwannoma, and its diagnostic performance was assessed using receiver operator characteristic plots. It proved possible to pre-select sensitivity and specificity, with an area under the curve of 0.8025. At 95% sensitivity, the trained system had a specificity of 56%, 30% better than audiological protocols with closest sensitivities. The sensitivities of previously-published audiological protocols ranged between 82-97%, and their specificities ranged between 15-61%.

DISCUSSION

The Gaussian Process ORdinal Regression Classifier increased the flexibility and specificity of the screening process for vestibular schwannoma when applied to a sample of matched patients with and without this condition. If applied prospectively, it could reduce the number of 'normal' magnetic resonance (MR) scans by as much as 30% without reducing detection sensitivity. Performance can be further improed through incorporating additional data domains. Current findings need to be reproduced using a larger dataset.

[Magnetic resonance: first choice test in the screening of internal auditory canal and cerebellopontine angle tumors]

Although internal auditory canal (IAC) and cerebellopontine angle (CPA) tumors are rare, their clinical suspicion is quite common in the otolaryngology office. MRI is the imaging modality of choice in diagnosing these tumors. Perceived high costs may prevent clinicians from using it as a screening tool. A protocol designed to improve cost-effectiveness in such diagnosis results in a more rationale clinical practice. Our aim was to evaluate the usefulness of MRI as screening tool in diagnosis of IAC and CPA tumors in our population. Between March 1998 and March 2000, a prospective series of 200 cases had a MRI screening requested. MRI were performed following Fast Spin Echo technique, providing T2-weighted images. Gadolinium enhanced MRI was reserved for selected cases. We report on 190 MRI done. We found 7 neuromas (3.5%), one CPA metastasis, one epidermoid cyst and 9 IAC vascular anomalies. Only 138 cases (69%) had normal MRI images. When used following a designed protocol, MRI is our procedure of choice while screening IAC and CPA tumors because it is a cost-effective tool.

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.

Outcome of using magnetic resonance imaging as an initial screen to exclude vestibular schwannoma in patients presenting with unilateral tinnitus

The improved cost-effectiveness of gadolinium-enhanced magnetic resonance imaging (MRIg) as a diagnostic tool for vestibular schwannoma has resulted in smaller tumours being diagnosed. There has been a change in the clinical presentation of these tumours and up to four per cent may present with unilateral tinnitus. The limitation of auditory brain stem response (ABR) as a screening tool that detects small tumours is recognized and there is a strong argument for using MRIg as the initial investigation. Various screening guidelines have been proposed, some include submitting patients with unilateral tinnitus for MRIg. This report describes the findings in a group of 174 patients presenting with unilateral tinnitus who underwent MRIg as part of a guideline-directed screen to exclude vestibular schwannoma. Five patients had a cause for their tinnitus diagnosed, one a vestibular schwannoma. Two had intracranial aneurysms and another three had pathology revealed that merited onward referral. A further nine patients had incidental findings that neither accounted for their symptoms nor needed further investigation or referral. The rationale for screening these patients with MRIg is discussed.