Risk Factors of Acoustic Neuroma: Systematic Review and Meta-Analysis

PURPOSE: Many epidemiological studies have investigated environmental risk factors for the development of acoustic neuroma. However, these results are controversial. We conducted a meta-analysis of case-control studies to identify any potential relationship between history of noise exposure, smoking, allergic diseases, and risk of acoustic neuroma. MATERIALS AND METHODS: We searched PubMed to identify relevant articles. Two researchers evaluated the eligibility and extracted the data independently. RESULTS: Eleven case-control studies were included in our meta-analysis. Acoustic neuroma was found to be associated with leisure noise exposure [odds ratio (OR)=1.33, 95% confidence interval (CI): 1.05-1.68], but not with occupational noise exposure and ever noise exposure (OR=1.20, 95% CI: 0.84-1.72 and OR=1.15, 95% CI: 0.80-1.65). The OR of acoustic neuroma for ever (versus never) smoking was 0.53 (95% CI: 0.30-0.94), while the subgroup analysis indicated ORs of 0.95 (95% CI: 0.81-1.10) and 0.49 (95% CI: 0.41-0.59) for ex-smoker and current smoker respectively. The ORs for asthma, eczema, and seasonal rhinitis were 0.98 (95% CI: 0.80-1.18), 0.91 (95% CI: 0.76-1.09), and 1.52 (95% CI: 0.90-2.54), respectively. CONCLUSION: Our meta-analysis is suggestive of an elevated risk of acoustic neuroma among individuals who were ever exposed to leisure noise, but not to occupational noise. Our study also indicated a lower acoustic neuroma risk among ever and current cigarette smokers than never smokers, while there was no significant relationship for ex-smokers. No significant associations were found between acoustic neuroma and history of any allergic diseases, such as asthma, eczema, and seasonal rhinitis.

Role of magnetic resonance imaging in evaluation of cerebellopontine angle tumors

Objective: to determine the role of MRI in evaluation of different Cerebellopontine angle tumors, and differentiation between them

Materials and Method: This study was conducted in the period between January 2009 and December 2012. Fifty four patients with CPA masses were selected on bases of neurotological complains that related to CPA

Results: Cerebellopontine angle masses in this study were classified into two groups: acoustic neuromas and non acoustic neuromas CPA masses. Twenty eight of cases [51.8%] were acoustic neuromas in which 26 cases were unilateral acoustic neuromas and 2 cases with bilateral neuromas, the remaining 26 cases [48.2%] were other non acoustic CPA masses. These included, one trigeminal neuroma [1.9%], 6 [11.1%] cases were CPA meningiomas, 6 [11.1] cases were epidermoid, 3 [5.6%] cases were arachnoid cyst, 2 [3.7%] cases were glomus jugulare tumors, 3 [5.6%] cases metastatic tumors and 5 [9.2%] cases were intraaxial and intraventricular tumors extending to the CPA, this included 2 cases cerebellar hemangioblastoma, 1 case pontine glioma and 2 cases were fourth ventricular ependymoma

Conclusion: MR imaging is considered the imaging method of choice to assess CPA tumors and to distinguish between them

Acoustic neurinomas

Acoustic neuromas [AN] are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma[VS] causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. In many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by MRI. In the majority of cases the tumor is small, leaving the clinician and patient with the options of either serial scanning or active treatment by gamma knife radiosurgery [GKR] or microneurosurgery. Despite the vast number of published treatment reports, comparative studies are few. The predominant clinical endpoints of AN treatment include tumor control, facial nerve function and hearing preservation. Less focus has been put on symptom relief and health-related quality of life [QOL]. It is uncertain if treating a small tumor leaves the patient with a better chance of obtaining relief from future hearing loss, vertigo or tinnitus than by observing it without treatment. In this paper we review the literature for the natural course, the treatment alternatives and the results of AN. Finally, we present our experience with a management strategy applied for more than 30 years

História do diagnóstico do neurinoma do acústico / History of the diagnosis of the acoustic neuroma

É realizada revisao da literatura sobre os neurinomas do acústico, abordando a incidência, as manifestaçoes clínicas, a propedêutica e o diagnóstico diferencial desses tumores. A designaçao mais precisa seria schwannoma do vestibular. Esses tumores constituem 8-10 por cento dos tumores intracranianos, com maior incidência no sexo feminino e na quarta década da vida. As observaçoes sugerem que as manifestaçoes clínicas dos tumores intracanaliculares diferem daquelas dos neurinomas de maior tamanho, existindo formas atípicas de apresentaçao. O crescimento tumoral pode ser diferente nos neurinomas da neurofibromatose tipo II. Os exames por RM e por TC de alta resoluçao para os ossos temporais sao, atualmente, os mais utilizados, existindo ainda, em certos casos, dificuldades no diagnóstico diferencial entre neurinoma do acústico e meningeoma.