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Journal of Neurosurgery Aug 2023The middle fossa approach is an effective option for the treatment of small (Koos grade I and II) vestibular schwannomas (VSs) when the goal is hearing preservation. The...
OBJECTIVE
The middle fossa approach is an effective option for the treatment of small (Koos grade I and II) vestibular schwannomas (VSs) when the goal is hearing preservation. The authors evaluated the rates of hearing preservation and examined the factors associated with improved hearing outcomes after the middle fossa approach for VSs.
METHODS
In this retrospective, single-center cohort study evaluating the clinical outcomes after resection of small VSs using the middle fossa approach, consecutive adult patients (> 18 years) who underwent surgery between January 2000 and December 2021 were included. Clinical and imaging characteristics were analyzed, including baseline hearing status, duration of surgery, anesthetic parameters, and imaging characteristics of the surgically treated tumors.
RESULTS
Among the 131 included patients, 102 had valid and discoverable pre- and postoperative audiology assessments. The mean follow-up was 26 months (range 1-180 months). There were 85 patients with serviceable hearing preoperatively, defined as American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A or B, of whom 78% retained class A or B hearing at the last follow-up. Binary logistic regression demonstrated that preoperative hearing AAO-HNS class (OR 0.19, 95% CI 0.05-0.77; p = 0.02), overlap between fundus and cochlea (OR 0.32, 95% CI 0.11-0.96; p = 0.04), and duration of anesthesia (OR 0.98, 95% CI 0.97-0.99; p = 0.03) were independent predictors of hearing outcomes. Additionally, 75% of patients with high diffusion-weighted imaging signal in the tumor (p = 0.009) and 67% of patients with the tumor originating at the modiolus of the cochlea (p = 0.004) had poor hearing outcomes.
CONCLUSIONS
The hearing preservation rates after microsurgical resection of small VSs using the middle fossa approach are high, with 78% of patients maintaining AAO-HNS class A or B hearing. Poor hearing status at baseline, longer duration of anesthesia, and large overlap between the fundus of the internal auditory canal and the cochlea were independently associated with unfavorable hearing outcomes. Imaging characteristics can be used to stratify patients' risk of hearing loss.
Topics: Humans; Male; Female; Middle Aged; Neuroma, Acoustic; Retrospective Studies; Adult; Aged; Treatment Outcome; Hearing; Neurosurgical Procedures; Hearing Loss; Cranial Fossa, Middle; Young Adult; Follow-Up Studies; Cohort Studies
PubMed: 36461828
DOI: 10.3171/2022.10.JNS221525 -
European Journal of Radiology Aug 2023Vestibular schwannoma (VS) is the most common mass of the internal auditory canal (IAC) and is responsible for unilateral sensorineural hearing loss. Magnetic resonance...
OBJECTIVES
Vestibular schwannoma (VS) is the most common mass of the internal auditory canal (IAC) and is responsible for unilateral sensorineural hearing loss. Magnetic resonance imaging (MRI) at 1.5 T and 3 T is the standard of care for the evaluation of VS, and the feasibility of using modern low-field MRI for imaging of the IAC has not yet been elucidated. Hence, the purpose of this prospective study was to assess image quality and diagnostic performance of a modern 0.55 T MRI.
MATERIALS AND METHODS
Fifty-six patients with known unilateral VS underwent routine MRI of the IAC at 1.5 T, followed immediately by 0.55 T MRI. Two radiologists independently evaluated the image quality, conspicuity of VS, diagnostic confidence, and image artifacts separately for isotropic T2-weighted SPACE images and for transversal and coronal T1-weighted fat-saturated contrast-enhanced images at 1.5 T and 0.55 T using 5-point Likert scales. In a second independent reading, both readers assessed lesion conspicuity and subjective diagnostic confidence in a direct comparison of 1.5 T and 0.55 T images.
RESULTS
Image quality of transversal T1-weighted images (p = 0.13 and p = 0.16 for Reader 1 and Reader 2, respectively) and T2-weighted SPACE images (p = 0.39 and p = 0.58) were rated equally at 1.5 T and 0.55 T by both readers, whereas image quality of coronal T1-weighted images was superior at 1.5 T (p = 0.009 and p = 0.001). Analysis of the conspicuity of VS, diagnostic confidence, and image artifacts of all sequences revealed no significant differences between 1.5 T and 0.55 T. In the direct comparison of 1.5 T with 0.55 T images, there were no significant differences in lesion conspicuity or diagnostic confidence for any sequence (p = 0.60-0.73).
CONCLUSIONS
Modern low-field MRI at 0.55 T provided a sufficient diagnostic image quality and seems feasible for the evaluation of VS of the IAC.
Topics: Humans; Neuroma, Acoustic; Prospective Studies; Magnetic Resonance Imaging; Image Interpretation, Computer-Assisted; Artifacts; Contrast Media
PubMed: 37379624
DOI: 10.1016/j.ejrad.2023.110927 -
Otolaryngology--head and Neck Surgery :... Nov 2023The video head impulse test (vHIT) and cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) are new methods for measuring peripheral vestibular...
OBJECTIVE
The video head impulse test (vHIT) and cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) are new methods for measuring peripheral vestibular function. The objectives of this study were to compare these tests and the traditionally used caloric test in patients with small and medium-sized untreated vestibular schwannoma (VS) and to measure the correlation between the tests' results and tumor volume.
STUDY DESIGN
National cross-sectional study.
SETTING
Tertiary university clinic.
METHODS
Prevalence of abnormal cVEMP, oVEMP, caloric test, and 6-canal vHIT results on the tumor side and the nontumor side were compared and related to tumor volume with regression analyses in 137 consecutive VS patients assigned to a wait-and-scan protocol in the period 2017 to 2019.
RESULTS
The sensitivity of 6-canal vHIT, caloric test, cVEMP, and oVEMP to detect vestibulopathy in VS patients was 51%, 47%, 39%, and 25%, respectively. Normal tests were found in 21% of the patients. The results of vHIT and caloric test were related to tumor volume, but this was not found for cVEMP and oVEMP.
CONCLUSION
The caloric test and 6-canal vHIT showed the highest sensitivity in detecting vestibulopathy in untreated VS patients. vHIT, and particularly the posterior canal, was limited with a high prevalence of abnormal results on the nontumor side. A combination of cVEMP and caloric test was favorable in terms of a relatively high sensitivity and low prevalence of abnormal results on the nontumor side. Larger tumors had a higher rate of pathology on caloric testing and vHIT.
Topics: Humans; Neuroma, Acoustic; Tumor Burden; Cross-Sectional Studies; Caloric Tests; Vestibular Evoked Myogenic Potentials; Head Impulse Test
PubMed: 37337472
DOI: 10.1002/ohn.399 -
Oncogene Mar 2024Neurofibromatosis Type 2 (NF2)-related schwannomatosis is a genetic disorder that causes development of multiple types of nervous system tumors. The primary and...
Neurofibromatosis Type 2 (NF2)-related schwannomatosis is a genetic disorder that causes development of multiple types of nervous system tumors. The primary and diagnostic tumor type is bilateral vestibular schwannoma. There is no cure or drug therapy for NF2. Recommended treatments include surgical resection and radiation, both of which can leave patients with severe neurological deficits or increase the risk of future malignant tumors. Results of our previous pilot high-throughput drug screen identified phosphoinositide 3-kinase (PI3K) inhibitors as strong candidates based on loss of viability of mouse merlin-deficient Schwann cells (MD-SCs). Here we used novel human schwannoma model cells to conduct combination drug screens. We identified a class I PI3K inhibitor, pictilisib and p21 activated kinase (PAK) inhibitor, PF-3758309 as the top combination due to high synergy in cell viability assays. Both single and combination therapies significantly reduced growth of mouse MD-SCs in an orthotopic allograft mouse model. The inhibitor combination promoted cell cycle arrest and apoptosis in mouse merlin-deficient Schwann (MD-SCs) cells and cell cycle arrest in human MD-SCs. This study identifies the PI3K and PAK pathways as potential targets for combination drug treatment of NF2-related schwannomatosis.
Topics: Humans; Animals; Mice; Neurofibromatosis 2; Neurofibromin 2; Phosphatidylinositol 3-Kinases; p21-Activated Kinases; Phosphatidylinositol 3-Kinase; Neurilemmoma; Indazoles; Skin Neoplasms; Sulfonamides; Neurofibromatoses
PubMed: 38336988
DOI: 10.1038/s41388-024-02958-w -
Journal of Neurological Surgery. Part... Feb 2024The evolution of acoustic neuroma (AN) care continues to shift focus on balancing optimized tumor resection and control with preservation of neurological function....
The evolution of acoustic neuroma (AN) care continues to shift focus on balancing optimized tumor resection and control with preservation of neurological function. Prior learning curve analyses of AN resection have demonstrated a plateau between 20 and 100 surgeries. In this study of 860 consecutive AN surgeries, we investigate the presence of an extended learning curve tail for AN resection. A retrospective cohort study of AN resections by a single interdisciplinary team between 1988 and 2018 was performed. Proportional odds models and restricted cubic splines were used to determine the association between the timing of surgery and odds of improved postoperative outcomes. The likelihood of improved postoperative House-Brackmann (HB) scores increased in the first 400 procedures, with HB 1 at 36% in 1988 compared with 79% in 2004. While the probability of a better HB score increased over time, there was a temporary decrease in slope of the cubic spline between 2005 and 2009. The last 400 cases continued to see improvement in optimal HB outcomes: adjusted odds of HB 1 score were twofold higher in both 2005 to 2009 (adjusted odds ratio [aOR]: 2.11, 95% confidence interval [CI]: 1.38-3.22, < 0.001) and 2010 to 2018 (aOR: 2.18, 95% CI: 1.49-3.19, < 0.001). In contrast to prior studies, our study demonstrates the steepest growth for learning, as measured by rates of preservation of facial function outcomes (HB 1), occurs in the first 400 AN resections. Additionally, improvements in patient outcomes continued even 30 years into practice, underlining the importance of lifelong learning.
PubMed: 38274479
DOI: 10.1055/a-1993-7906 -
American Journal of Otolaryngology 2023To quantify contralateral hearing outcomes after labyrinthectomy for unilateral Ménière's disease (MD).
OBJECTIVE
To quantify contralateral hearing outcomes after labyrinthectomy for unilateral Ménière's disease (MD).
STUDY DESIGN
Retrospective case series.
SETTING
Tertiary neurotology referral center.
PATIENTS
Labyrinth removal for the management of MD or translabyrinthine (TLAB) acoustic neuroma resection between 2008 and 2012.
MAIN OUTCOME MEASURE
Long-term hearing changes via pure tone averages (PTA).
RESULTS
Upon comparison of low-frequency PTA (250, 500, 1000 Hz), MD patients experienced a greater degree of hearing loss during the follow-up period when compared to the TLAB lab group (7.54 ± 2.11 dB vs 2.39 ± 1.10 dB, p = 0.035). This difference as attributable to 12 (28.6 %) MD patients experiencing a ≥30 dB increase in low-frequency PTA, whereas none (0.0 %) of the TLAB surpassed this threshold.
CONCLUSIONS
At 10 years post-labyrinthectomy there is a heightened risk for MD patients to develop low-frequency sensorineural hearing loss. Clinicians should monitor for audiometric changes through regular testing in the decade following labyrinth removal.
Topics: Humans; Meniere Disease; Follow-Up Studies; Retrospective Studies; Ear, Inner; Hearing
PubMed: 37459738
DOI: 10.1016/j.amjoto.2023.103989 -
World Neurosurgery Aug 2023Bruns nystagmus is a form of jerk nystagmus that has a localizing value in cerebellopontine angle (CPA) tumors. Hemangioblastomas involving the CPA is rare. A case of a...
Bruns nystagmus is a form of jerk nystagmus that has a localizing value in cerebellopontine angle (CPA) tumors. Hemangioblastomas involving the CPA is rare. A case of a 57-year-old male presented with Bruns nystagmus which led to the discovery of a large CPA hemangioblastoma is described. The nystagmus was compatible with the laterality of the tumor. High quality video of Bruns nystagmus was recorded.
Topics: Male; Humans; Middle Aged; Hemangioblastoma; Cerebellopontine Angle; Nystagmus, Pathologic; Neuroma, Acoustic; Cerebellar Neoplasms; Magnetic Resonance Imaging
PubMed: 37169073
DOI: 10.1016/j.wneu.2023.05.005 -
World Neurosurgery Oct 2023Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments,...
OBJECTIVE
Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments, including SRS. The effects of radiation parameters of SRS on hearing remain unknown. The goal of this study is to determine the effect of tumor volume, patient demographics, pretreatment hearing status, cochlear radiation dose, total tumor radiation dose, fractionation, and other radiotherapy parameters on hearing deterioration.
METHODS
Multicenter retrospective analysis of 611 patients who underwent SRS for VS from 1990-2020 and had pre- and post-treatment audiograms.
RESULTS
Pure tone averages (PTAs) increased and word recognition scores (WRSs) decreased in treated ears at 12-60 months while remaining stable in untreated ears. Higher baseline PTA, higher tumor radiation dose, higher maximum cochlear dose, and usage of single fraction resulted in higher post radiation PTA; WRS was only predicted by baseline WRS and age. Higher baseline PTA, single fraction treatment, higher tumor radiation dose, and higher maximum cochlear dose resulted in a faster deterioration in PTA. Below a maximum cochlear dose of 3 Gy, there were no statistically significant changes in PTA or WRS.
CONCLUSIONS
Decline of hearing at one year in VS patients after SRS is directly related to maximum cochlear dose, single versus 3-fraction treatment, total tumor radiation dose, and baseline hearing level. The maximum safe cochlear dose for hearingtbrowd preservation at one year is 3 Gy, and the use of 3 fractions instead of one fraction was better at preserving hearing.
Topics: Humans; Neuroma, Acoustic; Retrospective Studies; Radiosurgery; Follow-Up Studies; Hearing; Treatment Outcome
PubMed: 37268187
DOI: 10.1016/j.wneu.2023.05.098 -
Plastic and Reconstructive Surgery Feb 2024Facial paralysis secondary to neurofibromatosis type 2 (NF2) presents the reconstructive surgeon with unique challenges because of its pathognomonic feature of bilateral... (Review)
Review
BACKGROUND
Facial paralysis secondary to neurofibromatosis type 2 (NF2) presents the reconstructive surgeon with unique challenges because of its pathognomonic feature of bilateral acoustic neuromas, involvement of multiple cranial nerves, use of antineoplastic agents, and management. Facial reanimation literature on managing this patient population is scant.
METHODS
A comprehensive literature review was performed. All patients with NF2-related facial paralysis who presented in the past 13 years were reviewed retrospectively for type and degree of paralysis, NF2 sequelae, number of cranial nerves involved, interventional modalities, and surgical notes.
RESULTS
Twelve patients with NF2-related facial paralysis were identified. All patients presented after resection of vestibular schwannoma. Mean duration of weakness before surgical intervention was 8 months. On presentation, one patient had bilateral facial weakness, 11 had multiple cranial nerve involvement, and seven were treated with antineoplastic agents. Two patients underwent gracilis free functional muscle transfer, five underwent masseteric-to-facial nerve transfer (of whom two were dually innervated with a crossfacial nerve graft), and one patient underwent depressor anguli oris myectomy. Trigeminal schwannomas did not affect reconstructive outcomes if trigeminal nerve motor function on clinical examination was normal. In addition, antineoplastic agents such as bevacizumab and temsirolimus did not affect outcomes if stopped in the perioperative period.
CONCLUSIONS
Effectively managing patients with NF2-related facial paralysis necessitates understanding the progressive and systemic nature of the disease, bilateral facial nerve and multiple cranial nerve involvement, and common antineoplastic treatments. Neither antineoplastic agents nor trigeminal nerve schwannomas associated with normal examination affected outcomes.
CLINICAL QUESTION/LEVEL OF EVIDENCE
Therapeutic, V.
Topics: Humans; Neurofibromatosis 2; Facial Paralysis; Retrospective Studies; Facial Nerve; Neurilemmoma; Antineoplastic Agents
PubMed: 37075282
DOI: 10.1097/PRS.0000000000010561 -
Otolaryngology--head and Neck Surgery :... Aug 2023Audiometric outcomes at 12 months following simultaneous translabyrinthine (TL) resection of vestibular schwannoma (VS) and cochlear implantation (CI).
OBJECTIVE
Audiometric outcomes at 12 months following simultaneous translabyrinthine (TL) resection of vestibular schwannoma (VS) and cochlear implantation (CI).
STUDY DESIGN
Prospective cohort study.
SETTING
Tertiary referral center.
METHODS
Adult patients undergoing TL resection of sporadic, unilateral VS ≤ 2 cm were prospectively enrolled. Preoperative testing included binaural AZBio in noise and quiet and unilateral Consonant-Nucleus-Consonant (CNC). Tinnitus Handicap Index (THI) and Speech, Spatial, and Qualities of Hearing (SSQ) questionnaires were also completed. Patients underwent TL resection with simultaneous CI. The preoperative test battery was repeated at 1, 3, 6, and 12 months after activation. Statistical analysis was performed to characterize short-term outcomes (preoperative to 3 months), longer-term outcomes (3-12 months), and overall changes during the preoperative to 12-month period.
RESULTS
AZBio, CNC, and THI improved at 3 months with no significant changes thereafter and showed durable improvement at 12 months compared to preoperative testing. While SSQ did not improve at 12 months, a subset of patients showed either recovery or improvement of SSQ-spatial subscores. Patients with cerebellopontine angle tumors had poorer performance, although the impact of tumor size and location could not be deduced based on the small sample size.
CONCLUSION
Patients undergoing simultaneous CI and TL resection of VS had durable improvements in speech perception and tinnitus severity 12 months following surgery. Subjective improvements in localization were not observed. Additional studies are needed to determine which VS patients are optimal candidates for CI.
Topics: Adult; Humans; Cochlear Implantation; Tinnitus; Prospective Studies; Hearing; Hearing Loss, Unilateral; Neuroma, Acoustic; Cochlear Implants; Speech Perception; Treatment Outcome
PubMed: 36939583
DOI: 10.1002/ohn.261