MRI surveillance after translabyrinthine vestibular schwannoma resection and cochlear implantation: is it feasible?

PURPOSE: Cochlear implantation in patients with vestibular schwannomas is of increasing importance and interest. Two remaining challenges are the assessment of conduction of the cochlear nerve and the possibility of postoperative surveillance with magnetic resonance imaging. The aim of the current study was to assess follow-up imaging and determine the visibility of the internal auditory canal after vestibular schwannoma resection and cochlear implantation as well as in patients with persistent vestibular schwannomas and cochlear implants in place. Visibility of the internal auditory canal, cerebellopontine angle, and labyrinth were evaluated and graded. METHODS: For this retrospective study, 15 MR examinations of 13 patients after translabyrinthine vestibular schwannoma resection and ipsilateral cochlear implantation were included. All patients had been implanted with an MED-EL cochlear implant. Magnetic resonance imaging was carried out on a 1.5T device. All patients were prepped according to the manufacturer's recommendations. RESULTS: All 15 examinations were carried out without any adverse event during imaging, such as pain, magnet dislocation, or malfunction. The internal auditory canal and the cerebellopontine angle were sufficiently visible in all cases to allow for vestibular schwannoma follow-up. CONCLUSION: Magnetic resonance imaging surveillance of the internal auditory canal following vestibular schwannoma resection and cochlear implantation is feasible and safe with modern implants with a 1.5T magnetic resonance imaging device using metal artifact reduction sequences. Necessary follow-up imaging should not be a contraindication for cochlear implantation in patients with vestibular schwannomas.

The Functional Hearing Gain with an Active Transcutaneous Bone Conduction Implant Does Not Correlate with the Subjective Hearing Performance.

The functional hearing outcome with hearing implants does not always properly reflect the subjective benefit in everyday listening situations. In this study, the functional hearing gain and the impact on the subjective hearing ability and quality of life were assessed in patients with a Bonebridge. A chart review was performed on 45 patients with a Bonebridge who were provided with questionnaires regarding the hearing quality and health-related quality of life during their last clinical visit. The questionnaires consisted of the Speech, Spatial and Qualities (SSQ) and the Health Utility Index Mark 3 (HUI3). Eleven patients had to be excluded due to missing data. A total of 34 patients (37 ears) were included in the study. Aided hearing thresholds were significantly lower compared with the unaided condition, with a mean functional gain of 26.87 dB for patients with mixed/conductive hearing loss (MHL/CHL). Although patients with single-sided deafness (SSD) scored slightly lower on the SSQ compared with patients with MHL/CHL, all included patients reported improved subjective hearing quality with the BB compared with the hearing situation before implantation. No correlation was found between the functional hearing gain and the subdomains of the SSQ. SSD patients scored the HUI3 subdomain "hearing" slightly lower compared with MHL/CHL patients. Although not significant, a relationship was found between the functional gain and the "hearing" subdomain. No correlation was found for the other subdomains of the HUI3. Audiological measurements showed significantly improved hearing thresholds with the Bonebridge. Most importantly, the subjective benefit achieved in everyday listening situations was superior compared with the previous hearing condition. The lack of correlation between subjective questionnaire results and the functional hearing gain shows the importance of assessing both audiological and subjective hearing quality parameters in clinical routine.

Triamcinolone acetonide can be detected in cerebrospinal fluid after intratympanic injection.

Intratympanically applied treatments are of increasing interest to the otologic community to treat sudden sensorineural hearing loss or vestibular disorders but also to deliver gene therapy agents, or biologics to the inner ear. Further diversion from the middle ear and perilymph to blood circulation and cerebrospinal fluid via the cochlear aqueduct are one of the limiting factors and so far not understood well enough. In this study, intratympanically applied triamcinolone acetonide was determined in cerebrospinal fluid. Additionally, perilymph was sampled through the round window membrane as well as at the lateral semicircular canal to determine drug levels. Of the twenty-one included patients, triamcinolone acetonide was quantifiable in cerebrospinal fluid in 43% at very low levels (range 0 ng/ml-6.2 ng/ml) which did not correlate with perilymph levels. Drug levels at the two different perilymph sampling sites were within a range of 13.5 ng/ml to 1180.0 ng/ml. Results suggest an equal distribution of triamcinolone acetonide to semicircular canals, which might support the use of triamcinolone acetonide as a treatment option for vestibular pathologies such as Menièrés disease. On the other hand, the distribution to cerebrospinal fluid might be limiting current approaches in gene therapy where a central distribution is unwanted.

Current management of skull base osteomyelitis.

PURPOSE OF REVIEW: Skull base osteomyelitis (SBO) is a life-threatening condition. Due to an aging and increasingly multimorbid population, clinicians are more often challenged with this disease. Yet, there is no consensus on the optimal diagnostic and follow-up management. This review should aid clinicians in decision-making for their patients. RECENT FINDINGS: Treatment-resistant otalgia or headache is suspicious of SBO. Pseudomonas aeruginosa remains the most common pathogen but clinicians are challenged with increasing rates of sterile or fungal cultures due to previously applied antibiotics/steroids. No single imaging modality is able to detect the full extent of the disease. Whereas functional nuclear imaging with gallium-67 or methylene diphosphonate-technetium-99m was once advocated, its actual benefit is questionable. Newer modalities such as fluoro-D-glucose-positron emission tomography (PET)/computed tomography, PET/magnetic resonance imaging (MRI), or diffusion-weighted MRI seem to be promising in diagnosis and follow-up. Finding the causative pathogen is of utmost importance followed by long-term intravenous antibiotics until the disease has completely resolved. Surgery plays a minor role in treatment but can be helpful in selected cases. SUMMARY: The numerous challenges in SBO render management difficult, but with a clear work-up including regular clinical, laboratory and imaging examinations, outcome can be improved.

Titanium and Platinum-Fluoroplastic Stapes Prostheses Visualization on Cone Beam Computed Tomography and High-Resolution Computed Tomography.

Objective: The aim of this study was to evaluate whether stapes prostheses can be visualized with less metal artifacts and therefore more accurately on cone beam computed tomography in comparison to computed tomography imaging. Recent studies have shown that cone beam computed tomography has advantages when imaging metal artifacts. Patients with hearing loss or vertigo, who have undergone stapedotomy, often present a challenge for otologic surgeons. Imaging studies can deliver crucial additional information. Methods: A retrospective analysis of imaging studies and clinical data in a tertiary care center were carried out. Forty-one patients with forty-five implanted ears were evaluated in the study. All included patients had been implanted with a platinum-fluoroplastic (n = 19) or titanium (n = 26) piston and subsequently had undergone imaging months or years after surgery for various reasons. Patients underwent computed tomography or cone beam computed tomography of the temporal bone depending on availability. Piston visualization, prosthesis length, vestibular intrusion and audiologic results were compared between the groups. Piston position on imaging studies were compared to intraoperative findings. Results: Functional length measurements of all prostheses were carried out with a mean error of -0.17 mm (±0.20). Platinum-fluoroplastic protheses were significantly underestimated in length compared to titanium prostheses. To analyze the material-dependent difference in the measurement errors of the imaging techniques the interaction was tested in an ANOVA model and showed no statistically significant result (p = 0.24). The blinded neuroradiologist viewed two implants, both platinum-fluoroplastic pistons, as located outside of the vestibule due to an underestimation of the prothesis length and the missing radiodensity of the lower end of the prosthesis. Conclusion: Surgeons and radiologists should be aware of the different types and radiologic features of stapes prostheses and the missing radiodensity of some protheses parts. Cone beam computed tomography is an imaging alternative with a potential advantage of reduced radiation in patients after stapes surgery suffering from vertigo or hearing loss to evaluate piston position.

Performance With an Adhesive Bone Conduction Device in Active Transcutaneous Bone Conduction Implant Users.

OBJECTIVES: The aim of this study was to evaluate the performance and limits of an adhesive bone conduction hearing aid in patients implanted with an active transcutaneous bone conduction implant. Therefore, hearing performance and subjective benefit of patients with mixed and conductive hearing loss were assessed with both bone conduction devices. STUDY DESIGN AND PATIENTS: This cohort study was conducted at a tertiary care center. Fifteen subjects, who had been implanted with an active transcutaneous device previously, were included and used the adhesive hearing device for 3 weeks instead of the implant. Subjects underwent two sets of audiological tests as well as assessments of quality of life at the beginning and at the end of the testing period. RESULTS: Audiological results showed a significantly greater improvement in regards to functional hearing gain and word recognition scores with the transcutaneous bone conduction device than the nonimplantable adhesive device. Regression analysis showed a trend toward greater improvement with the transcutaneous device compared with the adhesive device in patients with an increasing bone conduction threshold. Hearing-specific and general quality-of-life questionnaires revealed no significant difference between the two devices. CONCLUSION: Patients with mixed or conductive hearing loss experience hearing gain with both, the adhesive device and the active transcutaneous device. The adhesive device may be a valuable alternative to the active transcutaneous device, depending on the individual bone conduction threshold.

The challenging diagnosis and follow-up of skull base osteomyelitis in clinical practice.

PURPOSE: The disease activity of skull base osteomyelitis can be challenging to assess by means of conventional imaging methods and renders monitoring of the disease difficult, especially in areas with restricted access to nuclear medicine imaging. Here, we provide clinically relevant data on the management of skull base osteomyelitis including assessment, treatment, and follow-up strategies with regards to the role of imaging. METHOD: A chart review was performed including 30 patients treated for SBO from 1993 to 2015. Clinical findings, treatment procedures, and complication rates were assessed. Special attention was paid to imaging procedures. RESULTS: The overall mortality rate was 36.7% and increased to 45% when cranial nerve palsies were present. An initial computed tomography (CT) scan was performed in all patients, MRI in 60% and nuclear imaging in 33%. CT scans failed to detect progression or regression in up to 80% after four to nine months. MRI examinations could reveal changes at a higher rate compared to CT. Nuclear medicine functional imaging was most likely to assess disease activity. CONCLUSION: A combination of different imaging modalities is recommended for diagnosing SBO. For the follow-up, MRI is preferable to CT as changes can be detected more readily with MRI. If available, nuclear medicine imaging should guide the decision of treatment discontinuation.

Long-term impact of olfactory dysfunction on daily life.

BACKGROUND: Olfactory dysfunction (OD) is common in the general population, affects the quality of life (QoL), and is suspected to cause depression. Long-term outcome data are lacking and there is a need to improve patient counselling regarding prognosis. We aimed to assess subjective long-term recovery rates, the QoL, and mood disturbance in a group of 65 patients, who were affected with OD. METHODS: Out of 325 patients treated for OD between 2003 and 2009 â€¯at a smell and taste clinic, 65 patients were included for a follow-up after an average of 8.6 years. A total of 28 patients answered questionnaires only and 37 patients were provided with an additional smell identification test. Among others, questionnaires included a short form of the World Health Organization quality of life questionnaire (WHOQOL-BREF) and the Beck's depression inventory. RESULTS: In the long run, subjective improvement was stated in 33.8% of all patients, with the highest rate of 42.3% in patients with postinfectious OD. The subjective rating of olfactory function on a visual analogue scale was significantly higher at study follow-up compared to first clinical contact (median 1.25 vs. 4.5; U = 469.5, p = 0.001), as were mean identification scores (6.0 ± 3.0 vs. 8.0 ± 4.0, t(18) = 2.51, p = 0.021). The QoL in general was considered reduced in 40% of all patients at follow-up. Furthermore, participants exhibited only minor, if any, depressive symptoms. CONCLUSION: Despite negative effects of OD on certain activities in daily life, such as cooking, detecting spoiled food, or personal hygiene, it seems that the patients included in this study adapted to the OD in the long-term. The current findings should aid clinicians in patient counselling.

Simultaneous Vestibular Schwannoma Resection and Cochlear Implantation Using Electrically Evoked Auditory Brainstem Response Audiometry for Decision-making.

OBJECTIVE: The aim of the study was to evaluate the predictive value regarding postoperative hearing benefit of electrically evoked auditory brainstem response audiometry in sporadic vestibular schwannoma patients undergoing simultaneous tumor resection and cochlear implantation. DESIGN: Patients were included in a prospective study conducted between October 2016 and January 2019. SETTING: The study was conducted at a tertiary care center. PARTICIPANTS: Subjects with unilateral sporadic vestibular schwannoma were screened for study participation. Patients underwent translabyrinthine vestibular schwannoma resection and cochlear implantation simultaneously. INTERVENTION: Electrically evoked brainstem response audiometry was performed during surgery before and after tumor removal using an intracochlear test electrode to objectively evaluate nerve conduction. MAIN OUTCOME MEASURE: Electrically evoked brainstem response audiometry results were correlated with postoperative sound field audiometry, word recognition tests, and speech reception thresholds. Quality of life was assessed before and 12 months after translabyrinthine tumor removal and cochlear implantation. RESULTS: Five patients, three male and two female, were included in the study and followed for at least 1 year after implantation. Three of the five patients are daily cochlear implant users with open set speech recognition. Two individuals with negative intraoperative electrically evoked auditory brainstem response results showed no auditory perception with cochlear implant. CONCLUSIONS: Simultaneous translabyrinthine vestibular schwannoma resection and cochlear implantation with intraoperative electrically evoked auditory brainstem response measurements is a feasible and promising option for sporadic vestibular schwannoma patients. Preservation of electrically evoked auditory brainstem responses seems to predict good subsequent hearing outcomes.

A Randomized Cross-over Trial Comparing a Pressure-free, Adhesive to a Conventional Bone Conduction Hearing Device.

OBJECTIVES: The main aim of this study was to compare the average daily wearing time of a conventional bone conduction device with a pressure-free, adhesive bone conduction device. Further, audiologic and quality-of-life outcome parameters were evaluated. METHODS: An academic, prospective, randomized cross-over trial was performed at a single center.Thirteen subjects between 12 and 63 years with conductive hearing loss were included.Average daily wearing time and subjective observations were assessed in a diary. Sound field audiometry, Freiburg monosyllables word test, and Oldenburg sentence test in quiet and in noise were carried out after 2 weeks of habituation to each device. AQoL-8D and SSQ-12 questionnaires were completed at baseline and after a 2-week test interval. RESULTS: Median wearing time of the devices was 8.1 hours (5.8-10.2 interquartile range) for the adhesive and 4.3 hours (2.7-7.1) for the conventional bone conduction device, the difference was statistically significant (p = 0.033). There were no statistically significant differences in sound field audiometry, Freiburg monosyllables word test, and Oldenburg sentence test when comparing the two devices. AQoL-8D and SSQ-12 showed a significant improvement with the devices in comparison with baseline, with no significant difference between devices in the total scores. Ten subjects reported pain using the conventional device, two subjects reported skin irritations using the adhesive device. CONCLUSION: For patients with mixed or conductive hearing loss, the adhesive device is a valuable alternative with a significantly longer daily wearing time.