SLC44A2 single nucleotide polymorphisms, isoforms, and expression: Association with severity of Meniere's disease?

SLC44A2 was discovered as the target of an antibody that causes hearing loss. Knockout mice develop age related hearing loss, loss of sensory cells and spiral ganglion neurons. SLC44A2 has polymorphic sites implicated in human disease. Transfusion related acute lung injury (TRALI) is linked to rs2288904 and genome wide association studies link rs2288904 and rs9797861 to venous thromboembolism (VTE), coronary artery disease and stroke. Here we report linkage disequilibrium of rs2288904 with rs3087969 and the association of these SLC44A2 SNPs with Meniere's disease severity. Tissue-specific isoform expression differences suggest that the N-terminal domain is linked to different functions in different cell types. Heterozygosity at rs2288904 CGA/CAA and rs3087969 GAT/GAC showed a trend for association with intractable Meniere's disease compared to less severe disease and to controls. The association of SLC44A2 SNPs with VTE suggests that thrombi affecting cochlear vessels could be a factor in Meniere's disease.

Changing Management of Intravestibular Schwannomas in the Era of Cochlear Implantation for Single-Sided Deafness.

OBJECTIVE: Intralabyrinthine schwannomas (ILSs) are a rare cause of deafness. Patients with ILS confined to the semicircular canals and the vestibule (intravestibular schwannomas) are potential candidates for cochlear implantation for hearing rehabilitation, a new option for patients with unilateral hearing loss since the 2019 FDA approval of cochlear implant (CI) for single-sided deafness. In this report, we describe an evolving management approach for ILSs causing hearing loss. PATIENTS: Adults (≥18 years) who underwent simultaneous ILS resection and CI between January 2019 and June 2023 (n = 3). INTERVENTION: Transmastoid labyrinthectomy with simultaneous cochlear implantation. MAIN OUTCOME MEASURES: Hearing performance with cochlear implantation measured as CNC Word Recognition scores and AzBio Sentence scores. RESULTS: Three patients with ILS confined to the semicircular canals and vestibule underwent simultaneous tumor resection via labyrinthectomy with CI placement. In all cases, complete tumor resection and full CI insertion were achieved. No patients experienced postoperative complications. Patients 1 and 2 underwent 6- and 9-month postactivation testing, respectively, with CNC scores 64% to 80% and AzBio 81% to 99% in the implanted ears. Patient 3 scored 0% on CNC and AzBio testing at 3 months and deferred her 6-month audiometry. CONCLUSIONS: Patients with ILS confined to the vestibule and semicircular canals can be considered for simultaneous tumor resection and CI placement.

Children with cochlear implants who live in monolingual and bilingual homes.

OBJECTIVE: To determine if exposure to a second language impacts the ability of children with cochlear implants to develop spoken English skills. STUDY DESIGN: Matched-pairs comparison of postoperative speech perception and speech/language data of children from monolingual and bilingual homes with cochlear implants. SETTING: Tertiary medical facility. SUBJECTS: Twelve matched pairs of children with unilateral cochlear implants who reside in monolingual or in bilingual homes. Pairs were matched for age of implantation, cochlear anatomy, educational setting, and device type. All subjects received their implant before the age of 6 years. INTERVENTION: Subjects participated in routine speech perception and speech and language assessments at various postimplantation time intervals. MAIN OUTCOME MEASURES: Matched-pairs t tests and mixed-model analyses were used to evaluate and compare scores obtained by the 2 groups on the Peabody Picture Vocabulary Test, The MacArthur-Bates Communicative Development Inventory: Words and Gestures, The Oral and Written Language Scales, The Infant-Toddler Meaningful Auditory Integration Scale, and the Student Oral Language Observation Matrix. RESULTS: No significant differences were found between the scores of children living in bilingual homes when compared with the scores obtained by children living in monolingual homes at any interval tested. CONCLUSION: This study supports the belief that exposure to a second language at home does not impair primary language acquisition for some young children with cochlear implants. The study suggests that some children with cochlear implants can learn multiple spoken languages and that parents of such children do not need to avoid using a minority language with their child who has a cochlear implant.

Immediate and Long-term Hearing Outcomes With the Middle Cranial Fossa Approach for Vestibular Schwannoma Resection.

OBJECTIVE: To analyze the immediate postoperative and long-term hearing outcome data in patients who have undergone hearing preservation attempts with the middle cranial fossa (MCF) approach for the resection of sporadic vestibular schwannoma. STUDY DESIGN: Retrospective review of a surgical patient cohort. SETTING: Tertiary academic referral center. PATIENTS: Adult patients with unilateral sporadic vestibular schwannoma. INTERVENTION: Surgical treatment with a MCF approach. MAIN OUTCOME MEASURE: Comparison of pre- and postoperative audiometric data in accordance with the 1995 and 2012 American Academy of Otolaryngology/Head and Neck Surgery guidelines on reporting hearing outcomes and with a word recognition score only scale. Long-term hearing outcome data were analyzed in the following postoperative groups: 3 to 5, 6 to 8, 9 to 11, and 12+ years after surgery. RESULTS: From 1999 to 2016, 174 patients underwent the MCF approach and 155 of them met inclusion criteria for analysis of hearing outcome data. Class A or B hearing was preserved in 70% of the entire cohort after recovery. Seventy-one patients with measurable hearing met criteria for long-term data analysis. The rate of American Academy of Otolaryngology/Head and Neck Surgery class A or B hearing preservation was 82% at 3 to 5 years and declined thereafter. The rate of word recognition score class I or II hearing preservation was 98% at 3 to 5 years and declined less rapidly thereafter. Patients with preoperative Class A hearing had significantly higher rates of successful hearing preservation at all postoperative intervals. CONCLUSION: Delayed hearing loss occurs in a progressively increasing fashion but speech understanding remains durable for a majority of patients whose hearing is initially preserved with the MCF approach.

Multicenter US Clinical Trial With an Electric-Acoustic Stimulation (EAS) System in Adults: Final Outcomes.

OBJECTIVE: To demonstrate the safety and effectiveness of the MED-EL Electric-Acoustic Stimulation (EAS) System, for adults with residual low-frequency hearing and severe-to-profound hearing loss in the mid to high frequencies. STUDY DESIGN: Prospective, repeated measures. SETTING: Multicenter, hospital. PATIENTS: Seventy-three subjects implanted with PULSAR or SONATA cochlear implants with FLEX electrode arrays. INTERVENTION: Subjects were fit postoperatively with an audio processor, combining electric stimulation and acoustic amplification. MAIN OUTCOME MEASURES: Unaided thresholds were measured preoperatively and at 3, 6, and 12 months postactivation. Speech perception was assessed at these intervals using City University of New York sentences in noise and consonant-nucleus-consonant words in quiet. Subjective benefit was assessed at these intervals via the Abbreviated Profile of Hearing Aid Benefit and Hearing Device Satisfaction Scale questionnaires. RESULTS: Sixty-seven of 73 subjects (92%) completed outcome measures for all study intervals. Of those 67 subjects, 79% experienced less than a 30 dB HL low-frequency pure-tone average (250-1000 Hz) shift, and 97% were able to use the acoustic unit at 12 months postactivation. In the EAS condition, 94% of subjects performed similarly to or better than their preoperative performance on City University of New York sentences in noise at 12 months postactivation, with 85% demonstrating improvement. Ninety-seven percent of subjects performed similarly or better on consonant-nucleus-consonant words in quiet, with 84% demonstrating improvement. CONCLUSION: The MED-EL EAS System is a safe and effective treatment option for adults with normal hearing to moderate sensorineural hearing loss in the low frequencies and severe-to-profound sensorineural hearing loss in the high frequencies who do not benefit from traditional amplification.

Superior Canal Dehiscence Syndrome Affecting 3 Families.

Importance: Superior canal dehiscence syndrome (SCDS) is an increasingly recognized cause of hearing loss and vestibular symptoms, but the etiology of this condition remains unknown. Objective: To describe 7 cases of SCDS across 3 families. Design, Setting, and Participants: This retrospective case series included 7 patients from 3 different families treated at a neurotology clinic at a tertiary academic medical center from 2010 to 2014. Patients were referred by other otolaryngologists or were self-referred. Each patient demonstrated unilateral or bilateral SCDS or near dehiscence. Interventions: Clinical evaluation involved body mass index calculation, audiometry, cervical vestibular evoked myogenic potential testing, electrocochleography, and multiplanar computed tomographic (CT) scan of the temporal bones. Zygosity testing was performed on twin siblings. Main Outcomes and Measures: The diagnosis of SCDS was made if bone was absent over the superior semicircular canal on 2 consecutive CT images, in addition to 1 physiologic sign consistent with labyrinthine dehiscence. Near dehiscence was defined as absent bone on only 1 CT image but with symptoms and at least 1 physiologic sign of labyrinthine dehiscence. Results: A total of 7 patients (5 female and 2 male; age range, 8-49 years) from 3 families underwent evaluation. Family A consisted of 3 adult first-degree relatives, of whom 2 were diagnosed with SCDS and 1 with near dehiscence. Family B included a mother and her child, both of whom were diagnosed with unilateral SCDS. Family C consisted of adult monozygotic twins, each of whom was diagnosed with unilateral SCDS. For all cases, dehiscence was located at the arcuate eminence. Obesity alone did not explain the occurrence of SCDS because 5 of the 7 cases had a body mass index (calculated as weight in kilograms divided by height in meters squared) less than 30.0. Conclusions and Relevance: Superior canal dehiscence syndrome is a rare, often unrecognized condition. This report of 3 multiplex families with SCDS provides evidence in support of a potential genetic contribution to the etiology. Symptomatic first-degree relatives of patients diagnosed with SCDS should be offered evaluation to improve detection of this disorder.

Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update) Executive Summary.

The American Academy of Otolaryngology-Head and Neck Surgery Foundation has published a supplement to this issue of Otolaryngology-Head and Neck Surgery featuring the "Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update)." To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose, and key action statements. The 14 recommendations developed emphasize diagnostic accuracy and efficiency, reducing the inappropriate use of vestibular suppressant medications, decreasing the inappropriate use of ancillary testing, and increasing the appropriate therapeutic repositioning maneuvers. An updated guideline is needed due to new clinical trials, new systematic reviews, and the lack of consumer participation in the initial guideline development group.

Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update).

Objective This update of a 2008 guideline from the American Academy of Otolaryngology-Head and Neck Surgery Foundation provides evidence-based recommendations to benign paroxysmal positional vertigo (BPPV), defined as a disorder of the inner ear characterized by repeated episodes of positional vertigo. Changes from the prior guideline include a consumer advocate added to the update group; new evidence from 2 clinical practice guidelines, 20 systematic reviews, and 27 randomized controlled trials; enhanced emphasis on patient education and shared decision making; a new algorithm to clarify action statement relationships; and new and expanded recommendations for the diagnosis and management of BPPV. Purpose The primary purposes of this guideline are to improve the quality of care and outcomes for BPPV by improving the accurate and efficient diagnosis of BPPV, reducing the inappropriate use of vestibular suppressant medications, decreasing the inappropriate use of ancillary testing such as radiographic imaging, and increasing the use of appropriate therapeutic repositioning maneuvers. The guideline is intended for all clinicians who are likely to diagnose and manage patients with BPPV, and it applies to any setting in which BPPV would be identified, monitored, or managed. The target patient for the guideline is aged ≥18 years with a suspected or potential diagnosis of BPPV. The primary outcome considered in this guideline is the resolution of the symptoms associated with BPPV. Secondary outcomes considered include an increased rate of accurate diagnoses of BPPV, a more efficient return to regular activities and work, decreased use of inappropriate medications and unnecessary diagnostic tests, reduction in recurrence of BPPV, and reduction in adverse events associated with undiagnosed or untreated BPPV. Other outcomes considered include minimizing costs in the diagnosis and treatment of BPPV, minimizing potentially unnecessary return physician visits, and maximizing the health-related quality of life of individuals afflicted with BPPV. Action Statements The update group made strong recommendations that clinicians should (1) diagnose posterior semicircular canal BPPV when vertigo associated with torsional, upbeating nystagmus is provoked by the Dix-Hallpike maneuver, performed by bringing the patient from an upright to supine position with the head turned 45° to one side and neck extended 20° with the affected ear down, and (2) treat, or refer to a clinician who can treat, patients with posterior canal BPPV with a canalith repositioning procedure. The update group made a strong recommendation against postprocedural postural restrictions after canalith repositioning procedure for posterior canal BPPV. The update group made recommendations that the clinician should (1) perform, or refer to a clinician who can perform, a supine roll test to assess for lateral semicircular canal BPPV if the patient has a history compatible with BPPV and the Dix-Hallpike test exhibits horizontal or no nystagmus; (2) differentiate, or refer to a clinician who can differentiate, BPPV from other causes of imbalance, dizziness, and vertigo; (3) assess patients with BPPV for factors that modify management, including impaired mobility or balance, central nervous system disorders, a lack of home support, and/or increased risk for falling; (4) reassess patients within 1 month after an initial period of observation or treatment to document resolution or persistence of symptoms; (5) evaluate, or refer to a clinician who can evaluate, patients with persistent symptoms for unresolved BPPV and/or underlying peripheral vestibular or central nervous system disorders; and (6) educate patients regarding the impact of BPPV on their safety, the potential for disease recurrence, and the importance of follow-up. The update group made recommendations against (1) radiographic imaging for a patient who meets diagnostic criteria for BPPV in the absence of additional signs and/or symptoms inconsistent with BPPV that warrant imaging, (2) vestibular testing for a patient who meets diagnostic criteria for BPPV in the absence of additional vestibular signs and/or symptoms inconsistent with BPPV that warrant testing, and (3) routinely treating BPPV with vestibular suppressant medications such as antihistamines and/or benzodiazepines. The guideline update group provided the options that clinicians may offer (1) observation with follow-up as initial management for patients with BPPV and (2) vestibular rehabilitation, either self-administered or with a clinician, in the treatment of BPPV.

Hearing preservation and facial nerve outcomes in vestibular schwannoma surgery: results using the middle cranial fossa approach.

OBJECTIVE: To evaluate surgical results using the middle cranial fossa approach for hearing preservation vestibular schwannoma surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral academic center. PATIENTS: Seventy-three consecutive patients with vestibular schwannoma operated on using the middle cranial fossa approach between February 1999 and February 2005. INTERVENTIONS: The tumors were removed via the middle cranial fossa approach with modifications to improve exposure. Standard auditory brainstem and facial nerve monitoring were used. MAIN OUTCOME MEASURES: Pre- and postoperative hearing measures and facial function, tumor size, and postoperative complications. Hearing status was categorized into Classes A, B, C, and D as described by the American Academy of Otolaryngology-Head and Heck Surgery "Guidelines for the Evaluation of Hearing Preservation in Acoustic Neuroma, 1995." RESULTS: Thirty-four patients presented with Class A hearing preoperatively. Among patients presenting with Class A hearing, a total of 27 (80%) maintained Class A or B hearing postoperatively. Of these, 21 (62%) remained in Class A, 6 (18%) deteriorated slightly to Class B, and 7 (20%) deteriorated to Class D postoperatively. Twenty-eight patients presented with Class B hearing preoperatively. Of these, 18 (64%) remained in Class B, 3 (11%) deteriorated to Class C, and 7 (25%) deteriorated to Class D. Three patients had Class C hearing preoperatively. Of these, 2 (66%) remained in Class C and 1 (33%) deteriorated to Class D. Eight patients presented in Class D and one of these improved to Class C postoperatively. Overall, 62 patients presented with useful (Class A or B) hearing and 45 (73%) remained in Class A or B. Nineteen patients had tumors larger than 10 mm in greatest dimension and had Class A or B hearing preoperatively. Of these, 11 (58%) retained Class A or B hearing postoperatively. At 4 months or greater follow-up, facial nerve outcome were excellent in 96%: House-Brackmann Grade I in 61 (85%), Grade II in 8 (11%), and Grade III in 3 (4%). There were no Grade IV, V, or VI results on final follow-up. Six (8%) patients developed cerebrospinal fluid leaks. CONCLUSION: By achieving excellent exposure and using meticulous microsurgical technique, it is possible to resect small vestibular schwannomas via the middle fossa approach, with preservation of hearing at excellent or preoperative levels in the majority of patients, with excellent or satisfactory facial nerve outcomes in 96% of patients.

Identification and characterization of choline transporter-like protein 2, an inner ear glycoprotein of 68 and 72 kDa that is the target of antibody-induced hearing loss.

The Kresge Hearing Research Institute-3 (KHRI-3) antibody binds to a guinea pig inner ear supporting cell antigen (IESCA) and causes hearing loss. To gain insight into the mechanism of antibody-induced hearing loss, we used antibody immunoaffinity purification to isolate the IESCA, which was then sequenced by mass spectroscopy, revealing 10 guinea pig peptides identical to sequences in human choline transporter-like protein 2 (CTL2). Full-length CTL2 cDNA sequenced from guinea pig inner ear has 85.9% identity with the human cDNA. Consistent with its expression on the surface of supporting cells in the inner ear, CTL2 contains 10 predicted membrane-spanning regions with multiple N-glycosylation sites. The 68 and 72 kDa molecular forms of inner ear CTL2 are distinguished by sialic acid modification of the carbohydrate. The KHRI-3 antibody binds to an N-linked carbohydrate on CTL2 and presumably damages the organ of Corti by blocking the transporter function of this molecule. CTL2 mRNA and protein are abundantly expressed in human inner ear. Sera from patients with autoimmune hearing loss bind to guinea pig inner ear with the same pattern as CTL2 antibodies. Thus, CTL2 is a possible target of autoimmune hearing loss in humans.

Corticosteroid response and supporting cell antibody in autoimmune hearing loss.

OBJECTIVE: To determine whether antibodies to supporting cells are associated with response to corticosteroids in patients with autoimmune sensorineural hearing loss. DESIGN: Prospective analysis of antibody to inner-ear antigens. SETTING: Collaborating otology practices in Pennsylvania, Michigan, and Indiana. PATIENTS: Sixty-three patients with rapidly progressive unilateral or bilateral sensorineural hearing loss of unknown cause suggestive of autoimmune sensorineural hearing loss. INTERVENTIONS: Pretreatment audiometry, serum analysis by Western blot (WB) and immunofluorescence (IF) tests, corticosteroid therapy, and follow-up audiometry. MAIN OUTCOME MEASURES: Antibody reactivity and audiogram changes were analyzed for association with response to treatment. RESULTS: More than half of the patients (37/63) had antibodies to both a 68- to 72-kDa protein and to inner-ear supporting cells, 16 patients had positive results on one assay only, and 10 had negative results on both. Twenty-eight patients improved and 35 did not. The WB findings did not correlate with response. Of the WB-positive patients, 49% (21/43) improved, as did 35% (7/20) of the WB-negative patients (P = .30). In contrast, 53% (25/47) of IF-positive patients improved, compared with only 19% (3/16) in the IF-negative group (P = .02). Of those who improved, 89% (25/28) were IF positive. CONCLUSIONS: Antibody to an inner-ear supporting cell antigen was significantly associated with hearing improvement after corticosteroid therapy (relative rate, 2.8). Patients with IF-positive serum are nearly 3 times more likely to experience improved hearing with corticosteroid treatment than those who are IF negative. Antibodies to inner-ear supporting cell antigen may have value in diagnosis and treatment of patients with autoimmune sensorineural hearing loss.

Facial nerve outcomes in middle cranial fossa vs translabyrinthine approaches.

OBJECTIVE: To compare the final facial nerve outcomes between middle cranial fossa (MCF) vs translabyrinthine (TL) resection of size-matched vestibular schwannomas. STUDY DESIGN AND SETTING: Retrospective case review at a tertiary care hospital. All patients who underwent resection utilizing either MCF or TL approaches with tumors 18 mm or smaller and complete data were included in the analysis. One hundred twenty-four patients were identified meeting the above criteria, with sixty-three in the translabyrinthine group and sixty-one in the middle fossa group. One-week-postoperative and final facial nerve examinations were compared in the two surgical groups. Patients were separately analyzed in subgroups: tumors smaller than 10 mm and those that were between 10 and 18 mm. RESULTS: The tumor size range for the MCF group was 3-18 mm while it was 4-18 mm for the TL group. No statistically significant difference was found in facial nerve outcomes between the two surgical groups, at the first postoperative visit week and at last follow-up. CONCLUSION: Facial nerve outcomes are similar using TL and MCF approaches for resection of vestibular schwannomas up to 18 mm in size. SIGNIFICANCE: Patients undergoing the MCF approach for hearing preservation can be counseled that there is no increased risk of permanent facial nerve weakness, compared to the TL approach.

Chronic Pseudomonas infections of cochlear implants.

OBJECTIVE: To discuss chronic, refractory Pseudomonas infections of cochlear implants and their management. DESIGN: Retrospective case series. SETTING: Two university-based cochlear implant programs. PATIENTS: Twenty-eight-year-old (Case 1) and 4-year-old (Case 2), different devices. INTERVENTIONS: Medical and surgical management. MAIN OUTCOME MEASURES: Clinical course. RESULTS: Both patients had delayed presentations, 4 months and 3 years postimplantation, respectively, with fluctuating scalp edema and pain resistant to multiple courses of oral antibiotics. Infections began as localized granulation and progressed to complete encasement of both devices with rubbery, poorly vascularized tissue. In each case, two different strains of multiresistant Pseudomonas aeruginosa were cultured. Infections progressed despite local debridement and targeted antipseudomonal antibiotic coverage, and sensitive organisms continued to appear in cultures of refractory granulation tissue. Both patients underwent partial explantation, with the electrode array left in the cochlea, then received 2 to 3 more months of further medical therapy and observation and then were reimplanted successfully with new devices. Both have shown excellent performance and no sign of recurrent infection. CONCLUSIONS: Infections of cochlear implants are uncommon, and cases of successful conservative management without device explantation have been reported. However, our experience and the implanted device literature suggest that chronic Pseudomonas infections may represent a distinct clinical entity, likely to fail protracted therapy and ultimately require device removal. Fortunately, successful reimplantation is possible.

Prediction of long-term facial nerve outcomes with intraoperative nerve monitoring.

OBJECTIVE: Evaluate the utility of a statistical equation using two independent intraoperative monitoring parameters in predicting long-term facial nerve function. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care hospital. PATIENTS: Sixty patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution. INTERVENTION: All patients underwent microsurgical resection of vestibular schwannomas with the use of intraoperative cranial nerve monitoring. MAIN OUTCOME MEASURE: Final facial nerve outcome measured using the House-Brackmann scale at least 6 months after microsurgical resection. RESULTS: Five out of 60 (8.3%) patients demonstrated significant long-term weakness (i.e., House-Brackmann grade III or worse). Intraoperative monitoring parameters (proximal stimulation threshold, proximal-to-distal response amplitude ratio) were accurate in predicting increased risk of long-term facial nerve dysfunction when used in a logistic regression model. A Student's t test confirmed the equation result was statistically significant in differentiating long-term facial nerve outcomes. CONCLUSION: Patients with immediate weakness are at higher risk of having long-term poor facial nerve function. The use of intraoperative monitoring parameters was reliable in predicting facial nerve outcomes. Patients with permanent facial nerve dysfunction often require rehabilitative procedures. The ability to predict facial nerve outcomes with intraoperative monitoring may allow early rehabilitative procedures to improve quality of life and prevent ocular complications.

Effects of trigeminal ganglion stimulation on the central auditory system.

A projection from the trigeminal ganglion to the ventral cochlear nucleus (VCN) of the guinea pig was recently described. The synaptic terminals of this projection terminate in the granule and magnocellular regions of the VCN. Stimulation of this projection has been shown to result in activation of neurons of the ventral cochlear nucleus. We investigated the effect of electrically stimulating the trigeminal ganglion on the central auditory system activity using 2-deoxyglucose (2-DG) autoradiographic techniques. Electrical stimuli were applied to the left trigeminal ganglion as bipolar pulses, 100 micros per phase, at intervals of 200 ms and an amplitude of 100 microA. Negative control animals were not stimulated. A positive control animal was stimulated in the left ear using a 1 kHz tone burst with 200 ms duration and an amplitude of 80 dB SPL. 2-DG was administered by intramuscular injection. Following a 1 h incorporation period, animals were sacrificed, the brains rapidly harvested, and prepared for autoradiography using standard techniques. Autoradiographs were analyzed using computer-assisted video densitometry to determine film optical density in the central auditory regions of interest. The cerebellum was also sampled as a gray matter indifferent intra-brain control region. Results showed systematic and significant differences between 2-DG uptake in the cochlear nucleus and higher auditory centers between control and stimulated animals. Trigeminally stimulated animals showed significantly higher uptake than unstimulated animals in all auditory centers examined, especially ipsilateral to the stimulation site. The activation pattern differs qualitatively from that seen with sound stimulation in that mainly contralateral pathways are activated with sound stimulation. These results demonstrate that a projection from the predominantly somatosensory trigeminal ganglion can influence the activity of central auditory neurons in a manner distinct from acoustic stimulation, suggesting activation of non-classical auditory pathways.

Cochlear implantation in the chronically diseased ear.

PURPOSE OF REVIEW: The presence of chronic ear disease in patients with profound SNHL presents a challenge to the otologic surgeon and was considered, in the past, a contraindication to cochlear implantation. This review discusses options for cochlear implantation in patients with chronically diseased ears. RECENT FINDINGS: Several management options are available for cochlear implantation in patients with chronic suppurative otitis media (CSOM) and severe to profound sensorineural hearing loss (SNHL). CONCLUSION: Cochlear implantation can be safely achieved in patients with CSOM. The approach chosen should be individualized based on clinical findings.

Intraoperative monitoring and facial nerve outcomes after vestibular schwannoma resection.

OBJECTIVE: To determine the predictive value of proximal facial nerve electrical threshold and proximal-to-distal facial muscle compound action potential amplitude ratio on facial nerve outcomes after resection of vestibular schwannomas. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care hospital. PATIENTS: Two hundred twenty-nine patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution. INTERVENTION: All patients underwent resection of vestibular schwannomas with the use of intraoperative monitoring. MAIN OUTCOME MEASURE: Facial nerve function was classified according to the House-Brackmann scale at the patient's last office follow-up. Last follow-up was at least 6 months after surgery. RESULTS: Good facial nerve function (House-Brackmann Grade I or II) was observed in 87% of the patients at their last office follow-up. Proximal-to-distal amplitude ratio and proximal electric threshold were statistically significant in predicting facial nerve outcome. A mathematical model predicting the probability of good outcome on the basis of the intraoperative parameters is presented. CONCLUSION: Intraoperative monitoring has significantly decreased facial nerve morbidity in vestibular schwannoma surgery. Despite the advances in surgery and monitoring, a group of patients still have poor facial nerve outcomes. The use of intraoperative nerve monitoring may be able to predict poor long-term facial nerve outcomes and thus modify the timing of rehabilitation.

External auditory canal closure in cochlear implant surgery.

OBJECTIVE: To evaluate surgical techniques and complications associated with external auditory canal (EAC) closure in cochlear implant surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center with a large cochlear implant program. PATIENTS: Twenty-eight patients (8 adults and 20 children) underwent multichannel cochlear implantation with EAC closure. The follow-up periods ranged between 1 and 10 years. Closure of the EAC was performed in conjunction with implantation of ears with chronic suppurative otitis media or cochlear drill-out procedures for ossification, or for access to the cochlea in patients with abnormal temporal bone anatomy. A modified Rambo technique was used for EAC closure in all but one case. INTERVENTIONS: Cochlear implantation with EAC closure and subsequent clinical and radiologic follow-up. MAIN OUTCOME MEASURES: Postoperative complications or the development of cholesteatoma in the implanted ear. RESULTS: Cholesteatoma developed in the implanted ear in two patients. Breakdown of EAC closure occurred in one of these patients. The details of these patients are reviewed. CONCLUSION: Closure of EAC can be done with relatively low risk. Close and careful follow-up is required for early detection of a developing cholesteatoma.

Cochlear implantation in prelingually deaf children with ossified cochleae.

OBJECTIVE: To evaluate the effects that degree of cochlear ossification has on performance of prelingually deafened children who receive cochlear implants. STUDY DESIGN: A matched-pairs analysis comparing speech perception results obtained 6 and 24 months after implant by children with ossified and nonossified cochleae. Additionally, long-term performance was evaluated in patients with follow-up periods longer than 24 months. Comparisons were also performed within the ossified cochleae group to determine if degree of cochlear ossification and surgical technique affected outcome with the cochlear implant. SETTING Large cochlear implant program in an academic tertiary care medical center. PATIENTS: Twenty-one pairs of prelingually deaf children with and without cochlear ossification. Meningitis was the etiology of hearing loss in children with ossified cochleae. The control group had nonmeningitic etiology for the hearing loss. INTERVENTIONS: Multichannel cochlear implantation and routine postoperative auditory rehabilitation and performance evaluation. MAIN OUTCOME MEASURES: Speech perception category ratings based on scores obtained on a battery of closed- and open-set speech recognition tests 6 and 24 months after implant. Longer follow-up period is also reported. RESULTS: As a group, children with cochlear ossification showed significant improvement in their speech perception abilities 6 and 24 months after implant. Children with cochlear ossification performed at a significantly lower speech perception category than a group of matched controls with nonossified cochleae at both the 6- and 24-month postimplant intervals. With longer implant use, open-set speech recognition was possible in some children with ossification. Within-group analysis of the children with ossified cochleae revealed that degree of ossification and surgical procedure used for implantation did not significantly affect outcome. CONCLUSIONS: Prelingually deafened children with postmeningitic hearing loss and ossified cochleae receive significant benefit from cochlear implants. Their performance is frequently poorer, however, than children with nonossified cochleae.

Cochlear implantation in chronic suppurative otitis media.

OBJECTIVE: To evaluate management options for cochlear implantation in patients with chronic suppurative otitis media. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center with a large cochlear implant program. PATIENTS: Ten patients with chronic suppurative otitis media who received cochlear implants were identified. Case history, etiology of hearing loss, and management of the ear with the implant were evaluated. INTERVENTIONS: Cochlear implantation and subsequent rehabilitation. MAIN OUTCOME MEASURES: Early and late complications were evaluated. RESULTS: No early or late complications were identified in this group of patients after an average follow-up period of about 4 years. CONCLUSION: Cochlear implantation can be safely achieved in patients with chronic suppurative otitis media. There are several options for the management of these patients, and the approach chosen should be individualized on the basis of clinical findings.