Full Insertion Research Articles

Cochlear Implantation Outcomes in Patients With Autoimmune and Immune-Mediated Inner Ear Disease

To compare hearing outcomes in patients with autoimmune inner ear disease (AIED) undergoing cochlear implantation to a group of controls, postlingually deafened by non-immune-mediated causes. Hearing performance in AIED patients who receive unilateral or bilateral cochlear implants is comparable to similarly treated postlingually deafened adults without AIED. Retrospective chart review. Academic neurotologic tertiary referral center. Ten patients with AIED with 12 implanted ears who met the audiological criteria for cochlear implantation were compared with 12 randomly selected controls, postlingually deafened by non-immune-mediated causes. Cochlear implantation using commercially available devices. Preoperative and postoperative hearing thresholds, words, and sentence scores. A note was made regarding the presence or absence of ossification or fibrosis noted within the scala tympani at the time of implant. The mean age was 49.6 ± 14 years in the AIED group and 56.8 ± 17 years in the control group (p = 0.31). The mean duration of deafness was 14 ± 26 months in the AIED group and 6.5 ± 4 months in the control group (p = 0.34). In the AIED group, 42% were men and 58% were women. In the control group, 33% were men and 67% women. Five patients in the AIED group (6 implanted ears) were found to have cochlear fibrosis and variable degrees of ossification. Two patients in that group required drill-out procedures. All patients had full insertion. The mean preoperative pure-tone averages in the AIED and control groups were 102 ± 18 and 90 ± 13 dB, respectively (p = 0.13). In the AIED, the mean short-term (≤12 mo of follow-up) postoperative word and sentence scores were 74.8% ± 15% and 94% ± 6%, respectively. In the control group, the mean short-term postoperative words and sentence scores were 72% ± 12% and 96% ± 4%, respectively. No statistical difference was present in the short-term postimplantation words (p = 0.7) and sentence scores (p = 0.49) between both groups. The mean long-term (after 12 mo of follow-up) postoperative word and sentence scores in the AIED group were 87.2% ± 11% and 96.8% ± 4%, respectively. In the control group, the long-term words and sentence scores were 77.2% ± 14% and 77.2% ± 7%, respectively. No statistical significance was found in the long-term postimplantation words (p = 0.17) and sentence scores (p = 0.7) between both groups. Cochlear implantation is a safe and viable option for hearing rehabilitation in patients deafened by progressive AIED. Hearing outcomes in AIED patients are excellent and support transition to implantation when hearing is lost or long-term steroid therapy becomes undesirable. Cochlear fibrosis or ossification seems to affect nearly 50% of implanted ears (41.6% of patients) in this study and implies that the cochlea is at risk for ossification changes long term. In appropriate candidates, earlier implantation may be indicated before postinflammatory obliterative changes in the cochlea.

Loop-Sheet Mechanism of Serpin Polymerization Tested by Reactive Center Loop Mutations

The serpin mechanism of protease inhibition involves the rapid and stable incorporation of the reactive center loop (RCL) into central β-sheet A. Serpins therefore require a folding mechanism that bypasses the most stable "loop-inserted" conformation to trap the RCL in an exposed and metastable state. This unusual feature of serpins renders them highly susceptible to point mutations that lead to the accumulation of hyperstable misfolded polymers in the endoplasmic reticulum of secretory cells. The ordered and stable protomer-protomer association in serpin polymers has led to the acceptance of the "loop-sheet" hypothesis of polymerization, where a portion of the RCL of one protomer incorporates in register into sheet A of another. Although this mechanism was proposed 20 years ago, no study has ever been conducted to test its validity. Here, we describe the properties of a variant of α(1)-antitrypsin with a critical hydrophobic section of the RCL substituted with aspartic acid (P8-P6). In contrast to the control, the variant was unable to polymerize when incubated with small peptides or when cleaved in the middle of the RCL (accepted models of loop-sheet polymerization). However, when induced by guanidine HCl or heat, the variant polymerized in a manner indistinguishable from the control. Importantly, the Asp mutations did not affect the ability of the Z or Siiyama α(1)-antitrypsin variants to polymerize in COS-7 cells. These results argue strongly against the loop-sheet hypothesis and suggest that, in serpin polymers, the P8-P6 region is only a small part of an extensive domain swap.

Cochlear Implantation in children with CHARGE syndrome.

CHARGE syndrome is a rare congenital condition that manifests with anomalies of coloboma, heart defects, choanal atresia, mental retardation, genitourinary and ear anomalies that can affect almost any part of the auditory pathway. In those patients with a significant sensorineural hearing loss, cochlear implantation has become a potential therapeutic option. Chart review of three cases from the Southern Cochlear Implant Programme. All patients met clinical diagnostic criteria of CHARGE syndrome, and had abnormal inner ear anatomy with profound sensorineural hearing loss. One child had previously undergone cochlear implantation which was unsuccessful due to increasing non-auditory stimulation. All patients had successful cochlear implantation with full insertion of a Nucleus Freedom Implant with contour Advance. All patients showed improvement in their audiological function; one child has high functioning verbal communication, one child uses both sign and verbal communication with improved speech quality and ability to speech read, and one child responds reliably to sound, understands short phrases and attempts to vocalize, but this is limited by tracheostomy. Cochlear implantation faces numerous challenges in children with CHARGE syndrome, but with appropriate patient selection can result in successful audiologic and quality of life outcomes.

Measurement Of Neuromagnetic Brain Function In Pre-school Children With Custom Sized MEG

Magnetoencephalography is a technique that detects magnetic fields associated with cortical activity [1]. The electrophysiological activity of the brain generates electric fields - that can be recorded using electroencephalography (EEG)- and their concomitant magnetic fields - detected by MEG. MEG signals are detected by specialized sensors known as superconducting quantum interference devices (SQUIDs). Superconducting sensors require cooling with liquid helium at -270 °C. They are contained inside a vacumm-insulated helmet called a dewar, which is filled with liquid. SQUIDS are placed in fixed positions inside the helmet dewar in the helium coolant, and a subject's head is placed inside the helmet dewar for MEG measurements. The helmet dewar must be sized to satisfy opposing constraints. Clearly, it must be large enough to fit most or all of the heads in the population that will be studied. However, the helmet must also be small enough to keep most of the SQUID sensors within range of the tiny cerebral fields that they are to measure. Conventional whole-head MEG systems are designed to accommodate more than 90% of adult heads. However adult systems are not well suited for measuring brain function in pre-school chidren whose heads have a radius several cm smaller than adults. The KIT-Macquarie Brain Research Laboratory at Macquarie University uses a MEG system custom sized to fit the heads of pre-school children. This child system has 64 first-order axial gradiometers with a 50 mm baseline[2] and is contained inside a magnetically-shielded room (MSR) together with a conventional adult-sized MEG system [3,4]. There are three main advantages of the customized helmet dewar for studying children. First, the smaller radius of the sensor configuration brings the SQUID sensors into range of the neuromagnetic signals of children's heads. Second, the smaller helmet allows full insertion of a child's head into the dewar. Full insertion is prevented in adult dewar helmets because of the smaller crown to shoulder distance in children. These two factors are fundamental in recording brain activity using MEG because neuromagnetic signals attenuate rapidly with distance. Third, the customized child helmet aids in the symmetric positioning of the head and limits the freedom of movement of the child's head within the dewar. When used with a protocol that aligns the requirements of data collection with the motivational and behavioral capacities of children, these features significantly facilitate setup, positioning, and measurement of MEG signals.

Measurement Of Neuromagnetic Brain Function In Pre-school Children With Custom Sized MEG

Magnetoencephalography is a technique that detects magnetic fields associated with cortical activity [1]. The electrophysiological activity of the brain generates electric fields - that can be recorded using electroencephalography (EEG)- and their concomitant magnetic fields - detected by MEG. MEG signals are detected by specialized sensors known as superconducting quantum interference devices (SQUIDs). Superconducting sensors require cooling with liquid helium at -270 °C. They are contained inside a vacumm-insulated helmet called a dewar, which is filled with liquid. SQUIDS are placed in fixed positions inside the helmet dewar in the helium coolant, and a subject's head is placed inside the helmet dewar for MEG measurements. The helmet dewar must be sized to satisfy opposing constraints. Clearly, it must be large enough to fit most or all of the heads in the population that will be studied. However, the helmet must also be small enough to keep most of the SQUID sensors within range of the tiny cerebral fields that they are to measure. Conventional whole-head MEG systems are designed to accommodate more than 90% of adult heads. However adult systems are not well suited for measuring brain function in pre-school chidren whose heads have a radius several cm smaller than adults. The KIT-Macquarie Brain Research Laboratory at Macquarie University uses a MEG system custom sized to fit the heads of pre-school children. This child system has 64 first-order axial gradiometers with a 50 mm baseline[2] and is contained inside a magnetically-shielded room (MSR) together with a conventional adult-sized MEG system [3,4]. There are three main advantages of the customized helmet dewar for studying children. First, the smaller radius of the sensor configuration brings the SQUID sensors into range of the neuromagnetic signals of children's heads. Second, the smaller helmet allows full insertion of a child's head into the dewar. Full insertion is prevented in adult dewar helmets because of the smaller crown to shoulder distance in children. These two factors are fundamental in recording brain activity using MEG because neuromagnetic signals attenuate rapidly with distance. Third, the customized child helmet aids in the symmetric positioning of the head and limits the freedom of movement of the child's head within the dewar. When used with a protocol that aligns the requirements of data collection with the motivational and behavioral capacities of children, these features significantly facilitate setup, positioning, and measurement of MEG signals.

The Effect of Reducing the Number of Electrodes on Spatial Hearing Tasks for Bilateral Cochlear Implant Recipients

Many studies have documented the effect of reducing spectral information for speech perception in listeners with normal hearing and hearing impairment. While it is understood that more spectral bands are needed for unilateral cochlear implant listeners to perform well on more challenging listening tasks such as speech perception in noise, it is unclear how reducing the number of spectral bands or electrodes in cochlear implants influences the ability to localize sound or understand speech with spatially separate noise sources. The purpose of this study was to measure the effect of reducing the number of electrodes for patients with bilateral cochlear implants on spatial hearing tasks. Performance on spatial hearing tasks was examined as the number of bilateral electrodes in the speech processor was deactivated equally across ears and the full frequency spectrum was reallocated to a reduced number of active electrodes. Program parameters (i.e., pulse width, stimulation rate) were held constant among the programs and set identically between the right and left cochlear implants so that only the number of electrodes varied. Nine subjects had used bilateral Nucleus or Advanced Bionics cochlear implants for at least 12 mo prior to beginning the study. Only those subjects with full insertion of the electrode arrays with all electrodes active in both ears were eligible to participate. Two test measures were utilized to evaluate the effect of reducing the number of electrodes, including a speech-perception-in-noise test with spatially separated sources and a sound source localization test. Reducing the number of electrodes had different effects across individuals. Three patterns emerged: (1) no effect on localization (two of nine subjects), (2) at least two to four bilateral electrodes were required for maximal performance (five of nine subjects), and (3) performance gradually decreased across conditions as electrode number was reduced (two of nine subjects). For the test of speech perception in spatially separated noise, performance was affected as the number of electrodes was reduced for all subjects. Two categories of performance were found: (1) at least three or four bilateral electrodes were needed for maximum performance (five of seven subjects) and (2) as the number of electrodes were reduced, performance gradually decreased across conditions (two of seven subjects). Large individual differences exist in determining maximum performance using bilateral electrodes for localization and speech perception in noise. For some bilateral cochlear implant users, as few as three to four electrodes can be used to obtain maximal performance on localization and speech-in-noise tests. However, other listeners show a gradual decrement in performance on both tasks when the number of electrodes is reduced.

Concurrent Cochlear Implantation with Resection of Skull Base Hemangiopericytoma following Sudden Deafness in an Only Hearing Ear

A 72-year-old man with a known left acoustic neuroma, left-sided deafness, and a recently diagnosed right infratemporal fossa (ITF) hemangiopericytoma, presented with sudden deafness in his right ear. Imaging revealed right-sided skull base extension and a large intracranial tumor component. The patient underwent a frontotemporal crainiotomy with concomitant ITF approach. Complete tumor resection was possible, though invasion of the otic capsule was present. Immediately postresection, a cochlear implant (CI) was performed via a transmastoid approach. Full electrode insertion was achieved and confirmed by visualization through the dehiscent middle fossa floor. Mastoid obliteration was then performed with a free fat graft. Postoperative imaging confirmed complete tumor resection (Simpson grade I) and adequate CI placement. Follow-up magnetic resonance imaging was performed at 6 and 12 months, and no tumor recurrence was seen. Prior to CI activation, the patient was completely deaf bilaterally. At 18-month follow-up, however, excellent hearing was achieved with the right CI (16 of 22 electrodes active), and the patient is now conversational with no obvious deficit. His cognitive function is excellent, corresponding to preoperative status, and he is independent in his activities of daily living. Following adjuvant radiation, our patient remains disease free at 18 months.

MnO powder as anode active materials for lithium ion batteries

MnO powder materials are investigated as anode active materials for Li-ion batteries. Lithium is stored reversibly in MnO through conversion reaction and interfacial charging mechanism, according to the results of ex situ XRD, TEM and galvanostatic intermittent titration technique. A layer of the solid electrolyte interphase with a thickness of 20–60 nm is covered on MnO particles after full insertion. MnO powder materials show reversible capacity of 650 mAh g −1 with average charging voltage of 1.2 V. It can deliver 400 mAh g −1 at a rate of 400 mA g −1. The cyclic performance of MnO is improved significantly after decreasing particle size and coating with a layer of carbon. Among observed transition metal oxides, MnO shows relatively lower voltage hysteresis (<0.7 V) between the discharging and the charging curves at 0.05 C. In addition to its environmental benign feature and high density (5.43 g cm −3), MnO seems a promising high capacity anode material for Li-ion batteries among transition metal oxides. However, the initial columbic efficiency is less than 65% and the voltage hysteresis is still too high. The origins of them are discussed.

A biomechanical study on preloaded compression effect on headless screws

Commonly used headless design screws such as Acutrak and Herbert screws have limited compressive effect on short fragment fixation. Therefore, we investigated whether preloaded compression techniques could be helpful in improving the compression effect. A prototype of interfragmentary compression screw was designed with a constant pitch to avoid self-compressive effect. Preloaded compression was achieved with a sleeve device before the insertion of the trailer side (the leading side was inserted). Prototype screw test results were compared with those of Acutrak and Herbert screws. Eight pullout and eight compression tests were performed for each of the three screws using homogenous synthetic bone blocks. The mean pullout forces of the Acutrak, Herbert and prototype screws were 67.21, 45.90 and 61.88 N, respectively. Preloaded compression (18.15 N) was higher than the compression produced by Acutrak (15.27 N) and Herbert (15.11 N) screws (p < 0.05). However, at the end of full insertion, half of the power obtained by preloaded compression was lost. Preloaded compression technique was successful in attaining maximum compression rate. During trailing-side insertion, constant pitch design failed to keep compression rate. Variable pitches can be useful to preserve or increase compression rate. In addition, sleeve usage may be more advantageous in thin fragment fixation.

Speech Perception after Cochlear Implantation in 53 Patients with Otosclerosis: Multicentre Results

Objectives: To analyse the speech perception performance of 53 cochlear implant recipients with otosclerosis and to evaluate which factors influenced patient performance in this group. The factors included disease-related data such as demographics, pre-operative audiological characteristics, the results of CT scanning and device-related factors. Methods: Data were reviewed on 53 patients with otosclerosis from 4 cochlear implant centres in the United Kingdom and the Netherlands. Comparison of demographics, pre-operative CT scans and audiological data revealed that the patients from the 4 different centres could be considered as one group. Speech perception scores had been obtained with the English AB monosyllable tests and Dutch NVA monosyllable tests. Based on the speech perception scores, the patients were classified as poor or good performers. The characteristics of these subgroups were compared. Results: There was wide variability in the speech perception results. Similar patterns were seen in the phoneme scores and BKB sentence scores between the poor and good performers. The two groups did not differ in age at onset of hearing loss, duration of hearing loss, progression, age at onset of deafness, or duration of deafness. Conclusions: The clinical presentation of the otosclerosis (rapid or slow progression) did not influence speech perception. Better performance was related to less severe signs of otosclerosis on CT scan, full insertion of the electrode array, little or no facial nerve stimulation and little or no need to switch off electrodes.

Cochlear implantation following treatment for medulloblastoma

Medulloblastoma is the most common pediatric malignant tumor of the central nervous system in children. Treatment includes surgical excision, external beam radiation, and multiagent chemotherapy. Otologic sequelae are common and may result from radiation and/or chemotherapy. Profound sensorineural hearing loss (SNHL) is a known complication of neuro-oncologic treatment and may render these patients eligible for cochlear implantation (CI). Issues of CI in this population, including diagnosis, treatment of preoperative middle ear disease, operative and postoperative course, performance data, and long-term tumor surveillance are highlighted and reviewed. Retrospective chart review. Three patients treated for pediatric medulloblastoma with surgical resection, postoperative hyperfractioned craniospinal radiotherapy, and multiagent adjuvant chemotherapy who underwent cochlear implantation were identified. Details of neuro-oncologic treatment and associated otologic complications are presented and analyzed. Primary outcome assessment includes treatment of middle ear pathology, perioperative cochlear implant course, and postimplantation performance data. Each patient required surgical treatment of chronic ear disease 4 to 16 years after chemoradiation. All progressed to profound SNHL and were implanted 8 to 17 years post-neuro-oncologic treatment. There were no intraoperative complications, and full insertion of the cochlear implant electrode array was achieved in each patient. One patient developed postoperative wound dehiscence requiring operative closure. Postimplantation performance data support significant benefit in all patients. Patients treated for pediatric medulloblastoma develop otologic sequelae, including profound SNHL, and may require cochlear implantation. Successful management of middle ear and mastoid pathology involves consideration of potential future cochlear implantation. Postoperative performance data supports cochlear implantation in this population.

Intact meatal skin, canal wall down approach for difficult cochlear implantation

The intact posterior meatal skin, canal wall down technique for difficult cochlear implantation provides expanded access to the middle ear for cochleostomy in cases of obscured middle-ear landmarks, limited facial recess access and limited mastoid cavity dimensions. Careful preservation of the posterior canal wall skin in this procedure obviates the need for obliteration of the middle-ear mucosa and closure of the external auditory canal. To present a canal wall down technique for cochlear implantation, which preserves the intact posterior external auditory canal wall skin. This approach is employed when a standard facial recess cochleostomy is not possible. Three cases of intact posterior meatal skin, canal wall down cochlear implantation are presented together with long-term follow-up results. In all three cases, implantation via a facial recess approach was not possible. One patient suffered from severe cochlear otosclerosis with obliteration of the round window niche. The second patient had severe middle-ear fibrosis with encasement of all middle-ear structures and obliteration of routine landmarks. The third patient had an anterior sigmoid sinus obscuring access to the facial recess. Cochlear implantation via the canal wall down, intact posterior canal wall skin technique was successfully performed in each of these patients. All three patients were successfully implanted, with full electrode insertion achieved. All patients subsequently became active implant users. One patient did suffer from a minor wound complication post-operatively, unrelated to the approach. Patient follow up ranged from four to six years.

The Spanish Case for Europe. The Power of Cultural Identity

Europe has not been for Spain an easily assumed identity, a home within which Spaniards could find accommodation. Yet, for the first time in modern history, Spain has become fully integrated in the political and economic system of Europe and it functions within it as a strong and dedicated partner. Paradoxically, this new order has developed simultaneously with the increasing assertion of the local nationalities. I propose that the current political and cultural situation in both Europe and Spain has created the appropriate conditions for an extensive reexamination of the conventional European/Spanish paradigm. That is so because the circumstances on both ends of the relation have changed and, for the first time, both sides not only desire but they need the reconstruction and redefinition of a relation that has been destructive for both parts. What Francisco José de Goya, Julián Sanz del Río, and Manuel Azaña, among others, conceived as a nearly impossible and illusory task can now become a reality. From Francisco Zurbarán, El Greco and Pedro Calderón de la Barca to Federico García Lorca, Luis Buñuel and Pablo Picasso, the various manifestations of its culture have been Spain’s unquestioned achievement. This cultural continuum is the most promising entryway for Spain in the Heimat of Europe. I also propose that the issue of the various historical nationalities within Spain can be approached from the perspective of what Andrzej Stasiuk calls the “private histories” of the minorities of Europe. In the last part of the article, I study Spain’s transcontinental identity. Without ignoring the legitimate issues raised by private narratives, I suggest that the country’s full insertion in the global reality and its immersion in realities that are beyond its own will lead to the contextualization of the internal national divide and the emergence of new and more productive approaches towards its resolution.

Labyrinthitis ossificans: How accurate is MRI in predicting cochlear obstruction?

Objective To determine the accuracy of preoperative MRI in predicting cochlear obstruction in pediatric patients with a history of bacterial meningitis. Methods A case series with chart review was performed at a tertiary care multidisciplinary cochlear implant program. Forty-five children with hearing loss that resulted from bacterial meningitis were implanted from 1991 to 2006. Twenty-five children had preoperative MRI with high-resolution axial T2-weighted images to assess for cochlear patency. Results Seventeen of 25 patients (68%) had surgical evidence of cochlear obstruction. Six patients (37.5%) required circummodiolar drill-outs, and one patient (6.25%) underwent placement of a double array cochlear implant. The nine remaining patients (56%) with cochlear obstruction required removal of fibrous tissue or drilling of the inferior basal turn, but did not require manipulation of the ascending basal turn to achieve full electrode insertion. The sensitivity, specificity, and positive and negative predictive value of MRI predicting intraoperative cochlear obstruction with 95 percent confidence intervals was 94.1 percent (71-99), 87.5 percent (47-99), 94.1 percent (71-99) and 87.5 percent (47-99), respectively. Conclusion Preoperative high-resolution T2 MRI may be useful in predicting cochlear obstruction in patients with a prior history of bacterial meningitis.

Subjective and Objective Results After Bilateral Cochlear Implantation in Adults

To assess and compare subjective and objective results after bilateral cochlear implantation with a special emphasis on time interval between the first and second implant. Clinical trial. Tertiary referral center. All consecutively bilaterally implanted adult patients who had used the second implant for more than 6 months were selected for the study. They had to have the mental capacity to answer questions regarding their hearing abilities and fill out a questionnaire (n = 34). Twenty-nine patients (85%) finally could be included in the study (age at first implantation, 31.0 +/- 16 yr [mean +/- standard deviation {SD}], time to second implantation, 5.6 +/- 5.7 yr [mean +/- SD]). In all patients, a full insertion (21 electrodes) of the implant was achieved. For the subjective part of the study, the patients were matched with unilaterally implanted subjects selected according to specified criteria. Sequential or simultaneous cochlear implantation with a Nucleus device. Speech comprehension measures were performed using the Oldenburger sentences in quiet and in noise with unilateral and bilateral implant use. Summation effect, head shadow effect, squelch effect, and interaural difference in quiet and noise were calculated. Advantage for binaural stimulation with respect to the unilateral condition was assessed for each individual. Additionally, a localization test was performed using 12 speakers arranged in a circle. Subjective benefit was assessed by a questionnaire (The Speech, Spatial and Qualities of Hearing Scale). Results were analyzed with special emphasis on effects of timing and intervals. There was a statistically significant advantage for the head shadow effect test (p < 0.05) when the sound source was located on the activated side. There was also a statistically significant correlation of the subjective and objective results and a strong correlation of the interaural difference of speech intelligibility in quiet and the time interval between the first and the second implant (p < 0.001; r = 55%). In the bi-implanted state, an interaural difference of 18 +/- 27% and 3 +/- 2.2 dB signal-to-noise ratio (mean +/- SD) was measured in quiet and noise, respectively. The mean results for the bilateral condition for the summation effect, the squelch effect, and speech discrimination in quiet were better than in the unilateral condition but were not statistically significant. The subjective results of the bilateral group were better in all categories than the results of the unilateral group but were just below statistical significance. Speech understanding in noise is improved with bilateral cochlear implantation with unambiguous evidence that the second implant expands the sound field for effective speech recognition. Communication in daily life is facilitated, as determined by the subjective Speech, Spatial and Qualities of Hearing Scale test. The correlation of the subjective and objective results confirms the practical benefits in daily activities. Although there was improvement with a second Cochlear implant even after a long implantation interval, short intervals lead to better results.

Normalized Distance Along the Colon Centerline: A Method for Correlating Polyp Location On CT Colonography and Optical Colonoscopy

OBJECTIVE. The ability to accurately locate a polyp found on CT colonography (CTC) at subsequent optical colonoscopy (OC) is an important part of the successful implementation of CTC for colorectal cancer screening. The purpose of this study was to determine whether a polyp's normalized distance along the colon centerline derived from CTC data can accurately predict its location on OC.MATERIALS AND METHODS. The polyp population consisted of 152 polyps in 121 patients. CTC polyp findings were verified by same-day segmentally-unblinded OC. Each polyp's normalized distance along the colon centerline was computed by dividing its distance from the anorectal junction measured along the colon centerline by the length of the colon at CTC. The predicted polyp location at OC was computed by multiplying the normalized distance along the colon centerline by the colon length at OC (i.e., the distance to the cecum as determined at full colonoscope insertion). The differences between the true and predicted polyp locatio...

The use of intra-operative electrical auditory brainstem responses to predict the speech perception outcome after cochlear implantation

Electrically evoked auditory brainstem responses (EABR) were obtained intra-operatively from children receiving full insertion of Cochlear CI24 implant. The EABR waveform was quantified according to the presence or absence of waves (eII-eV). Each trace was scored from 0–3 providing a maximum score for all 22 electrodes of 66 in the monopolar mode. Speech perception scores were measured after one year in 245 children and after two years of cochlear implant use in 148 children. Significant differences in the EABR waveforms were found between those recipients who achieved scores of 4 or greater on the Melbourne scale and those recipients who only had a modest outcome. After two years, the outcome showed even greater differences. The group of 103 children who had outcomes of 4 or greater at one year improved from a mean score of 4.7 to 5.7. The group of 45 children who had outcomes of 3 or less at one year only improved from a mean score of 2.9 to 3.15. In this latter group, only four children showed any significant improvement. Copyright © 2009 John Wiley & Sons, Ltd.

Technique of Open Ivor Lewis Esophagectomy

Technique of Open Ivor Lewis Esophagectomy

Auditory performance and central auditory processing after cochlear implantation in patients deafened by meningitis

The objective of this study was to describe the auditory performance of patients deafened by meningitis in closed-set, open-set and language tests (Luria's test). Ten paediatric subjects deafened by meningitis were compared with a peer group of ten paediatric congenitally deaf subjects. All the subjects had a full insertion of a Nucleus device. Three of the subjects in each group had a longer follow-up period and were selected to perform the Luria test. The closed-set tests did not show statistically significant differences between the two groups (p < 0.21) but comparative results of open-set bisyllabic tests did show statistically significant differences (p < 0.003). It was concluded that meningitis might affect the central auditory processing and acquisition process of language. Copyright © 2009 John Wiley & Sons, Ltd.

La participación y su viabilidad en Costa Rica

Recibido 03 de agosto 2007 • Aprobado 20 de noviembre 2007&#x0D; &#x0D; &#x0D; Este artículo reflexiona sobre la legislación existente en Costa Rica en lo referente a participación comunal y estudiantil.&#x0D; Está enfocado en las comunidades rurales, por ser lugares con serias limitaciones, pero a la vez, con grandes potencialidades para el desarrollo.&#x0D; Se hace necesaria una educación para la participación efectiva del habitante rural, desde sus primeros aprendizajes, para lograr una inserción plena y efectiva de éstos en el mercado nacional y global.&#x0D;