Vestibular Schwannoma Surgery Research Articles

Predictive Factors of Post-Operative Hearing Loss Following Vestibular Schwannoma Surgery

Predictive Factors of Post-Operative Hearing Loss Following Vestibular Schwannoma Surgery

Intraoperative cochlear nerve mapping with the mobile cochlear nerve compound action potential tracer in vestibular schwannoma surgery.

The authors describe the usefulness and limitations of the cochlear nerve compound action potential (CNAP) mobile tracer (MCT) that they developed to aid in cochlear nerve mapping during vestibular schwannoma surgery (VSS) for hearing preservation. This MCT device requires no more than 2 seconds for stable placement on the nerve to obtain the CNAP and thus is able to trace the cochlear nerve instantaneously. Simultaneous bipolar and monopolar recording is possible. The authors present the outcomes of 18 consecutive patients who underwent preoperative useful hearing (defined as class I or II of the Gardner-Robertson classification system) and underwent hearing-preservation VSS with the use of the MCT. Mapping was considered successful when it was possible to detect and trace the cochlear nerve. Mapping of the cochlear nerve was successful in 13 of 18 patients (72.2%), and useful hearing was preserved in 11 patients (61.1%). Among 8 patients with large tumors (Koos grade 3 or 4), the rate of successful mapping was 62.5% (5 patients). The rate of hearing preservation in patients with large tumors was 50% (4 patients). In addition to microsurgical presumption of the arrangement of each nerve, frequent probing on and around an unidentified nerve and comparison of each waveform are advisable with the use of both more sensitive monopolar and more location-specific bipolar MCT. MCT proved to be useful in cochlear nerve mapping and may consequently be helpful in hearing preservation. The authors discuss some limitations and problems with this device.

Risk Factors for Readmission with Cerebrospinal Fluid Leakage Within 30 Days of Vestibular Schwannoma Surgery.

Cerebrospinal fluid (CSF) leak is a well-recognized complication after surgical resection of vestibular schwannomas and is associated with a number of secondary complications, including readmission and meningitis. To identify risk factors for and timing of 30-d readmission with CSF leak. Patients who had undergone surgical resection of a vestibular schwannoma from 1995 to 2010 were identified in the California Office of Statewide Health Planning and Development database. The most common admission diagnoses were identified by International Classification of Disease, ninth Revision, diagnosis codes, and predictors of readmission with CSF leak were determined using logistic regression. A total of 6820 patients were identified. CSF leak, though a relatively uncommon cause of admission after discharge (3.52% of all patients), was implicated in nearly half of 490 readmissions (48.98%). Significant independent predictors of readmission with CSF leak were male sex (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.32-2.25), first admission at a teaching hospital (OR 3.32, 95% CI 1.06-10.39), CSF leak during first admission (OR 1.84, 95% CI 1.33-2.55), obesity during first admission (OR 2.10, 95% CI 1.20-3.66), and case volume of first admission hospital (OR of log case volume 0.82, 95% CI 0.70-0.95). Median time to readmission was 6 d from hospital discharge. This study has quantified CSF leak as an important contributor to nearly half of all readmissions following vestibular schwannoma surgery. We propose that surgeons should focus on technical factors that may reduce CSF leakage and take advantage of potential screening strategies for the detection of CSF leakage prior to first admission discharge.

Revision Surgery for Vestibular Schwannomas.

Objectives To describe clinical outcomes of patients undergoing revision surgery for vestibular schwannomas. Design Retrospective case series. Setting Tertiary private neurotologic practice. Participants Patients who underwent revision surgeries for recurrent/residual vestibular schwannomas between 1985 and 2015. Main Outcome Measures Degree of resection, facial nerve function, cerebrospinal fluid (CSF) leak. Results A total of 234 patients underwent 250 revision surgeries for recurrent/residual vestibular schwannomas. Of these, 86 carried a diagnosis of neurofibromatosis type 2 (NF2). The mean number of prior surgeries was 1.26, and 197 (85%) prior surgeries had been performed elsewhere. The average age at surgery was 43. The most common approach employed at the time of revision surgery was translabyrinthine (87%), followed by transcochlear (6%), middle fossa (5%), and retrosigmoid (2%). Gross total resection was achieved in 212 revision surgeries (85%). Preoperative House-Brackmann facial nerve function was similar in non-NF2 and NF2 groups (mean: 2.7). Mean postoperative facial nerve function at last follow-up was 3.8 in the non-NF2 group and 3.9 in the NF2 group. History of radiation and the extent of resection were not associated with differences in facial nerve function preoperatively or postoperatively. CSF leaks occurred after 21 surgeries (8%), and six (2%) patients required reoperation. Conclusions This is the largest series of revision surgery for vestibular schwannomas to date. Our preferred approach is the translabyrinthine craniotomy, which can be readily modified to include the transcochlear approach for improved access. CSF leak rate slightly exceeds that of primary surgery, and gross total resection is achievable in the vast majority of patients.

Does Hospital Volume Affect Outcomes in Patients Undergoing Vestibular Schwannoma Surgery?

To determine the effect of hospital surgical case volume on the outcomes of vestibular schwannoma surgery. Retrospective case review. University HealthSystem Consortium member hospitals (includes nearly every US academic medical center). Three thousand six hundred ninety-seven patients who underwent vestibular schwannoma resection over a 3-year timespan (2012-2015) grouped by race, age, comorbidities, payer, and sex. Surgical resection of vestibular schwannoma. Morbidity and mortality following vestibular schwannoma excision are compared by hospital volume (low, medium, and high) including deciles. There was significantly longer length of stay (p ≤ 0.005) among groups with low-volume hospitals followed by medium-volume hospitals and high-volume hospitals. Low-volume hospitals had a significantly higher rate of complications including stroke, aspiration, and respiratory failure (p ≤ 0.0175). Patient characteristics of age, sex, sex, and baseline comorbidities were similar between hospital groups. However, patients at high-volume hospitals were more likely to be Caucasian (83.1%, p = 0.0001) and have private insurance (76.7%, p < 0.0001). There was a strong negative correlation between complication rates and hospital volume (r = -0.8164, p = 0.0040). The volume of vestibular schwannoma surgeries performed at a hospital impacts length of stay and rates of postoperative complications. Demographics among hospital groups were similar though high-volume hospitals had significantly more patients who were privately insured and Caucasian.

The Role of Fast Imaging Employing Steady-State Acquisition (FIESTA) Magnetic Resonance Imaging for Assessment of Delayed Enhancement of Fat Graft Packing on Postoperative Imaging After Vestibular Schwannoma Surgery.

To investigate the role and efficacy of fast imaging employing steady-state acquisition (FIESTA) imaging in distinguishing fat graft enhancement from residual or recurrent tumor after vestibular schwannoma (VS) surgery. A retrospective study of 33 patients who underwent VS resection via the retrosigmoid or translabyrinthine approach with fat graft reconstruction was performed. Magnetic resonance imaging (MRI) was collected at different time points: preoperative, immediate postoperative (24-48 hours), delayed postoperative (3-6 months after surgery), and yearly postoperative. The image sets contained T1, T2, fat-suppressed T1-weighted with gadolinium, and FIESTA. The radiographs were analyzed for tumor recurrence by the primary neurosurgeon and an independent blinded neuroradiologist. If fat-suppressed T1-weighted images demonstrated postoperative enhancement in the resection bed, a comparison was made with FIESTA imaging. At 3-6 months postoperatively and at 1 year and beyond, 28 (84.8%) and 33 (100%) of patients, respectively, displayed delayed enhancement of the fat graft on postgadolinium fat-suppressed T1-weighted MRI. The enhancement seen on postgadolinium, fat-suppressed, T1-weighted MRI consistently correlated with the characteristic fat graft signal on FIESTA imaging and not tumor recurrence. FIESTA imaging was able to distinguish residual tumor from enhancing fat graft compared with postgadolinium, fat-suppressed, T1-weighted MRI (P < 0.0001) due to distinctive signaling patterns. FIESTA is an effective tool in discerning fat graft enhancement from residual or recurrent tumor on delayed postoperative imaging after VS resection. Fat graft used in reconstruction consistently enhances on delayed postoperative postgadolinium, fat-suppressed, T1-weighted imaging, which correlates with the fat graft signal seen on FIESTA images.

National Trends in Vestibular Schwannoma Surgery: Influence of Patient Characteristics on Outcomes

Objective To characterize current vestibular schwannoma (VS) surgery outcomes with a nationwide database and identify factors associated with increased complications and prolonged hospital course. Study Design Retrospective review utilizing the University HealthSystem Consortium national inpatient database. Setting US academic health centers. Subjects and Methods Data from patients undergoing VS surgery were analyzed over a 3-year time span (October 2012 to September 2015). Surgical outcomes, such as length of stay (LOS), complications, and mortality, were analyzed on the basis of race, sex, age, and comorbidities during the 30-day postoperative period. Results A total of 3697 VS surgical cases were identified. The overall mortality rate was 0.38%, and the overall complication rate was 5.3%. Advanced age significantly affected intensive care unit LOS, mortality, and complications ( P = .04). Comorbidities, including hypertension, obesity, and depression, also significantly increased complication rates ( P = .02). Sixty-eight patients (1.8%) had a history of irradiation, and they had a significantly increased LOS ( P = .03). Conclusion Modern VS surgery has a low mortality rate and a relatively low rate of complications. Several factors contribute to high complication rates, including age and comorbidities. These data will help providers in counseling patients on which treatment course might be best suited for them.

Delayed facial nerve palsy after vestibular schwannoma surgery

Background: Facial nerve dysfunction may occur immediately after vestibular schwanoma surgery. Electromyographyc monitoring of motor cranial nerves during cerebellopontine angle surgery has become an essential tool. Although delayed onset of facial nerve dysfunction hours to months following vestibular schwanoma surgery are rare. Case description: We describe the case of a 70-years-old male who was admitted with a left side tinnitus and hearing loss of the last 3 years. Magnetic resonance imaging (MRI) T1-weighted demonstrated an isointensity lesion, 30mm in diameter, at the left cerebello-pontine angle with a small portion in the internal auditory canal. The patient was surgically treated by means of a standart suboccipital retrosigmoid approach. The facial nerve was monitored by continuously during surgery. Surgical removal was macroscopically complete. The facial nerve was well-preserved during surgery and showed at the end of the procedure normal electromyographic activity. The patient did well postoperatively and was discharged at the 4th postoperative day and facial function was normal (House-Brackmann grade I). On the 10th postoperative day he notices difficult closing his left eye that progressed to complete facial nerve palsy (House-Brackmann grade III). Steroid therapy was performed for five days associated with physical therapy. One month later his facial nerve function had completely recovered. After six months, the patient remains asymptomatic and neurologically intact. MRI obtained at the 16th postoperative day showed intense enhancement of the intracranial facial nerve segment and also demonstrated no residual tumor. Immunological study at the time of onset showed herpes simplex virus antibody titer normal as well as those for herpes zoster virus. Conclusions: Delayed facial nerve palsy remains an under reported and consequently not very known phenomenon in the neurosurgical practice and literature. Because of the 2009favorable rate of recovery, patients should be reassured in the interim and should not undergo any corrective surgical procedures to improve facial nerve function. Delayed facial nerve palsy is uncommon after vestibular schwannoma surgery. Excellent recovery of facial nerve function to the original postoperative status nearly always occurs in those circumstances.

Postoperative Tinnitus After Vestibular Schwannoma Surgery Depends on Preoperative Tinnitus and Both Pre- and Postoperative Hearing Function.

Tinnitus is one of the most common symptoms before and/or after the surgical removal of a vestibular schwannoma (VS) affecting almost half of the patients. Although there is increasing evidence for the association of hearing impairment and VS-associated tinnitus, the effect of hearing deterioration due to surgery and its relation to the postoperative tinnitus (postTN) is poorly investigated. This knowledge, however, might (i) enlighten the pathophysiology of VS-associated tinnitus (i.e., peripheral or central origin) and (ii) improve preoperative patient counseling. The aim of this study was to understand the predisposition factors for a postTN in relation to hearing outcome after surgery. This retrospective study analyzed the presence of tinnitus in 208 patients with unilateral VS before and after surgical removal. A binomial logistic regression was performed to ascertain the effect of pre- and postoperative hearing as well as age, gender, tumor side, and size, and intraoperative cochlear nerve resection (CNR) on the likelihood of postoperative VS-associated tinnitus. Preoperative tinnitus was the strongest predictor of postTN. In addition, deterioration of functional hearing was increasing, while functional deafferentation (i.e., postoperative hearing loss) of non-functional hearing was reducing the risk of postTN. At the same time, patients with no preoperative tinnitus but complete hearing loss had the lowest risk to suffer from postTN. Patient age, gender, tumor side, and size as well as CNR played a subordinate role. While the presence of preoperative tinnitus was the strongest predictor of postTN, there is a distinct relationship between hearing outcome and postTN depending on the preoperative situation. Functional or anatomical deafferentation due to surgical tumor removal does not prevent postTN per se.

Progression of vestibular schawnnoma after GammaKnife radiosurgery: A challenge for microsurgical resection

ObjectiveWe aimed to evaluate the outcome of patients who underwent salvage microsurgery for vestibular schwannoma (VS) that failed primary Gammaknife radiosurgery (GKS). Patients and MethodsAmong the 1098 patients who received GKS for the treatment of VS in our center between January 2004 and December 2012, the follow-up was organized in our institution for 290 patients who lived in our recruitment area. Tumor progression was noted in 23 patients. A salvage microsurgical resection was performed in 11 patients, who were included in our study. Grading of facial function was done according to the House & Brackman scale. ResultsThe mean age at diagnosis was 50.2 years (19–68 years) and the mean follow-up was 9.4 years (4–13 years). The mean dose was 11.8 Gy (11–12 Gy) and the mean volume was 922 mm3 (208–2500 mm3). The mean period between GKS and diagnosis of tumor progression was 32 months (18–72 months). Concerning salvage microsurgery, complete resection was obtained in 8 patients. Small residual tumor on the facial nerve was deliberately left in 3 patients and no tumor progression was noted with a mean follow-up of 26 months. At last follow-up, facial nerve function was grade 1 in 4 patients, grade 2 in 3 patients, grade 3 in 1 patient and grade 4 in 3 patients. ConclusionSalvage surgery of recurrent vestibular schwannoma after failed initial GKS remains a good treatment. However, facial nerve preservation is more challenging in this case and small tumor remnant could be sometimes deliberately left.

Preoperative diffusion tensor imaging-fiber tracking for facial nerve identification in vestibular schwannoma: a systematic review on its evolution and current status with a pooled data analysis of surgical concordance rates.

OBJECTIVE Total tumor excision with the preservation of neurological function and quality of life is the goal of modern-day vestibular schwannoma (VS) surgery. Postoperative facial nerve (FN) paralysis is a devastating complication of VS surgery. Determining the course of the FN in relation to a VS preoperatively is invaluable to the neurosurgeon and is likely to enhance surgical safety with respect to FN function. Diffusion tensor imaging-fiber tracking (DTI-FT) technology is slowly gaining traction as a viable tool for preoperative FN visualization in patients with VS. METHODS A systematic review of the literature in the PubMed, Cochrane Library, and Web of Science databases was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and those studies that preoperatively localized the FN in relation to a VS using the DTI-FT technique and verified those preoperative FN tracking results by using microscopic observation and electrophysiological monitoring during microsurgery were included. A pooled analysis of studies was performed to calculate the surgical concordance rate (accuracy) of DTI-FT technology for FN localization. RESULTS Fourteen studies included 234 VS patients (male/female ratio 1:1.4, age range 17-75 years) who had undergone preoperative DTI-FT for FN identification. The mean tumor size among the studies ranged from 29 to 41.3 mm. Preoperative DTI-FT could not visualize the FN tract in 8 patients (3.4%) and its findings could not be verified in 3 patients (1.2%), were verified but discordant in 18 patients (7.6%), and were verified and concordant in 205 patients (87.1%). CONCLUSIONS Preoperative DTI-FT for FN identification is a useful adjunct in the surgical planning for large VSs (> 2.5 cm). A pooled analysis showed that DTI-FT successfully identifies the complete FN course in 96.6% of VSs (226 of 234 cases) and that FN identification by DTI-FT is accurate in 90.6% of cases (205 of 226 cases). Larger studies with DTI-FT-integrated neuronavigation are required to look at the direct benefit offered by this specific technique in preserving postoperative FN function.

The utility of "low current" stimulation threshold of intraoperative electromyography monitoring in predicting facial nerve function outcome after vestibular schwannoma surgery: a prospective cohort study of 103 large tumors.

To investigate the predictive utility of stimulation threshold (ST) of intraoperative electromyography monitoring for facial nerve (FN) outcomes among vestibular schwannoma (VS) patients postoperatively. The authors enrolled 103 unilateral VS patients who underwent surgical resection into a prospective cohort observational study from January 2013 to April 2015 in our hospital. ST values were used to categorize 81 patients into the "low current" (ST ≤ 0.05mA) group and 22 patients into the control (ST > 0.05mA) group. The FN function outcomes were summarized and correlated with these two groups at 1, 3, 6, and 12 months after surgery. Binary regression analysis revealed that the percentage of "good" FN outcome, defined by House-Brackmann (HB) classification of facial function (I-II), in the "low current" group was significantly higher than that of the control group (42.0 vs. 4.5% at 1 month, P = 0.015; 64.2 vs. 31.8% at 3 months, P = 0.024; 72.8 vs. 40.9% at 6 months, P = 0.021; 84.0 vs. 45.5% at 12 months, P = 0.002). Ordinal regression analysis showed that the distribution of HB scores was shifted in a favorable direction in the "low current" group at 1, 3, 6, and 12 months postoperatively. For patients with HB IV at the first month postoperative period, the recovery rate of the "low current" group was significantly higher than that of control group (P = 0.003). "Low current" can predict FN function outcomes better and has faster recovery rates than that of the control group.

Ménière's Disease Pathophysiology: Endolymphatic Sac Immunohistochemical Study of Aquaporin-2, V2R Vasopressin Receptor, NKCC2, and TRPV4.

Objectives Endolymphatic sac (ELS) pathophysiology in Ménière's disease (MD) remains poorly understood. We identified from the literature a group of proteins expressed on the ELS and involved in endolymph volume regulation: aquaporin-2 (AQP2), vasopressin receptor V2R, sodium potassium chloride cotransporter 2 (NKCC2), and transient receptor potential cation channel V4 (TRPV4). Our objective was to determine whether their ELS expression was altered in MD, to better understand the pathophysiology of endolymphatic hydrops. Study Design Prospective case-control study. Setting Tertiary care center. Subjects Twenty-four patients with definite MD undergoing endolymphatic duct blockage surgery were recruited, as well as 23 controls with no history of MD undergoing surgery for vestibular schwannoma (VS). Methods ELS biopsies and blood samples for plasma arginine vasopressin (AVP) were obtained. Immunohistochemistry for AQP2, V2R, NKCC2, and TRPV4 was performed. Slides were scanned digitally for highly sensitive pixel density analysis by specialized software (VIS; Visiopharm). Results Global scores generated by the software represent total and relative protein expression density of 3 staining intensity levels, exclusively on ELS epithelium. AQP2 expression density was significantly elevated in MD compared to VS ( P = .003). There was no significant difference in plasma AVP, V2R, NKCC2, and TRPV4 expression. Conclusion This original study evaluates simultaneous in situ expression of AQP2, V2R, NKCC2, and TRPV4 on the human ELS in MD, with a control group. Our results show only AQP2 upregulation on the ELS of patients with MD. We suggest a constitutively increased expression of AQP2 in MD, independent of its regulatory axis (AVP-V2R). Acquired regulator sequence mutations could support this model.

Expanded Transcanal Transpromontorial Approach: A Novel Surgical Technique for Cerebellopontine Angle Vestibular Schwannoma Removal.

Objective Vestibular schwannoma (VS) is a benign tumor of the lateral skull base. Different microscopic surgical techniques are described in literature: the retrosigmoid and translabyrinthine approaches are used to treat big tumors located in the cerebellopontine angle, and the middle cranial fossa approach is utilized for small tumors with good hearing preservation. The expanded transcanal transpromontorial (ExpTT) approach is a combined microscopic-endoscopic technique previously indicated for Koos stage I and II VS and now proposed for larger VS, up to 3 cm in diameter, with linear progression into the cerebellopontine angle and touching the brainstem. Study Design The study was a retrospective case series of patients who underwent ExpTT surgery for VS in our ear, nose, and throat department. Setting We reviewed the surgical videos and electrophysiologic data recorded during the surgical operations. Subjects and Methods From January 2015 to January 2017, 20 patients affected by Koos stage II and III VS underwent surgery in our department with the ExpTT approach. This novel technique is described step by step, with a focus on the surgical procedure and anatomic landmarks; outcomes are detailed in terms of early and late complications. The mean follow-up was 15 months. Results The ExpTT approach permitted, in all patients, gross total resection of the tumor without any complication and with preservation of facial nerve function. All patients had a good postoperative recovery. Conclusion The ExpTT technique is a new approach that combines the advantages of a microscopic technique with the ones offered by the endoscope in removal of VS.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Intraoperative Cranial Nerve Monitoring in Vestibular Schwannoma Surgery.

Does intraoperative facial nerve monitoring during vestibular schwannoma surgery lead to better long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery regardless of tumor characteristics. Level 3: It is recommended that intraoperative facial nerve monitoring be routinely utilized during vestibular schwannoma surgery to improve long-term facial nerve function. Can intraoperative facial nerve monitoring be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Intraoperative facial nerve can be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery. Specifically, the presence of favorable testing reliably portends a good long-term facial nerve outcome. However, the absence of favorable testing in the setting of an anatomically intact facial nerve does not reliably predict poor long-term function and therefore cannot be used to direct decision-making regarding the need for early reinnervation procedures. Does an anatomically intact facial nerve with poor electromyogram (EMG) electrical responses during intraoperative testing reliably predict poor long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Poor intraoperative EMG electrical response of the facial nerve should not be used as a reliable predictor of poor long-term facial nerve function. Should intraoperative eighth cranial nerve monitoring be used during vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted. Is direct monitoring of the eighth cranial nerve superior to the use of far-field auditory brain stem responses? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: There is insufficient evidence to make a definitive recommendation. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-manage-ment-patients-vestibular-schwannoma/chapter_4.

Surgery of Vestibular Schwannomas in the Era of with Gamma-Knife Radiosurgery: A Two-Center Comparative Study with 702 Cases

Surgery of Vestibular Schwannomas in the Era of with Gamma-Knife Radiosurgery: A Two-Center Comparative Study with 702 Cases

PREHAB vs. REHAB - presurgical treatment in vestibular schwannoma surgery enhances recovery of postural control better than postoperative rehabilitation: Retrospective case series.

To evaluate post-surgical postural stability when treating patients with remaining vestibular function with intratympanic gentamicin (PREHAB) prior to schwannoma surgery. 44 consecutive patients with some form remaining vestibular function scheduled for vestibular schwannoma surgery. 20 were medically deafferented with intratympanic gentamicin before surgery and 24 were not. Both groups were of the same age, had the same tumor size, same type of surgery, and same perioperative sensory rehabilitation (training exercises), and no surgical complications. Postural stability measured as energy expenditure while standing on a force platform during vibratory stimulation of the calf muscles, performed prior to surgery (or gentamicin treatment) and 6 months after surgery. Patients pretreated with gentamicin had significantly better postural stability at the time for follow-up (p < 0.05) and displayed a better adaptive capacity when faced with a postural challenge (p < 0.01). They were also able to use vision more efficiently to control their stability (p < 0.05). By separating the sensory loss (through intratympanic gentamicin, that ablates the remaining vestibular function) from the intracranial surgical trauma, the postural control system benefited from a better short-term (adaptation) and long-term (habituation) recovery, when experiencing a postural challenge or resolving a sensory conflict. The benefits could be attributed to; active and continuous motor learning as the vestibular function slowly attenuates; no concomitant central nervous dysfunction due to effects from neurosurgery, thus allowing time for a separate unimpeded recovery process with more limited challenges and objectives; and the initiation and certain progression of sensory reweighting processes allowed prior to surgery. In contrast, worse compensation could be due to; immobilization from nausea after surgery, harmful amount of stress and cognitive dysfunction from the combination of surgical and sensory trauma and an abrupt vestibular deafferentation and its consequences on sensory reweighting.

What Is the Safety and Efficacy of Chemical Venous Thromboembolism Prophylaxis Following Vestibular Schwannoma Surgery?

The benefit of routine chemical prophylaxis use for venous thromboembolism (VTE) prevention in skull base surgery is controversial. Chemical prophylaxis can prevent undue morbidity and mortality, however there are risks for hemorrhagic complications. Retrospective case-control. A retrospective chart review of patients who underwent surgery for vestibular schwannoma from 2011 to 2016 was performed. Patients were divided by receipt of chemical VTE prophylaxis. Number of VTEs and hemorrhagic complications (intracranial hemorrhage, abdominal hematoma, and postauricular hematoma) were recorded. One hundred twenty-six patients were identified, 55 received chemical prophylaxis, and 71 did not. All the patients received mechanical prophylaxis. Two patients developed a deep vein thrombosis (DVT) and one patient developed a pulmonary embolism (PE). All patients who developed a DVT or PE received chemical prophylaxis. There was no difference in DVT (p = 0.1886) or PE (p = 0.4365) between those who received chemical prophylaxis and those who did not. Five patients developed a hemorrhagic complication, two intracranial hemorrhage, three abdominal hematoma, and zero postauricular hematoma. All five patients with a complication received chemical prophylaxis (p = 0.00142). The relative risk of a hemorrhagic complication was 14.14 (95% CI = 0.7987-250.4307; p = 0.0778). There was a significant difference between the number of hemorrhagic complications but not between numbers of DVT or PE. Mechanical and chemical prophylaxis may lower the risk of VTE but in our series, hemorrhagic complications were observed. These measures should be used selectively in conjunction with early ambulation.

Cerebrovascular Complications during Vestibular Schwannoma Surgery

Cerebrovascular Complications during Vestibular Schwannoma Surgery

Variation in Coding Practices for Vestibular Schwannoma Surgery

Variation in Coding Practices for Vestibular Schwannoma Surgery