Audiological deficits in brain-injured children and adolescents

A retrospective chart review of 62 children aged 2 to 18.5 yean admitted over a 4-year period to a brain injury rehabilitation unit was performed. Glasgow Coma Scales were not always recorded at the referring institutions, but all but three of the children in the series experienced a period of unresponsiveness to the environment for a period of at least one hour. Available Glasgow Coma scores at the time of injury ranged from 3 to 13. Maximum coma duration was 3 months. All children received an audiological evaluation. Sixteen per cent of the children had conductive hearing losses, 13% had sensorineural hearing loss, and 16% had central auditory processing problems. Three of these children were found to have combined losses, one with both conductive and sensorineural hearing loss, and two with sensorineural hearing loss and central auditory processing problems. Of the five patients with the most severe injuries and prolonged comas, none had hearing deficits. Twenty-five of the 62 patients, or 40%, had hearing deficits, of which 15 are known to persist.     

Hearing loss in infants with congenital diaphragmatic hernia treated without extracorporeal membrane oxygenation: report of two cases

The authors report the cases of 2 infants with congenital diaphragmatic hernia (CDH) treated without extracorporeal membrane oxygenation (ECMO) therapy who were discovered to have hearing loss at 1 year of age. Both boys had been diagnosed as having CDH antenatally and were treated with surgery and high-frequency oscillatory (HFO) therapy. The patterns of hearing loss were consistent with sensorineural deafness and believed to be associated with HFO therapy, prolonged mechanical ventilation, and a high pH.     

Experience of the ENT clinic--rehabilitation hospital of Iaşi in the diagnosis of hearing loss in children between 1 and 5 years of age

The aim of this study is to asses the average age of diagnosis of congenital hearing loss in children up to 5 years old. A group of 48 children aged between 1-5 years old were admitted in our clinic in 2005 because of hearing impairment, noticed in most cases by their parents. All cases were investigated in our clinic by transient evoked oto-acoustic emission test, threshold auditory brainstem response, impedance-metry and, whenever possible, audiometry. Sensori-neural hearing loss of variable gravity was diagnosed in 30 cases, most of them in the 2-3 yrs group of age (9 cases). The etiology of hearing loss could be established in 9 cases only. 19 patients (63%) were hearing aided, but follow-up was not possible. The average age of congenital hearing loss diagnosis may be reduced by applying universal neonatal hearing screening and a well established modality of confirmation of deafness in infants identified by the universal screening.     

Hearing disorders screening in neonates at risk

The present report concerns a three year, eight month hearing screening in 1 531 high-risk neonates by means of two successive transient evoked otoacoustic emissions (TEOAE) recordings followed, cin cases of suspected hearing loss, by brainstem auditory evoked potential (BAEP) recording and otolaryngology (ORL) consultation. After TEOAE1 and 2 and BAEP testing, 1 361 infants (88.9%) were declared normal, and 170 (11%) suspected of hearing loss. Of these 170, 58 showed bilateral and 26 unilateral impairment. Definite hearing loss on ORL consultation was diagnosed in 14 infants (0.9% of the screened population as a whole); 22 are still followed, while 86 (5.6%) failed to consult for diagnosis. The mean age on diagnosis of definite hearing loss on ORL consultation was 9.9 +/- 4.9 (range 4-20) months. Several auditory function risk factors have been proved to be more frequent in deaf than in normal children. Our results show that early hearing loss screening in at-risk neonates needs to be pursued.     

Congenital aural atresia surgery: long-term results.

OBJECTIVES: The study goal was to evaluate the stability of hearing results from short- to long-term follow-up in patients who underwent surgery for congenital aural atresia. We also reviewed complications such as external auditory canal stenosis, lateralization and perforation of the tympanic membrane, sensorineural hearing loss, and facial palsy. METHODS: We conducted a retrospective chart review of 116 patients who underwent congenital aural atresiaplasty between 1985 and 2002 at the House Ear Clinic. There were 116 atretic ears. Complication rates and short- and long-term (up to 13.6 years) hearing results were evaluated for primary and revision cases. RESULTS: Closure of the air-bone gap (ABG) to 30 dB or less at short-term follow-up occurred in 58.5% of primary surgeries and 56% of revisions. The long-term postoperative ABG was 30 dB or less in 50.8% of the primary cases and 39.1% of the revisions. Paired comparison analysis found no significant change in ABG from short- to long-term follow-up for either primary or revision cases. Soft tissue stenosis was seen in 8% of primary surgeries and 3.4% of revisions. Ossicular chain refixation was seen in 11.5% and 6.9% of primary and revision surgeries, respectively. There were no dead ears. CONCLUSION: Atresiaplasty surgery in individuals with congenital aural atresia can yield reliable, lasting hearing results with a low incidence of complications.     

Steroid-responsive cochlear dysfunction in the MRL/lpr autoimmune mouse.

Corticosteroids historically have been used to treat autoimmune sensorineural hearing loss, although little is known of how steroids restore normal inner ear function. Therefore, to identify a potential model for this field of research, this study examined the effects of prednisolone on auditory brain stem response thresholds in the MRL/lpr mouse model of autoimmune sensorineural hearing loss. Mice treated with prednisolone after auditory threshold elevations demonstrated significant improvement and stabilization of thresholds compared with untreated controls. MRL/lpr mice treated with steroids before the onset of autoimmune disease and cochlear dysfunction demonstrated decreased serum immune complexes, higher survival rates, and lower auditory thresholds compared with untreated controls. These positive results suggest the autoimmune mouse may be useful for studies of steroid-responsive mechanisms of the cochlea in autoimmune sensorineural hearing loss, as well as any hearing disorder in which steroid therapy is currently used.     

The evaluation of auditory function in homozygous sickle cell disease.

The most significant clinical manifestations of sickle cell disease (SCD) are those associated with CNS involvement. This disease is systemic in character, with the tissues of the CNS being the most sensitive to even temporary anoxia. For this reason, the incidence of peripheral and central auditory dysfunction in patients with SCD may be greater than in the "normal" population. We examined the peripheral auditory function of 54 patients with homozygous sickle cell disease and the central auditory function of 28 of these patients. Results were compared with a control population. Peripheral hearing loss was found in 11% (6) of the SCD population. Central auditory testing indicated that 46% (13) of the sickle cell population had mild central auditory dysfunction not involving Heschl's gyrus. This study suggests a higher than usual incidence of peripheral and central auditory impairment in sickle cell disease.     

Otosclerotic involvement of the cochlea: a histologic and audiologic study

This study sought correlations between sensorineural hearing loss and otosclerotic endosteal involvement in 29 temporal bones examined histologically. The sensorineural hearing loss of the affected parts of the cochlea was determined by the last antemortum bone conduction audiogram available. There were eight temporal bones with only stapes footplate involvement, six with one discrete focus of otosclerotic endosteal involvement, and 15 with two or more foci of endosteal involvement. Analysis of audiometric data showed that the group of bones with two or more foci of endosteal involvement had a similar incidence of 45 dB sensorineural loss (9 of 15 or 60%) as did the group with no endosteal involvement (5 of 8 or 62%). The group with two or more foci had a greater incidence of 60 dB or greater sensorineural loss (46%) compared with the groups with none (12%) or one focus (16%) involved. Correlation between hearing loss and involvement of cochlear endosteum was poor. Correlation existed in only 2 of 15 ears with two or more foci involving the cochlear endosteum. There was no correlation in the other groups. It appears that cochlear endosteal involvement alone may not be sufficient explanation for the sensorineural hearing loss found with otosclerosis, except in the most severely involved ears.     

The use of diagnostic testing in asymmetric sensorineural hearing loss

The etiology of an asymmetric sensorineural hearing loss can often be difficult to determine. Because a wide variety of pathologic processes may be responsible for the hearing loss, numerous diagnostic tests are usually used in the initial evaluation, including pure-tone audiometry, acoustic reflex testing, imaging, serologic testing, and auditory brainstem response testing. The diagnostic evaluations of 225 consecutive cases of asymmetric sensorineural hearing loss are reviewed. A cochlear site-of-lesion was demonstrated in the majority (194) of patients. Because all retrocochlear lesions (31) were associated with an abnormal auditory brainstem response, imaging should be performed in that group of patients. Magnetic resonance imaging offers greater specificity than computed tomography. Reflex decay, acoustic reflex testing, and rollover were all associated with a high false-negative rate. Whereas serologic testing for syphilis yielded several cases of otosyphilis, thyroid function testing was of little value. A diagnostic protocol for asymmetric sensorineural hearing loss is presented.     

Time course of hearing loss in an animal model of pneumococcal meningitis.

A leading cause of morbidity from bacterial meningitis is an irreversible, usually profound sensorineural hearing loss, with an incidence as high as 30% in some studies. Bacterial meningitis remains the most common cause of acquired postnatal sensorineural deafness. Although several clinical studies have examined the long-term outcome of hearing in meningitis, few studies have examined the time course of hearing loss during the acute course of the disease. We have developed an animal model of meningogenic hearing loss in the rat and have plotted the time course of that hearing loss. Serial auditory brain stem responses (ABRs) were measured in rats inoculated in the cisterna magna (subarachnoid space) with Streptococcus pneumoniae (10(5) to 10(7) colony-forming units). All rats injected developed meningitis as evidenced by increased cerebrospinal fluid (CSF) white cell counts and positive CSF cultures. Serial ABR measurements taken 6, 12, 15, 18, 21, and 24 hours after inoculation demonstrated significant threshold shifts and eventual loss of the ABR waveform as compared with measurements in control rats injected with sterile culture medium. Hearing loss began approximately 12 to 15 hours after inoculation and progressed to complete loss by 24 hours (17 of 18 animals). No correlation was found between the magnitude of hearing loss and CSF white cell count or bacterial titer. Temporal bone histology of rats with meningitis shows a dense inflammatory cell infiltrate throughout the subarachnoid space. Labyrinthine inflammatory cells were confined to the scala tympani. The cochlear aqueduct is the proposed route of infection from the meninges to the labyrinth (scala tympani). Endolymphatic hydrops was also noted throughout the cochlea. These experiments both establish a reproducible animal model of meningogenic hearing loss and support the hypothesis that this hearing loss is progressive rather than abrupt in onset and is related to the duration of untreated infection. CSF inflammatory cells appear to enter the cochlea through the cochlear aqueduct. This reliable animal model will enable future studies directed toward further understanding the pathogenesis and pathophysiology of this hearing loss.     

Aminoglycoside ototoxicity in pediatric patients receiving long-term peritoneal dialysis

We evaluated 14 children on long-term peritoneal dialysis for ototoxicity associated with aminoglycoside (AG) therapy. Baseline evaluation of all patients and 7 controls included pure-tone audiometry (PTA) and click-evoked auditory brain stem response (ABR). Nine patients had repeat PTA and ABR evaluations and vestibular testing 1 year after study entry. Five patients had an additional assessment following intraperitoneal AG therapy. The baseline auditory function of the patients was significantly poorer than controls at 6.0 and 8.0 kHz by PTA (p<0.05), whereas the results of ABR testing were not different. Of the 14 patients, 4 (28%) had hearing loss, 3 of whom had a history of intravenous AG therapy. In contrast, none of the patients who received intraperitoneal AG therapy only, or without a history of AG therapy, had hearing loss (P<0.005). There was no evidence of progressive loss of hearing acuity with time or associated with intraperitoneal AG therapy. One patient had findings of vestibular dysfunction. We conclude that children receiving peritoneal dialysis are at risk of AG ototoxicity. While intraperitoneal administration of AG may be associated with less ototoxicity than intravenous administration, further study is necessary to verify this finding and close monitoring of AG levels remains mandatory irrespective of the route of administration. PTA rather than click-evoked ABR appears to be the best indicator of abnormal hearing acuity in this population.     

Risk of progressive sensorineural hearing loss and Meniere’s disease after breast implantation

OBJECTIVE: The association of various immunologic abnormalities with the presence of silicone breast implants in women has been described. In addition, some studies report a correlation between autoimmune disorders and silicone breast implants, whereas other studies indicate no difference in the incidence of disease between women with silicone breast implants and control groups. Until recently, no reports had attempted to identify an association between silicone breast implants and hearing impairment. A recent study suggested a possible correlation between prior silicone breast implants and the development of various forms of hearing loss. This study tried to determine whether such a correlation could be duplicated. METHODS: To determine whether such a correlation could be established, we studied 119 female patients with either Meniere’s disease or progressive sensorineural hearing loss and 100 age-matched healthy controls. Subjects completed questionnaires that provided various types of information, including the presence or absence of previous silicone breast implants. Serum from all 119 patients with Meniere’s disease and progressive sensorineural hearing loss had been subjected to previous Western blot testing for reactivity to a 68 kD protein associated with certain forms of autoimmune hearing loss. RESULTS: Results indicated no significant difference in frequency of prior silicone breast implants among the patients with Meniere’s disease, patients with sensorineural hearing loss, or controls. The presence or absence of the 68 kD protein also was not significantly relevant to the frequency of silicone breast implants. CONCLUSIONS: Our data did not show evidence of a significant relationship between the presence of silicone breast implants and later development of Meniere’s disease, progressive sensorineural hearing loss, or positive 68 kD serum. (Otolaryngol Head Neck Surg 1998;118:747-50.)     

A study of the high-risk registry for sensorineural hearing impairment

In the medical evaluation, rehabilitation, and education of the hearing impaired, the first line of defense is the high-risk factor screening for sensorineural damage of all neonates. The most efficacious means of neonatal screening for those factors affecting sensorineural hearing damage is the employment of a high-risk registry. Based on a retrospective study of 109 children with sensorineural loss, high-risk factors and how improved use of the high-risk registry permits earlier detection (and statistically more successful rehabilitation) for such auditory-impaired children are discussed. The importance of pediatric screening of all neonates for hearing loss, in addition to use of the high-risk registry, is evidenced by the fact that only 46% of the children retrospectively identified in our study would have routinely appeared among the high-risk infants were the registry used alone.     

Perilymph fistulas in infants and children

During the years 1975 through 1981 we performed exploratory tympanotomies on 33 infants and children (44 ears) to verify the presumptive diagnosis of perilymph fistula (PLF). A PLF was identified at the round window, oval window, or both in 29 (66%) of the 44 ears explored. After surgery hearing was unchanged in 86%, improved in 5%, and worsened in 9% of the ears in which PLFs had been observed. Complaints of vertigo subsided in all children in whom a PLF was repaired. Preoperative factors determined to be highly suggestive of the presence of a PLF included the following: sudden onset of sensorineural hearing loss (SNHL), congenital deformities of the head, and abnormal findings on tomograms of the temporal bones, especially Mondini-like inner ear dysplasias. Middle ear abnormalities (primarily congenital) were observed in 20 of the 44 ears. Abnormal results of preoperative vestibular function studies, which included a fistula test, and sex were not consistently found to be associated with an observed PLF at tympanotomy.     

Stapedectomy in congenital stapes fixation: are hearing outcomes poorer?

OBJECTIVE: To evaluate outcomes of stapedectomy surgery for congenital stapes fixation. STUDY DESIGN: Retrospective chart review. METHODS: The charts of 463 stapedectomies performed by 1 surgeon from 1996 to 2003 were reviewed. Patients with a history of childhood hearing loss and operative findings consistent with congenital fixation of the stapes were included. Patients with a history of trauma or chronic otitis media and those with otosclerosis were excluded. Thirty-six patients underwent stapedectomy for congenital fixation. Revision cases and those with inadequate postoperative bone or air conduction data were excluded. Inclusion criteria were met for 25 patients. Operative findings and hearing outcomes were evaluated. RESULTS: The study group was comprised of 25 stapedectomies. Closure of the air-bone gap to less than 10 dB was achieved in 48% of cases, and 80% had closure within 20 dB. A gap of more than 30 dB remained in 3 cases. There were 2 cases of sensorineural hearing loss with worsening of the bone conduction thresholds by 15 dB and 30 dB. There were no instances of perilymph gusher. In addition to an excluded case that was not reconstructed because of facial nerve position, 3 of the included patients were found to have a dehiscent facial nerve at surgery. There were no facial nerve injuries, and fixation of the malleus or incus was not found in any of the included patients. When hearing outcomes were compared with our results for otosclerosis over the same time period, rates of closure to within 10 dB and 20 dB were significantly worse in the congenital group. CONCLUSION: Closure of the air-bone gap in this population differs from our results in stapedectomy done for otosclerosis. This difference likely reflects subtle anatomic variations in the congenital group that affect the effectiveness of the prosthesis. Despite the difference in results, stapedectomy for congenital fixation remains an effective method to achieve significant hearing improvement in the majority of patients. EBM rating: B-3b.     

Vaccine-preventable pediatric postmeningitic sensorineural hearing loss in southern India.

OBJECTIVE: The study goal was to assess vaccine-preventable pediatric postmeningitic sensorineural hearing loss in southern India. STUDY DESIGN AND SETTING: We conducted a prospective pilot study from January through March 2001 in a tertiary pediatric hospital in southern India. RESULTS: Sixty-five patients were studied. Thirty-five (54%) patients had positive cerebrospinal fluid cultures, with the most common organisms being Streptococcus pneumoniae and Haemophilus influenzae. An additional 10 (15%) patients were diagnosed with tuberculous meningitis. Of 28 patients who could comply with audiometric evaluations, 8 (28%) had sensorineural hearing loss. CONCLUSIONS: The etiologic organisms of bacterial meningitis in this study population are similar to those organisms in the developed world, with the minority exception of tuberculous meningitis. Further, a similar prevalence of postmeningitic sensorineural hearing loss occurred. SIGNIFICANCE: An effective vaccination program against S. pneumoniae and H. influenzae type b should reduce the prevalence of sensorineural hearing loss due to bacterial meningitis in developing countries with similar bacterial profiles.     

Stapedectomy in children.

Stapes surgery for correction of conductive hearing loss in adults with otosclerosis is a well-established procedure. Its effectiveness in children, however, has received less scrutiny in the literature. Previous studies from our and other institutions demonstrated similar results in children and adults. Between 1980 and 1994 stapedectomies were done on 95 ears of 81 patients younger than 18 years (83 primary and 12 revisions). Data regarding age of onset, family history, associated anomalies, surgical findings, technique, hearing results, and complications were reviewed. Two groups were identified: congenital stapedial fixation and juvenile otosclerosis. Patients with congenital stapedial fixation had an earlier onset of hearing loss (3 vs 10 years, P < 0.001), a greater incidence of abnormalities of the malleus and incus (25% vs 3%, P < 0.001), and a slightly greater preoperative air-bone gap (35.2 +/- 12.9 vs 27.8 +/- 8.9, P = 0.002). Patients with otosclerosis had a greater frequency of a positive family history of deafness (53% vs 10%, P < 0.001). Overall, 79% of primary cases and 89% of revision cases had an improvement in hearing, with mean postoperative air-bone gaps of 15 dB and 22 dB, respectively. The gap did not widen significantly during the entire length of follow-up (mean 72 months). In primary cases, 59.1% obtained a postoperative air-bone gap of 10 dB or less. Eighty-two percent of children operated on for otosclerosis obtained excellent results (postoperative air-bone gap < or = 10 dB), compared with only 44% of children with congenital stapedial ankylosis (P = 0.02). In revision surgery, 29% of children obtained excellent results. Poorer results in both cases of congenital stapedial fixation and revision stapedectomy appear to be related to the greater incidence of associated anomalies of the malleus and incus. Indications, technique, complications, and considerations pertinent to childhood stapedectomy are discussed.     

Unilateral sensorineural deafness in children

Heredity, viral infection, and head or acoustic trauma are considered the common etiologies for a unilateral sensorineural deafness in children. The incidence of perilymphatic fistula in a unilateral hearing loss is still unknown. Inner ear-related symptoms in children are scarce, and little diagnostic laboratory testing is available. A definite diagnosis of a perilymphatic fistula can therefore be made only by an exploratory tympanotomy. Four children, ages 5 to 15 years, with a history of a recent and rapidly progressive unilateral sensorineural hearing loss, were explored. Preoperative laboratory data, which included a fistula test, ENG, CT scan of the temporal bones, and an ABR, were all within normal limits. An overt fistula was found in only one of the patients. Only an exploratory tympanotomy can arrest and possibly reverse a unilateral hearing loss or discontinue a middle ear-cranial cavity communication. It is therefore our feeling that, in patients with an appropriate history, the potential benefit outweighs the risk and morbidity of an exploratory tympanotomy.     

Effects of sevoflurane on QT parameters in children with congenital sensorineural hearing loss

Sevoflurane prolongs the QT interval (QTI). Patients with congenital sensorineural hearing loss (SNHL) often have a prolonged QTI. This study was to investigate the effects of sevoflurane on the QTI in SNHL and control children. Thirty patients with SNHL and 30 controls were studied. The corrected QT interval (QTc), interval from peak to end of T wave (Tp-e) and QT variability index (QTVI) were analysed. QTc and Tp-e were estimated by the average QTc and Tp-e measured beat-by-beat for 15 min. Heart rate power spectral analysis was performed. In both groups, QTc and QTVI increased during anaesthesia, but Tp-e did not change. There were no differences in QTc, QTVI, Tp-e, low- and high-frequency power between the two groups. In both groups, sevoflurane lengthened the QTc and QTVI intervals but not Tp-e.     

Speech and hearing problems in a high-risk population.

A retrospective study was conducted on 85 neonatal intensive care unit (NICU) survivors, all of whom had been mechanically ventilated. Mean birth weight was 1,726 +/- 778 g and mean gestational age was 32.3 +/- 3.8 weeks. Infants were evaluated for various risk factors previously reported to cause hearing loss. Language development was assessed using the Early Language Milestone (ELM) scale and hearing was tested by free field responses (FFR). Twenty-four children (28.2%) had an abnormal ELM or FFR result. Seventeen children failed an FFR; 14 of these were normal on follow-up and 3 defaulted. There was thus no permanent sensorineural hearing loss in the sample assessed. Eleven children failed an ELM, of whom 5 had speech problems on long-term follow-up. There was a significant correlation between the ELM and neurodevelopmental scores (P = 0.045). Intraventricular haemorrhage also correlated significantly with the ELM score (P = 0.0016). Thus the overall incidence of hearing loss in this NICU population was low, but there was a significant occurrence of speech problems, which correlated with neurological damage.