Role of the neurotologist in posterior fossa meningioma surgery.

Posterior fossa meningiomas that impinge on structures of the temporal bone or clivus may be difficult to access for optimal resection that maximizes tumor control and minimizes short- and long-term morbidities. To address this challenge, the contemporary neurosurgery-neurotology team works collaboratively by managing patients jointly at every stage of care: preoperative evaluation, intraoperative intervention, and postoperative treatment. The neurotologist is important at all stages of posterior fossa meningioma surgery. First, detailed preoperative evaluation of auditory, facial, vestibular, and lower cranial nerve integrity enables assessment of new neurologic deficit risk, prognosis of functional recovery, and pros and cons of candidate surgical approaches. Second, intraoperative partitioning of surgical steps by provider and adopting an overlapping tumor resection philosophy creates an efficient and confident surgical team built on trust. Third, postoperative closure of cerebrospinal fluid leak and treatment of facial weakness, audiovestibular dysfunction, and voicing and swallowing impairments organized by the neurotologist reduces the impact of negative outcomes. The role of the neurotologist in posterior fossa meningioma surgery is to deliver nuanced evaluative metrics, facilitate shared decision making, perform precise bone and soft tissue microsurgery, and mitigate perioperative morbidities.

Corticostriatal functional connectivity of bothersome tinnitus in single-sided deafness.

Subjective tinnitus is an auditory phantom perceptual disorder without an objective biomarker. Bothersome tinnitus in single-sided deafness (SSD) is particularly challenging to treat because the deaf ear can no longer be stimulated by acoustic means. We contrasted an SSD cohort with bothersome tinnitus (TIN; N = 15) against an SSD cohort with no or non-bothersome tinnitus (NO TIN; N = 15) using resting-state functional magnetic resonance imaging (fMRI). All study participants had normal hearing in one ear and severe or profound hearing loss in the other. We evaluated corticostriatal functional connectivity differences by placing seeds in the caudate nucleus and Heschl's Gyrus (HG) of both hemispheres. The TIN cohort showed increased functional connectivity between the left caudate and left HG, and left and right HG and the left caudate. Within the TIN cohort, functional connectivity between the right caudate and cuneus was correlated with the Tinnitus Functional Index (TFI) relaxation subscale. And, functional connectivity between the right caudate and superior lateral occipital cortex, and the right caudate and anterior supramarginal gyrus were correlated with the TFI control subscale. These findings support a striatal gating model of tinnitus and suggest tinnitus biomarkers to monitor treatment response and to target specific brain areas for innovative neuromodulation therapies.

Reducing Radiation Dose for High-resolution Flat-panel CT Imaging of Superior Semicircular Canal Dehiscence.

OBJECTIVE: High-resolution flat panel computed tomography (FPCT) is useful for the evaluation of temporal bone pathologies. While radiation exposure remains a concern, efforts have been devoted to reduce dose, while maintaining image quality. We hypothesize that removing the antiscatter grid (ASG) results in decreased radiation exposure, while maintaining diagnostic image quality for the evaluation of superior semicircular canal dehiscence (SSCD). METHODS: Ten patients with clinical suspicion for SSCD participated in this prospective study. Two sequential collimated 20-second FPCT acquisitions were performed (first: grid in; second: grid removed) in all patients. Secondary reconstructions were created by manually generating the volume of interest to include the middle ear using a voxel size of 0.1 mm and 512 × 512 matrix. Radiation dose parameters (air kerma (Ka,r) in mGy and dose area product (DAP) in µGym) were recorded. Three reviewers analyzed images for the ability to diagnose SSCD, to identify the stapes crurae, and to determine if an ASG was present. RESULTS: The average Ka,r and DAP for the grid-in acquisitions were 246.7 mGy (SD 47.9) and 2838.0 µGym (SD 862.8), versus 160.2 mGy (SD 33.2) and 2026.3 µGym (SD 644.8) for the grid-out acquisitions, respectively (p<0.001 for both Ka,r and DAP). Radiation exposure was reduced by approximately 30% solely by removing the ASG. All reviewers correctly identified all patients with SSCD (confirmed at surgery), with mean AUC of 0.99 (κ = 0.90). CONCLUSION: Removing the antiscatter grid during FPCT imaging of the temporal bones is a simple and effective way to reduce radiation exposure while maintaining diagnostic image quality for the evaluation of SSCD.

A Prospective Study of Pain From Magnetic Resonance Imaging With Cochlear Implant Magnets In Situ.

OBJECTIVE: To describe changes in pain associated with magnetic resonance imaging (MRI) with cochlear implant magnets in place. STUDY DESIGN: Prospective, single-arm study. SETTING: Tertiary referral center. SUBJECTS: Adults with cochlear implants requiring MRI. INTERVENTION: Tight head wrapping over internal device during MRI. MAIN OUTCOME MEASURES: Change in pain score using an 11-point visual analogue scale, duration/completion of MRI, body mass index (BMI), quality of pain, status of the skin, functioning of implant, displacement/polarity change of magnet, willingness to repeat MRI without magnet removal. RESULTS: A total of 27 subjects obtained 42 MRI scans. Subjects were 59% male with age range of 21 to 80 years. All three manufacturers were represented. Forty-eight percent of scans imaged the brain/head while 52% imaged other sites. The mean individual change in pain was 3.9 (SD 3.5, range 0-10). The pain was most commonly described as "pressure", "heat", or "sharp". There was no significant correlation between change in pain and scan duration, BMI, or body part imaged. Eighty-eight percent of the scans were completed. There were no skin complications except temporary erythema (29%) and there were no magnet/device complications. Eighty-eight percent said they would undergo MRI without magnet removal again. CONCLUSION: The pain associated with obtaining an MRI without cochlear implant magnet removal is highly variable. Increase in pain is not related to duration of MRI scan, body part imaged, or BMI. Despite the pain, almost all patients prefer MRI scanning with the magnet in place, to avoid two surgical procedures.

Long-Term Patient-Reported Outcomes After Surgery for Superior Canal Dehiscence Syndrome.

OBJECTIVE: Evaluate the long-term patient-reported outcomes of surgery for superior canal dehiscence syndrome (SCDS). STUDY DESIGN: Cross-sectional survey. SETTING: Tertiary referral center. PATIENTS: Adults who have undergone surgery for SCDS with at least 1 year since surgery. MAIN OUTCOME MEASURE(S): Primary outcome: change in symptoms that led to surgery. SECONDARY OUTCOMES: change in 11 SCDS-associated symptoms, change in psychosocial metrics, and willingness to recommend surgery to friends with SCDS. RESULTS: Ninety-three (43%) respondents completed the survey with mean (SD) time since surgery of 5.3 (3.6) years. Ninety-five percent of respondents reported the symptoms that led them to have surgery were "somewhat better," "much better," or "completely cured." Those with unilateral symptoms were more likely to report improvement than those with bilateral symptoms. There was no difference between those with short (1-5 yr) versus long (5-20 yr) follow-up. Each of the SCDS-associated symptoms showed significant improvement. The largest improvements were for autophony, pulsatile tinnitus, audible bodily sounds, and sensitivity to loud sound. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Most patients reported improvements in quality of life, mood, and ability to function at work and socially. Ninety-five percent of patients would recommend SCDS surgery. CONCLUSIONS: Respondents demonstrated durable improvements in the symptoms that led them to have surgery. Auditory symptoms had the greatest improvements. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Nearly, all patients would recommend SCDS surgery to others. These results can be used to counsel patients regarding the lasting benefits of surgery for SCDS.

Spontaneous Intracranial Hypotension after Vestibular Schwannoma Resection Due to an Unexpected Pathology: Tarlov Cysts.

While infrequent, cerebrospinal fluid (CSF) leaks are known to occur after surgical resection of vestibular schwannomas. Early signs of CSF leak often include headache and altered mental status. If untreated, life-threatening complications can occur, including brainstem herniation and meningitis. The appropriate surgical treatment for a CSF leak requires accurate localization of the source. While the most likely location of a CSF leak after lateral skull base surgery is through the aerated portions of the temporal bone, we present a unique case of a man with a prolonged CSF leak after an acoustic tumor removal who was ultimately found to have an occult spinal perineural (Tarlov) cyst as the source. Accurate localization was ultimately achieved with CT myelogram after empirically obliterating his mastoid failed to restore intracranial CSF volume. Tarlov cysts are the most common cause of idiopathic intracranial hypotension, and this case highlights the importance of considering this entity in the differential diagnosis of postoperative CSF leaks.

Surgical Complications from Superior Canal Dehiscence Syndrome Repair: Two Decades of Experience.

Objective To determine the incidence of surgical complications associated with superior canal dehiscence syndrome (SCDS) repair and identify the demographic, medical, and intraoperative risk factors that are associated with SCDS complications. Study Design Cases series with chart review, including patients who underwent SCDS repair between 1996 and 2015. Setting A tertiary care academic medical center. Subjects and Methods Data were collected from 220 patients, including demographic information, medical comorbidities, prior otologic surgical history, surgical approach, intraoperative findings, and postoperative complications. Relative risk analysis and multivariable logistic regression evaluated the associations between perioperative risk factors and SCDS complications. Results A total of 242 consecutive cases were performed: 95.5% middle fossa and 4.5% transmastoid approach (mean age: 47.8 ± 10.6 years; 54.5% female). Surgical complications were reported in 27 (11.2%) cases; 20 (8.3%) had Clavien-Dindo grade I complications, most commonly benign paroxysmal positional vertigo (n = 11, 4.5%) and profound sensorineural hearing loss (n = 6, 2.5%). Two cases (0.8%) had grade II; 4 cases (1.7%), grade III; and 1 case (0.4%), grade IV complications. In the analysis of comorbidities, only preoperative coagulopathy was significantly associated with increased risk of complications (relative risk = 6.4, P < .01). Following multivariate logistic regression adjusting for demographic covariates, coagulopathy was still associated with increased odds of complications (odds ratio = 15.7, P = .03). There were no significant associations between other risk factors and complications. Conclusion SCDS repair has low rates of adverse events. We observed an incidence of 11.2% complications, most commonly postoperative benign paroxysmal positional vertigo. The risk of nonotologic intracranial complications (1.7%) is low.

Intratympanic (IT) Therapies for Menière's Disease: Some Consensus Among the Confusion.

PURPOSE OF REVIEW: Aminoglycosides and corticosteroids are commonly used to treat Menière's disease. Intratympanic (IT) administration of these medications allows high inner ear concentrations without significant adverse systemic effects. As a direct result, IT therapy has grown in popularity. Recent studies have compared patient outcomes between IT aminoglycosides and corticosteroids. This review summarizes these findings. RECENT FINDINGS: Trials comparing IT corticosteroids to IT placebo or oral therapy have had conflicting results. Most recently, Lambert et al. investigated the effect of IT dexamethasone in a sustained-release formulation compared to placebo. Their findings demonstrated improvement in some secondary measures of vertigo with the sustained-release formulation.IT gentamicin is known to be effective in controlling vertigo in Menière's disease. In a recent study from 2016, Patel et al compared IT gentamicin and IT methylprednisolone in a double-blind, randomized controlled trial and identified no significant differences between the two in vertigo control. SUMMARY: IT injections of aminoglycosides and corticosteroids can improve vertigo control. Hearing and vestibular loss however may result with IT aminoglycosides. Corticosteroids demonstrate limited hearing loss but may not have the same efficacy in controlling vertigo. Further investigation in the etiology of Menière's disease is needed to tailor the proposed treatment to suit the disease mechanism.

Multifactor Influences of Shared Decision-Making in Acoustic Neuroma Treatment.

OBJECTIVE: To identify factors associated with treatment modality selection in acoustic neuromas. STUDY DESIGN: Prospective observational study. SETTING: Tertiary care neurotology clinic. PATIENTS: Data were prospectively collected from patients initially presenting to a tertiary care neurotology clinic between 2013 and 2016. Patients who did not have magnetic resonance imaging (MRI), demographic, psychometric, or audiometric data were excluded from analysis. INTERVENTION: Demographic information, clinical symptoms, tumor characteristics, and psychometric data were collected to determine factors associated with undergoing acoustic neuroma surgical resection using univariate and multiple logistic regression analysis. MAIN OUTCOME MEASURE: The decision to pursue acoustic neuroma surgical resection versus active surveillance. RESULTS: A total of 216 patients with acoustic neuroma (mean age 55 years, 58% women) were included. Ninety eight patients (45.4%) pursued surgical resection, 118 patients (54.6%) pursued active surveillance. Surgical treatment was significantly associated with patient age less than 65, higher grade tumors, growing tumors, larger volume tumors, lower word discrimination scores, Class D hearing, headache, and vertigo as presenting symptoms, higher number of total symptoms, and higher headache severity scores (p < 0.05). There was no significant association between surgical intervention and preoperative quality of life, depression, and self-esteem scores. On multiple logistic regression analysis, the likelihood of undergoing surgical resection significantly decreased for patients older than age 65 (odds ratio [OR] 0.19; 0.05-0.69) and increased in patients with medium (OR 4.34; 1.36-13.81), moderately large (OR 33.47; 5.72-195.83), large grade tumors (OR 56.63; 4.02-518.93), tumor growth present (OR 4.51; 1.66-12.28), Class D hearing (OR 3.96; 1.29-12.16), and higher headache severity scores (OR 1.03; 95% confidence interval [CI] 1.01-1.05). The likelihood of undergoing surgical resection was completely predictive for giant grade tumors and not significant for small grade tumors and Class B or C hearing. CONCLUSIONS: Non-elderly acoustic neuroma patients with larger tumors, growing tumors, significant hearing loss, and worse headaches are more likely to pursue surgical resection rather than active surveillance. Psychological factors such as quality of life, depression, and self-esteem do not seem to influence decision-making in this patient population.

TeleAudiology in the Veterans Health Administration.

OBJECTIVE: To assess effectiveness of TeleAudiology for hearing aid services. STUDY DESIGN: Retrospective case-control. SETTING: Ambulatory Veterans Health Administration and Community-Based Outpatient Clinics (CBOCs). PATIENTS: 42,697 veterans who received hearing aids from January through September, 2014. INTERVENTION(S): TeleAudiology (TA) and conventional in-person (IP) audiology care. MAIN OUTCOME MEASURE(S): International Outcome Inventory for Hearing Aids (IOI-HA) outcomes data. The IOI-HA is a 7-item survey used to assess hearing aid effectiveness. Scored from 7 to 35 points, higher scores are more favorable. RESULTS: Among veterans nationwide who received hearing aids and completed the IOI-HA survey, 1,009 received TA and 41,688 received IP care. TA and IP groups have comparable mean IOI-HA values (TA = 29.6, SD = 3.9; IP = 28.7, SD = 4.2). Although comparison showed a statistically significant difference (p < 0.0001, t test), principally because of large sample size, the distinction is not clinically meaningful.Subgroup analysis of veterans from San Francisco and six affiliated CBOCs showed 169 received TA and 338 received IP care. TA and IP groups have similar mean age (TA = 74, SD = 9.8; IP = 76, SD = 10.3) and sex distribution (TA male = 100%; IP male = 96%) with statistically significant (p < 0.01, t test) but clinically insignificant differences. Mean IOI-HA scores (TA = 30.7, SD = 3.6; IP = 30.5, SD = 3.1) are not different between groups (p > 0.05, t test). CONCLUSION: TA and IP encounters to provide hearing aid services to veterans are comparable, as both are highly effective based on IOI-HA results. The noninferiority of TA suggests its adoption to non-veterans may improve access while preserving high satisfaction. Financial impact of migration to TA will require future econometric analysis.

Revision Surgery for Superior Canal Dehiscence Syndrome.

OBJECTIVE: To identify factors associated with surgical failure for superior canal dehiscence syndrome (SCDS) and define rates of complications and cure after revision SCDS repair. STUDY DESIGN: Retrospective patient series. SETTING: Tertiary care referral center. PATIENTS: Adults who underwent revision surgery for SCDS. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Initial surgical approach, intraoperative findings at the time of revision, persistence of symptoms, and complications for revision surgery. RESULTS: Two hundred twenty-two surgical SCDS patients were identified, including 21 subjects who underwent 23 revision surgeries. Fourteen (61%) underwent previous middle fossa and nine (39%) underwent previous transmastoid approaches. Intraoperative findings showed that in 17 (74%) the previous material used to plug or resurface the canal was present but not entirely covering the dehiscence. In one (4%) the material was not present. In one (4%) the material was in proper position, whereas in four (17%) the material was in proper position with very thin bone adjacent. After revision surgery, symptoms were completely resolved in eight (35%), partially resolved in seven (30%), and not resolved in seven (30%). Findings of thin bone adjacent to the previous plug was associated with failure of symptom resolution (p = 0.03). Hearing outcomes were compared to a previously studied cohort of primary surgery patients, and outcomes were similar. Three subjects (13%) had a significant decrease in their word recognition score after revision surgery (p=0.52), and seven (30%) had a significant increase in their pure-tone average (p=0.78). CONCLUSION: Revision surgery for SCDS can be curative in carefully selected patients, but there may be a higher failure rate than primary surgery, with similar hearing outcomes.

Spatial plasticity of the auditory cortex in single-sided deafness.

OBJECTIVES/HYPOTHESIS: To evaluate spatial plasticity of the auditory cortex in single-sided deafness (SSD). STUDY DESIGN: Cross-sectional study comparing a cohort with adult-onset, idiopathic SSD to a cohort with normal hearing. METHODS: Demographic, audiometric, magnetoencephalographic imaging, and magnetic resonance imaging data were collected for 13 SSD adult subjects and 13 normal-hearing controls. Locations of peak activation corresponding to the M100 response in auditory cortices ipsilateral and contralateral to tonal stimuli (0.5 kHz and 4 kHz) were extracted from advanced biomagnetic source imaging analyses. Spatial extent of frequency representation across the 0.5 kHz to 4 kHz zone was computed for the two hemispheres. RESULTS: Spatial separation distance between peak locations for 0.5 kHz and 4 kHz stimuli in SSD showed increased activation spread distance in the hemisphere contralateral to the only hearing ear and decreased distance in the ipsilateral hemisphere. In contrast, normal hearing controls had nearly the same activation spread distance in the two hemispheres for ipsilateral and contralateral inputs. The difference between interhemispheric activation spread distance in SSD is significantly increased to 6.5 mm, when compared to 1.7 mm in normal controls (P < .05). CONCLUSIONS: Loss of unilateral peripheral input in SSD is associated with spatial reorganization of the auditory cortex in both hemispheres. This change in central auditory functional organization may in turn lead to higher order hearing deficits that rely on interhemispheric processing. Hearing optimization in the only hearing ear may require remediation of both spatial and temporal central auditory changes in SSD. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2785-2791, 2016.

Tinnitus following treatment for sporadic Acoustic neuroma.

OBJECTIVES/HYPOTHESIS: To evaluate the impact of treatment modality, tumor size, time from therapy, and demographic features on tinnitus distress, as measured by the Tinnitus Functional Index (TFI) in patients treated for sporadic acoustic neuroma. STUDY DESIGN: Cross-sectional observation study. METHODS: A Web-based 44-question online survey was made available on the Acoustic Neuroma Association Web site for 3 months. Of 154 unique surveys that were completed in entirety, further screening netted 143 study participants. Questions included the TFI, treatment modality, tumor size, time from therapy, demographic features, and hearing status of both ears. RESULTS: Tinnitus distress following treatment for acoustic neuroma is independent of treatment type, tumor size, tumor laterality, time after treatment, age, and gender. Tinnitus Functional Index scores closely mirror severity profile of the study population as reported in the pivotal TFI instrument validation study by Meikle et al.(17) Tinnitus is "not a problem" in 20% of respondents, a "small problem" in 20%, a "moderate problem" in 11%, a "big problem" in 22%, and a "very big problem" in 27%. Subscale analysis suggests that acoustic tumor patients struggle most with tinnitus intrusiveness and loss of control. CONCLUSIONS: Whereas tinnitus is a common symptom in acoustic neuroma patients in both the pre- and posttreatment settings, clinicians can provide counsel that choice of treatment modality, tumor size, age, and gender have little to no bearing on severity of posttreatment tinnitus distress. Tinnitus severity does not differ among the treatment choices of open microsurgery, stereotactic radiosurgery, external beam radiation, and observation. LEVEL OF EVIDENCE: NA Laryngoscope, 126:1639-1643, 2016.

Infectious complications and ventilation tubes in pediatric cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: At many centers, ventilating tubes (VTs) are placed routinely in otitis-prone pediatric cochlear implant recipients. However, this practice is controversial, as many otologists believe VTs represent a possible route for contamination of the device. Toward better understanding of the safety of VTs, we reviewed our center's infectious complications and their relationship to the presence of tubes. STUDY DESIGN: Retrospective cohort study. METHODS: All patients undergoing cochlear implantation at our institution between 1990 and 2012 were reviewed for complications and their association with the presence of VTs. RESULTS: A total of 478 patients (557 ears) were reviewed, representing over 2,978 patient-years of follow-up. In 135 ears (24.2%), a VT was present at time of, or placed at some point after, implantation. The remainder either never had a VT or it had extruded prior to implantation. Overall, 63 complications occurred, of which 17 were infectious. The most common were cellulitis (four), device infection (five), and meningitis (four). Only one occurred while a tube was present, and was a device infection in an ear having a retained VT in place for almost 4 years. No difference was observed in overall rates of infectious complications between the group with VTs and those who never had VTs. CONCLUSIONS: This series, the largest to date, indicates that infectious complications after cochlear implantation are rarely associated with the presence of VTs, supporting the concept that, overall, VTs are safe in cochlear implant recipients. Close monitoring is essential, including prompt removal of tubes when they are no longer needed. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:1671-1676, 2016.

Temporal Cortical Plasticity in Single-Sided Deafness: A Functional Imaging Study.

HYPOTHESIS: To refine and extend the knowledge on cortical plasticity in single-sided deafness (SSD) by assessing magnetoencephalographic imaging in a well-defined group of subjects. BACKGROUND: SSD causes difficulties with directional hearing, signal extraction in noise, and multispeaker identification and separation. In SSD, the ipsilateral auditory cortex is never powerfully driven by sound, which may lead to plastic change and contribute to higher-order psychoacoustic dysfunction beyond loss of a peripheral sound sensor. STUDY DESIGN: A cross-sectional study on 12 subjects with long-term, adult-onset, nontraumatic SSD and 12 normal-hearing controls was conducted using magnetoencephalographic imaging, magnetic resonance imaging, and validated hearing instruments. Pure-tone stimuli at five frequencies were presented to each hearing ear individually. M100 activation peak times of the ipsilateral and contralateral auditory cortices were analyzed. RESULTS: Controls showed an M100 interhemispheric mean latency difference of 6.6 milliseconds. In contrast, subjects with SSD exhibited a mean of 1.7 milliseconds. This loss of interhemispheric latency difference was statistically significant (p < 0.05, analysis of variance with repeated measures). SSD subjects confirmed degraded hearing function on both Hearing Handicap Inventory for Adults (p < 0.001) and Speech, Spatial, and Qualities of Hearing Scale instruments (p < 0.001). CONCLUSION: SSD disrupts M100 latency difference between the two hemispheres to sound stimulation. This finding may represent maladaptive temporal cortical plasticity because of loss of a peripheral sensor. Based on this premise, a new generation of neurophysiologically inspired auditory treatments to correct or mitigate central consequences of SSD may be considered to optimize hearing in individuals with only one functional ear.

Willingness-to-accept Gamma knife radiosurgery for tinnitus among career San Francisco firefighters.

OBJECTIVE: Measure willingness-to-accept novel Gamma knife (GK) radiosurgery of the caudate nucleus to treat tinnitus among career firefighters who are at higher risk of hearing loss because of occupational noise exposure. STUDY DESIGN: Cross-sectional survey. MATERIALS AND METHODS: A Web-based 80-item survey was distributed to 800 San Francisco firefighters and satisfactorily completed by 101 respondents. Demographic and work-related characteristics including occupational noise exposure, hearing handicap using the Hearing Handicap Inventory for Adults (HHIA), and tinnitus severity using the tinnitus functional index (TFI) were assessed. Willingness-to-accept GK radiosurgery for tinnitus was profiled using a 7-point scale for 6 decremental levels of expected tinnitus improvement. RESULTS: Respondents were a majority male (82%) and Caucasian (56%). Nearly all (95%) reported significant daily or weekly occupational noise exposure. Mean HHIA (16.3) and mean TFI (14.6) were mild. At the 100% (complete) tinnitus improvement level, more than 60% of respondents were "likely" willing-to-accept Gamma knife radiosurgery. At the 75% tinnitus improvement level, 43% of respondents were "likely" willing-to-accept GK radiosurgery. Below the 75% tinnitus improvement level, willingness-to-accept dropped off steeply. CONCLUSION: Gamma knife radiosurgery to area LC, a locus of the caudate nucleus, for tinnitus would be of interest to a large population with moderate or lower tinnitus distress. Should this innovative intervention be considered in the future, a rigorous clinical trial will be necessary to establish safety and efficacy.