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Neurosurgical Focus Mar 2018OBJECTIVE During the last decade, the primary objective for large vestibular schwannoma (VS) management has progressively shifted, from tumor excision to nerve... (Meta-Analysis)
Meta-Analysis
OBJECTIVE During the last decade, the primary objective for large vestibular schwannoma (VS) management has progressively shifted, from tumor excision to nerve preservation by using a combined microsurgical and radiosurgical approach. The aim of this study was to provide a systematic review and meta-analysis of the available literature regarding the combined strategy of subtotal resection (STR) followed by stereotactic radiosurgery (SRS) for large VSs. METHODS The authors performed a systematic review and meta-analysis in compliance with the PRISMA guidelines for article identification and inclusion using the PubMed, Embase, and Cochrane databases. Established inclusion criteria were used to screen all identified relevant articles published before September 2017 without backward date limit. RESULTS The authors included 9 studies (248 patients). With a weighted mean follow-up of 46 months (range 28-68.8 months), the pooled rate of overall tumor control was 93.9% (95% CI 91.0%-96.8%). Salvage treatment (second STR and/or SRS) was necessary in only 13 (5.24%) of 18 patients who experienced initial treatment failure. According to the House-Brackmann (HB) grading scale, functional facial nerve preservation (HB grade I-II) was achieved in 96.1% of patients (95% CI 93.7%-98.5%). Serviceable hearing after the combined approach was preserved in 59.9% (95% CI 36.5%-83.2%). CONCLUSIONS A combined approach of STR followed by SRS was shown to have excellent clinical and functional outcomes while still achieving a tumor control rate comparable to that obtained with a total resection. Longer-term follow-up and larger patient cohorts are necessary to fully evaluate the rate of tumor control achieved with this approach.
Topics: Combined Modality Therapy; Humans; Microsurgery; Neuroma, Acoustic; Neurosurgical Procedures; Radiosurgery; Treatment Outcome
PubMed: 29490553
DOI: 10.3171/2017.12.FOCUS17669 -
Acta Neurochirurgica Jun 2017Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) <3 cm in need of... (Comparative Study)
Comparative Study Review
OBJECTIVE
Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) <3 cm in need of intervention. In this systematic review we aimed to compare results from single-fraction stereotactic radiosurgery (SRS) to fractionated stereotactic radiotherapy (FSRT) for patients with VS.
DATA SOURCES AND ELIGIBILITY CRITERIA
We systematically searched MEDLINE, Web of Science, Embase and Cochrane and screened relevant articles for references. Publications from 1995 through 2014 with a minimum of 50 adult (>18 years) patients with unilateral VS, followed for a median of >5 years, were eligible for inclusion. After screening titles and abstracts of the 1094 identified articles and systematically reviewing 98 of these articles, 19 were included.
INTERVENTION
Patients with unilateral VS treated with radiosurgery were compared to patients treated with fractionated stereotactic radiotherapy.
RESULTS
No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45% for FSRT, respectively. The risk for facial nerve deterioration was 3.6% for SRS and 11.2% for FSRT and for trigeminal nerve deterioration 6.0% for SRS and 8.4% for FSRT. Since these results were obtained from case series, a regular meta-analysis was not attempted.
CONCLUSION
SRS and FSRT are both noninvasive treatment alternatives for patients with VS with low rates of treatment failure in need of rescue therapy. In this selection of patients, the progression-free survival rates were on the order of 92-100% for both treatment options. There is a lack of high-quality studies comparing radiation therapy alternatives for patients with VS. Finally, 19 articles reported long-term tumor control after SRS, while only 2 articles reported long-term FSRT results, making effect estimates more uncertain for FSRT.
Topics: Adult; Aged; Disease-Free Survival; Dose Fractionation, Radiation; Facial Nerve; Female; Humans; Male; Microsurgery; Neuroma, Acoustic; Postoperative Complications; Radiosurgery; Trigeminal Nerve
PubMed: 28409393
DOI: 10.1007/s00701-017-3164-6 -
Journal of Neurosurgery Nov 2016OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) of the eighth cranial nerve (CN) are exceedingly rare. To date the literature has focused on MPNSTs occurring... (Review)
Review
OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) of the eighth cranial nerve (CN) are exceedingly rare. To date the literature has focused on MPNSTs occurring after radiation therapy for presumed benign vestibular schwannomas (VSs), while MPNSTs arising without prior irradiation have received little attention. The objectives of the current study are to characterize the epidemiology, clinical presentation, disease course, and outcome using a large national cancer registry database and a systematic review of the English literature. Additionally, a previously unreported case is presented. METHODS The authors conducted an analysis of the Surveillance, Epidemiology, and End Results (SEER) database, a systematic review of the literature, and present a case report. Data from all patients identified in the SEER database with a diagnosis of MPNST involving the eighth CN, without a history of prior radiation, were analyzed. Additionally, all cases reported in the English literature between January 1980 and March 2015 were reviewed. Finally, 1 previously unreported case is presented. RESULTS The SEER registries identified 30 cases between 1992 and 2012. The average incidence was 0.017 per 1 million persons per year (range 0.000-0.0687 per year). The median age at diagnosis was 55 years, and 16 (53%) were women. Thirteen cases were diagnosed upon autopsy. Of the 17 cases diagnosed while alive, the median follow-up was 118 days, with 3 deaths (18%) observed. When compared with the incidence of benign VS, 1041 VSs present for every 1 MPNST arising from the eighth CN. Including a previously unreported case from the authors' center, a systematic review of the English literature yielded 24 reports. The median age at diagnosis was 44 years, 50% were women, and the median tumor size at diagnosis was 3 cm. Eleven patients (46%) reported isolated audiovestibular complaints typical for VS while 13 (54%) exhibited facial paresis or other signs of a more aggressive process. Treatment included microsurgery alone, microsurgery with adjuvant radiation, or microsurgery with chemoradiation. Sixty-one percent of patients receiving treatment experienced recurrence, 22% of which were diagnosed with drop metastases to the spine. Ultimately, 13 patients (54%) died of progressive disease at a median of 3 months following diagnosis. The ability to achieve gross-total resection was the only feature that was associated with improved disease-specific survival. CONCLUSIONS MPNSTs of the eighth CN are extremely rare and portend a poor prognosis. Nearly half of patients initially present with findings consistent with a benign VS, often making an early diagnosis challenging. In light of these data, early radiological and clinical follow-up should be considered in those who elect nonoperative treatment, particularly in patients with a short duration of symptoms or atypical presentation. These data also provide a baseline rate of malignancy that should be considered when estimating the risk of malignant transformation following stereotactic radiosurgery for VS.
Topics: Adult; Cranial Nerve Neoplasms; Female; Humans; Male; Middle Aged; Nerve Sheath Neoplasms; Vestibulocochlear Nerve; Vestibulocochlear Nerve Diseases
PubMed: 26745487
DOI: 10.3171/2015.7.JNS151056 -
The Journal of International Advanced... Aug 2018In light of missing systematic reviews in the literature, the objective of this paper is to present the contemporary knowledge on the molecular biology of vestibular... (Meta-Analysis)
Meta-Analysis
In light of missing systematic reviews in the literature, the objective of this paper is to present the contemporary knowledge on the molecular biology of vestibular schwannomas (VS), based on a systematic literature search. In addition, current and prospected medical therapy based on molecular biology is addressed. A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The systematic search was performed in the Pubmed and Embase databases. The following were the words searched: acoustic neuroma/vestibular schwannoma, molecular biology, gene, and microRNA. Specific inclusion and exclusion criteria were determined prior to search. The systematic search rendered 486 articles, ultimately yielding 69 included articles, whereas 35 were from relevant references. The occurrence of at least one mutation in the merlin gene was reported to range between 54% and 76%, whereas the loss of heterozygosity (LOH) corresponding to chromosome 22 occurs in 25% to 83% of sporadic VS. Global gene expression studies indicate that a number of genes other than merlin are at play. No high-level methylation of the merlin gene has been found. Several miRNAs are deregulated in tumor tissue, among others let-7d, miR-221, and miR-21. The acquired knowledge on molecular biology has led to several clinical implementations. Lack of the tumor suppressor merlin plays a principal role in the development of VS. Existing knowledge on the molecular biology has led to the first attempts of targeted medical treatment to prevent tumor growth. Future research is likely to introduce potential imaging markers with prognostic value and new targets for medical therapy.
Topics: Chromosomes, Human, Pair 22; DNA Methylation; Gene Expression; Humans; Loss of Heterozygosity; MicroRNAs; Molecular Biology; Mutation; Neuroma, Acoustic; Signal Transduction
PubMed: 30100540
DOI: 10.5152/iao.2018.4929 -
Neurosurgical Review Feb 2021The surgical injury of the intracranial portion of the facial nerve (FN) is a severe complication of many skull base procedures, and it represents a relevant issue in... (Comparative Study)
Comparative Study Meta-Analysis
Comparison between VII-to-VII and XII-to-VII coaptation techniques for early facial nerve reanimation after surgical intra-cranial injuries: a systematic review and pooled analysis of the functional outcomes.
The surgical injury of the intracranial portion of the facial nerve (FN) is a severe complication of many skull base procedures, and it represents a relevant issue in terms of patients' discomfort, social interactions, risk for depression, and social costs. The aim of this study was to investigate the surgical and functional outcomes of the most common facial nerve rehabilitation techniques. The present study is a systematic review of the pertinent literature, according to the PRISMA guidelines. Two different online medical databases (PubMed, Scopus) were screened for studies reporting the functional outcome, measured by the House-Brackman (HB) scale, and complications, in FN early reanimation, following surgical injuries on its intracranial portion. Data on the VII-to-VII and XII-to-VII coaptation, the surgical technique, the use of a nerve graft, the duration of the deficit, and complications were collected and pooled. The XII-to-VII end-to-side coaptation seems to provide higher chances for functional restoration (HB 1-3) than the VII-to-VII (68.8% vs 60.6%), regardless of the duration of the palsy deficit, the use or not of a nerve graft, and the use of stitches or glues. However, its complication rate was as high as 28.6%, and a second procedure is then often needed. The XII-to-VII side-to-end coaptation is the most effective in providing a functional outcome (HB 1-3), even though it is associated to a higher complication rate. Further trials are needed to better investigate this relevant topic, in terms of health-related social costs and patients' quality of life.
Topics: Facial Nerve; Facial Nerve Injuries; Facial Paralysis; Humans; Hypoglossal Nerve; Neurosurgical Procedures; Postoperative Complications; Skull Base; Treatment Outcome
PubMed: 31912333
DOI: 10.1007/s10143-019-01231-z -
Journal of the International... Oct 2018Neurofibromatosis type 1 (NF1) is a genetic disorder in which the most frequent complication in children is learning disabilities. Over the past decade, growing... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
Neurofibromatosis type 1 (NF1) is a genetic disorder in which the most frequent complication in children is learning disabilities. Over the past decade, growing arguments support the idea that executive dysfunction is a core deficit in children with NF1. However, some data remain inconsistent. The aim of this study was to determine the magnitude of impairment for each executive function (EF) and clarify the impact of methodological choices and participant's characteristics on EFs.
METHODS
In this meta-analysis, 19 studies met the selection criteria and were included with data from a total of 805 children with NF1 and 667 controls. Based on the Diamond's model (2013), EF measures were coded separately according to the following EF components: working memory, inhibitory control, cognitive flexibility, planning/problem solving. The review protocol was registered with PROSPERO (International prospective register of systematic reviews; CRD42017068808).
RESULTS
A significant executive dysfunction in children with NF1 is demonstrated. Subgroup analysis showed that the impairment varied as a function of the specific component of executive functioning. The effect size for working memory and planning/problem solving was moderate whereas it was small for inhibitory control and cognitive flexibility. Executive dysfunction seems to be greater with increasing age whereas assessment tool type, intellectual performance, attention deficit hyperactivity disorder and control group composition did not seem to affect EF results.
CONCLUSIONS
EF deficits are a core feature in children with NF1 and an early identification of executive dysfunctions is essential to limit their impact on the quality of life. (JINS, 2018, 24, 977-994).
Topics: Child; Executive Function; Humans; Neurofibromatosis 2
PubMed: 30375317
DOI: 10.1017/S1355617718000383 -
BioMed Research International 2016. Vestibular schwannomas (VS) are benign tumours of the vestibular nerve and can lead to hearing loss, tinnitus, vertigo, facial palsy, and brainstem compression.... (Meta-Analysis)
Meta-Analysis
. Vestibular schwannomas (VS) are benign tumours of the vestibular nerve and can lead to hearing loss, tinnitus, vertigo, facial palsy, and brainstem compression. Audiovestibular diagnostic tests are essential for detection and treatment planning. . Medline was used to perform a systematic literature review with regard to how audiovestibular test parameters correlate with symptoms, tumour size, and tumour location. . The auditory brainstem response can be used to diagnose retrocochlear lesions caused by VS. Since hearing loss correlates poorly with tumour size, a retrocochlear lesion is probably not the only cause for hearing loss. Also cochlear mechanisms seem to play a role. This can be revealed by abnormal otoacoustic emissions, despite normal ABR and new MRI techniques which have demonstrated endolymphatic hydrops of the inner ear. Caloric and head impulse tests show frequency specific dynamics and vestibular evoked myogenic potentials may help to identify the location of the tumour regarding the involved nerve parts. . In order to preserve audiovestibular function in VS, it is important to stop the growth of the tumour and to avoid degenerative changes in the inner ear. A detailed neurotological workup helps to diagnose VS of all sizes and can also provide useful prognostic information.
Topics: Evoked Potentials, Auditory, Brain Stem; Hearing Loss; Humans; Magnetic Resonance Imaging; Neuroma, Acoustic; Vertigo; Vestibular Function Tests; Vestibule, Labyrinth
PubMed: 27747231
DOI: 10.1155/2016/4980562 -
Acta Otorhinolaryngologica Italica :... May 2024
Meta-Analysis
Topics: Humans; Neuroma, Acoustic; Hearing Loss
PubMed: 38745520
DOI: 10.14639/0392-100X-suppl.1-44-2024-N2900 -
Neurosurgery Feb 2018What sequences should be obtained on magnetic resonance imaging (MRI) to evaluate vestibular schwannomas before and after surgery?
Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Imaging in the Diagnosis and Management of Patients With Vestibular Schwannomas.
QUESTION 1
What sequences should be obtained on magnetic resonance imaging (MRI) to evaluate vestibular schwannomas before and after surgery?
TARGET POPULATION
Adults with vestibular schwannomas.
RECOMMENDATIONS
Initial Preoperative Evaluation Level 3: Imaging used to detect vestibular schwannomas should use high-resolution T2-weighted and contrast-enhanced T1-weighted MRI. Level 3: Standard T1, T2, fluid attenuated inversion recovery, and diffusion weighted imaging MR sequences obtained in axial, coronal, and sagittal plane may be used for detection of vestibular schwannomas. Preoperative Surveillance Level 3: Preoperative surveillance for growth of a vestibular schwannoma should be followed with either contrast-enhanced 3-dimensional (3-D) T1 magnetization prepared rapid acquisition gradient echo (MPRAGE) or high-resolution T2 (including constructive interference in steady state [CISS] or fast imaging employing steady-state acquisition [FIESTA] sequences) MRI. Postoperative Evaluation Level 2: Postoperative evaluation should be performed with postcontrast 3-D T1 MPRAGE, with nodular enhancement considered suspicious for recurrence.
QUESTION 2
Is there a role for advanced imaging for facial nerve detection preoperatively (eg, CISS/FIESTA or diffusion tensor imaging)?
TARGET POPULATION
Adults with proven or suspected vestibular schwannomas by imaging.
RECOMMENDATION
Level 3: T2-weighted MRI may be used to augment visualization of the facial nerve course as part of preoperative evaluation.
QUESTION 3
What is the expected growth rate of vestibular schwannomas on MRI, and how often should they be imaged if a "watch and wait" philosophy is pursued?
TARGET POPULATION
Adults with suspected vestibular schwannomas by imaging.
RECOMMENDATION
Level 3: MRIs should be obtained annually for 5 yr, with interval lengthening thereafter with tumor stability.
QUESTION 4
Do cystic vestibular schwannomas behave differently than their solid counterparts?
TARGET POPULATION
Adults with vestibular schwannomas with cystic components.
RECOMMENDATION
Level 3: Adults with cystic vestibular schwannomas should be counseled that their tumors may more often be associated with rapid growth, lower rates of complete resection, and facial nerve outcomes that may be inferior in the immediate postoperative period but similar to noncystic schwannomas over time.
QUESTION 5
Should the extent of lateral internal auditory canal involvement be considered by treating physicians?
TARGET POPULATION
Adult patients with vestibular schwannomas.
RECOMMENDATION
Level 3: The degree of lateral internal auditory canal involvement by tumor adversely affects facial nerve and hearing outcomes and should be emphasized when interpreting imaging for preoperative planning.
QUESTION 6
How should patients with neurofibromatosis type 2 (NF2) and vestibular schwannoma be imaged and over what follow-up period?
TARGET POPULATION
Adult patients with NF2 and vestibular schwannomas.
RECOMMENDATION
Level 3: In general, vestibular schwannomas associated with NF2 should be imaged (similar to sporadic schwannomas) with the following caveats: 1. More frequent imaging may be adopted in NF2 patients because of a more variable growth rate for vestibular schwannomas, and annual imaging may ensue once the growth rate is established. 2. In NF2 patients with bilateral vestibular schwannomas, growth rate of a vestibular schwannoma may increase after resection of the contralateral tumor, and therefore, more frequent imaging may be indicated, based on the nonoperated tumor's historical rate of growth. 3. Careful consideration should be given to whether contrast is necessary in follow-up studies or if high-resolution T2 (including CISS or FIESTA-type sequences) MRI may adequately characterize changes in lesion size instead.
QUESTION 7
How long should vestibular schwannomas be imaged after surgery, including after gross-total, near-total, and subtotal resection?
TARGET POPULATION
Adult patients with vestibular schwannomas followed after surgery.
RECOMMENDATION
Level 3: For patients receiving gross total resection, a postoperative MRI may be considered to document the surgical impression and may occur as late as 1 yr after surgery. For patients not receiving gross total resection, more frequent surveillance scans are suggested; annual MRI scans may be reasonable for 5 yr. Imaging follow-up should be adjusted accordingly for continued surveillance if any change in nodular enhancement is demonstrated. The full guideline can be found at https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_5.
Topics: Humans; Magnetic Resonance Imaging; Neuroma, Acoustic
PubMed: 29309686
DOI: 10.1093/neuros/nyx510 -
NeuroRehabilitation 2024NF2-schwannomatosis (NF2) is an autosomal dominant disorder prone to hearing loss. Auditory brainstem implants (ABIs) offer a promising solution for hearing... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
NF2-schwannomatosis (NF2) is an autosomal dominant disorder prone to hearing loss. Auditory brainstem implants (ABIs) offer a promising solution for hearing rehabilitation in NF2.
OBJECTIVE
To synthesize existing literature on ABI implantation in NF2, focusing on audiological outcomes and ABI-related complications.
METHODS
The systematic review followed PRISMA guidelines and was registered in the PROSPERO database (CRD42022362155). Relevant studies were identified by searching PubMed, EMBASE, CENTRAL, CMB, and CNKI from inception to August 2023. Data on environmental sound discrimination, open-set discrimination, closed-set discrimination, and ABI-related complications were extracted and subjected to meta-analysis. Publication bias was evaluated using funnel plots and Egger's test.
RESULTS
Thirty-three studies were included. The pooled estimate was 58% (95% CI 49-66%) for environmental sound discrimination and 55% (95% CI 40-69%) for closed-set discrimination. Regarding open-set discrimination, the pooled estimates were 30% (95% CI 19-42%) for sound only, 46% (95% CI 37-54%) for lip-reading only, and 63% (95% CI 55-70%) for sound plus lip-reading. The pooled occurrence of ABI-related complications was 33% (95% CI 15-52%).
CONCLUSION
This meta-analysis underscores the effectiveness and safety of ABIs in NF2, providing valuable insights for evidence-based decision-making and hearing rehabilitation strategies.
Topics: Humans; Auditory Brain Stem Implants; Neurofibromatosis 2; Auditory Brain Stem Implantation; Treatment Outcome; Hearing; Retrospective Studies; Neurilemmoma; Skin Neoplasms; Neurofibromatoses
PubMed: 38427506
DOI: 10.3233/NRE-230198