Lower Four Cranial Nerves in the Management of Glomus Jugulare: Anatomical Study

Abstract Introduction The surgical management that achieves minimal morbidity and mortality for patients with glomus and non-glomus tumors involving the jugular foramen (JF) region requires a comprehensive understanding of the complex anatomy, anatomic variability, and pathological anatomy of this region. Objective The aim of this study is to propose a rational guideline to expose and preserve the lower cranial nerves (CNs) in the lateral approach of the JF. Methods The technique utilized is the gross and microdissection of 4 fixed cadaveric heads to revise the JF's surgical anatomy and high part of the carotid sheath compared with surgical cases to understand and preserve the integrity of lower CNs. The method involves radical mastoidectomy, microdissection of the JF, facial nerve, and high neck just below the carotid canal and the JF. The CNs IX, X, XI, and XII are microscopically dissected and kept in sight up to the JF. Results This study realized well the surgical and applied anatomy of the lower CNs with relation to the facial nerve and JF. Conclusions The JF anatomy is complicated, and the key to safely operate on it and preserving the lower CNs is to find the posterior belly of the digastric muscle, to skeletonize the facial nerve, to remove the mastoid tip preserving the stylomastoid foramen, to skeletonize the sigmoid sinus and posterior fossa dura not only anterior but also posteroinferior to reach and drill the jugular tubercle.

Lower Four Cranial Nerves in the Management of Glomus Jugulare: Anatomical Study.

Introduction The surgical management that achieves minimal morbidity and mortality for patients with glomus and non-glomus tumors involving the jugular foramen (JF) region requires a comprehensive understanding of the complex anatomy, anatomic variability, and pathological anatomy of this region. Objective The aim of this study is to propose a rational guideline to expose and preserve the lower cranial nerves (CNs) in the lateral approach of the JF. Methods The technique utilized is the gross and microdissection of 4 fixed cadaveric heads to revise the JF's surgical anatomy and high part of the carotid sheath compared with surgical cases to understand and preserve the integrity of lower CNs. The method involves radical mastoidectomy, microdissection of the JF, facial nerve, and high neck just below the carotid canal and the JF. The CNs IX, X, XI, and XII are microscopically dissected and kept in sight up to the JF. Results This study realized well the surgical and applied anatomy of the lower CNs with relation to the facial nerve and JF. Conclusions The JF anatomy is complicated, and the key to safely operate on it and preserving the lower CNs is to find the posterior belly of the digastric muscle, to skeletonize the facial nerve, to remove the mastoid tip preserving the stylomastoid foramen, to skeletonize the sigmoid sinus and posterior fossa dura not only anterior but also posteroinferior to reach and drill the jugular tubercle.

Transcutaneous Baha Attract system: Long-term outcomes of the French multicenter study.

BACKGROUND: Bone conduction implants based on abutment-driven acoustic transmission result in good hearing outcomes; however, skin complications impact the quality of life (QOL) and possibly the viability of the device for many patients. The transcutaneous magnetic Baha® Attract technology was developed with the goal of minimising skin complications. OBJECTIVES: To analyse surgical, auditory and QOL outcomes for patients implanted with the Baha® Attract. DESIGN: Prospective multicentre cohort study. SETTING: Four French tertiary referral centres. PARTICIPANTS: Thirty-two patients implanted with the Baha® Attract, including 25 with conductive and mixed hearing loss and 7 with single-sided deafness. MAIN OUTCOME MEASURES: Postoperative follow-up involved the visual analysis of soft tissue adaptation and sound processor magnet strength measurement. The audiometric outcomes were evaluated in quiet and noise, and the QOL was assessed using three different questionnaires. RESULTS: After 12 months of use, soft tissue was thinner, and mean magnet strength was significantly decreased (3.7-3.1, P < 0.05) relative to measures during surgery. The speech recognition threshold in quiet significantly improved compared to unaided situation (73-44 dB HL respectively, P < 0.001) as did functional gain in noise (+2.8). All QOL scores improved, and the APHAB questionnaire score correlated with the audiometric outcomes. CONCLUSIONS: The Baha® Attract technology results in significant hearing gain and improves QOL. Skin complications were not observed, although surgeons, audiologists and patients should be aware of soft tissue evolution during the first postoperative year. The reversibility of this implant is a major advantage that allows switching to another system if hearing degrades.

Multicenter evaluation of Neurelec Digisonic® SP cochlear implant reliability.

Over the past decade, the adoption of universal hearing screening in newborns has led to earlier detection of hearing problems and significant lowering of the age of first cochlear implantation. As a consequence, recipients are now expected to keep their cochlear implants (CIs) for a longer period of time. Comprehensive longitudinal information on CI reliability is essential for device choice. The aim of this study was to assess the reliability (in children and adults) of the latest generation of the Digisonic(®) SP CI launched in 2006 by Neurelec. Failure rate (FR) and cumulative survival rate (CSR) for a 5-year period were calculated. This survey is a multicenter retrospective study. A questionnaire was sent to nine CI centers requesting information about patients implanted with Neurelec Digisonic(®) SP CIs. FR and CSR over a 5-year period were calculated on this group. Collaborating centers collected data on 672 patients (362 children and 310 adults) implanted between March 2006 and March 2011. The overall rate of explantation was 2.23 % (15 cases): six devices were explanted due to device failure (0.89 %) and nine were explanted for medical reasons (1.34 %). Four patients were lost to follow-up. The CSR at 5 years was 98.51 % on all patients, 98.48 % for children and 98.57 % for adults. FR was 0.97 % for adults and 0.83 % for children. This first independent study that assesses FR and CSR on the current generation of Digisonic(®) SP CI represents an important resource that can help clinicians and patients during their device choice.

Static and dynamic posture control in postlingual cochlear implanted patients: effects of dual-tasking, visual and auditory inputs suppression.

Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body's position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral localization of the vestibular system, close to the cochlea, makes vestibular damage possible following cochlear implant (CI) surgery. Impaired vestibular function in CI patients, if any, may have a strong impact on posture stability. The simple postural task of quiet standing is generally paired with cognitive activity in most day life conditions, leading therefore to competition for attentional resources in dual-tasking, and increased risk of fall particularly in patients with impaired vestibular function. This study was aimed at evaluating the effects of postlingual cochlear implantation on posture control in adult deaf patients. Possible impairment of vestibular function was assessed by comparing the postural performance of patients to that of age-matched healthy subjects during a simple postural task performed in static (stable platform) and dynamic (platform in translation) conditions, and during dual-tasking with a visual or auditory memory task. Postural tests were done in eyes open (EO) and eyes closed (EC) conditions, with the CI activated (ON) or not (OFF). Results showed that the postural performance of the CI patients strongly differed from the controls, mainly in the EC condition. The CI patients showed significantly reduced limits of stability and increased postural instability in static conditions. In dynamic conditions, they spent considerably more energy to maintain equilibrium, and their head was stabilized neither in space nor on trunk: they behaved dynamically without vision like an inverted pendulum while the controls showed a whole body rigidification strategy. Hearing (prosthesis on) as well as dual-tasking did not really improve the dynamic postural performance of the CI patients. We conclude that CI patients become strongly visual dependent mainly in challenging postural conditions, a result they have to be awarded of particularly when getting older.

Cochlear implantation and contralateral auditory brainstem implantation.

OBJECTIVE: Report outcomes of 2 first known cases using a cochlear implant (CI) and a contralateral auditory brainstem implant (ABI). PATIENTS: Two adult patients with postlingual sensorineural deafness. INTERVENTION: Both patients had unilateral CI insertion followed by contralateral ABI insertion. In 1 case, there was a large left vestibular schwannoma in the only hearing left ear. CI insertion was first performed in the right longstanding deaf ear. Shortly afterward during the left translabyrinthine surgery, a left ABI was simultaneously inserted. The second patient had Ménière's disease controlled initially by right translabyrinthine vestibular neurectomy but complicated by a right dead ear. When symptoms recurred she underwent left retrosigmoid vestibular neurectomy with auditory nerve preservation. This allowed left CI insertion and a subsequent right ABI insertion. MAIN OUTCOME MEASURES: Pure tone audiometry (PTA), speech discrimination in quiet (SDq), speech discrimination in noise (SDn), and sound localization. Testing was performed with the following: 1) ABI activated alone, 2) CI activated alone, 3) CI and ABI activation (CI-ABI), and 4) CI linked to a contralateral routing of sound (CROS) hearing aid system (CI-CROS). Quality of life assessments were made using a validated questionnaire. RESULTS: PTA was worst with the ABI activated alone. SDq was best with the CI-CROS. Regarding SDn with noise coming from the CI side, the head shadow effect was only overcome by the CI-ABI; however, the CI-CROS worked best in the presence of noise opposite to the CI. The CI activated alone and CI-ABI produced useful sound localization. Quality-of-life assessments were best with the CI-CROS. CONCLUSION: Bilateral sound detection seems more beneficial than unilateral in profoundly deaf cases with only 1 functioning auditory nerve. A CI-CROS may produce similar gains to a CI-ABI.

Multicenter evaluation of the digisonic SP cochlear implant fixation system with titanium screws in 156 patients.

OBJECTIVES: We describe and evaluate the process of fixation of the Digisonic SP cochlear implant with two titanium screws. METHODS: The characteristics of this implant allow cochlear implantation using a minimal incision, a subperiosteal pocket, and fixation with two titanium screws, without drilling a custom-fitted seat or creating suture-retaining holes in the skull. The fixation system relies on two tailfins for use of osseo-integratable screws, incorporated into the cochlear implant housing. The first version of this fixation system was modified after a case of device migration: the size of the titanium insert inside the silicone tailfin was increased. Data on 156 patients (8 months to 86 years of age) from a 4-year period in 6 cochlear implantation centers were retrospectively evaluated. Ten patients have undergone bilateral implantation. RESULTS: Of 166 implantations, 4 postoperative infections and 1 device failure after head trauma were reported. No cerebrospinal fluid leaks or epidural hematomas were reported. One device migration was observed in the first series; no device migrations occurred in the second series. CONCLUSIONS: The fixation system with screws embedded in the Digisonic SP involves a fast and simple surgical technique that seems to efficiently prevent implant migration.

Speech perception performance for 100 post-lingually deaf adults fitted with Neurelec cochlear implants: Comparison between Digisonic® Convex and Digisonic® SP devices after a 1-year follow-up.

CONCLUSION: Patients implanted with the Digisonic® SP device showed better identification scores than those implanted with the Convex device, with skills continuing to improve over a longer time period. Technological improvements were beneficial in terms of speech perception in quiet. OBJECTIVE: To compare speech perception skills for post-lingually deaf patients implanted with a previous Neurelec device, the Digisonic® Convex, with those implanted with a more recent one, the Digisonic® SP, which provides more electrodes and a faster stimulation rate. METHODS: This was a retrospective study of 100 implanted patients, 45 with the Digisonic® Convex implant and 55 with the Digisonic® SP. Speech perception (dissyllabic words and sentences, in open set) was evaluated until 1 year after implantation. RESULTS: Patients fitted with the Digisonic® SP implant showed significantly better scores after 3, 6, and 12 months (mean scores: 53%, 62%, and 68% for words; 58%, 69%, and 75% for sentences) than those fitted with the Convex implant (34%, 42%, and 43% for words; 38%, 59%, and 51% for sentences). The improvement in speech perception after implantation for SP patients continued throughout the 12 months for words and 6 months for sentences, versus 6 months for words and 3 months for sentences for Convex patients.

Mastoid hyperpneumatization with atlantoaxial fistulization presenting as head rotation-induced aural fullness.

OBJECTIVE: To describe a unique presentation of mastoid hyperpneumatization with atlantoaxial air fistulization. PATIENTS: Case report, 30-year-old male patient. INTERVENTIONS: Descriptive case report. MAIN OUTCOME MEASURES: Subjective aural fullness, with objective tympanogram changes, induced by head rotation. RESULTS: The patient complained of left ear fullness exclusively and repeatedly during neck extension and head rotation to the right side. These head positional changes cause a change of pressure of the atlantoaxial intra-articular emphysematous air, and these fluctuations in pressure are transmitted through the communicating mastoid fistula to the middle ear and tympanic membrane, leading to the sensation of ear fullness. CONCLUSION: We hereby describe the first case of mastoid hyperpneumatization fistulizing into the atlantoaxial joint and presenting with an ipsilateral aural fullness that occurs mainly during contralateral head rotation and extension. This is a characteristic clinical sign that has not been previously described.

New perspectives for middle ear implants: first results in otosclerosis with mixed hearing loss.

Middle ear implantation is an efficient procedure to restore moderate to severe sensorineural hearing loss (HL) in selected patients. Implantation of such devices requires ossicular chain integrity. Patients suffering from otosclerosis with mixed HL should be eligible for this treatment after stapes surgery with air-bone gap closure. To address this issue, we report four cases of middle ear implantation after or during stapes surgery. Results and complications obtained with Vibrant SoundBridge, MedEl and Middle Ear Transducer, Otologics are reported. Audiologic results were similar to those obtained in cases of sensorineural HL. One case of postoperative labyrinthitis was observed.

Does repeated hyperbaric exposure to 4 atmosphere absolute cause hearing impairment? Study in Guinea pigs and clinical incidences.

HYPOTHESIS: Direct pressure applied on the inner ear cannot induce hearing loss. BACKGROUND: Three possible causes have been described in the literature for inner ear permanent lesions during scuba diving: pressure imbalance between the middle ear and the external ear, appearance of microbubbles in the internal ear, and direct effect of pressure on the inner ear. We seek to determine whether this last factor can be involved. METHODS: We submitted two groups of guinea pigs previously implanted with an electrode in the round window to a protocol of air diving in a hyperbaric chamber. Eardrums of animals in one of the two groups had been perforated beforehand. Twenty dives were practiced over 4 weeks. We chose dive parameters consistent with common sport diving: maximal pressure of 4 atmosphere absolute and duration of 30 minutes. Auditory threshold and cochlear spontaneous activity were recorded at regular intervals. Furthermore, we recorded spontaneous cochlear activity in Heliox 400-m and 600-m dives to determine whether our conclusions hold for "extreme" diving. RESULTS: In the group with perforated eardrums, no variation of those parameters were recorded, even in extreme diving. Important variations were noticed in the other group. CONCLUSIONS: Pressure applied directly on the inner ear during diving does not disturb cochlear activity.

Cerebellopontine angle paraganglioma.

BACKGROUND: Acoustic neuroma account for 80% of cerebellopontine angle tumors. Paraganglioma is a rare tumor in this region. OBJECTIVE: The authors report a case of cerebellopontine angle paraganglioma arising from the anterior inferior cerebellar artery. RESULTS: The clinical and radiologic features were indistinguishable from those of a neuroma, and only the intraoperative view showed a vascular tumor. Definitive diagnosis was made by histopathologic methods. CONCLUSIONS: This unique paraganglioma location may be explained by existing embryologic data. The minimal retrosigmoid approach, assisted by endoscopy, allows safe and complete removal of the tumor.

Retrosigmoid approach for small and medium-sized acoustic neuromas.

OBJECTIVE: Clinical study of the keyhole acoustic neuroma retrosigmoid approach for facial nerve and hearing preservation. STUDY DESIGN: This was a prospective case review from October 1993 to December 1998 in a referral hospital care unit. PATIENTS: A total of 119 consecutive patients with a tumor size of <25 mm in the cerebellopontine angle corrected by a retrosigmoid approach were included in the study. INTERVENTIONS: Standard audiometric and imaging assessments, complete tumor removal by using endoscopy-assisted control, and nerve monitoring. MAIN OUTCOME MEASURES: House-Brackmann facial nerve grade and hearing level by the American Academy of Otolaryngology-Head and Neck Surgery classification. RESULTS: Grades I and II facial nerve function was obtained in 96% of cases, measurable hearing was preserved in 49% of cases, and 30% of cases achieved serviceable hearing. CONCLUSION: The retrosigmoid approach is a safe and reliable approach in random patients with small and medium-sized acoustic neuromas.