Role of Tobacco Use in the Etiology of Acoustic Neuroma

Two previous studies suggest that cigarette smoking reduces acoustic neuroma risk; however, an association between use of snuff tobacco and acoustic neuroma has not been investigated previously. The authors conducted a case-control study in Sweden from 2002 to 2007, in which 451 cases and 710 population-based controls completed questionnaires. Cases and controls were matched on gender, region, and age within 5 years. The authors estimated odds ratios using conditional logistic regression analyses, adjusted for education and tobacco use (snuff use in the smoking analysis and smoking in the snuff analysis). The risk of acoustic neuroma was greatly reduced in male current smokers (odds ratio (OR) = 0.41, 95% confidence interval (CI): 0.23, 0.74) and moderately reduced in female current smokers (OR = 0.70, 95% CI: 0.40, 1.23). In contrast, current snuff use among males was not associated with risk of acoustic neuroma (OR = 0.94, 95% CI: 0.57, 1.55). The authors’ findings are consistent with previous reports of lower acoustic neuroma risk among current cigarette smokers than among never smokers. The absence of an association between snuff use and acoustic neuroma suggests that some constituent of tobacco smoke other than nicotine may confer protection against acoustic neuroma

Incidence of acoustic neuroma in Malta

Objective: Establishing the incidence of acoustic neuroma in Malta over the last 17 years. Methods: A retrospective study whereby records of patients referred for treatment abroad were reviewed along with the Magnetic Resosnance Images of the Internal Auditory Meatus (MRIAMs) performed from 2009 until 2016. All new cases of acoustic neuroma were included in the study. Results: 76 new cases of acoustic neuroma were discovered over the 17 years, resulting in an incidence of 1.1 per 100000. Conclusion: This is the first study trying to establish the incidence and epidemiology of acoustic neuroma in Malta.peer-reviewe

Cochlea-sparing acoustic neuroma treatment with 4π radiation therapy.

PurposeThis study investigates whether 4π noncoplanar radiation therapy can spare the cochleae and consequently potentially improve hearing preservation in patients with acoustic neuroma who are treated with radiation therapy.Methods and materialsClinical radiation therapy plans for 30 patients with acoustic neuroma were included (14 stereotactic radiation surgery [SRS], 6 stereotactic radiation therapy [SRT], and 10 intensity modulated radiation therapy [IMRT]). The 4π plans were created for each patient with 20 optimal beams selected using a greedy column generation method and subsequently recalculated in Eclipse for comparison. Organ-at-risk (OAR) doses, homogeneity index, conformity, and tumor control probability (TCP) were compared. Normal tissue complication probability (NTCP) was calculated for sensorineural hearing loss (SNHL) at 3 and 5 years posttreatment. The dose for each plan was then escalated to achieve 99.5% TCP.Results4π significantly reduced the mean dose to both cochleae by 2.0 Gy (32%) for SRS, 3.2 Gy (29%) for SRT, and 10.0 Gy (32%) for IMRT. The maximum dose to both cochleae was also reduced with 4π by 1.6 Gy (20%), 2.2 Gy (15%), and 7.1 Gy (18%) for SRS, SRT, and IMRT plans, respectively. The reductions in mean/maximum brainstem dose with 4π were also statistically significant. Mean doses to other OARs were reduced by 19% to 56% on average. 4π plans had a similar CN and TCP, with a significantly higher average homogeneity index (0.93 vs 0.92) and significantly lower average NTCP for SNHL at both 3 years (30.8% vs 40.8%) and 5 years (43.3% vs 61.7%). An average dose escalation of approximately 116% of the prescription dose achieved 99.5% TCP, which resulted in 32.6% and 43.4% NTCP for SNHL at 3 years and 46.4% and 64.7% at 5 years for 4π and clinical plans, respectively.ConclusionsCompared with clinical planning methods, optimized 4π radiation therapy enables statistically significant sparing of the cochleae in acoustic neuroma treatment as well as lowering of other OAR doses, potentially reducing the risk of hearing loss

Environmental factors and risk of acoustic neuroma

The aim of this thesis was to increase the knowledge about environmental risk factors of acoustic neuroma and to increase the understanding of the methodological problems encountered when studying this tumor. Acoustic neuroma is a benign, usually slow growing, intracranial tumor of the vestibulocochlear nerve (cranial nerve VIII), the nerve that transmits information about hearing and balance from the inner ear to the brain. Acoustic neuroma is usually not life threatening, the most common symptoms are unilateral hearing loss and balance problems, but more severe symptoms like hydrocephalus may occur because of its intracranial location. Very little is known about acoustic neuroma etiology. The only well-established environmental risk factor is ionizing radiation, but associations have been observed with non-smoking, income, and education. This thesis includes studies that investigated the associations between acoustic neuroma and mobile and cordless phone use, occupational and leisure time exposure to loud noise, and occupational exposure to chemical agents. In addition, a validation of self-reported start year of mobile phone use was performed, using operator data as gold standard. The thesis is based on a Swedish nationwide population based case- control study of acoustic neuroma risk factors. The study includes 451 cases of acoustic neuroma and 710 controls, matched on age, sex and residential region. Postal questionnaires were used to collect exposure information about environmental and lifestyle factors. No evidence was found for an association between use of mobile phones and acoustic neuroma risk. Odds ratios for regular use and for long-term use of mobile phones were close to unity. An elevated odds ratio was found for the highest quartile of lifetime cumulative duration of calls but no corresponding increase in the highest quartile of cumulative number of calls. An association was found for regular use of cordless phones, but not for long term use. Also for cordless phones an increased odds ratio was found in the highest quartile of cumulative duration of calls but not for number of calls. The increased odds ratios were confined to cases without histological confirmation of the tumor, which may indicate that mobile and cordless phone use increases the probability of detection of the acoustic neuroma tumors. Odds ratios were generally higher for mobile phone use on the non-tumor side of the head and the laterality analyses indicated that laterality specific analyses suffered from reversed causality as cases changed the preferred side of use because of hearing loss on the tumor side. The validation showed large random errors in the self-reported information about start year of mobile phone use. Associations were found between acoustic neuroma and exposure to leisure time loud noise, but not with occupational noise, and associations were found for occupational exposure benzene, diesel engine exhaust, gasoline, and methylene chloride

Patient Decision Making in Vestibular Schwannoma: A Survey of the Acoustic Neuroma Association.

Objective To assess the decision-making process of patients with vestibular schwannoma (VS). Study Design Patients with VS completed a voluntary survey over a 3-month period. Setting Surveys were distributed online through email, Facebook, and member website. Subjects and Methods All patients had a diagnosis of VS and were members of the Acoustic Neuroma Association (ANA). A total of 789 patients completed the online survey. Results Of the 789 participants, 474 (60%) cited physician recommendation as a significant influential factor in deciding treatment. In our sample, 629 (80%) saw multiple VS specialists and 410 (52%) sought second opinions within the same specialty. Of those who received multiple consults, 242 (59%) of patients reported receiving different opinions regarding treatment. Those undergoing observation spent significantly less time with the physician (41 minutes) compared to surgery (68 minutes) and radiation (60 minutes) patients ( P < .001). A total of 32 (4%) patients stated the physician alone made the decision for treatment, and 29 (4%) felt they did not understand all possible treatment options before final decision was made. Of the 414 patients who underwent surgery, 66 (16%) felt they were pressured by the surgeon to choose surgical treatment. Conclusion Deciding on a proper VS treatment for patients can be complicated and dependent on numerous clinical and individual factors. It is clear that many patients find it important to seek second opinions from other specialties. Moreover, second opinions within the same specialty are common, and the number of neurotologists consulted correlated with higher decision satisfaction

Advances in ENT imaging

Over the last ten years or so radiology has shown dramatic technological developments especially in cross sectional imaging and the investigation and management of the complex ENT patient has benefitted enormously. Plain radiographs are being utilised less and less as their limitations are becoming more apparent and various studies have shown for example a 75% discrepancy between plain sinus radiographs and coronal sinus CT in children1,2 . The incorporation of small and flexible ultrasound transducers with high-resolution imaging into the tips of endoluminal catheters has allowed good quality endoluminal ultrasound. Recently endolaryngeal ultrasound has been clinically evaluated in 38 patients with a variety of laryngeal pathology including vocal fold polyps, laryngeal cysts, chronic laryngitis, epithelial dysplasia and cancer 5 . Using this technique tumour size and infiltration could be measured and involvement of the thyroid cartilage or anterior commissure could be visualised. Not surprisingly it was not able to detect any specific changes in the sonographic picture of patients suffering from chronic laryngitis, epithelial dysplasia or microinvasive cancer. Although these results are encouraging, its relative lack of availability will result in it only having a limited role in evaluating laryngeal pathology.peer-reviewe

The changing landscape of vestibular schwannoma diagnosis and management: A cross-sectional study.

ObjectivesTo assess the current state of the diagnosis and management of vestibular schwannoma (VS) as well as treatment trends, and to evaluate the role of treatment setting and various specialists in treatment plan.MethodsPatients diagnosed with VS completed a voluntary and anonymous survey. The questionnaires were distributed through Acoustic Neuroma Association website, Facebook page, and e-mail newsletters from January to March 2017.ResultsIn total, 789 VS patients completed the survey. Of those, 414 (52%) underwent surgery; 224 (28%) underwent radiotherapy; and 121 (15%) were observed. General otolaryngologists diagnosed 62% of responders, followed by primary care (11%) and neurotologists (10%). Patients who underwent surgery were significantly younger and had larger tumors compared to those treated with radiation or observation. The ratio of patients having nonsurgical versus surgical resection changed from 1:2 to 1:1 for the periods of 1979 through 2006 versus 2007 through 2017, respectively. Neurosurgeons (40%) and neurotologists (38%) were the most influential in treatment discussion. Neurotologists (P < 0.001) and general otolaryngologists (P = 0.04) were more influential than neurosurgeons for the decision process in patients with smaller tumors. Patients treated at academic versus nonacademic private institutions reported similar tumor sizes (P = 0.27), treatment decisions (P = 0.09), and decision satisfaction (P = 0.78).ConclusionThere is a continuing trend toward nonsurgical management, with approximately half of the patients opting for nonsurgical management. In this cohort, the patients commonly presented with otologic symptoms and otolaryngologists made the most diagnoses. Neurotologists and neurosurgeons were the most influential in treatment discussion.Level of evidenceNA Laryngoscope, 130:482-486, 2020

Surgical treatment of sporadic vestibular schwannoma in a series of 1006 patients. Trattamento chirurgico degli schwannomi vestibolari: risultati su una serie di 1006 pazienti

La gestione dello schwannoma vestibolare (SV) sporadico si è gradualmente evoluta negli ultimi decenni. Lo scopo di questo studio è di analizzare l’evoluzione negli esiti chirurgici dell’exeresi di queste lesioni, realizzata da un team neurotologico tra il 1990 e il 2006, attraverso differenti approcci. È stata eseguita una revisione retrospettica monocentrica dei dati clinici di 1006 pazienti. Al fine di valutare eventuali modifiche e progressi, il periodo di 17 anni è stato diviso in tre periodi, ciascuno comprendente rispettivamente 268 SV (1990- 1996), 299 SV (1997-2001), e 439 SV (2002-2006). Il follow-up medio è stato di 5,9 ± 2,4 anni. Complessivamente l’asportazione totale è stata ottenuta nel 99,4% dei casi. Il tasso di mortalità è stato dello 0,3%, la meningite e la perdita di liquido cefalo rachidiano (LCR) sono stati osservati nel 1,2% e il 9% dei casi, rispettivamente. La frequenza della perdita di LCR è diminuita dal 11,6% al 7,1% tra il primo e dell’ultimo periodo (p < 0,01) e la revisione chirurgica dal 3,4% al 0,9% (p < 0,05). Il nervo facciale è stato anatomicamente conservato nel 97,7% dei casi. Ad un anno, una buona funzione del nervo facciale è stata osservata nel 85,1% dei pazienti (I e II grado HouseBrackmann), con una variazione tra il primo e l’ultimo periodo che andava dal 78,4% al 87,6% (p < 0,05). Ad un anno post-operatorio la conservazione dell’udito è stata ottenuta nel 61,6% dei pazienti, passando dal 50,9% del primo periodo, al 69,0% del periodo piú recente (p < 0,05) (classe A + B + C dalla classificazione AAO-HNS). L’udito utile (classe A + B) è stato conservato nel 33,5% dei casi complessivamente, con percentuali comprese tra il 21,8% e 42% nel primo e nell’ultimo periodo rispettivamente (p < 0,01). Gli esiti chirurgici dell’asportazion dello schwannoma vestibolare sporadico sono migliorati negli anni per quanto riguarda i risultati funzionali del nervo facciale, la conservazione dell’udito, le perdite di liquido cefalorachidiano, principalmente grazie all’esperienza del team neurotologico. I risultati funzionali dopo la rimozione microchirurgica completa SV di grandi dimensioni dipendono dall’ esperienza maturata sulle lesioni di piccole dimensioniThe management of sporadic vestibular schwannoma (VS) has evolved in the last decades. The aim of this study was to analyse the evolution in surgical outcomes of VSs operated by a neurotological team between 1990 and 2006 by different approaches. A monocentric retrospective review of medical charts of 1006 patients was performed. In order to assess eventual changes and progress, the 17-years period was divided in three periods, each one comprehending 268 VS (1990-1996), 299 VS (1997-2001), and 439 VS (2002-2006). Mean follow-up was 5.9 ± 2.4 years. Overall, complete VS removal was achieved in 99.4% of cases. Mortality rate was 0.3%, meningitis and CSF leaks were observed in 1.2 % and 9 % of the cases, respectively. CSF leakage decreased from 11.6% to 7.1% between the first and last period (p < 0.01) as well as revision surgery from 3.4 % to 0.9 % (p < 0.05). Facial nerve was anatomically preserved in 97.7% of cases. At one year, a good facial nerve function was observed in 85.1% of patients (grade I and II of House-Brackmann grading scale), which ranged between the first and last period from 78.4% to 87.6% (p <0.05). At one year, hearing preservation was obtained in 61.6% of patients, which increased from the first period to the last one from 50.9% to 69.0% (p < 0.05) (class A+B+C from the AAO-HNS classification). Useful hearing (class A+B) was observed in 33.5% of cases overall, with 21.8% and 42% in the first and last period, respectively (p < 0.01). Surgical outcomes of sporadic vestibular schwannoma have improved concerning facial nerve function outcomes, hearing preservation and cerebrospinal fluid (CSF) leaks, mainly due to the neuro-otological team's experience. Functional results after complete microsurgical removal of large VS depend on experience gained on small VS removal

Subtotal resection of vestibular schwannoma: evaluation with Ki-67 measurement, magnetic resonance imaging, and long-term observation

Purpose The aim of this study was to compare the postoperative clinical and radiological data of patients with vestibular schwannomas who were initially managed by near total resection (NTR) or subtotal resection (STR). The Ki-67 analysis results were compared with tumor regrowth to determine the presence of a correlation between this proliferative index and postoperative tumor regrowth. Study Design Seventeen adult patients (7 male, 10 female) were retrospectively reviewed. Nine (52.9%) and eight (47.1%) patients underwent NTR and STR, respectively. Postoperative clinical and radiological data associated with vestibular schwannoma growth were compared with the Ki-67 immunohistochemical analysis results. Results Evidence of clinically significant regrowth was observed in four (23.5%) patients. Patients who underwent NTR had a lower rate/incidence of tumor regrowth than did patients who underwent STR. Patients with a higher Ki-67 index had the highest tumor regrowth rates. Conclusions Our study indicates that assessment of the Ki-67 index may be useful for determining the probability of regrowth of vestibular schwannomas when only partial removal is accomplished

Immunohistochemical localization and mRNA expression of aquaporins in the macula utriculi of patients with Meniere’s disease and acoustic neuroma

Meniere’s disease is nearly invariably associated with endolymphatic hydrops (the net accumulation of water in the inner ear endolymphatic space). Vestibular maculae utriculi were acquired from patients undergoing surgery for Meniere’s disease and acoustic neuroma and from autopsy (subjects with normal hearing and balance). Quantitative immunostaining was conducted with antibodies against aquaporins (AQPs) 1, 4, and 6, Na+K+ATPase, Na+K+2Cl co-transporter (NKCC1), and α-syntrophin. mRNA was extracted from the surgically acquired utricles from subjects with Meniere’s disease and acoustic neuroma to conduct quantitative real-time reverse transcription with polymerase chain reaction for AQP1, AQP4, and AQP6. AQP1 immunoreactivity (−IR) was located in blood vessels and fibrocytes in the underlying stroma, without any apparent alteration in Meniere’s specimens when compared with acoustic neuroma and autopsy specimens. AQP4-IR localized to the epithelial basolateral supporting cells in Meniere’s disease, acoustic neuroma, and autopsy. In specimens from subjects with Meniere’s disease, AQP4-IR was significantly decreased compared with autopsy and acoustic neuroma specimens. AQP6-IR occurred in the sub-apical vestibular supporting cells in acoustic neuroma and autopsy samples. However, in Meniere’s disease specimens, AQP6-IR was significantly increased and diffusely redistributed throughout the supporting cell cytoplasm. Na+K+ATPase, NKCC1, and α-syntrophin were expressed within sensory epithelia and were unaltered in Meniere’s disease specimens. Expression of AQP1, AQP4, or AQP6 mRNA did not differ in vestibular endorgans from patients with Meniere’s disease. Changes in AQP4 (decreased) and AQP6 (increased) expression in Meniere’s disease specimens suggest that the supporting cell might be a cellular target