Monitoring Cochlear Health With Intracochlear Electrocochleography During Cochlear Implantation: Findings From an International Clinical Investigation.

OBJECTIVES: Electrocochleography (ECochG) is emerging as a tool for monitoring cochlear function during cochlear implant (CI) surgery. ECochG may be recorded directly from electrodes on the implant array intraoperatively. For low-frequency stimulation, its amplitude tends to rise or may plateau as the electrode is inserted. The aim of this study was to explore whether compromise of the ECochG signal, defined as a fall in its amplitude of 30% or more during insertion, whether transient or permanent, is associated with poorer postoperative acoustic hearing, and to examine how preoperative hearing levels may influence the ability to record ECochG. The specific hypotheses tested were threefold: (a) deterioration in the pure-tone average of low-frequency hearing at the first postoperative follow-up interval (follow-up visit 1 [FUV1], 4 to 6 weeks) will be associated with compromise of the cochlear microphonic (CM) amplitude during electrode insertion (primary hypothesis); (b) an association is observed at the second postoperative follow-up interval (FUV2, 3 months) (secondary hypothesis 1); and (c) the CM response will be recorded earlier during electrode array insertion when the preoperative high-frequency hearing is better (secondary hypothesis 2). DESIGN: International, multi-site prospective, observational, between groups design, targeting 41 adult participants in each of two groups, (compromised CM versus preserved CM). Adult CI candidates who were scheduled to receive a Cochlear Nucleus CI with a Slim Straight or a Slim Modiolar electrode array and had a preoperative audiometric low-frequency average thresholds of ≤80 dB HL at 500, 750, and 1000 Hz in the ear to be implanted, were recruited from eight international implant sites. Pure tone audiometry was measured preoperatively and at postoperative visits (FUV1 and follow-up visit 2 [FUV2]). ECochG was measured during and immediately after the implantation of the array. RESULTS: From a total of 78 enrolled individuals (80 ears), 77 participants (79 ears) underwent surgery. Due to protocol deviations, 18 ears (23%) were excluded. Of the 61 ears with ECochG responses, amplitudes were < 1 µV throughout implantation for 18 ears (23%) and deemed "unclear" for classification. EcochG responses >1 µV in 43 ears (55%) were stable throughout implantation for 8 ears and compromised in 35 ears. For the primary endpoint at FUV1, 7/41 ears (17%) with preserved CM had a median hearing loss of 12.6 dB versus 34/41 ears (83%) with compromised CM and a median hearing loss of 26.9 dB ( p < 0.014). In assessing the practicalities of measuring intraoperative ECochG, the presence of a measurable CM (>1 µV) during implantation was dependent on preoperative, low-frequency thresholds, particularly at the stimulus frequency (0.5 kHz). High-frequency, preoperative thresholds were also associated with a measurable CM > 1 µV during surgery. CONCLUSIONS: Our data shows that CM drops occurring during electrode insertion were correlated with significantly poorer hearing preservation postoperatively compared to CMs that remained stable throughout the electrode insertion. The practicality of measuring ECochG in a large cohort is discussed, regarding the suggested optimal preoperative low-frequency hearing levels ( < 80 dB HL) considered necessary to obtain a CM signal >1 µV.

Head and Neck MRI Findings in CHARGE Syndrome.

Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital and/or urinary abnormalities, and Ear abnormalities and deafness (CHARGE) syndrome is a disorder with multiple congenital anomalies seen on imaging. A retrospective review of 10 patients with CHARGE syndrome who underwent MR imaging of the brain as part of a preoperative evaluation for cochlear implantation was conducted. Structural abnormalities of the entire MR imaging of the head were evaluated, including the auditory system, olfactory system, face, skull base, and central nervous system. The most frequent MR imaging findings included dysplasias of the semicircular canals and hypoplasia of the frontal lobe olfactory sulci. Less frequent findings included cleft lip/palate and coloboma. Our study uncovered new findings of a J-shaped sella, dorsal angulation of the clivus, and absent/atrophic parotid glands, not previously described in patients with CHARGE. Our results emphasize the utility of MR imaging in the diagnosis and management of patients with CHARGE syndrome.

Atypical and low-grade malignant vestibular schwannomas: clinical implications of proliferative activity.

OBJECTIVE: To examine the relationship between histopathology, immunohistochemistry, and clinical behavior in atypical and low-grade malignant vestibular schwannomas. STUDY DESIGN: The study design was a retrospective case review in conjunction with a histopathologic and immunohistochemical proliferation marker study of archival specimens. DATA SOURCES: A tertiary referral center's anatomic pathology and vestibular schwannoma computerized databases. METHODS: The diagnosis of atypical or low-grade malignant vestibular schwannoma was based on the number of mitotic figures present per tumor slide. MIB1 labeling indices were used to compare the proliferative activity of the atypical and low-grade malignant groups with that in an age-matched and size-matched control group. RESULTS: Eight cases of atypical and six cases of low-grade malignant vestibular schwannoma were diagnosed from 1990 to 1998. In the atypical and low-grade malignant groups, respectively, the average patient age was 54.3 years (range, 38-74 yr) and 50 years (range, 38-72 yr), and the average total tumor size was 1.53 cm (range, 0.7-3.5 cm) and 1.55 cm (range, 1.5-2 cm). Two recurrences were identified from the low-grade malignant group, and there was one postoperative House-Brackmann Grade III facial weakness. There were no recurrences or facial palsies in the atypical group. No distant metastasis or aggressive local invasion was observed in either group. MIB1 labeling indices were significantly (p < or = 0.001) higher in the atypical (4.69%) and low-grade malignant (5.23%) groups than in the control group (1.99%). CONCLUSIONS: These findings suggest a tendency for recurrence in proliferative tumors; however, the designation of malignancy should be reconsidered.

Cochlear reimplantation: surgical techniques and functional results.

OBJECTIVES/HYPOTHESIS: The most common indication for cochlear reimplantation is device failure. Other, less frequent indications consist of "upgrades" (e.g., single to multichannel), infection, and flap breakdown. Although the percentage of failures has decreased over time, an occasional patient requires reimplantation because of device malfunction. The varying designs of internal receiver/stimulators and electrode arrays mandate an examination of the nature and effects of reimplantation for the individual designs. The purpose of the current study was to investigate the reimplantation of several implant designs and to determine whether differences in surgical technique, anatomical findings, and postoperative performance exist. STUDY DESIGN: Retrospective chart review. METHODS: The subjects were 33 of 618 severely to profoundly deaf adults and children who had implantation at the New York University Medical Center (New York, NY) between February 1984 and December 2000. The subjects had previously had implantation with either a single-channel 3M/House (House Ear Institute, Los Angeles, CA) or 3M/Vienna (Technical University of Vienna, Vienna, Austria) device or with one of the multichannel Clarion (Advanced Bionics, Sylmar, CA), Ineraid (Smith & Nephew Richards, TN), or Nucleus (including the Contour) devices (Cochlear Corp., Englewood, CO) before reimplantation. RESULTS: Length of use before reimplantation ranged from 1 month to 13 years and included traumatic and atraumatic (electronic) failures, as well as device extrusion or infection. Results indicated that postoperative performance was either equal to or better than scores before failure. None of the devices explanted caused damage that precluded the implantation of the same or an upgraded device. These findings support the efficacy and safety of internal implant designs as related to the maintenance of a functional cochlea for the purpose of reimplantation. CONCLUSIONS: Cochlear reimplantation can be performed safely and without decrement to performance. The number of implanted electrodes at reinsertion were either the same or greater in all cases.

Histopathology of cochlear implants in humans.

The insertion of an intrascalar electrode array during cochlear implantation causes immediate damage to the inner ear and may result in delayed onset of additional damage that may interfere with neuronal stimulation. To date, there have been reports on fewer than 50 temporal bone specimens from patients who had undergone implantation during life. The majority of these were single-channel implants, whereas the majority of implants inserted today are multichannel systems. This report presents the histopathologic findings in temporal bones from 8 individuals who in life had undergone multichannel cochlear implantation, with particular attention to the type and location of trauma and to long-term changes within the cochlea. The effect of these changes on spiral ganglion cell counts and the correlation between speech comprehension and spiral ganglion cell counts were calculated. In 4 of the 8 cases, the opposite, unimplanted ear was available for comparison. In 3 of the 4 cases, there was no significant difference between the spiral ganglion cell counts on the implanted and unimplanted sides. In addition, in this series of 8 cases, there was an apparent negative correlation between residual spiral ganglion cell count and hearing performance during life as measured by single-syllable word recognition. This finding suggests that abnormalities in the central auditory pathways are at least as important as spiral ganglion cell loss in limiting the performance of implant users.

Cell cycle regulation of myosin-V by calcium/calmodulin-dependent protein kinase II.

Organelle transport by myosin-V is down-regulated during mitosis, presumably by myosin-V phosphorylation. We used mass spectrometry phosphopeptide mapping to show that the tail of myosin-V was phosphorylated in mitotic Xenopus egg extract on a single serine residue localized in the carboxyl-terminal organelle-binding domain. Phosphorylation resulted in the release of the motor from the organelle. The phosphorylation site matched the consensus sequence of calcium/calmodulin-dependent protein kinase II (CaMKII), and inhibitors of CaMKII prevented myosin-V release. The modulation of cargo binding by phosphorylation is likely to represent a general mechanism regulating organelle transport by myosin-V.

Autoimmune inner ear disease.

The known etiologies of acquired sensorineural hearing loss include acoustic trauma, physical trauma, ototoxicity, genetic predisposition, infections, Meniere's disease, aging, and autoimmune disease. Treatments are directed at eliminating or managing the underlying disease process and aiding hearing with amplification. Rarely is it possible to improve unaided hearing after sensorineural loss except when the severe to profound level of loss is reached and cochlear implantation becomes an option. Autoimmune inner ear disease, however, is a treatable cause of sensorineural hearing loss and it is important for physicians and hearing health professionals to recognize that proper early diagnosis and management strategies may result in stabilization and possibly improvement in hearing.

Synthesis of the spirocyclic cyclohexadienone ring system of the schiarisanrins.

[structure: see text] Studies on the synthesis of the spirocyclic cyclohexadienone ring system 2 of the schiarisanrin family of natural products 1 are described and were based on the Lewis acid-promoted C-alkylation of the corresponding phenolic precursor.

Electrode to modiolus proximity: a fluoroscopic and histologic analysis.

HYPOTHESIS: This study was conducted to evaluate the electrode to modiolus proximity of two commonly used electrodes (Nucleus and Clarion) and a new prototype electrode. BACKGROUND: Theoretical advantages of modiolus-hugging cochlear implant electrodes include reduced stimulus energy requirements, more efficient power management and longer battery life, more discreet ganglion cell population stimulation, and reduced facial nerve stimulation. METHODS: Fluoroscopic analysis and histologic surface preparation analysis of electrode position and trauma. RESULTS: The Nucleus straight electrode occupied an outer wall position in the scala tympani. The Clarion electrode occupied a more intermediate position. The actively coiling prototype electrode was modiolus hugging but caused more trauma than the other two electrodes tested. CONCLUSIONS: The optimal modiolus-hugging atraumatic intracochlear electrode does not currently exist.

Shaw scalpel in revision cochlear implant surgery.

The use of traditional electrocautery is prohibited in revision or replacement cochlear implant surgery because of the concern for end organ tissue damage. Additionally, electrical current spread to the malfunctioning device could interfere with an accurate cause-of-failure analysis. Clinical reports have confirmed the utility of the Shaw scalpel for dermatologic, ophthalmic, and head and neck surgery. The Shaw scalpel is a thermally activated cutting blade that provides a bloodless field through immediate capillary and small vessel hemostasis. Avoidance of wound and flap complications is of primary concern in cochlear implant surgery. The long-term wound healing compared favorably to that of other surgical cutting instruments in several experimental reports. We have routinely used the Shaw scalpel in revision cochlear implant surgery and in primary surgery whenever electrocautery was contraindicated. We have retrospectively evaluated 22 cases in which the Shaw scalpel was used for cochlear implant revision and primary surgery. The chart review included patient demographics, the indication for surgery, the contraindication for electrocautery, intraoperative surgical notes, the wound healing evaluation, the evaluation for alopecia, and postoperative speech understanding. No significant complications occurred intraoperatively, and the long-term wound healing results were no different from those obtained with conventional surgical techniques. The explanted devices were undamaged, and valuable diagnostic information could be obtained. All patients performed at or better than their preoperative levels on speech recognition testing. Our results indicate that the Shaw scalpel is a relatively safe, easy-to-use, and effective instrument.

Regulation of melanosome movement in the cell cycle by reversible association with myosin V.

Previously, we have shown that melanosomes of Xenopus laevis melanophores are transported along both microtubules and actin filaments in a coordinated manner, and that myosin V is bound to purified melanosomes (Rogers, S., and V.I. Gelfand. 1998. Curr. Biol. 8:161-164). In the present study, we have demonstrated that myosin V is the actin-based motor responsible for melanosome transport. To examine whether myosin V was regulated in a cell cycle-dependent manner, purified melanosomes were treated with interphase- or metaphase-arrested Xenopus egg extracts and assayed for in vitro motility along Nitella actin filaments. Motility of organelles treated with mitotic extract was found to decrease dramatically, as compared with untreated or interphase extract-treated melanosomes. This mitotic inhibition of motility correlated with the dissociation of myosin V from melanosomes, but the activity of soluble motor remained unaffected. Furthermore, we find that myosin V heavy chain is highly phosphorylated in metaphase extracts versus interphase extracts. We conclude that organelle transport by myosin V is controlled by a cell cycle-regulated association of this motor to organelles, and that this binding is likely regulated by phosphorylation of myosin V during mitosis.

A comparison of the growth of open-set speech perception between the nucleus 22 and nucleus 24 cochlear implant systems.

OBJECTIVE: To compare the short-term development of open-set speech perception between implementations of the spectral peak (SPEAK) strategy in adults using the Nucleus 22 (N22) Spectra processor and the Nucleus 24 (N24) system with the SPrint processor. STUDY DESIGN: Two sets of patients with a follow-up period of 3 months were compared. SETTING: This study was conducted at the New York University (NYU) Medical Center. PATIENTS: Thirty-six profoundly hearing-impaired adults were included in this study. INTERVENTION: Sixteen adults received the N22 cochlear implant with the Spectra speech processor and twenty adults received the N24 cochlear implant with the SPrint speech processor. MAIN OUTCOME MEASURES: Open-set speech perception for the patients with N22 implants was evaluated preoperatively and postoperatively using the following measures: NU-6 monosyllabic words, Iowa sentences, and CID sentences. CNC words, CUNY sentences, and HINT sentences were used to assess the patients with N24 implants. RESULTS: Results revealed that the N22 and N24 cochlear implant recipients had significant open-set speech recognition 3 and 6 months after implantation. The apparent favorable absolute scores for the patients with N24 implants were equalized when a multivariate analysis was performed to account for their younger age at time of implantation and shorter length of deafness. CONCLUSIONS: The growth of open-set word and sentence recognition in similar between the N22 and N24 cochlear implants. Longitudinal studies are needed to determine if higher ceiling scores are present in the N24. Further exploration of monopolar versus bipolar stimulation is warranted.

Early results using the nucleus CI24M in children.

OBJECTIVE: To report early postimplantation speech recognition results in children who received Nucleus CI24M cochlear implants. STUDY DESIGN: The study group consisted of 19 consecutively implanted children. PATIENTS AND SETTING: Congenitally deaf children (20 months to 15 years old) were implanted with the Nucleus CI24M and followed-up at New York University Medical Center for a period of 3 to 12 months. MAIN OUTCOME MEASURES: Speech perception was evaluated preoperatively and postoperatively using the Early Speech Perception (ESP) test, the Glendonald Auditory Screening Procedure (GASP) word and sentence tests, Phonetically Balanced Kindergarten (PBK) monosyllabic word lists, Common Phrases test, the Multisyllabic and Lexical Neighborhood (MLNT, LNT) tests, and the Banford-Kowal-Bench (BKB) sentence test. RESULTS: One-way analyses of variance revealed significant improvement in open-set speech recognition in children able to perform measurement tasks. CONCLUSIONS: The Nucleus CI24M cochlear implant provides significant benefit to children after short-term use.

Paradoxical spread of renal cell carcinoma to the head and neck.

OBJECTIVES: To present cases of renal cell carcinoma presenting with only head and neck metastases, to review theories of physiology and anatomy describing this phenomenon, and to discuss the role of the otolaryngologist in the treatment of these lesions. STUDY DESIGN: Retrospective review of the records of three patients who presented with renal cell carcinoma with head and neck metastases over the 3-year period from 1992 to 1995. METHODS: Retrospective review of the records of three patients who presented with renal cell carcinoma with head and neck metastases. In addition, English-language literature was reviewed with special focus on the anatomic and physiologic pathways possible to allow for such a phenomenon. CONCLUSIONS: Renal cell carcinoma has an occasional presentation as a head and neck mass without evidence of disease elsewhere. Various routes of spread have been postulated. Batson's venous plexus, as postulated by Nahum and Bailey, is an anatomic route through which emboli could navigate to the head and neck and avoid pulmonary vascular filtration. Interactions on the cellular level may also be responsible for the seemingly paradoxical spread. We recommend local excision of head and neck metastases of renal cell carcinoma without sacrifice of vital structures as a sound treatment regimen.

Stability of the cochlear implant array in children.

OBJECTIVE: To determine cochlear implant electrode stability in the young patient. Electrode migration due to future skull growth was a concern that led to prohibiting implantation in children less than 2 years of age. Recently, the high level of performance achieved by young implantees has led to a re-evaluation of this lower age limit, requiring an assessment of the effects of skull growth over time. STUDY DESIGN: Prospective radiographic analysis of electrode position of cochlear implants in young children. METHODS: Twenty-seven children implanted with the Nucleus (Cochlear Corp., Denver, CO) or Clarion (Advanced Bionics Inc., Sylmar, CA) multi-channel cochlear prostheses were subjects for this study. Follow-up radiographic studies were obtained for a period of 1 month to 5 years after implantation. The age at time of implantation ranged from 14 months to 5 years. An intraoperative modified Stenver's view plain radiograph was obtained as a baseline. After implantation, on a yearly basis transorbital Stenver's and base views were obtained for comparative purposes. Additional radiographs were obtained whenever a change in performance or electrode map caused suspicion for extrusion. Electrode position was determined using a computer graphics enhancement technique whereby image contrast filters enhanced the visibility of the electrode array and surrounding bony structures. RESULTS: An analysis of the data revealed no migration of the electrode array over time. CONCLUSIONS: The confirmation of the stability of the electrode array alleviates the concern of the effects of skull growth on cochlear implantation in young children.

Impact of comorbidity on outcome of young patients with head and neck squamous cell carcinoma.

BACKGROUND: Comorbid conditions have a significant impact on the actuarial survival of patients with head and neck cancer. However, no studies have evaluated the impact of comorbidity on tumor- and treatment-specific outcomes. This study was performed to evaluate the impact of comorbidity, graded by the Kaplan-Feinstein comorbidity index (KFI) on the incidence and severity of complications, disease-free interval, and tumor-specific survival in patients undergoing curative treatment for head and neck cancer. METHODS: A multi-institutional, retrospective cohort of 70 patients 45 years of age and under with head and neck squamous cell carcinoma (SCC) presenting over an 11-year period was studied. RESULTS: Advanced comorbidity (KFI grade 2 or 3) was present in 21 patients (30%). Patients with advanced comorbidity did not differ from patients with low-level comorbidity (KFI grades 0 or 1) in sex distribution, race, presence of human immunodeficiency virus (HIV) infection, tobacco use, location of primary lesion, stage at presentation, pathologic differentiation of the tumor, or type of initial treatment. The overall incidence of treatment-associated complications was similar between the groups (57% versus 49%; p > 0.05), but a higher proportion of patients with advanced comorbidity developed high-grade complications (24% versus 6%; p = .04). The median disease-free interval (11.1 months versus 21.6 months; p = .045) and tumor-specific survival (13.7 months versus 57.6 months; p = .03) was poorer for patients with advanced comorbidity. The effects of comorbidity on survival remained significant even after adjusting for the confounding effects of HIV status and tumor stage (p = .05). CONCLUSIONS: The presence of comorbid conditions has a significant impact on tumor- and treatment-specific outcomes. Although the presence of advanced comorbid conditions is not associated with an increase in the rate of treatment-associated complications, complications tend to be more severe in this population. More importantly, advanced comorbidity has a detrimental effect on the disease-free interval and tumor-specific survival in patients with head and neck cancer, independent of other factors. This suggests that comorbidity may impact on tumor behavior, presumably by altering the host's response to cancer. Accordingly, to be more predictive and reliable, the current staging system for head and neck cancer should include a description of the patient's comorbidity.

Validation of the Charlson comorbidity index in patients with head and neck cancer: a multi-institutional study.

Comorbid conditions are medical illnesses that accompany cancer. The impact of these conditions on the outcome of patients with head and neck cancer is well established. However, all of the comorbidity studies in patients with head and neck cancer reported in the literature have been performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce and validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use. Study design was a retrospective cohort study. The study population was drawn for three academic tertiary care centers and included 88 patients 45 years of age and under who underwent curative treatment for head and neck cancer. All patients were staged by the KFI and the CI for comorbidity and divided into two groups based on the comorbidity severity staging. Group 1 included patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully applied to 80% of this study population, and the CI was successfully applied in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices independently predicted the tumor-specific survival (P = 0.007), even after adjusting for the confounding effects of TNM stage by multivariate analysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidity staging by the CI independently predicted survival, was easier to use, and more readily applied, it may be better suited for use for retrospective comorbidity studies.

Results of speech processor upgrade in a population of Veterans Affairs cochlear implant recipients.

OBJECTIVE: This study aimed to evaluate the change in performance when the Speak processing strategy replaced the Mpeak strategy. SUBJECTS: Twenty-one veterans who participated in the original Department of Veterans Affairs Multicenter Cochlear Implant Study, received the Nucleus F0F1F2 processor (Cochlear Corp., Englewood, CO, U.S.A.) (WSP) and were subsequently upgraded to the Mpeak (MSP) processing strategy. METHODS: Closed- and open-set speech recognition in quiet and in noise in auditory only conditions at the phoneme, word, and sentence levels were evaluated. RESULTS: Changes in audiologic parameters were evaluated using a paired t-test for related samples. Statistically significant improvements in mean scores were found for all tests and were greatest for the speech-in-noise conditions. An examination of individual data revealed that 61% of the subjects improved for tests administered in quiet, whereas up to 69% of the subjects had improved performance in noise. Subjects with no open set speech discrimination using the Mpeak strategy showed no improvement with the Speak strategy. CONCLUSIONS: Cochlear implants can provide improved performance using modifications to external speech processor hardware and software without changing the internal implant.