Acoustic neuroma: correlation among tumor size, symptoms, and patient age

Analysis of semicircular canal function as evaluated by video Head Impulse Test in patients with vestibular schwannoma

OBJECTIVE

The aim of the present study was to investigate the factors influencing semicircular canal function as evaluated by video Head Impulse Test (vHIT) in patients with vestibular schwannoma.

METHODS

Twenty-four patients with untreated vestibular schwannoma underwent vHIT examination. The correlations between semicircular canal function and factors including age, tumor size, disease duration and hearing loss were evaluated.

RESULTS

The functions of all three semicircular canals on the affected side evaluated by vHIT were significantly lower than those on the unaffected side. Although there were no significant correlations between semicircular canal function and age, tumor size or disease duration, a negative significant correlation between vestibulo-ocular reflex (VOR) gain as evaluated by vHIT and hearing loss was observed.

CONCLUSIONS

From the results of the relationship between hearing loss and VOR gain, the damage to the audio and vestibular systems in patients with VS may be correlated. As it has been suggested that tumor size was not a significant factor in the VOR gain evaluated by vHIT, multifactorial causes rather than the simple compression of the vestibular nerves alone may be related to the dysfunction of the semicircular canals in patients with vestibular schwannoma.

The "hype" of hydrops in classifying vestibular disorders: a narrative review

Background

Classifying and diagnosing peripheral vestibular disorders based on their symptoms is challenging due to possible symptom overlap or atypical clinical presentation. To improve the diagnostic trajectory, gadolinium-based contrast-enhanced magnetic resonance imaging of the inner ear is nowadays frequently used for the in vivo confirmation of endolymphatic hydrops in humans. However, hydrops is visualized in both healthy subjects and patients with vestibular disorders, which might make the clinical value of hydrops detection on MRI questionable.

Objective

To investigate the diagnostic value of clinical and radiological features, including the in vivo visualization of endolymphatic hydrops, for the classification and diagnosis of vestibular disorders.

Methods

A literature search was performed in February and March 2019 to estimate the prevalence of various features in healthy subjects and in common vestibular disorders to make a graphical comparison between healthy and abnormal.

Results

Of the features studied, hydrops was found to be a highly prevalent feature in Menière’s disease (99.4%). Though, hydrops has also a relatively high prevalence in patients with vestibular schwannoma (48.2%) and in healthy temporal bones (12.5%) as well. In patients diagnosed with (definite or probable) Menière’s disease, hydrops is less frequently diagnosed by magnetic resonance imaging compared to the histological confirmation (82.3% versus 99.4%). The mean prevalence of radiologically diagnosed hydrops was 31% in healthy subjects, 28.1% in patients with vestibular migraine, and 25.9% in patients with vestibular schwannoma. An interesting finding was an absolute difference in hydrops prevalence between the two diagnostic techniques (histology and radiology) of 25.2% in patients with Menière’s disease and 29% in patients with vestibular schwannoma.

Conclusions

Although the visualization of hydrops has a high diagnostic value in patients with definite Menière’s disease, it is important to appreciate the relatively high prevalence of hydrops in healthy populations and other vestibular disorders. Endolymphatic hydrops is not a pathognomic phenomenon, and detecting hydrops should not directly indicate a diagnosis of Menière’s disease. Both symptom-driven and hydrops-based classification systems have disadvantages. Therefore, it might be worth to explore features “beyond” hydrops. New analysis techniques, such as Radiomics, might play an essential role in (re)classifying vestibular disorders in the future.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10278-8) contains supplementary material, which is available to authorized users.

Symptoms in primary care with time to diagnosis of brain tumours

Background

Brain tumours often present with varied, non-specific features with other diagnoses usually being more likely.

Objective

To examine how different symptoms and patient demographics predict variations in time to brain tumour diagnosis.

Methods

We conducted a secondary analysis of brain tumour cases from National Audit of Cancer Diagnosis in Primary Care. We grouped neurological symptoms into six domains (headache, behavioural/cognitive change, focal neurology, 'fits, faints or falls', non-specific neurological, and other/non-specific) and calculated times for patient presentation, GP referral, specialist consultation and total pathway interval. We calculated odds ratios (ORs) for symptom domains comparing the slowest to other quartiles.

Results

Data were available for 226 cases. Median (interquartile range) time for the total pathway interval was 24 days (7-65 days). The most common presentation was focal neurology (33.2%) followed by 'fits, faints or falls' and headache (both 20.8%). Headache only (OR = 4.11, 95% CI = 1.10, 15.5) and memory complaints (OR = 4.82, 95% CI = 1.15, 20.1) were associated with slower total pathway compared to 'fits, faints or falls'. GPs were more likely to consider that there had been avoidable delays in referring patients with headache only (OR = 4.17, 95% CI = 1.14, 15.3).

Conclusion

Patients presenting to primary care with headache only or with memory complaints remain problematic with potentially avoidable delays in referral leading to a longer patient pathway. This may or may not impact on the efficacy and morbidity of therapies. Additional aids are required to help doctors differentiate when to refer headaches and memory complaints urgently for a specialist opinion.

Could IGF-I levels play a neuroprotective role in patients with large vestibular schwannomas?

Aim

To evaluate the possible superiority of outcome in patients with elevated IGF-I levels after vestibular schwannoma (VS) resection.

Patients & methods

This retrospective study included 65 patients (34 male, 52.3%) with VS operated in between January 2009 and April 2014 (follow-up 3.2 ± 0.7 years). Preoperative or postoperative IGF-I levels were identified for each patient.

Results

Patients were divided into two groups: Group A (small size tumor), 56 patients; and Group B (large size tumor), 9 cases. IGF-I levels in Group A (195.8 ± 32.9 ng/ml) were compared with those of Group B (242.2 ± 22.2 ng/ml) and were found to have statistically significant difference (p = 0.001).

Conclusion

Increased IGF-I levels could hold a key role in nerve recovery in patients undergoing surgical resection of large VS.

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor

BACKGROUND AND PURPOSE

Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor.

METHODS

Twenty-eight patients (21 women; age=64±12 years, mean±SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification.

RESULTS

Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction.

CONCLUSIONS

Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

Cognitive delay as a risk factor for late presentation of vestibular schwannoma

OBJECTIVE

The majority of patients with vestibular schwannoma (VS) initially experience audiovestibular dysfunction prompting medical evaluation. Over the past several years, the authors have noticed a significant disparity in clinical presentation among patients with preexisting cognitive impairment compared with the general population. The objective of the current study is to review the clinical presentation of 5 consecutive patients with baseline cognitive delay who were ultimately diagnosed with VS.

DESIGN

Retrospective review.

SETTING

Two tertiary academic referral centers.

PATIENTS

Consecutive subjects with baseline cognitive impairment who were evaluated for VS between 2010 and 2013.

MAIN OUTCOME MEASURES

Presenting symptoms and tumor characteristics.

RESULTS

Five adult subjects were identified. The most common reasons for seeking medical care included worsening ataxia and headaches, despite the fact that all patients had profound ipsilateral hearing loss. Additionally, 2 patients endorsed facial numbness, and 2 had partial facial paresis. MRI revealed a median preoperative tumor size of 4.7 cm (4.3-5.7 cm), and all patients had varying degrees of hydrocephalus and peritumoral vasogenic edema.

CONCLUSION

Preexisting cognitive impairment is a risk factor for late presentation of VS. Patients with normal cognitive function most commonly seek medical care after unilateral hearing loss and tinnitus. In contrast, individuals with poor cognitive capacity may be unable to acknowledge such symptoms or communicate their presence. In such patients, the diagnosis of VS is elusive, and clinicians should maintain a low threshold for imaging to avoid further delays in diagnosis and treatment.

Prospective evaluation of the clinical profile and referral pattern differences of vestibular schwannomas and other cerebellopontine angle tumors

OBJECTIVE

To evaluate the clinical profile, referral pattern, delay in diagnosis, and impact of tumor size of cases involving vestibular schwannomas (VS) versus other cerebellopontine angle (CPA) tumors in an Egyptian population.

STUDY DESIGN

Case series study.

SETTING

Tertiary referral center.

PATIENTS

A prospective study of possible retrocochlear lesions was conducted from 2008 to 2010.

INTERVENTION(S)

Patients were subjected to a full clinical history, complete otorhinolaryngological examination, a basic audiologic evaluation, auditory brainstem response assay, and gadolinium-enhanced magnetic resonance imaging. According to the findings of magnetic resonance imaging, patients with retrocochlear lesions were divided into 2 groups: those with VS (n = 17) and those with other CPA lesions (n = 14).

MAIN OUTCOME MEASURE(S)

Diagnostic delay and criteria of VS and CPA tumors.

RESULTS

Unilateral hearing loss and tinnitus were presented in 52.9% of VS cases with a diagnostic delay of 15.5 months. For cases involving other CPA lesions, a combination of otologic symptoms was observed in 9 (64%) of 14 cases, and a diagnostic delay of 47.5 months was experienced. An absence of auditory brainstem response waves was identified significantly (p < 0.05) for the affected ears of both groups. Only differences in Wave V latency were significant between the 2 groups (p < 0.05).

CONCLUSION

A longer diagnostic delay was associated with cases involving other types of CPA lesions versus cases of VS, and tumor size and volume did not affect the diagnostic delay of the former. Moreover, the only significant difference in clinical presentation for these 2 groups of intracranial tumor involved Wave V latency.

Audiological correlates of tumor parameters in acoustic neuromas

The objective of this study was undertaken to evaluate a correlation of pure tone audiometry, speech audiometry with tumor size, the presence of intrameatal extension, contralateral pure tone audiometry, and contralateral speech audiometry results at acoustic neuroma (AN) patients. Seventy-six patients with a unilateral-cerebellopontine angel tumor with/without internal acoustic canal (IAC) were included in this study. Data on pure tone audiometry, speech discrimination scores (SDS), speech reception thresholds (SRT), tumour size, and extension to IAC were analyzed retrospectively. As a result, patients with unilateral ANs had an asymmetric sensorineural hearing loss and had an asymmetric finding on the results of speech audiometry was present. We could not find any correlation between the size of the tumor and the hearing levels at each frequency. In addition, there appeared to be no significant correlation between the extension of tumor to the IAC and the audiological findings.

Immunohistochemical investigation of hormone receptors and vascular endothelial growth factor concentration in vestibular schwannoma

OBJECTIVES

To determine if a relationship exists between the presence of estrogen receptors (ER), progesterone receptors (PR), or vascular endothelial growth factor (VEGF) and the size, growth rate, and behavior of vestibular schwannoma tumors.

DESIGN

Nine tumor samples from young female patients with large vestibular schwannoma tumors were preselected because they were presumed to be faster growing, more aggressive tumors. Immunohistochemical staining was performed using monoclonal mouse antibodies to ER, PR, and VEGF.

RESULTS

The mean age of the study sample was 32.3 years, mean tumor size was 3.2 cm, and the average growth rate was 0.4 cm per 2 months. The results of immunohistochemical staining for ER and PR in all nine samples were unequivocally negative. Eight of nine tumor samples stained positive for VEGF, with five demonstrating low intensity and three demonstrating moderate intensity staining.

CONCLUSIONS

There is histopathological evidence for the expression of VEGF in vestibular schwannomas but not for ER and PR. Further studies are necessary to determine the role of VEGF and other molecular pathways in the growth of vestibular schwannomas and the application of anti-VEGF therapy as a potential treatment option in the future.

Predictors of volumetric growth and auditory deterioration in vestibular schwannomas followed in a wait and scan policy

OBJECTIVE

The purpose of this study was to identify factors predicting growth and audiologic deterioration during follow-up (FU) in a wait and scan (W&S) policy of vestibular schwannomas (VSs) using a novel volumetric measuring tool. So far, only consecutive magnetic resonance imaging (MRI) is able to show growth objectively, and growth, combined with hearing function, generally dictates further intervention. Other factors predicting growth or hearing deterioration would be invaluable and might ease clinical decision making.

STUDY DESIGN

Retrospective case study.

SETTING

Tertiary referral center.

PATIENTS

Sixty-three patients diagnosed with VS at Maastricht University Medical Center between 2003 and 2008, with FU data available from 36 patients.

INTERVENTION(S)

A W&S policy for unilateral VS with sequential contrast-enhanced T1- and T2-weighted MRI and audiograms during FU.

MAIN OUTCOME MEASURE(S)

1. Patient and radiologic VS features potentially related to growth and auditory function during a W&S policy. 2. The correlation between increase in VS volume and audiologic deterioration during FU.

RESULTS

Labyrinthine hypointensity on T2-weighted magnetic resonance images and complaints of hearing loss at presentation are predictive of a faster deterioration of hearing (p < 0.05). Growth during the first FU year predicts further growth. Vestibular schwannoma volume does not correlate with audiologic deterioration significantly.

CONCLUSION

Hypointensity on T2-weighted image of the affected labyrinth will result in a significant faster deterioration of hearing. Hearing loss was more profound, and hearing will deteriorate significantly faster in patients presenting with complaints of hearing loss. Significant growth during the first year of FU predicts further growth during FU. Sequential MRI cannot be substituted by audiologic examinations solely because increase in VS volume does not correlate with audiologic deterioration significantly.

Microsurgical excisions of vestibular schwannomas: A tumor-size-based analysis of neurological outcomes and surgical complications

INTRODUCTION

Vestibular schwannomas (VS) are benign tumors originating from Schwann cells in vestibulocochlear nerve. This study aimed at evaluating outcomes of microsurgical resections of VS based on tumor sizes in a South Asian country.

METHODS

The chart notes of 71 patients who underwent microsurgical resections of VS at a single academic center over a 20-year period (1990-2009) were reviewed, and relevant information was extracted. For analyzing outcomes, patients were divided into two groups based on tumor size at initial presentation: (1) Group A (tumor size ≤ 4 cm) and (2) Group B (tumor size > 4 cm). Pearson's chi-square and Fisher's exact tests were used for comparison of proportions; the independent sample t-test was used for comparison of means.

RESULTS

The average tumor diameter was 4.1 ± 1.5 (range, 1-6.6) cm. Complete resection was achieved more frequently in patients in Group A (P < 0.001). Duration of hospital stay and cost of treatment were significantly higher in Group B patients (P < 0.003 and P < 0.04, respectively). The severity of postoperative facial nerve injury, assessed by House-Brackmann grading system, was significantly higher in Group B (P < 0.01). Cerebrospinal fluid (CSF) leak and lower cranial nerve deficits also occurred more frequently after resection in Group B (P = 0.031 and P = 0.003, respectively).

CONCLUSION

We conclude that advanced stage tumors suggestive of delayed presentation are fairly common in Pakistan, and limit curative resection in the majority of patients. Postoperative morbidity is significantly higher in patients with tumor size > 4 cm.

Communicating hydrocephalus after gamma knife radiosurgery for vestibular schwannoma: an MR imaging study

Vestibular schwannomas are common, and gamma knife radiosurgery is a treatment option of symptomatic tumors. Hydrocephalus may be a complication of gamma knife treatment of vestibular schwannoma, though the cause-and-effect relationship can be debated because tumors can cause hydrocephalus without treatment. We present an MR imaging study of an unusual case of communicating hydrocephalus after gamma knife radiosurgery of a vestibular schwannoma in which the timeline of events strongly suggests that gamma knife played a contributory role in the development of hydrocephalus. We discuss risk factors for the development of hydrocephalus after radiation therapy and the role of MR CSF cine-flow study in the evaluation of treatment options for hydrocephalus in this setting.

Guiding patients through the choices for treating vestibular schwannomas: balancing options and ensuring informed consent. 2007

Counseling patients who are diagnosed with vestibular schwannomas, formerly known as acoustic neuromas, can be challenging. The health care provider has the responsibility to explain, in understandable language, to the patient or legal representative the proposed treatment options, risks and complications associated with each form of treatment, and alternatives to treatment, including no therapy. Patients should be encouraged to gather information before making a treatment decision. For the physicians managing these patients, information should be delivered in a balanced way to ensure patient understanding of their options leading to adequate informed consent.

Guiding patients through the choices for treating vestibular schwannomas: balancing options and ensuring informed consent

Counseling patients who are diagnosed with vestibular schwannomas, formerly known as acoustic neuromas, can be challenging. The health care provider has the responsibility to explain, in understandable language, to the patient or legal representative the proposed treatment options, risks and complications associated with each form of treatment, and alternatives to treatment, including no therapy. Patients should be encouraged to gather information before making a treatment decision. For the physicians managing these patients, information should be delivered in a balanced way to ensure patient understanding of their options leading to adequate informed consent.

Conservative management of vestibular schwannomas - second review of a prospective longitudinal study

Vestibular schwannomas have been traditionally managed with microsurgical removal and in recent years, stereotactic radiotherapy. However, there is a group of patients in whom a conservative management approach might represent a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. This is a prospective cohort review of a previously published group of patients [Clin. Otolaryngol. (2000) 25, 28-39] with unilateral vestibular schwannoma that were initially analysed at our institution in 1998 [Walsh R.M., Bath A.P., Bance M.L. et al., Clin. Otolaryngol. (2000) 25, 28]. The mean duration of follow-up was 80 months (range 52-242 months). All the patients in the study underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of rapid radiological tumour growth and/or increasing signs and symptoms, which necessitated active intervention. The mean tumour growth rate for the entire group at the second review was 1 mm/year (range -0.84-9.65 mm/year). The mean growth rate for cerebellopontine angle tumours (1.3 mm/year) was significantly greater than that of internal auditory canal (IAC) tumours (0 mm/year) (P = 0.005). The majority of tumours (87.14%) grew <2 mm/year. There was significant tumour growth seen in 38.9%, no or insignificant growth in 41.7%, and negative growth in 19.4%. Twenty-three patients (32%) failed conservative management at the second review. There was no difference in the outcome of these failed patients in comparison with patients who underwent primary treatment without a period of conservative management. The mean growth rate of tumours in patients that failed conservative management (3.1 mm/year) was significantly greater than that in patients who did not fail (0.2 mm/year) (P < 0.001). No factors predictive of tumour growth or failure of conservative management were identified. Hearing deterioration with pure tone averages (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred irrespective of tumour growth. This prospective study further emphasizes the role of conservative management in selected cases of vestibular schwannomas. Tumours in this study confined to the IAC typically demonstrated minimal or no growth on serial MRI scanning. Regular follow-up with interval scanning is mandatory in all patients.

Psycho-socio-economic outcomes in acoustic neuroma patients and their carers related to tumour size

The objective was to explore psycho-socio-economic outcomes of a 2-year cohort of patients having surgery for an acoustic neuroma, and carers and their relationship to tumour size after surgery. The Wessex Patient Carer Questionnaire was designed in conjunction with Patients and Carers, to determine psycho-socio-economic outcomes. The results were juxtaposed against clinical profiles. The House-Brackman (HB) scale was used to assess facial function at 6 and 12 months after operation. The cohort contained 102 patients. There were 87% effective responders. Half were aged below 54 years and 30% had school-aged children. The majority (93%) of patients were operated via the translabyrinthine approach. Patients with large tumours, i.e. greater than 3 cm (28%), had most post-treatment physical problems, including hearing and balance difficulties, and 42% reported difficulty eating in public. Thirty-four per cent felt 'stressed' and 18%'depressed'. After 6 months, facial function was recorded as HB scale 5/6 in 21% of patients but by 1 year only 8% of patients were HB 5/6. Patients and carers were generally very satisfied with their in-patient neurosurgical care, but significantly dissatisfied with post-discharge care - particularly the shortcoming of the community services. The majority of families felt 'unsupported' and only 20% of patients had confidence in their General Practitioner's knowledge. Families faced severe socio-economic disruption and patients"time-off-work' was estimated to cost pound 954,000. Carers carried considerable post-discharge psychological burdens and costs to the public purse were calculated to be pound 52,000.

Comparison of cohorts of elective and emergency neurosurgical patients: psychosocial outcomes of acoustic neuroma and aneurysmal sub arachnoid hemorrhage patients and carers

OBJECTIVES

To compare the psychosocial outcomes of cohorts of elective [Acoustic Neuroma (AN)] and emergency [Aneu-rysmal Sub Arachnoid Hemorrhage (ASAH)] Neurosurgical patients and carers.

METHODS

The standardized Wessex Patient Carer Questionnaire was designed with patients and carers and provided psychosocial and economic outcome data following elective or emergency surgery. Clinical data on size of tumor and size of bleed, respectively, were extracted from Consultant notes.

RESULTS

Both cohorts were generally satisfied with neurosurgical in-patient care but both suffered high-economic costs and were predominately very dissatisfied with community care. There were significant psychosocial differences between elective and emergency patients, and despite greater relative physical disability among elective patients, it was the emergency cohort who had worse psychosocial outcomes.

CONCLUSIONS

Despite many common psychosocial features, the differences between the cohorts were mainly psychological rather than physiological, because of greater 'post-traumatic-stress-reaction' in the emergency cohort, indicating the need for appropriate psychosocial care immediately after neurosurgery to reduce unnecessary distress and costs to patients, carers, and community.

Hearing deterioration in patients with a non-growing vestibular schwannoma

OBJECTIVE

The aim of this study was to document and analyse the course of several audiometric parameters in 49 patients with a non-growing unilateral vestibular schwannoma (VS).

MATERIAL AND METHODS

Patients received conservative management and absence of tumour growth was ascertained by means of serial magnetic imaging studies. Pure-tone audiometry and speech audiometry were performed at yearly intervals.

RESULTS

Pure-tone audiometry revealed a significant increase in thresholds at all frequencies, except for 8.0 kHz. The maximum yearly threshold increase was 2.4 dB hearing level at 1.0 and 2.0 kHz. Speech audiometry revealed a significant decrease in maximum discrimination over the course of time. No significant changes were observed in the following parameters: the intensity level at which maximum discrimination was achieved; the roll-over index; the speech reception threshold; and the slope of the curve in the speech audiogram. No change was observed in the relation between pure-tone audiometry thresholds and speech audiometry scores. Apparently, the deterioration of pure-tone perception and speech discrimination ran parallel courses.

CONCLUSIONS

The results of this study indicate that hearing loss is a predominant symptom in patients with a non-growing VS, as is also known in patients with a growing lesion. Moreover, it seems unlikely that the hearing loss in VS patients is merely the result of mechanical influences on retrocochlear neural or vascular structures.

Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas: comparative observations of 125 patients treated at one institution

BACKGROUND

Stereotactic radiosurgery (SRS) and, more recently, fractionated stereotactic radiotherapy (SRT) have been recognized as noninvasive alternatives to surgery for the treatment of acoustic schwannomas. We review our experience of acoustic tumor treatments at one institution using a gamma knife for SRS and the first commercial world installation of a dedicated linac for SRT.

METHODS

Patients were treated with SRS on the gamma knife or SRT on the linac from October 1994 through August 2000. Gamma knife technique involved a fixed-frame multiple shot/high conformality single treatment, whereas linac technique involved daily conventional fraction treatments involving a relocatable frame, fewer isocenters, and high conformality established by noncoplanar arc beam shaping and differential beam weighting.

RESULTS

Sixty-nine patients were treated on the gamma knife, and 56 patients were treated on the linac, with 1 NF-2 patient common to both units. Three patients were lost to follow-up, and in the remaining 122 patients, mean follow-up was 119 +/- 67 weeks for SRS patients and 115 +/- 96 weeks for SRT patients. Tumor control rates were high (> or =97%) for sporadic tumors in both groups but lower for NF-2 tumors in the SRT group. Cranial nerve morbidities were comparably low in both groups, with the exception of functional hearing preservation, which was 2.5-fold higher in patients who received conventional fraction SRT.

CONCLUSION

SRS and SRT represent comparable noninvasive treatments for acoustic schwannomas in both sporadic and NF-2 patient groups. At 1-year follow-up, a significantly higher rate of serviceable hearing preservation was achieved in SRT sporadic tumor patients and may therefore be preferable to alternatives including surgery, SRS, or possibly observation in patients with serviceable hearing.

Determinants of tumor size and growth in vestibular schwannomas

OBJECT

This study was undertaken to analyze factors associated with the size of unilateral vestibular schwannomas (VSs).

METHODS

A retrospective analysis of an unselected and sequential series of 433 patients with unilateral VSs was conducted. Tumor size was defined by the largest dimension of the tumor in the cerebellopontine angle, and the size was tested for a relationship with patient age and sex. In a subgroup of 231 patients in whom data were available, tumor size was also tested for a relationship with tumor cysts or the absence of an internal auditory canal (IAC) component. Some patients underwent a period of surveillance with serial imaging studies to monitor for tumor growth. Data from these patients, excluding those with cystic tumors, were analyzed to see if tumor growth was related to patient age, sex, or tumor size. CONCLUSIONS; Larger tumors were found in younger patients, in females, in the subgroup of cystic tumors, and in patients in whom there was no tumor component in the IAC. The probable explanations for these larger tumors are a faster growth rate and/or a delay in symptom onset. When untreated tumors are managed with observation, measurable growth is more often seen in larger tumors, although smaller tumors have a faster relative growth rate than larger ones.

Patient-assessed outcomes after excision of acoustic neuroma: postoperative symptoms and quality of life

OBJECT

The aim of this study was to assess whether outcomes from excision of acoustic neuroma vary among patients and have a material impact on their quality of life (QOL).

METHODS

A questionnaire concerning postoperative symptoms and the Short Form 36 (SF-36) QOL instrument were mailed to 97 consecutive patients who had undergone acoustic neuroma surgery via the translabyrinthine approach. The survey response rate was 78% and the symptomatology was consistent with other reports, supporting the representativeness of the sample. The respondents' QOL was rated significantly below published norms and their work capacity was reportedly reduced. Specifically, the following SF-36 dimensions were reduced: physical functioning and role-physical, together with vitality, general health, and social functioning. Greater numbers of postoperative symptoms and larger tumors were associated with a worse rating of physical functioning. More severe balance problems were associated with lower ratings of social functioning. The disparity between the patient's self-estimate and self-measurement and the clinician's assessment of the patient's facial functioning raises doubts about the validity of subjective reports and assessment.

CONCLUSIONS

The present study supports the use of generic QOL measures to assess outcome and to draw comparisons between different populations.

Vertigo and dysequilibrium with associated hearing loss

There are numerous disorders that can present with hearing loss and vertigo or dysequilibrium. The combination of vertigo and imbalance associated with hearing loss are symptoms suggestive of a peripheral vestibular disorder. This article summarizes presentation, diagnosis, and treatment of the various common and rare peripheral vestibular disorders that can present with these symptoms.

The role of conservative management of vestibular schwannomas

Although microsurgery is generally regarded as the conventional treatment of choice for most vestibular schwannomas, there remains a group of patients in whom a conservative management approach may be a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. The reasons for conservative management included poor general health, age, patient preference, small tumour size, minimal or no symptoms, and tumour in the only/better hearing ear. The mean duration of follow-up was 39.8 months (range 12-194 months). All patients underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of continuous or rapid radiological tumour growth and/or increasing symptoms or signs. The mean tumour growth rate, according to the 1995 guidelines of the American Academy of Otolaryngology/Head and Neck Surgery, was 1.16 mm/year (range: 0.75 9.65 mm/year). Approximately 83% of tumours grew at < 2 mm/year. Significant tumour growth was seen in 36.4%, no or insignificant growth in 50%, and negative growth in 13.6% of tumours. The growth rate of CPA tumours (1.4 mm/year) was significantly greater than that of IAC tumours (0.2 mm/year) (P = 0.001). Failure of conservative management, in which active treatment was required, occurred in 15.3%. The outcome of these patients appeared to be as favourable to a comparable group who underwent primary treatment, without a period of conservative management. The mean growth rate of tumours in patients who failed conservative management (4.2 mm/year) was significantly greater than that in patients who did not fail (0.5 mm/year) (P < 0.01). No factors predictive of tumour growth or failure of conservative management were identified. Deterioration of mean pure tone average (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred regardless of whether radiological tumour growth was demonstrated or not. This study suggests that in a select number of cases of vestibular schwannoma, a conservative management approach may be appropriate. Regular follow-up with serial MRI is mandatory. Deterioration of auditory function occurs even in the absence of tumour growth.