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La Clinica Terapeutica May 2021Over the process of establishing the causal relation-ship, medical and legal methodologies may be at variance over the definitional standards and terminologies applied,...
Can a causal relationship be established between acoustic neuroma and occupational exposure to non-ionizing radiations from mobile devices? Comparison between scientific literature data and medico-legal methodology.
BACKGROUND
Over the process of establishing the causal relation-ship, medical and legal methodologies may be at variance over the definitional standards and terminologies applied, which can hinder the activities of expert witnesses.
OBJECTIVES
The article's authors have set out to assess whether, and under what conditions, a causal relationship can be established between acoustic neuroma and exposure to non-ionizing radiation from mobile communication devices.
METHODS
The study design is a Systematic Review. The authors have drawn upon a 2020 Turin Court of Appeals ruling which found such a causal relationship in a somewhat peculiar case: rare tumor and exposure to non-ionizing radiation of unusually long and regular dura-tion. The case presents several peculiarities, herein analyzed in light of a) scientific evidence relative to the etiopathogenesis of the neuroma; b) available medico-legal literature defining causality evaluation criteria, and lastly c) court filings in regard to the probability standards applied to prove causal relationship.
RESULTS
A direct tie cannot be proven, not even in cases of sub-stantially intense and lengthy exposure, if the medico-legal standards applied are not consistent enough to prove that nexus is more likely than not.
DISCUSSION
Several elements suggest a causal relationship is unlikely: a) a dearth of evidence on humans; b) rats exposed to such radiation have developed cardiac tumors, not in their ears; c) exposure has caused no tumors in mice; d) the length of exposure is incompat-ible with tumor size and type. That fourth point only concerns the case herein explored, whereas the first three have a general scope of validity. The main limitation of the present study design is the heterogeneity among the included studies. Retrospective and prospective studies have been included, which may be a source of bias.
Topics: Animals; Causality; Computers, Handheld; Humans; Mice; Neuroma, Acoustic; Occupational Exposure; Radiation, Nonionizing; Rats; Risk Factors
PubMed: 33956036
DOI: 10.7417/CT.2021.2313 -
International Journal of Molecular... Mar 2023Although diagnosis and treatment of vestibular schwannomas (VSs) improved in recent years, no factors have yet been identified as being capable of predicting tumor...
Although diagnosis and treatment of vestibular schwannomas (VSs) improved in recent years, no factors have yet been identified as being capable of predicting tumor growth. Molecular rearrangements occur in neoplasms before any macroscopic morphological changes become visible, and the former are the underlying cause of disease behavior. Tumor microenvironment (TME) encompasses cellular and non-cellular elements interacting together, resulting in a complex and dynamic key of tumorigenesis, drug response, and treatment outcome. The aim of this systematic, narrative review was to assess the level of knowledge on TME implicated in the biology, behavior, and prognosis of sporadic VSs. A search (updated to November 2022) was run in Scopus, PubMed, and Web of Science electronic databases according to the PRISMA guidelines, retrieving 624 titles. After full-text evaluation and application of inclusion/exclusion criteria, 37 articles were included. VS microenvironment is determined by the interplay of a dynamic ecosystem of stromal and immune cells which produce and remodel extracellular matrix, vascular networks, and promote tumor growth. However, evidence is still conflicting. Further studies will enhance our understanding of VS biology by investigating TME-related biomarkers able to predict tumor growth and recognize immunological and molecular factors that could be potential therapeutic targets for medical treatment.
Topics: Humans; Ecosystem; Neuroma, Acoustic; Treatment Outcome; Tumor Burden; Tumor Microenvironment
PubMed: 37047498
DOI: 10.3390/ijms24076522 -
Journal of Neurological Surgery. Part... Dec 2021Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review...
Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review of hearing outcomes comparing neurofibromatosis 2 (NF2) and sporadic VS undergoing CI. A comparison of the two populations and predictor of outcome was assessed. This is an update to a previously presented study. Systemic data searches were performed in PubMed NCBI and Scopus by an academic librarian. No restrictions based on the year of publication were used. Studies were selected if patients had a diagnosis of NF2 and a CI placed in the affected side with reports of hearing outcome. Two independent reviewers screened each abstract and full-text article. Studies were extracted at the patient level, and the assessment of quality and bias was evaluated according to the National Institutes of Health Quality Assessment Tool. Outcome predictors were determined by using the chi-square test and Student's -test. Overall, most CI recipients functioned in the high-to-intermediate performer category for both sporadic and NF2-related VS. Median AzBio (Arizona Biomedical Institute Sentence Test) was 72% (interquartile range [IQR]: 50) in NF2 patients and 70% (IQR: 7.25) in sporadic patients. Larger tumor size predicted a poorer final audiometric outcome. Categorization of hearing outcome into superior performance and inferior performance based on sentence recognition revealed a generally good hearing outcome regardless of treatment or patient population. Select patients with sporadic and NF2 VS may benefit from CI.
PubMed: 34745832
DOI: 10.1055/s-0040-1715606 -
Brazilian Journal of Otorhinolaryngology 2023To determine the cut-off point of the cochlear radiation dose as a risk factor for hearing loss in patients with vestibular schwannoma treated with radiosurgery. (Review)
Review
OBJECTIVES
To determine the cut-off point of the cochlear radiation dose as a risk factor for hearing loss in patients with vestibular schwannoma treated with radiosurgery.
METHODS
A systematic review of the literature was performed without language or publication year restrictions in the MEDLINE/PubMed, EMBASE, Web of Science, LILACS/VHL and Cochrane Library databases. Studies that met the following criteria were included: 1) population: adults of both sexes who underwent radiosurgery for vestibular schwannoma treatment; 2) exposure: cochlear radiation; 3) outcome: hearing loss; 4) type of study: cohort. Two independent reviewers conducted the entire review process. The registration number in PROSPERO was CRD42020206128.
RESULTS
From the 333 articles identified in the searches, seven were included after applying the eligibility criteria. There was no standardization as to how to measure exposure or outcome in the included studies, and most studies did not present sufficient data to enable meta-analysis.
CONCLUSION
It was not possible to determine a cut-off point for high cochlear dose that could be considered a risk factor for hearing loss.
Topics: Adult; Female; Humans; Male; Deafness; Hearing Loss; Neuroma, Acoustic; Radiation Dosage; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 37579571
DOI: 10.1016/j.bjorl.2023.101300 -
European Archives of... Feb 2020Cochlear implantation (CI) in patients with sensorineural hearing loss caused by a vestibular schwannoma (VS) represents a unique subtype of hearing rehabilitation, as... (Comparative Study)
Comparative Study
PURPOSE
Cochlear implantation (CI) in patients with sensorineural hearing loss caused by a vestibular schwannoma (VS) represents a unique subtype of hearing rehabilitation, as the outcome may be compromised by vestibulocochlear nerve injury as part of the natural VS history or due to iatrogenic trauma induced by surgical tumor removal. This paper aims to review and report contemporary knowledge and practice regarding feasibility and outcomes of simultaneous vestibular schwannoma resection and cochlear implantation to serve as a reference and guide for future surgery and studies.
METHODS
The current literature was searched systematically according to the PRISMA guidelines and after criteria-based selection, 29 studies were identified, including a total of 86 patients who had undergone surgical resection of a vestibular schwannoma and subsequent cochlear implantation in a single procedure.
RESULTS
The postoperative outcomes were reported with a high degree of heterogeneity, hindering a proper meta-analysis. However, pooling those cases with reported speech discrimination outcomes demonstrated mean scores equivalent to moderate-to-high performance. A few cases had no audibility. A positive cochlear nerve test result was not a secure positive predictor of success. Complications were rare.
CONCLUSION
NF2-associated and sporadic VS had good and comparable postoperative outcomes despite significant differences in tumor size, location and surgical approach.
Topics: Cochlear Implantation; Genes, Neurofibromatosis 2; Hearing Loss, Sensorineural; Humans; Neuroma, Acoustic; Vestibulocochlear Nerve; Vestibulocochlear Nerve Injuries
PubMed: 31802225
DOI: 10.1007/s00405-019-05741-w -
Neurosurgical Review Apr 2021Hydrocephalus (HC) can be associated with vestibular schwannoma (VS) at presentation. Although spontaneous resolution of HC after VS removal is reported, first-line... (Meta-Analysis)
Meta-Analysis
Hydrocephalus (HC) can be associated with vestibular schwannoma (VS) at presentation. Although spontaneous resolution of HC after VS removal is reported, first-line treatment is varied including preoperative ventriculoperitoneal (VP) shunt, external ventricular drainage (EVD), or lumbar drainage (LD). We performed a systematic review to clarify optimal management of HC associated with VS at presentation, as well as characteristics of patients with initial and persistent HC after VS removal, and prevalence of HC associated with VS. Fourteen studies were included. Patients were grouped according to the timing of HC treatment. The overall rate of VP shunts was 19.4%. Among patients who received VS removal as first-line treatment, 6.9% underwent permanent shunts. In a subgroup of 132 patients (studies with no-aggregate data), t test analysis for mean tumor size (P = 0.02) and mean CSF protein level (P < 0.001) demonstrated statistically significant differences between patients with resolved HC (3.48 cm and 201 mg/dL) and patients with persistent HC (2.46 cm and 76.8 mg/dL) after VS resection. Transient treatment of HC using EVD or LD further resolved the HC in 87.5% and 82.9% of patients, respectively, before and after VS removal. The overall prevalence of HC associated with VS in a population of 2336 patients was 9.3%. Schwannoma removal as first-line treatment is justified by its low rate of persistent HC requiring VP shunt (roughly 7%). Patients with smaller VS and lower CSF proteins present higher risk of persistent HC after schwannoma removal. Temporary treatment of HC contributes to its resolution, both before and after VS removal.
Topics: Adult; Aged; Aged, 80 and over; Disease Management; Drainage; Female; Humans; Hydrocephalus; Male; Middle Aged; Neuroma, Acoustic; Retrospective Studies; Ventriculoperitoneal Shunt
PubMed: 32266553
DOI: 10.1007/s10143-020-01287-2 -
Otology & Neurotology : Official... Oct 2023Vestibular schwannoma (VS) is a tumor of the vestibulocochlear nerve. Current literature indicates that 1.6% of patients undergoing magnetic resonance imaging of the... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
Vestibular schwannoma (VS) is a tumor of the vestibulocochlear nerve. Current literature indicates that 1.6% of patients undergoing magnetic resonance imaging of the internal auditory meatus (MRI IAM) for audiovestibular symptoms are diagnosed with a VS. However, there is limited research reporting on patients who present with unilateral tinnitus without asymmetrical hearing loss. This study is a systematic review and meta-analysis evaluating how many of those patients had a VS diagnosed on MRI IAM.
DATABASES USED
Online searches of PubMed, Medline, and Embase databases were performed up to October 2022.
METHODS
This meta-analysis was undertaken aligning with PRISMA guidelines. Articles reporting on patients having MRI IAM for unilateral tinnitus without asymmetrical hearing loss were included. Outcomes measures were patient demographics, VS cases, incidental findings, size, and management of tumor. A meta-analysis of proportions was performed using a random-effects model with the restricted maximum likelihood method. Quality assessment was performed using the Joanna Briggs Institute critical appraisal checklist.
RESULTS
Seven case series were included in the review: a total of 1,394 patients. Seven patients had a VS, with a median size of 4 mm. The pooled detection rate for VS was 0.08% (95% confidence interval = 0.00-0.45). Subsequent management was reported in six cases of which four were actively monitored and two surgically excised. The most common incidental finding was sinus disease (49 patients).
CONCLUSION
Our findings indicate that MRI IAM has a low diagnostic yield for VS detection in patients presenting with unilateral tinnitus without asymmetrical hearing loss, with mostly small tumors that are conservatively managed.
Topics: Humans; Neuroma, Acoustic; Tinnitus; Incidence; Cochlear Nerve; Databases, Factual
PubMed: 37621105
DOI: 10.1097/MAO.0000000000003987 -
Stereotactic and Functional Neurosurgery 2021Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting the trigeminal nerve pathways. The most frequent are meningiomas and vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has emerged as a valuable treatment, with heterogeneity of clinical results. We sought to review the medical literature on TN treated with SRS for meningiomas and VS and investigate the rates of improvement of TN symptoms.
METHODS
We reviewed articles published between January 1990 and December 2019 in PubMed. Pain relief after SRS, the maintenance of pain relief, and TN recurrence and complications were evaluated with separate meta-analyses, taking into account the data on individual patients.
RESULTS
Pain relief after SRS was reported as Barrow Neurological Institute (BNI) pain intensity scores of BNI I in 50.5% (range 36-65.1%) of patients and BNI I-IIIb in 83.8% (range 77.8-89.8%). There was no significant difference in series discussing outcomes for tumor targeting versus tumor and nerve targeting. Recurrences were described in 34.7% (range 21.7-47.6; tumor targeting). Maintenance of BNI I was reported in 36.4% (range 20.1-52.7) and BNI I-IIIb in 41.2% (range 29.8-52.7; tumor targeting series). When both the nerve and the tumor were targeted, only 1 series reported 86.7% with BNI I-IIIb at last follow-up. Complications were encountered in 12.6% (range 6.3-18.8; tumor targeting series) of patients; however, they were much higher, as high as 26.7%, in the only study reporting them after targeting both the nerve and the tumor. The most common complication was facial numbness.
CONCLUSION
SRS for TNB secondary to benign tumors, such as meningiomas and VS, is associated with favorable clinical course, but less favorable than in idiopathic TN. There was, however, heterogeneity among reports and targeting approaches. Although targeting both the nerve and the tumor seemed to achieve better long-term results, the rate of complications was much higher and the number of patients treated was limited. Future clinical studies should focus on the standard reporting of clinical outcomes and randomization of targeting methods.
Topics: Humans; Meningeal Neoplasms; Meningioma; Neuroma, Acoustic; Pain Management; Radiosurgery; Retrospective Studies; Treatment Outcome; Trigeminal Neuralgia
PubMed: 32906130
DOI: 10.1159/000509842 -
Journal of Neuro-oncology Aug 2022Gross total resection remains the gold-standard approach for vestibular schwannomas (VS) when surgery is indicated. In select cases, incomplete resection (IR) becomes a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Gross total resection remains the gold-standard approach for vestibular schwannomas (VS) when surgery is indicated. In select cases, incomplete resection (IR) becomes a desired alternative to preserve the facial nerve function and the patient's quality of life. While a lot of earlier studies described incompletely resected sporadic VSs as dormant, more recent studies reported a higher growth rate following IR, therefore an evaluation of the residual VS growth rates could have important implications for the follow-up treatment protocols and provide relevant information for neurosurgeons, neuro-otologists, neuropathologists, and radiologists. Although prognostic factors predicting preoperative VS growth have been previously investigated, these factors have not been investigated following IR. Our review aims to examine the growth rate of residual sporadic VS following IR and to examine variables associated with the regrowth of residual VS.
METHODS
The review was conducted in accordance with the PRISMA guidelines. Six databases (MEDLINE (Ovid), Embase (Ovid), CINAHL Plus (EBSCO), Cochrane Central Register of Controlled Trials (CENTRAL), WHO International Clinical Trials Registry Platform and UK Clinical Trials Gateway (WHO ICTRP) were searched. Full-text articles analysing growth rates in at least ten patients who had residual VS after IR were assessed. We conducted a meta-analysis using a random-effects model via RevMan.
RESULTS
14 studies totalling 849 patients were included in the analysis. The mean planimetric growth rate was 1.57 mm/year (range 0.16-3.81 mm/year). The mean volumetric growth rate was 281.725 mm/year (range 17.9-530.0 mm/year). Age, sex, pre-operative tumour size/volume, cystic tumour sub-type, MIB-1 index, and intracanalicular tumour location were not associated with residual growth. Residual tumour size/volume was statistically significant to growth (OR = 0.65, 95% CI 0.47-0.90, p = 0.01). Radiological re-growth occurred in an average of 26.6% of cases (range 0-54.5%).
CONCLUSION
From our analysis, only the residual tumour volume/size was associated with residual VS growth. Therefore, close postoperative surveillance for the first year, followed by an annual MRI scan for at least 5 years, and subsequently extended interval surveillance remains of utmost importance to monitor disease progression and provide timely surgical and adjuvant interventions. Our study shows that future work should be aimed at molecular and histological characteristics of residual VSs to aid prognostic understanding of growth.
Topics: Disease Progression; Humans; Neoplasm, Residual; Neuroma, Acoustic; Quality of Life; Tumor Burden
PubMed: 35761159
DOI: 10.1007/s11060-022-04051-2 -
Journal of Neuro-oncology Jan 2022Neurofibromatosis type 2 (NF2) is characterized by often bilateral vestibular schwannomas (VS) that result in progressive hearing loss and compression of nearby... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Neurofibromatosis type 2 (NF2) is characterized by often bilateral vestibular schwannomas (VS) that result in progressive hearing loss and compression of nearby brainstem structures causing cranial nerve palsies. Treatment of these tumors remains challenging, as both surgical removal and expectant management can result in symptom progression. Stereotactic radiosurgery (SRS) has been investigated for the management of NF2-associated VS; however, the role, promises, and pitfalls of this treatment modality remain unclear.
METHODS
Ovid MEDLINE, EMBASE, Web of Science, and Cochrane Reviews were searched for studies assessing SRS outcome in NF2-associated VS only. Primary endpoints included tumor control, serviceable hearing, presence of tinnitus, and cranial nerve V and VII symptoms.
RESULTS
A total of 16 studies (589 patients harboring 750 tumors) were analyzed. Clinical tumor control was achieved in 88% of cases (95% CI 80-95%); salvage surgery was needed in 8% (95% CI 4-13%) of cases. Treatment resulted in a worsening of pre-treatment serviceable hearing (OR = 0.26, p < 0.01), increased facial nerve (OR = 1.62, p < 0.01) and trigeminal nerve (OR = 1.42, p = 0.07) impairment. The incidence of vestibular symptoms and hydrocephalus were not consistently reported and thus could not be assessed.
CONCLUSIONS
The treatment of NF2-associated VS continues to pose a challenge, as current SRS regimens result in impaired hearing and worse cranial nerve comorbidities, despite achieving high tumor control. It remains unclear if these findings have to be regarded as treatment complications or, rather, continued disease progression.
Topics: Hearing Loss; Humans; Neurofibromatosis 2; Neuroma, Acoustic; Radiosurgery; Treatment Outcome
PubMed: 35040021
DOI: 10.1007/s11060-021-03910-8