Biomedical subjects

Blake C Papsin

Publications and source records attributed to Blake C Papsin.

At least 19 recordsLinked to original sources

PubMed2007

Bone-anchored hearing aids in infants and children younger than 5 years.

OBJECTIVE: While bone-anchored hearing aids (BAHAs) are currently indicated for rehabilitation in children older than 5 years with bilateral maximal conductive hearing loss, our objective was to capitalize on potentially important stages of auditory and speech-language development by providing BAHAs to children younger than 5 years. DESIGN: A retrospective review of surgical data of children receiving BAHA implants over a 10-year period. SETTING: The Hospital for Sick Children, Toronto, Ontario. PATIENTS: Twenty children 5 years or younger (mean +/- SD age, 3.21 +/- 1.65 years) served as the study group, while 20 older children (mean +/- SD age, 7.63 +/- 1.55 years) served as the comparison group. INTERVENTIONS: All patients received BAHA implants. Children with cortical bone thickness less than 2.5 mm underwent a 2-stage procedure; children with cortical bone thickness greater than 4 mm underwent a single-stage procedure. MAIN OUTCOME MEASURES: Traumatic and skin revision complication rates and implantation interstage intervals were compared between groups. RESULTS: The mean +/- SD interstage interval was 7.72 +/- 3.81 months for the younger children, which was significantly longer than for the older children (4.41 +/- 2.51 months) (P<.003). Two traumatic fixture losses occurred in the younger children, while 4 occurred in the older children. Skin site revision was required in 3 younger children. All children are currently wearing their BAHAs. CONCLUSION: Two-stage BAHA implantation with a prolonged interval between stages yields surgical success in younger children comparable to that routinely observed in older children.

Child, Preschool↗

PubMed2006

The role of conservative management in congenital tracheal stenosis: an evidence-based long-term follow-up study.

BACKGROUND/PURPOSE: Surgery has been the management of choice for severe congenital tracheal stenosis (CTS). The role of conservative management of CTS however is not clear. The aim of this study is to characterize the natural history of CTS, review the radiologic evidence of tracheal growth, and evaluate the clinical outcome and selection criteria of conservative management of CTS. METHODS: A retrospective study was carried out on 22 consecutive children with symptomatic CTS admitted into a single institution between 1982 and 2001. The patients were categorized into operation (n = 11) and observation (n = 11) groups. Six patients of the observation group were followed up with serial computed tomography scan. Their tracheal growth was compared with that of healthy children of the same age. RESULTS: The mortality rates of observation and operation groups were 9% and 27%, respectively, although the latter group consisted of more severely affected patients. The pathologic categorization of the CTS influenced the survival rates (P = .046, chi2), with the long segment type having the worst prognosis (67%). Serial computed tomography scans of 6 conservatively managed patients revealed that all stenotic tracheas continued to grow (P = .039, 2-tailed paired Student's t test). Of the 6 stenotic tracheas, 5 grew at a faster-than-normal rate, and the stenotic tracheal diameters approached those of normal diameters by the age of 9 years. CONCLUSIONS: The management of patients with symptomatic CTS should be individualized. A selected group of patients with CTS can be safely managed nonoperatively.

Disease Progression↗

PubMed2006

Auditory responses in cochlear implant users with and without GJB2 deafness.

OBJECTIVE/HYPOTHESIS: It is reasonable to suppose that the pattern of sensorineural damage along the length of the cochlea depends on the etiology of a hearing loss (HL). In GJB2-related deafness, we hypothesize that gap junction deficits are uniformly distributed and will result in similar damage along the length of the cochlea as compared with non-GJB2 subjects. We assessed this by measuring patterns of neural activity and hearing from apical versus basal cochlear implant electrode regions. STUDY DESIGN: This was a prospective, blind, controlled study. METHODS: Blood from 301 pediatric cochlear implant users was analyzed for mutations in GJB2 by direct sequencing. After exclusion of patients with monoallelic GJB2 mutations, associated syndromes, or risk factors for HL that were not congenital, 39 children with biallelic GJB2 mutations and 58 without GJB2 mutations were evaluated. Hearing was measured before implantation at frequencies ranging from 250 Hz to 8 kHz. After implantation, neural activity at the apical and basal ends of the implanted array was measured using electrically evoked compound action potentials of the auditory nerve (ECAPs) and evoked stapedius reflexes (ESRs). RESULTS: GJB2 and non-GJB2 groups were not significantly different with respect to sex, age at implantation, duration of auditory deprivation, hearing aid use, duration of aided hearing, ear implanted, implant model, or depth of insertion (P>.05). Children with GJB2-related HL had greater similarities between low- and high-frequency residual hearing and between neural activity electrically evoked at apical and basal regions of the cochlea as compared with children with non-GJB2-related HL who demonstrated larger deficits in basal regions. CONCLUSION: Results suggest more consistent spiral ganglion survival along the length of the cochlea in GJB2-related HL as compared with non-GJB2-related HL, which appears to involve a decreasing gradient of spiral ganglion survival from the apex to the base of the cochlea. Our findings support our premise that in GJB2-related HL, dysfunction of gap junctions likely occurs to a similar degree in the apical and basal regions of the cochlea. This knowledge might be used to customize implantable devices for patients with HL in the future.

Adolescent↗

PubMed2006

Incidence and characteristics of facial nerve stimulation in children with cochlear implants.

OBJECTIVES: Electrical stimulation from a cochlear implant can spread beyond the auditory nerve. The aims of this study were to accurately measure facial nerve stimulation in pediatric implant users and to determine the characteristics and incidence of this unwanted activity. Part A consisted of a prospective study of a randomized sample of 44 pediatric implant users. Part B consisted of a retrospective analysis of 121 children with previously recorded electrically evoked auditory brainstem responses (EABR). STUDY DESIGN AND METHODS: Responses were evoked by 3 electrodes along the implant array in three groups of children: 1) postmeningitic, 2) abnormal cochlea, and 3) neither. Intraoperative measures were obtained under anesthesia; all other recordings were completed in awake children. RESULTS: Intraoperative recordings revealed large nonauditory responses in a number of channels, including the midline EABR. Under paralysis, these responses disappeared, and clear EABRs were recorded. Similarly, prospective postoperative electromyographic (EMG) responses from the facial nerve were found in more than 59% (26 of 44) of experienced implant users (Nucleus 24): 31% of postmeningitic children (4 of 13), 80% of those with abnormal cochlea (8 of 10), and 66% of those with neither (14 of 21). Retrospective analysis of previously recorded postoperative EABRs demonstrated facial nerve stimulation in 35% (42 of 121). In most cases, facial nerve stimulation occurred when levels were perceptually loud but comfortable. CONCLUSIONS: 1) Facial nerve potentials can be recorded using EMG in a large proportion of cochlear implant users at high levels of stimulation. 2) The EABR can be obscured in the presence of facial nerve stimulation and care should be taken to distinguish it from the EMG response, particularly when auditory brainstem activity is in question. 3) Use of surface EMG provides an additional objective measure to ensure the safe and comfortable use of cochlear implants.

Auditory Perception↗

PubMed2006

Temporal bone imaging in GJB2 deafness.

OBJECTIVE: To describe temporal bone findings on computed tomography (CT) imaging in GJB2-related hearing loss (HL). We asked whether evaluation of the temporal bone is required in individuals with biallelic GJB2 mutations. STUDY DESIGN: Randomized, blinded, controlled, prospective measurement. METHODS: Blood from 264 pediatric cochlear implant users was analyzed for mutations in the GJB2 gene. Thirty-six aspects of the temporal bone on CT imaging were evaluated in 53 individuals (106 ears) with biallelic disease causing GJB2 mutations. A subset of patients was age matched and compared with normally hearing individuals. Subjects with biallelic GJB2 mutations were tested for mutations in the SLC26A4 gene to rule out Pendred syndrome as a confounding cause of large vestibular aqueduct syndrome. RESULTS: Approximately 53% of ears of subjects (72% of subjects) with biallelic GJB2 mutations had at least one temporal bone anomaly. The most common findings were 1) dilated endolymphatic fossa (28%); 2) hypoplastic modiolus (25%); 3) large vestibular aqueduct (8%); 4) hypoplastic horizontal semicircular canal (8%); 5) hypoplastic cochlea (4%). Compared with normally hearing individuals, the GJB2 group had hypoplasia of the cochlear nerve canal, lateral semicircular canal vestibule, internal auditory canal (t tests, P < .001), and were 11 times more likely to have a hypoplastic modiolus. Dilated endolymphatic fossae were 1.4 times more common in the GJB2 group, and large vestibular aqueducts were 3 times more common in the GJB2 group, as compared with normally hearing controls. CONCLUSIONS: Temporal bone anomalies are common in GJB2-related HL, and imaging of the temporal bone should be included in routine evaluation of these individuals.

Child↗

PubMed2006

Inner ear dysplasia is common in children with Down syndrome (trisomy 21).

OBJECTIVES/HYPOTHESIS: Middle and external ear anomalies are well recognized in Down syndrome (DS, trisomy 21). Inner ear anomalies are much less frequently described. This study reviews inner ear morphology on imaging to determine the prevalence of cochlear and vestibular anomalies in children with DS. STUDY DESIGN: The authors conducted a retrospective review of imaging features of (DS) inner ear structures. METHODS: Fifty-nine sequential patients with DS with imaging of the inner ear were identified by a radiology report text search program. Quantitative biometric assessment of the inner ear was performed on patients with high-resolution computed tomography or magnetic resonance images of the petrous bone. Petrous imaging was performed for evaluation of inflammatory disease or hearing loss. Spinal imaging, which included petrous views, was performed in most cases to exclude C1 to 2 dislocation, a potential complication of DS. Measurements were compared with normative data. RESULTS: Inner ear dysplasia is much more common in DS than previously reported. Inner ear structures are universally hypoplastic. Vestibular malformations are particularly common and a small bony island of the lateral semicircular canal (<3 mm in diameter) appears highly typical. Additional findings in some patients were persistent lateral semicircular anlage with fusion of the lateral semicircular canal and vestibule into a single cavity, vestibular aqueduct and endolymphatic sac fossa enlargement, cochlear nerve canal hypoplasia, and stenosis or duplication of the internal auditory canal. Stenosis of the external meatus, poor mastoid pneumatization, middle ear and mastoid opacification, and cholesteatoma were common, as expected.

Adolescent↗

PubMed2006

Multidimensional voice program analysis in profoundly deaf children: quantifying frequency and amplitude control.

Characterization of the vocal profile of profoundly deaf children using an objective voice analysis was carried out in a university-based pediatric otolaryngology clinic. 21 persons ages 3.5 to 18 years were assessed. From each sustained phonation of the vowel /a/ the following acoustic variables were extracted: fundamental frequency (F0), jitter percentage, shimmer percentage, fundamental frequency variation (vF0), peak amplitude variation (vAM), and first, second, and third formant frequencies (F1, F2, F3). Mean F0 was 267.8 Hz and consistent with established normative data. Mean measurements of jitter (0.88%) and shimmer (3.5%) were also within normal limits. The notable feature of the acoustic analysis was a statistically significant elevation in vF0 (2.81%) and vAM (23.58%). With the exception of one subject, the F1, F2, and F3 formant frequencies were comparable to those for normal hearing children. Auditory deprivation results in poor long-term control of frequency and amplitude during sustained phonation. The inability to maintain a sustained phonation may represent the partial collapse of an internal model of voice and speech.

Adolescent↗

PubMed2005

Atypical cortical responses underlie poor speech perception in children using cochlear implants.

Variability in speech perception abilities after years of cochlear implant use could reflect differences in central auditory processing of the electrical input provided. Cortical responses were measured in 23 experienced pediatric cochlear implant users who were 12.3+/-3.1 years of age at testing and had used their implants for 6.0+/-2.9 years. All had prelingual onset of deafness. An observer identified blind three types of cortical waveforms ranging from those similar to previous reports to more atypical responses. Children displaying atypical types of responses were implanted at a wide range of ages and had significantly poorer behavioral speech perception scores (P<0.05) than their peers with expected waveforms. Results suggest a persistent immaturity and/or abnormal organization in the auditory cortex in some children.

Age Factors↗

PubMed2005

An evoked potential study of the developmental time course of the auditory nerve and brainstem in children using cochlear implants.

Central auditory responses to electrical stimulation from a cochlear implant were studied in 75 pre-lingually deafened children and 11 adults. Electrically evoked auditory brainstem response (EABR) latencies significantly decreased with duration of cochlear implant use and were not significantly affected by the age at implant activation. Significant decreases in early latency waves and interwaves occurred within the first 1-2 months of implant use, whereas longer term changes (6-12 months) were found for eV and eIII-eV, which measure activity in the more rostral brainstem. Comparisons to acoustically evoked auditory brainstem response (ABR) in children with normal hearing suggested shorter interwave EABR latencies, reflecting either distinct neural generators or increased neural synchrony, but similar rates of change in the later latency eV and eIII-eV with time in sound. In sum, normal-like development of the rostral auditory brainstem is promoted by cochlear implant use in children of a wide range of ages.

Adolescent↗

PubMed2005

Effects of cochlear implant use on the electrically evoked middle latency response in children.

The electrically evoked middle latency response (eMLR) reflects central auditory activity in cochlear implant users. This response was recorded repeatedly in 50 children over the first year of cochlear implant use and in 31 children with 5.3+/-2.9 years of implant experience. The eMLR was rarely detected at the time of implantation in anaesthetized or sedated children and was detected in only 35% of awake children at initial device stimulation. The detectability of the eMLR increased over the first year of implant use becoming 100% detectable in children after at least one year. Acutely evoked responses were more likely to be present in older children despite longer periods of auditory deprivation. Within six months of implant use, most children had detectable eMLRs. At early stages of device use, eMLR amplitudes were lower in children implanted below the age of 5 years compared to children implanted at older ages; amplitudes increased over time in both groups. Latencies after six months of implant use were prolonged in the younger group and decreased with implant use. EMLR changes with chronic cochlear implant use suggest an activity-dependent plasticity of the central auditory system. Results suggest that the pattern of electrically evoked activity and development in the auditory thalamocortical pathways will be dependent upon the duration of auditory deprivation occurring in early childhood.

Adolescent↗

PubMed2005

Retropharyngeal and parapharyngeal infections in children: the Toronto experience.

OBJECTIVE: To review the Hospital of Sick Children, Toronto's experience of the diagnosis and management of retropharyngeal and parapharyngeal infections with particular emphasis on the role of computed tomography (CT) imaging in diagnosing the presence of an abscess. METHODS: A retrospective analysis of all patients diagnosed with retropharyngeal and parapharyngeal infections from 1987 to 1999 was performed. Demographic data, presenting symptoms, season of presentation, management and complications were reviewed. The CT scans of 27 patients who underwent surgical treatment were retrospectively examined by two neuroradiologists who were blinded to the patient's history and outcome. The sensitivity, specificity and predictive values for the specific features and overall assessment were calculated. RESULTS: Fifty-four children were identified. There were 46 retropharyngeal infections, 6 parapharyngeal infections and 2 patients had both retropharyngeal and parapharyngeal infections. All patients were treated with parenteral antibiotics. Thirty-seven patients underwent surgical drainage and in 27 there was a positive finding of pus. The retrospectively assessed CT scans of the 21 patients who underwent surgery were found to have a sensitivity of 81% in detecting an abscess by CT scan but the specificity was 57%. There were four complications including mediastinitis, aspiration pneumonia, internal jugular vein thrombosis and common carotid artery aneurysm. All patients recovered but abscess recurred in five patients. CONCLUSION: Not all patients with retropharyngeal and parapharyngeal abscesses require surgery. Whilst CT scans are helpful in diagnosing and assessing the extent of these infections they are not always accurate in detecting an abscess. A decision to drain an abscess should therefore not be made based solely on the CT findings.

Abscess↗

PubMed2005

Conversion disorder in a child presenting as sudden sensorineural hearing loss.

Pseudohypoacacusis is a form of conversion disorder in which a hearing loss is found in the absence of organic disease. A case of an 11-year-old boy with auditory conversion disorder after mild head trauma is reported. The child presented with unilateral hearing loss, with no accompanying vestibular symptoms and no history of otologic disease. Auditory testing revealed severe right-sided sensorineural hearing loss, however, CT scan was normal. There was a family history of conversion disorder and the child was undergoing an emotionally stressful period. It was decided to treat the child conservatively with close monitoring and a repeat audiogram 2 weeks later. One week after presentation, the child's hearing suddenly returned to normal after a second very minor head injury. It is important to consider pseudohypoacusis or conversion disorder even in cases such as trauma, when the clinical history supports a diagnosis of hearing loss.

Audiometry, Pure-Tone↗

PubMed2005

Cochlear implantation in children with anomalous cochleovestibular anatomy.

OBJECTIVES/HYPOTHESIS: To evaluate outcomes after cochlear implantation in children with anomalous cochleovestibular anatomy, a review of radiological classification, surgical implantation, and outcome of 103 children with such anomalies was performed. The hypothesis was that children with anomalous cochleovestibular anatomy would have poorer outcomes and therefore be poorer candidates as a result of their diminished ability to interpolate and use auditory information delivered through a cochlear implant. STUDY DESIGN: A series of studies was carried out to review the cochleovestibular anomalies among 298 children implanted over the decade ending in January 2002. Children were grouped based on cochleovestibular anatomy as follows: normal (n = 195), common cavity deformity (n = 8), hypoplastic cochlea (n = 16), incomplete partition (n = 42), and vestibular aqueduct enlargement (n = 37). Concomitant anomalies of the posterior labyrinth (n = 26) and internal auditory canal/cochlear canal (n = 11) were also identified. Findings at surgery, postoperative speech perception outcomes, and speech processor programmability were examined as a function of cochleovestibular anatomy. METHODS: A database containing demographics (age at implant, duration of implant use), audiological characteristics, pure-tone average, surgical findings (cerebrospinal fluid leak/perilymph leak, abnormal facial nerve anatomy), speech perception data (from two closed-set and three open-set tests), and data relating to speech processor programmability were used for analysis. Electrically evoked auditory brainstem response was measured in 94 of the children (2 cases of common cavity deformity, 7 of hypoplastic cochlea; 10 of incomplete partition; and 12 of vestibular aqueduct enlargement). Response morphological findings were assessed by visual inspection of the waveforms. Data were analyzed using analyses of variance with post hoc testing using the Bonferroni multiple-comparisons test. To further assess differences in outcomes between different categories of cochleovestibular anomalies, linear regression analyses were performed. The significance level was set at P < .05. RESULTS: The use of high-resolution imaging techniques resulted in the detection of a cochleovestibular anomaly in 35% of implanted ears. Implantation was more challenging in 24% of the children as a result of abnormal middle ear anatomy (17.5%) or cerebrospinal fluid leak/perilymph leak (6.7%). There was no significant difference in speech perception scores in children with anomalous cochleae compared with children with normal cochleovestibular anatomy. Children with narrowing of the internal auditory canal/cochlear canal performed more poorly than all other groups. Children with common cavity deformity and hypoplastic cochlea had reduced dynamic range and increased incidence of facial simulation and were judged to be more difficult to program despite the fact that no fewer electrodes were inserted. Children with common cavity deformity and hypoplastic cochlea tended to require wider pulse widths more often than children in other groups, and these requirements were associated with abnormal morphological findings on evoked auditory brainstem response testing. CONCLUSION: The authors have been continuing to assess the candidacy of each child applying for cochlear implantation individually, and the results of present study have suggested that the presence of anomalous cochleovestibular anatomy, with the exception of narrowing of the internal auditory canal/cochlear canal, should not play a significant role in candidacy assessment. Children with narrow internal auditory canal/cochlear canal should be carefully and individually considered. In children with anomalous cochleovestibular anatomy, the potentially increased difficulty in the establishment of optimal stimulation levels and the higher potential for surgical difficulty must be weighed in candidacy decisions but do not universally preclude successful implantation and a good outcome.

Cerebrospinal Fluid Otorrhea↗

PubMed2005

Temporal bone findings on computed tomography imaging in branchio-oto-renal syndrome.

OBJECTIVES/HYPOTHESIS: To describe temporal bone findings using visual inspection and direct measurement on computerized tomography (CT) in individuals with branchio-oto-renal syndrome (BOR). We ask if it is possible for the untrained observer to use a battery of CT observations as a tool in the overall evaluation of the BOR phenotype. STUDY DESIGN: Retrospective evaluation of CT findings in individuals with a clinical diagnosis of BOR based on criteria derived from genotype-phenotype analyses. METHODS: Prospective measurement of temporal bone CT imaging in 21 individuals (42 ears) with BOR and 21 normally hearing controls (21 ears) was performed. Thirty-nine aspects of each temporal bone were evaluated: 17 by direct measurement, 5 computed from direct measurement, and 17 by visual inspection. Thirty-eight recordings from each ear were made on axial section and 1 was made on coronal section. RESULTS: Statistically significant differences were found between BOR and control groups in 30 of 39 categories (76.9%). The most common and easily identifiable characteristics of BOR by visual inspection were 1) hypoplastic apical turn of the cochlea, 2) facial nerve deviated to the medial side of the cochlea, 3) funnel-shaped internal auditory canal, and 4) patulous eustachian tube. The embryological origin of temporal bone anomalies in BOR are described. CONCLUSIONS: CT evaluation of the temporal bone, when properly investigated, should be used as an important tool in the overall evaluation of the BOR phenotype.

Adolescent↗

PubMed2004

Device fixation and small incision access for pediatric cochlear implants.

OBJECTIVE: Small incision cochlear implant surgery has been advocated to improve cosmesis and reduce post-operative morbidity. However, with standard small incision techniques, it is not possible to securely fix the device in place. This risks displacement of the device, particularly in active children. This paper describes the development of a technique which combines secure ligature tie-down of the device with a small incision. METHODS: A 25 mm skin incision is positioned close to the hair line behind the pinna. Specially modified instruments are used to drill a well for the receiver-stimulator pedestal down to dura. In younger children, ligature tie-down holes are drilled through the calvarium. Alternative methods for older children are described. Outcome data are reviewed. RESULTS: One hundred children have been implanted with the small incision technique. No complications have occurred related to the current technique (maximum follow up 22 months). In five cases, during early development of the technique, the receiver-stimulator device was only secured by a tight periosteal pocket. In one of these cases, the device became dislodged from its well. CONCLUSIONS: Secure fixation of the receiver-stimulator unit of a cochlear implant is particularly important in children because of the risk of displacement with trauma. The conventional means of securing the device with a ligature has been combined with modified small incision techniques to meet this requirement successfully.

Adolescent↗

PubMed2004

Toward a battery of behavioral and objective measures to achieve optimal cochlear implant stimulation levels in children.

OBJECTIVES: Children require audible and comfortable stimulation from their cochlear implants immediately after device activation. To accomplish this, a battery of objective measures may be needed that could include the electrically evoked stapedius reflex (ESR), compound action potential from the auditory nerve (ECAP), and/or auditory brain stem response (EABR). In the present study, the following specific research questions were asked: In children using cochlear implants, 1) Can the ECAP, EABR, and ESR be recorded at the time of cochlear implantation? 2) What is the feasibility of measuring the ECAP, EABR, and the ESR repeatedly without the use of sedation over the first year of implant use? 3) Do ECAP, EABR, and ESR thresholds or behavioral measures change over time? 4) What is the relation between ECAP, EABR, and ESR thresholds and behavioral measures of threshold and comfortably loud levels? DESIGN: In 68 children, ECAP, EABR, and ESR responses as well as behavioral measures of stimulation threshold and maximum stimulation were recorded at regular intervals over the first year of implant use. In each child, responses were recorded to electrical pulses provided by three different electrodes along the implanted array. Visual inspections of the stapedius reflex (V-ESR) evoked by activation of the same three electrodes at the time of surgery were performed in an additional 20 children. RESULTS: ECAP and EABR measures were obtained in more than 84% of electrodes tested and 89% of children tested both in the operating room at the time of implant surgery (OR) and after surgery in nonsedated children. ESRs were recorded by using immittance measures in more than 65% of electrodes tested and 67% of children tested by 3 mo of implant use, but this technique was less successful in the OR and during early stages of device use. V-ESRs and ECAP thresholds were higher in the OR than ESRs and ECAPs at postoperative recording times. EABR and ECAP thresholds did not significantly change over the first 6 and 12 mo of implant use, respectively, whereas ESR thresholds increased. Behavioral measures of threshold decreased over time, whereas maximum stimulation levels rose over time. Behavioral measures of threshold and loudness were highly correlated at all test times. ECAP, EABR, and behavioral measures were lower when evoked by an electrode at the apical end of the implanted array than by more basal electrodes. Behavioral thresholds could be predicted mainly by ECAP thresholds, whereas maximum stimulation levels could best be predicted by ESR thresholds; both were significantly affected by the age at implantation. CONCLUSIONS: A combination of nonbehavioral measures can aid in the determination of useful cochlear implant stimulation levels, particularly in young children and infants with limited auditory experience. These measures can be made in the operating room and can be repeated after surgery when needed. Correction factors to predict threshold stimulation levels should be based on ECAP thresholds or EABR thresholds if necessary. Correction factors should be made for at least one apical and mid-array electrode, should take into account the age of the child, and may have to be revised during the first year of implant use. Maximum stimulation levels may be best determined by using the ESR.

Acoustic Stimulation↗

PubMed2004

Cochlear implant surgery at 12 months of age or younger.

OBJECTIVES: Early presentation of congenitally deaf children for cochlear implantation is leading to surgery in younger candidates. The safety of cochlear implantation in children aged 12 months and younger is reviewed with radiologic assessment of mastoid bone anatomy and surgical outcome data. STUDY DESIGN: Analysis of case records and temporal bone computed tomography (CT) scans with description of surgical technique in infants. METHODS: Chart analysis of children aged 12 months or younger at cochlear implantation. Mastoid bone anatomy was compared with older children (mean age 2 years) using CT scans. RESULTS: Twenty-five infants received implants at 7 to 12 months of age because of meningitis (n = 4) or early detection of deafness (n = 21). Mastoid marrow content on CT scan was significantly greater in this age group (P < .001 Mann-Whitney rank sum test), but pneumatization was always adequate for safe identification of surgical landmarks. The smaller size of the mastoid bone was not restrictive. An extended postauricular approach was used in the first 11 cases and a 2.5 cm hair-line incision in the remainder. Ligature tie-down of the device was completed in all cases. No complications occurred. All are full-time implant users, except one with other neurologic sequelae of preoperative meningitis. CONCLUSIONS: In our experience, cochlear implant surgery is safe in children aged 7 to 12 months with appropriate anesthetic and postoperative support. The small incision technique is particularly suited to this age group. Ligature fixation of the device is considered advisable because of the increased risk of displacement from frequent falls when learning to walk.

Age Factors↗

PubMed2004

Skin breakdown over cochlear implants: prevention of a magnet site complication.

OBJECTIVE: To determine the prevalence of inflammation of the skin around the magnet of cochlear implants. METHOD: A postal survey of 232 children implanted at The Hospital for Sick Children, Toronto, detailing the timing and severity of skin inflammation near the magnet. RESULTS: Sixty-three children (27%) had at least one episode of skin erythema at the magnet site. In most cases, this resolved after reducing magnet field strength. Nine children stopped wearing the device briefly, and five were treated with antibiotics. Skin ulceration occurred in two cases. No surgical treatment was required. Reactions tended to occur in younger children (2.8 vs 4.3 years; p = .002, Mann-Whitney rank sum test). CONCLUSIONS: Skin inflammation commonly occurs in children between magnets of the transmitter and receiver coils of a cochlear implant. If inflammation fails to resolve after loosening the magnet, use of the implant should be discontinued temporarily. Antibiotics should be prescribed for cellulitis to prevent an implant-threatening infection.

Adolescent↗