Evaluation of hearing preservation in adults with a slim perimodiolar electrode.

PURPOSE: Numerous endeavors have been undertaken to preserve hearing in cochlear implant (CI) patients. Particularly, optimization of electrode array design aims at preservation of residual hearing (RH). This study examines whether a slim perimodiolar (PM) electrode array could bear the capability to preserve hearing. METHODS: A total of 47 patients underwent cochlear implantation receiving the PM electrode. (i) Patients with pure tone audiogram (PTA) thresholds better than 85 dB and/or hearing loss for Freiburg speech test numbers less than 60 dB and more than 50% maximum monosyllabic understanding were assigned to the RH group (n = 17), while all others belonged to the noRH group (n = 30). (ii) Another group implanted with a slim straight, lateral wall (LW) electrode was recruited for comparison. RESULTS: We compared 17 RH-30 noRH patients all receiving the PM electrode. RH in PM recipients decreased faster than in LW recipients. No significant differences were observed between both (RH v/s noRH) groups in NRT thresholds, Freiburg speech test and A§E® phonemes. Analogous satisfaction levels were indicated through the questionnaires in terms of sound quality, hearing in silence, noise and directional hearing in both groups. CONCLUSIONS: The results suggest that hearing preservation is influenced not only by electrode shape but various factors. This study opens an avenue for further investigations to elucidate and enumerate the causes for progressive hearing loss.

Increase in N-terminus-pro-B-type natriuretic peptide during exercise of patients with univentricular heart after a total cavopulmonary connection.

An increase in N-terminus pro-B-type natriuretic peptide (NT-proBNP) during exercise is related to myocardial ischemia, myocardial dysfunction, and inflammatory stress. Its value for patients with a univentricular heart after total cavopulmonary connection (TCPC) is unknown. For 66 patients with TCPC, a cardiopulmonary exercise test was performed. Venous NT-proBNP samples were drawn with the patient at rest and then 2-3 min after peak exercise. The median NT-proBNP during rest was 82 ng/l (range, 11-2,554 ng/l), with 22 patients above the upper reference limit. A higher NT-proBNP during rest was related to a worse peak oxygen uptake (peak [Formula: see text]), a higher ventilatory equivalent (VE/VCO(2) slope), and a need for diuretics administration. A small but significant increase in NT-proBNP during exercise at 6 ng/l (range, 0-314 ng/l) was related mainly to its resting value. The relative increase was solely related to a higher body mass and not to any of the investigated functional parameters. Usually, NT-proBNP during rest is not elevated in TCPC patients. If so, it is a valuable predictor of cardiac function. During exercise, only a minor increase in NT-proBNP occurs. Its extent is not related to any of the investigated functional parameters. Maybe the filling restriction from the lungs prevents atrial and ventricular overload as well as BNP secretion in TCPC patients.

Exercise capacity, quality of life, and daily activity in the long-term follow-up of patients with univentricular heart and total cavopulmonary connection.

AIMS: Patients with congenital heart disease usually show diminished exercise capacity and quality of life. However, there is only little information about daily activity, a marker for lifestyle, exercise capacity, and the prevention of arteriosclerosis. This study investigated exercise capacity, quality of life, daily activity, and their interaction with univentricular heart physiology after total cavopulmonary connection (TCPC). METHODS AND RESULTS: Fifty-seven patients (18 females, 39 males, age 8-52 years) after TCPC (lateral tunnel 28, extra-cardiac conduit 29) who underwent surgery during 1994-2001 were examined in our institution. They performed a symptom-limited cardiopulmonary exercise test. Those patients 14 years of age and older filled in the health-related quality-of-life questionnaire SF-36, and those who were 8-13 years of age, the CF-87. Daily activity parameters were obtained by using a triaxial accelerometer over the next three consecutive days. Exercise capacity was severely reduced after TCPC (25.0 mL/min/kg corresponding to 59.7% of age- and sex-related reference values). Daily activity was within the recommendations of the United Kingdom Expert Consensus Group (> or =60 min, > or =3 metabolic equivalent, > or =5 days/week) in 72% of the investigated patients. It was reduced in older patients (Spearman r = - 0.506, P < 0.001) and patients with a lower peak oxygen uptake (Spearman r = 0.432, P = 0.001). In children <14 years, mental health was related to daily activity. CONCLUSION: Despite their diminished exercise capacity, patients after TCPC show a fairly normal activity pattern. However, their activity depends not only on age, but also on exercise capacity, which, in contrast to healthy people, decreases already from early adolescence on.

Histology of the Cochlear Outer Sulcus Cells in Normal Human Ears, Presbycusis, and Menière's Disease.

HYPOTHESIS: Outer sulcus cell features and distribution are hypothesized to differ throughout regions of the human cochlea and between diseased and normal specimens. BACKGROUND: Outer sulcus cells play a role in inner ear fluid homeostasis. However, their anatomy and distribution in the human are not well described. METHODS: Temporal bone specimens with normal hearing (n = 10), Menière's disease (n = 10), presbycusis with flat audiograms (n = 4), and presbycusis with sloping audiograms (n = 5) were examined by light microscopy. Outer sulcus cells were assessed quantitatively and qualitatively in each cochlear turn. One specimen was stained for tubulin immunofluorescence and imaged using confocal microscopy. RESULTS: Outer sulcus cells interface with endolymph throughout the cochlea, with greatest contact in the apical turn. Mean outer sulcus cell counts in the upper apical turn (8.82) were generally smaller (all p < 0.05) than those of the upper basal (17.71), lower middle (18.99) upper middle (18.23), and lower apical (16.42) turns. Mean outer sulcus cell counts were higher (p < 0.05) in normal controls (20.1) than in diseased specimens (15.29). There was a significant correlation between mean cell counts and tonotopically expected hearing thresholds in the upper basal (r = -0.662, p = 0.0001), lower middle (r = -0.565, p = 0.0017), and upper middle (r = -0.507, p = 0.0136) regions. Other differences in cell morphology, distribution, or relationship with Claudius cells were not appreciated between normal and diseased specimens. Menière's specimens had no apparent unique features in the cochlear apex. Immunofluorescence staining demonstrated outer sulcus cells extending into the spiral ligament in bundles forming tapering processes which differed between the cochlear turns in morphology. CONCLUSION: Outer sulcus cells vary throughout the cochlear turns and correlate with hearing status, but not in a manner specific to the underlying diagnoses of Menière's disease or presbycusis.

Impact of cochlear tonotopy on electrically evoked compound action potentials (ECAPs).

BACKGROUND: A wide range of cochlear implant electrode designs exists. Lateral wall electrodes may be favored for their potential to preserve residual hearing by virtue of being thin and delicate; whereas perimodiolar electrodes may have advantages in case of profound hearing loss, due to electrode positioning in close proximity to the auditory nerve fibers. AIM: The aim of this study was to investigate the impact of these two array designs on the interaction between electrodes and the auditory nerve in different tonotopic regions of the cochlea. PATIENTS AND METHODS: A retrospective study of both adult and pediatric cochlear implant recipients (CI24RE/CI512 or CI422, Cochlear®) was undertaken. The differences of threshold Neural Response Telemetry (tNRT) acquired 12 months after surgery were analyzed with respect to the tonotopic location. RESULTS: The results of 168 implants showed that perimodiolar arrays had lowest thresholds in the basal region whereas straight arrays had lowest thresholds in the apex. Highest thresholds for both array types were encountered in the medial parts. CONCLUSIONS AND SIGNIFICANCE: tNRTs differ depending on electrode type and location inside the cochlea. This should be considered pre implantation when choosing the electrode array type and post-implantation when mapping the CI program.

Delineation of the intratemporal facial nerve in a cadaveric specimen on diffusion tensor imaging using a 9.4 T magnetic resonance imaging scanner: a technical note.

The purpose of this study was to determine whether the intratemporal facial nerve could be delineated on 9.4 T magnetic resonance imaging (MRI) using T2-weighted and diffusion tensor imaging (DTI). DTI using a b value of 3000 and an isotropic resolution of 0.4 mm3 on a 9.4 T MRI scanner was performed on a whole-block celloidin-embedded cadaveric temporal bone specimen of a 1-year-old infant with normal temporal bones. The labyrinthine, tympanic, and mastoid segments of the facial nerve and the chorda tympani nerve were readily depicted on DTI. Therefore, DTI performed using a high b value on a high-field strength MRI scanner could help evaluate the intratemporal facial nerve in whole temporal bone ex vivo specimens.

Newly Diagnosed Meniere's Disease: Clinical Course With Initiation of Noninvasive Treatment Including an Accounting of Vestibular Migraine.

OBJECTIVE: To describe the course of Meniere's disease with noninvasive treatment during the first few years after initial diagnosis. METHODS: A retrospective review of consecutive patients with newly diagnosed definite Meniere's disease between 2013 and 2016 and a minimum follow-up of 1 year. Patients received a written plan for low sodium, water therapy, and treatment with a diuretic and/or betahistine. Subjects were screened and treated for vestibular migraine as needed. Vertigo control and hearing status at most recent follow-up were assessed. RESULTS: Forty-four subjects had an average follow up of 24.3 months. Thirty-four percent had Meniere's disease and vestibular migraine, and 84% had unilateral Meniere's disease. Seventy-five percent had vertigo well controlled at most recent follow-up, with only noninvasive treatments. Age, gender, body mass index, presence of vestibular migraine, bilateral disease, and duration of follow-up did not predict noninvasive treatment failure. Worse hearing threshold at 250 Hz and lower pure tone average (PTA) at the time of diagnosis did predict failure. Fifty-two percent of ears had improved PTA at most recent visit, 20% had no change, and 28% were worse Conclusions: Encountering excellent vertigo control and stable hearing after a new diagnosis of Meniere's disease is possible with noninvasive treatments. Worse hearing status at diagnosis predicted treatment failure.

Histopathology of the Mucosa of Eustachian Tube Orifice at the Middle Ear in Chronic Otitis Media With Effusion: Possible Insight Into Tuboplasty Failure.

INTRODUCTION: Balloon dilation of the cartilaginous segment of the Eustachian tube has emerged as a means to directly augment tubal dilatory function, and this has been applied as a potential treatment for otitis media with effusion (OME). Although results of clinical studies involving this modality appear promising, there are still a moderate number of ears affected by OME that do not respond. The purpose of this study was to investigate the status of mucosa of the Eustachian tube at the middle ear orifice in OME as it may relate to some cases of tuboplasty failure. METHODS: Twenty-three temporal bone specimens with OME were identified within an institutional archived collection. Each specimen was inspected for the presence of a fixed obstruction at the level of the Eustachian tube orifice at the protympanum. In addition, the mucosa at the tubal orifice was graded on a 4-point scale. RESULTS: Overall, 3 cases (13%) were normal (Grade 1), 6 cases (26%) were mildly thickened (Grade 2), 11 (48%) were severely thickened (Grade 3), and 3 (13%) were severely thickened with polypoid degeneration (Grade 4). A single case was noted to have a complete fixed obstruction in the form of a mucosal web. CONCLUSION: In ears affected by OME, the mucosa of the Eustachian tubal orifice at the middle ear is most often severely thickened. Normal mucosa, mucosa with severe polypoid changes, or a complete fixed obstruction are possible but uncommon. The majority of specimens studied had sufficiently diseased mucosa to raise questions regarding whether thickened mucosa in the tubal orifice may act as a barrier to middle ear ventilation that would not be directly addressed by cartilaginous Eustachian tube balloon dilation.

Human Superior Olivary Nucleus Neuron Populations in Subjects With Normal Hearing and Presbycusis.

INTRODUCTION: Normative data on superior olivary nucleus neuron counts derived from human specimens are sparse, and little is known about their coherence with structure and function of the cochlea. The purpose of this study was to quantify the neuron populations of the divisions of the superior olivary nucleus in human subjects with normal hearing and presbycusis and investigate potential relationships between these findings and histopathology in the cochlea and hearing phenotype Methods: Histopathologic examination of temporal bone and brainstem specimens from 13 subjects having normal hearing or presbycusis was undertaken. The following was determined for each: number and density of superior olivary nucleus and cochlear nucleus neurons, inner and outer hair cell counts, spiral ganglion cell counts, and pure tone audiometry. RESULTS: The results demonstrate a significant relationship between cells within structures of the cochlear nucleus and the number of neurons of the medial superior olivary nucleus. No relationship between superior olivary nucleus neuron counts/density and cochlear histopathology or hearing phenotype was encountered. CONCLUSION: Normative data for superior olivary nucleus neuron populations are further established in the data presented in this study that includes subjects with normal hearing and also presbycusis.

Radiological and NRT-Ratio-Based Estimation of Slim Straight Cochlear Implant Electrode Positions: A Multicenter Study.

OBJECTIVES: An intraoperative neural response telemetry-ratio (NRT-ratio) was established, which can provide information about the intraoperative intracochlear electrode array position for perimodiolar electrodes. METHODS: In a retrospective controlled study in 2 tertiary referral centers, the electrophysiological data sets of 50 patients with measured intraoperative auto-NRTs and postoperative radiological examinations were evaluated. All patients were implanted with Nucleus slim straight electrodes. The NRT-ratio was calculated by dividing the average auto-NRT data from electrodes 16 to 18 with the average from electrodes 5 to 7. Using a flat panel tomography system or a computed tomography, the position of the electrode array was certified radiological. RESULTS: Radiologically, 2 out of 50 patients were identified with an electrode translocated from the scala tympani into the scala vestibuli. The radiologically estimated electrodes indicating a scalar change showed a regular NRT-ratio but nonspecific NRT-level changes at the localization of translocation.