Quantifying the effect of shoulder size on operation duration: an analysis of stapes surgery outcomes.

OBJECTIVE: To investigate the effect of body mass index on hearing outcomes, operative time and complication rates following stapes surgery. METHOD: This is a five-year retrospective review of 402 charts from a single tertiary otology referral centre from 2015 to 2020. RESULTS: When the patient's shoulder was adjacent to the surgeon's dominant hand, the average operative time of 40 minutes increased to 70 minutes because of a significant positive association between higher body mass index and longer operative times (normal body mass index group (<25 kg/m2) r = 0.273, p = 0.032; overweight body mass index group (25-30 kg/m2) r = 0.265, p = 0.019). Operative times were not significantly longer upon comparison of low and high body mass index groups without stratification by laterality (54.9 ± 19.6 minutes vs 57.8 ± 19.2 minutes, p = 0.127). CONCLUSION: There is a clinically significant relationship between body mass index and operating times. This may be due to access limitations imposed by shoulder size.

Preoperative Evaluation of Otosclerosis: A National Survey of Otologists.

OBJECTIVE: Describe practice patterns in preoperative assessment for stapedectomy. STUDY DESIGN: Survey. SETTING: Tertiary referral center. SUBJECTS: Active members of the American Neurotologic Society and American Otologic Society. INTERVENTION: Survey. MAIN OUTCOME MEASURES: Percent of respondents performing preoperative testing with acoustic reflexes (ARs), electrocochleography, vestibular evoked myogenic potentials, and computed tomography (CT). Further analysis of those not ordering routine CT to determine whether imaging would be ordered for previous ear surgery, vestibular complaints, childhood hearing loss, AR inconsistent with otosclerosis, possible advanced otosclerosis, or atypical complaints, including autophony. Further subgroup analysis based on years in practice and practice setting (private versus academic). RESULTS: Most respondents (56.5%) had practiced more than 15 years and worked in academic settings (69.4%). Rates of routine use of preoperative AR, vestibular evoked myogenic potential, and electrocochleography were 80, 4.7, and 0%, respectively. There were no significant differences based on time in practice or practice settings. For CT, 35.3% reported routine use with a statistically significant difference between academic and private practice respondents (42.4% versus 19.2%, p = 0.040). For CT contingent on specific clinical factors, only AR inconsistent with otosclerosis showed a statistically significant difference between academic and private practice providers (85.3% versus 57.1%, p = 0.020). CONCLUSION: Most otologists routinely obtain AR before stapedectomy. Academic providers more commonly order CT routinely and for AR inconsistent with otosclerosis. Most respondents not ordering routine CT ordered imaging in specific clinical scenarios. Overall, there is a high level of consistency in preoperative testing regardless of practice setting or time in practice.

Progression of Hearing Loss in Observed Non-Growing Vestibular Schwannoma.

OBJECTIVE: To assess hearing outcomes in observed vestibular schwannoma (VS) with focus on non-growing tumors. STUDY DESIGN: Retrospective review. SETTING: Two tertiary neurotology centers. PATIENTS AND INTERVENTIONS: Patients with sporadic VS undergoing at least 3 years' observation. MAIN OUTCOME MEASURES: Changes in pure tone averages (PTA) and word recognition scores (WRS) normalized to the contralateral ear. RESULTS: During the study period, 39 of 105 included patients (37.1%) had tumor growth. Patients with tumor growth had a mean normalized increase in PTA of 8.0 dB HL ( p = 0.008) corresponding to a normalized average worsening of their PTA of 1.8 dB per year. Patients with non-growing tumors less than 5 mm in maximal dimension did not have significant ongoing normalized hearing loss ( p > 0.05). Patients with non-growing tumors more than or equal to 5 mm had a mean normalized increase in PTA of 7.4 dB HL ( p = 0.001) corresponding to an average of 2.0 dB HL per year, which was similar to the loss observed in growing tumors regardless of size ( p > 0.05). Normalized decline in PTA of at least 5 dB HL was seen in 72% of patients with growing tumors, 53% of patients with nongrowing tumors more than or equal to 5 mm, and 38% of patients with non-growing tumors less than 5 mm. CONCLUSIONS: A long-term analysis of hearing outcomes in observed vestibular schwannoma is presented. With observation, VS more than or equal to 5 mm is associated with continued hearing loss even without tumor growth, while non-growing tumors less than 5 mm are not associated with continuing hearing loss. These data inform expectations for observed VS for providers and patients.

Audiologic comparison of classification systems of advanced otosclerosis.

OBJECTIVE: To identify which patients with advanced otosclerosis may have the greatest audiologic improvement with stapedotomy based on different classifications of advanced otosclerosis. STUDY DESIGN: Retrospective chart review. SETTING: Single tertiary neurotology center. METHODS: Patients were divided into different classifications of advanced otosclerosis based on either a bone conduction threshold of greater than 60 dB HL (Bone Conduction (BC) Group), a word recognition score of less than 70% (Word Recognition (WRS) Group), or pure tone average of greater than 85 dB HL (Pure Tone Average (PTA) Group). Audiologic outcomes and complication profiles were compared between these groups. RESULTS: Nineteen patients met criteria for one or more group. There were 18 patients in the PTA group, 11 in the BC group, and 12 in the WRS group. There was no significant difference in the pre- or postoperative audiologic status between the different groups. CONCLUSIONS: Patients with advanced otosclerosis have significant improvements in pure tone averages and air-bone gaps following stapedotomy regardless of the classification criteria used. Stapedotomy remains a reasonable primary intervention for the majority of patients with advanced otosclerosis.

Outcomes of Stapedotomy in Patients With Concomitant Otosclerosis and Superior Semicircular Canal Dehiscence: Should a Radiographic Third-Window Be a Contraindication to Stapes Surgery?

OBJECTIVE: Review surgical outcomes of stapedotomy in patients with concomitant otosclerosis and superior semicircular canal dehiscence. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients with otosclerosis and radiographic superior semicircular canal dehiscence undergoing stapedotomy between 2008 and 2020. INTERVENTION: Stapedotomy. MAIN OUTCOME MEASURES: Pre- and postoperative hearing and unmasking of third-window symptoms. Hearing was measured by air conduction (AC) and bone conduction (BC) pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). Third-window symptoms included hyperacusis, autophony, sound- or pressure-induced vertigo, imbalance, or oscillopsia. RESULTS: Twenty patients with otosclerosis and radiographic superior semicircular canal dehiscence underwent stapedotomy, 13 primary and 7 revision. Mean AC PTA was 49.3 dB preoperatively and 35.6 dB postoperatively (p = 0.0077), while the ABG improved on average from 23.9 to 9.68 dB (p < 0.0001). The ABG improved to ≤10 dB in 12/20 patients (60%), and ≤20 dB in 18/20 patients (90%). There was no significant difference in BC PTA or WRS postoperatively. Two patients (10%) experienced potential transient unmasking of third-window symptoms-hyperacusis and prolonged imbalance-which both resolved. There were no other complications. There was no significant difference in audiologic outcomes or unmasking of third window symptoms between primary or revision cases. CONCLUSIONS: Persistent conductive hearing loss is common following stapedotomy for otosclerosis in patients with concomitant superior semicircular canal dehiscence. However, a majority of patients can achieve excellent hearing outcomes, while unmasking of third window symptoms appears to be rare. Radiographic superior semicircular canal dehiscence may not be an absolute contraindication to stapes surgery for otosclerosis.

Revision Stapes Surgery: Hearing Symptoms and Associations With Intraoperative Findings and Outcomes.

OBJECTIVE: Stapes surgery for otosclerosis occasionally requires revision due to recurrent or persistent conductive hearing loss (CHL). This study examines outcomes after revision stapes surgery. STUDY DESIGN: Retrospective review. SETTING: Single tertiary neurotology center. METHODS: Patients undergoing revision stapes surgery for otosclerosis from 2008 to 2017 were reviewed. Postoperative air-bone gaps (ABGs) were the primary outcome measure. RESULTS: During the study period, 150 patients underwent revision stapes surgery. One hundred patients (67%) had gradually progressive recurrent CHL; 16 (11%), sudden recurrent CHL; 13 (9%), persistent CHL; and 21 (14%), no CHL. For 129 patients with CHL, the mean ABG improved from 23.7 to 9.3 dB (P < .0005). The most common intraoperative findings for these patients were prosthesis displacement with incus necrosis (38%) or without it (43%), normal anatomy with seemingly good prosthesis placement (6%), and abundant scar tissue (6%). Patients with recurrent hearing loss achieved lower mean ABGs than patients with persistent hearing loss (8.8 vs 13.2 dB, P = .02). There were no associations between onset pattern of CHL or intraoperative findings and hearing outcomes (P > .05). Four patients (2.7%) developed sensorineural hearing loss after revision, defined as an increase in bone conduction pure tone average ≥15 dB, all of whom had previous replacement of a malpositioned prosthesis. CONCLUSIONS: Revision stapes surgery confers significant improvement in hearing for patients with persistent and recurrent CHL, although patients with persistent CHL after initial surgery see less improvement with revision.

Outcomes in primary and revision surgery for pediatric onset stapedial pathology.

OBJECTIVES: To analyze audiometric outcomes of surgery for pediatric onset stapedial pathology (POSP). STUDY DESIGN: Retrospective cohort study. SETTING: Single-institution database. METHODS: Retrospective analysis of 809 stapes procedures performed at a single high-volume tertiary referral otology practice, 75 of which were POSP cases. RESULTS: Oval window drillout for thick footplate and aborting the procedure were more common in POSP cases compared to the rest of the cohort (28.0% versus 9.8% [p < .001] and 5.3% versus 1.2% [p = .007], respectively). Postoperative complications were rare. Postoperative Air-Bone Gap (pABG) closure to ≤20 dB was significantly lower in the POSP group (80.0% versus 89.0%, p = .021). Rates of sensorineural hearing loss (SNHL) were not different between the two groups. Poor audiometric outcomes in the POSP group were largely driven by revision cases; pABG≤10 dB was 60.3% in primary cases but only 11.8% in revisions (p < .001), and postoperative SNHL was significantly higher in revisions (29.4% versus 0.0%, p < .001). In multivariate analysis, POSP was not a predictor of successful closure of the pABG at either level, nor did it predict significant postoperative SNHL. CONCLUSIONS: Surgery for pediatric onset stapedial pathology had significantly worse audiometric outcomes, particularly in revision cases, as compared to the rest of the cohort.

Rate of Development of Venous Thromboembolism in Lateral Skull Base Surgery.

OBJECTIVES: Venous thromboembolism (VTE) is a major cause of morbidity and mortality for surgical patients. This article aims to determine factors that may have contributed to the development of VTE in patients undergoing lateral skull base surgery, to assess the validity of the Caprini Risk Assessment Model (RAM) score in this subset of patients, and to determine the efficacy of mechanical DVT prophylaxis alone in preventing VTE. STUDY DESIGN: Retrospective chart review. METHODS: A retrospective chart review was conducted of patients who underwent skull base surgery for vestibular schwannoma, and the rate of VTE was assessed. Patient demographics, comorbidities, and treatment factors were examined to determine risk factors associated with the development of a postoperative thrombotic event. Caprini RAM scores were compared for patients who developed a VTE. RESULTS: Among 197 patients, the rate of VTE formation was 3.5%. No individual risk factor independently contributed to the development of a thrombotic event. The mean Caprini RAM score was 4.06 in patients who did not develop a VTE and 5.14 in the patients that did develop a VTE (P = .005). The Caprini score was significant for the risk of VTE formation, with an odds ratio of 2.8 (P = .009, 95% CI = 1.3-6.2). CONCLUSION: Venous thromboembolism rates are relatively low following lateral skull base surgery. While there is no individual risk factor associated with increased VTE risk, the Caprini RAM score appears to be a useful predictor of risk. The Caprini score may be useful in identifying high-risk patients who may benefit from chemoprophylaxis for VTE prevention. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:662-667, 2022.

Audiologic Outcomes of Footplate Drillout for Obliterative Otosclerosis.

OBJECTIVE: To evaluate the audiologic outcomes of microdrill fenestration for obliterative otosclerosis compared to traditional stapedotomy technique. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into groups that underwent either microdrill or laser fenestration based on intraoperative severity of disease. Audiologic outcomes and complications were compared between the two groups. RESULTS: There were 588 ears in 519 patients that were evaluated. There was a significant postoperative improvement in pure tone average, air-bone gap, and mean bone conduction thresholds for both the obliterative and nonobliterative group (p < 0.001). There was no significant difference in the pre- or postoperative hearing status between the two groups. There was no significant difference in complications between the two groups, including no cases of postoperative profound hearing loss in the drill fenestration group. CONCLUSIONS: Audiologic outcomes are similar between microdrill fenestration and laser fenestration for otosclerosis. Pure tone average, air-bone gap, and mean bone conduction thresholds all improved postoperatively and were similar between groups.

Comparison of Cranioplasty Techniques Following Translabyrinthine Surgery: Implications for Postoperative Pain and Opioid Usage.

OBJECTIVE: To assess differences in postoperative pain, opioid usage, and surgical outcomes between cranioplasty using abdominal fat graft (AFG) versus hydroxyapatite cement (HAC) following translabyrinthine surgery. STUDY DESIGN: Retrospective case control. SETTING: Tertiary referral center. PATIENTS: Sixty translabyrinthine procedures were evaluated, including 30 consecutive HAC patients and 30 matched AFG patients. Patients were matched by age, gender, body mass index, and tumor size. INTERVENTION: Cranioplasty using HAC or AFG following translabyrinthine resection of vestibular schwannoma. MAIN OUTCOME MEASURES: Postoperative patient pain ratings, narcotic usage, inpatient length of stay, and complication rates. RESULTS: Patients who underwent HAC cranioplasty had lower postoperative pain scores on several measures (p < 0.05) and less postoperative narcotic usage (mean difference of 36.7 morphine equivalents, p = 0.0025) when compared to those that underwent AFG closure. HAC cranioplasty patients had shorter average length of hospital stay (2.2 vs 3.4 days, p = 0.0441). Postoperative cerebrospinal fluid leaks (one in HAC group, two in AFG group) and skin reactions in AFG closure patients (n = 1) were infrequent. CONCLUSION: HAC cranioplasty is a safe technique comparable to AFG closure following translabyrinthine surgery which can decrease postoperative pain, narcotic usage, and hospital length of stay.

Risk Factors for Complications Following Lateral Skull Base Surgery and the Utility of ICU Monitoring.

OBJECTIVE: To examine the role of intensive care unit (ICU) management following lateral skull base surgery for vestibular schwannoma and identify risk factors for complications warranting admission to the ICU. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: Two hundred consecutive patients undergoing lateral skull base surgery for vestibular schwannomas. INTERVENTION: Lateral skull base approach for resection of vestibular schwannoma and postoperative monitoring. MAIN OUTCOME MEASURES: Patients were grouped if they sustained an ICU complication, a non-ICU complication, or no complication. Analysis was performed to determine patient or treatment factors that may be associated with ICU complications. Multivariate and three-way analysis of variance compared groups, and multivariate logistic regression determined adjusted odds ratios (aOR) for analyzed factors. RESULTS: Seventeen of 200 patients sustained ICU complications (8.5%), most commonly hypertensive urgency (n = 15). Forty-six (23%) sustained non-ICU complications, and 137 (68.5%) had no complications. When controlling for age, sex, obesity, and other comorbidities, only hypertension (aOR 5.43, 95% confidence interval (CI) 1.35-21.73, p = 0.017) and tumor volume (aOR 3.29, 95% CI 1.09-9.96, p = 0.035) were independently associated with increased risk of ICU complications. CONCLUSIONS: The necessity of intensive care following lateral skull base surgery is rare, with the primary ICU complication being hypertensive urgency. Preoperative hypertension and large tumor volume (>4500 mm3) were independently associated with increased risk for ICU complications. These findings may allow for risk stratification of patients appropriate for admission to stepdown units following resection of vestibular schwannomas. Further prospective, multi-center, randomized studies are necessary to validate these findings before systematic changes to current postoperative care practices.

Surgical Outcomes After Conservative Resection of Vestibular Schwannoma in the Elderly.

OBJECTIVE: To assess outcomes after surgery for vestibular schwannoma in patients over 70 years of age. STUDY DESIGN: Retrospective chart review. SETTING: Two tertiary otology and neurotology centers. PATIENTS AND INTERVENTIONS: Patients undergoing primary surgery for vestibular schwannoma between 2007 and 2018. MAIN OUTCOME MEASURES: Postoperative complications and surgical outcomes. RESULTS: A total of 452 patients met inclusion criteria, 31 of whom (6.9%) were over 70 years of age. Age ranged from 18 to 90 years with a mean of 53 years. Elderly patients were more likely to have pre-existing hypertension (58.1% versus 34.0%, p = 0.007) and diabetes mellitus (19.4% versus 7.4%, p = 0.02). Elderly patients were less likely to undergo gross total resections of their tumors (35.5% versus 60.6%, p = 0.05) although they were not statistically significantly more likely to undergo subtotal (<95%) resections (25.8% versus 14.7%, p > 0.05). Elderly patients were also less likely to undergo second stage procedures (0% versus 9.5%, p = 0.04). There were no significant differences between elderly and non-elderly patients in the rates of any complications, ultimate facial nerve function, or duration of surgery. No patients over 70 years of age expired within 1 year of surgery. CONCLUSIONS: Conservative surgery for vestibular schwannoma in appropriately selected elderly patients is appropriate and safe, given adequate consideration to risk-benefit analysis and goals of care.

Effect of Surgical Start Time on Stapedotomy Outcomes.

OBJECTIVE: To examine if performing stapedotomy as the first case of the day provides improved outcomes compared with those performed later in the day. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into either a first case group or a later case group based on surgical start time. Audiologic outcomes and complications were compared between the two groups. RESULTS: The first case group had a smaller postoperative air-bone gap (ABG) compared with the later case group of 9.81 dB HL compared with 11.73dB HL and 3.79 dB HL compared with 6.29 dB HL at 1000 and 2000 Hz, respectively (p = 0.03, p < 0.01). The mean postoperative ABG was 10.63 dB HL for the first start group compared with 12.12 dB HL for the later start group, which was statistically significant (p = 0.05). CONCLUSIONS: First start stapedotomy is associated with slightly improved audiologic outcomes compared with those starting later in the day, although both groups had significantly improved postoperative outcomes overall. There was no significant difference in complications when comparing stapedotomy by case start time.

Early Outcomes of Simultaneous Translabyrinthine Resection and Cochlear Implantation.

OBJECTIVES/HYPOTHESIS: Hearing rehabilitation after translabyrinthine resection of a vestibular schwannoma (VS) has largely been based on the transfer of acoustic stimulus to the contralateral ear, typically through a contralateral routing of signal hearing aid or bone-anchored hearing aid (BAHA). Cochlear implant, either as a subsequent surgery or simultaneously, has become a more common treatment option; however, there is still relatively limited data available on its success. The purpose of this study is to evaluate the early outcomes of simultaneous cochlear implantation in patients with sporadic VS undergoing translabyrinthine resection. STUDY DESIGN: Prospective, nonrandomized study. METHODS: A prospective study of nonrandomized patients was completed at a tertiary care neurotology center. Audiologic outcomes, primarily based on AzBIO in quiet and background noise, as well as consonant-nucleus-consonant (CNC) testing of the affected ears were utilized. Tinnitus, dizziness, and spatial hearing questionnaries were also completed. Audiologic outcomes and questionnaires were compared between the pre- and postoperative groups. RESULTS: Ten patients were included in the study with 3 month follow-up data. There was statistically significant improvement in AzBO with +10 and +5 signal to noise ratio and in quiet, as well as in CNC testing (P < .05). There was a significant improvement in Tinnitus Handicap Inventory between the two groups. CONCLUSIONS: Simultaneous cochlear implantation is a viable treatment for hearing loss after translabyrinthine approach to VS. These patients have improved hearing in background noise and tinnitus compared to their preoperative state. Further prognostic data are required to determine which patients are the best candidates. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2312-E2317, 2021.

Is Menière's Disease a Contraindication to Stapedectomy?

OBJECTIVE: Review surgical outcomes of stapedectomy for otosclerosis in patients with Menierè's disease. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients with otosclerosis and Menière's disease undergoing stapedectomy between 2010 and 2017. INTERVENTION: Stapedectomy. MAIN OUTCOME MEASURES: Pre- and postoperative hearing and complications. Hearing was measured by air conduction (AC) and bone conduction (BC) pure-tone frequency, pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). RESULTS: Among 1,499 patients with otosclerosis, the incidence of concomitant Menière's disease was 1.7%. Fifteen patients with otosclerosis and Menière's disease underwent stapedectomy, 12 primary and three revisions. Mean AC PTA was 43 dB preoperatively, and 25 dB postoperatively (p = 0.0007), while the ABG improved on average from 20 to 5 dB (p = 0.0001). There was no significant difference in BC PTA or WRS postoperatively. Two patients experienced fluctuation of hearing in the postoperative period, one of which resolved with a course of steroids. The mean follow-up time was 41 months. CONCLUSIONS: In patients with otosclerosis and Menière's disease, stapedectomy provides excellent hearing outcomes in a majority of patients. As is characteristic of Menière's disease, some patients will continue to experience fluctuating hearing postoperatively, which may progress to severe sensorineural hearing loss. Menière's disease may not be an absolute contraindication to stapes surgery.

Outcomes After Tympanic Membrane Perforation During Primary Stapes Surgery for Otosclerosis.

OBJECTIVE/HYPOTHESIS: Stapes surgery is occasionally complicated by an intraoperative tympanic membrane perforation (ITMP), traditionally indicating abortion of the procedure due to concerns for postoperative infection and sensorineural hearing loss (SNHL). This work examines outcomes and complications in completed primary stapes surgeries with and without ITMP. STUDY DESIGN: Retrospective review. METHODS: All patients diagnosed with otosclerosis between February 2008 and September 2017 at a tertiary otology referral center were reviewed retrospectively. Primary outcome measures were post-operative air-bone gap (ABG), air conduction and bone conduction pure tone averages, and post-operative complications. RESULTS: Review revealed 652 primary stapes operations meeting inclusion criteria, of which ITMP occurred in 10. There were no significant differences in pre-operative hearing metrics or demographic characteristics between ears with and without ITMP. There were also no significant differences in post-operative ABG (6.4 vs. 8.0 dB HL, P = .43) or change in ABG after surgery (-21.6 vs. -18.2 dB, P = .34) between these two groups. Patients with ITMP were more likely to complain of post-operative dysgeusia (30.0% vs. 5.3%, P = .015) but were no more likely to develop reparative granuloma, otitis media, or SNHL (P > .05). CONCLUSIONS: The first review of ITMP and hearing outcomes after stapes surgery is presented. Our findings suggest that it is likely safe and appropriate to proceed with primary stapes surgery and concurrent tympanoplasty in the presence of a small ITMP with minimal risk of infection, SNHL, or worsened hearing outcomes. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2026-E2030, 2021.

Pre-existing Vestibular Symptoms Are Associated With Acute Vestibular Symptoms After Gamma Knife Therapy for Vestibular Schwannoma.

OBJECTIVE: To identify pretreatment variables associated with the development of acute vestibular symptoms after Gamma Knife (GK) treatment for Vestibular Schwannoma (VS). STUDY DESIGN: Retrospective case series. SETTING: Tertiary neurotology referral center. PATIENTS: Patients treated with GK radiosurgery for VS between March 2007 and March 2017 were considered for this study. Patients with neurofibromatosis type II, previous VS surgery, follow-up less than 6 months, or the lack of T2 magnetic resonance imaging (MRI) sequences from the day of treatment were excluded. MAIN OUTCOME MEASURES: The presence of acute vestibular symptoms arising within 6 months after GK was the main outcome variable. Tumor, patient, and treatment characteristics were gathered from the medical record. RESULTS: In total, 98 patients met inclusion criteria. The incidence of acute vestibular symptoms occurring within 6 months after GK treatment was 46.9%. Post-GK vestibular symptoms were reported at a significantly higher frequency among subjects who had reported vestibular symptoms before their treatment (p = 0.001). Tumor size was not associated with a propensity to develop acute vestibular symptoms (p = 0.397). The likelihood of receiving a referral to vestibular rehabilitation services was not significantly different among patients with larger versus smaller tumor size, as defined by 1.6 cm and 1.4 cm thresholds (p = 0.896, p = 0.654). CONCLUSIONS: Inquiries aimed at revealing a history of vestibular complaints may prove useful in counseling patients on the likelihood of experiencing acute vestibular symptoms after treatment of Vestibular Schwannoma with Gamma Knife therapy.