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Diagnostic tools in pseudohypacusis in children
International Journal of Pediatric Otorhinolaryngology (2005) 69, 1235—1238
www.elsevier.com/locate/ijporl
Diagnostic tools in pseudohypacusis in children N. Saravanappa, G.A. Mepham, D.A. Bowdler * Department of Otorhinolaryngology and Head & Neck Surgery, University Hospital Lewisham, Lewisham High Street, London SE13 6LH, UK Received 11 June 2003; received in revised form 28 February 2005; accepted 1 March 2005
KEYWORDS Pseudohypacusis; Functional hearing loss; Otoacoustic emissions
Summary Pseudohypacusis is the term used for a non-organic or functional hearing loss. The mainstay of diagnosis is a lack of consistency in audiological testing. It is usually easier to diagnose in children than in adults, as children are less able to reproduce consistently erroneous results on repeated testing. Nevertheless, the diagnosis is often missed in children, probably due to a lack of awareness of the condition. In a previous study from our department, we highlighted the usefulness of speech audiometry in establishing the diagnosis. However, with the advent of otoacoustic emissions testing, we have changed the emphasis of our testing protocol. Using otoacoustic emissions, the diagnosis of pseudohypacusis can be established quickly and easily. # 2005 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Pseudohypacusis has been defined as functional or non-organic hearing loss that cannot be explained on the basis of an organic condition [1]. Carhart first described the term pseudphypacusis in 1961 to describe a condition in which a person presents with a hearing loss, which is not consistent with clinical or audiometric findings [2]. Other terminologies used include psychogenic hearing loss, functional hearing loss and malingering. In most cases of childhood pseudohypacusis, it may be difficult to know the exact reason for such a presentation. An adult presenting with pseudohypacusis usually presents for financial rewards or to * Corresponding author. Tel.: +44 208 3333 191; fax: +44 208 3333 188. E-mail address: [email protected] (D.A. Bowdler).
evade taking up responsibilities. However, this is not the case in children. Most cases of childhood pseudohypacusis are identified due to a failed hearing test at school. Until such an event, even the parents may not be aware that their child has a non-organic loss. As a whole, pseudohypacusis in children has a higher prevalence than is suspected in the population [3] and this condition is frequently misdiagnosed or missed in children [1,3]. The hearing loss in a small minority of children may be part of a formalised conversion disorder, which is a psychological defence mechanism wherein subconscious emotional conflict is translated into physical disability. In such cases, hearing loss is one of several neurological symptoms associated with conversion disorders. However, hearing loss may not be associated with childhood hysteria at all [1,3]. Whatever the underlying cause, it is important to have a high index of suspicion in order to make an
0165-5876/$ — see front matter # 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2005.03.039
1236
early diagnosis [3]. The mainstay of diagnosis is a lack of consistency in audiological testing. It is usually easier to diagnose in children than in adults, as children are less able to produce consistently erroneous results on repeated testing. However, the diagnosis is often missed in children, largely due to a lack of awareness of the condition. In some children, non-organic hearing loss may indicate underlying problems, which merit detailed investigation and treatment [4]. Having established the diagnosis of psudohypacusis, the treatment may range from simple observation to psychotherapy and counselling [5].
2. Patients and methods The aim of this study was to analyse the changing trends in establishing the diagnosis of pseudohypacusis in our department and to stress the importance of the role of otoacoustic emissions (OAE) testing in establishing the diagnosis. This study was conducted as a retrospective case-notes review. Approximately, 3000—3500 new children are seen in our department annually. The number of children diagnosed with pseudohypacusis per year is around 10—20. The clinical notes of children diagnosed of pseudohypacusis over a 4-year period (1997—2000) were reviewed and the data collected on the type of investigations performed to confirm the diagnosis. This was compared with the results of a previous study from our department (1995—1996). This study was aimed at analysing the changing trends in establishing the diagnosis of pseudohypacusis. For testing otoacoustic emissions, we use OAE Echoport ILO288 system from Otodynamics, which was used to record the transient evoked acoustic emissions.
3. Results During 1997—1998, 31 children between the ages of 5 and 16 years (mean of 12) were diagnosed with pseudohypacusis. Repeat pure-tone audiogram showed normal hearing in 22 cases and confirmed diagnosis. Three children required speech audiogram to rule out any organic cause. The remaining six children underwent brainstem evoked response audiometry, which confirmed the presence of wave V at threshold of 20 dB or less. In a previous study (1995—1996) from our department [1], all children suspected of having pseudohypacusis based on pure-tone audiometry underwent speech audiometry. In 90% of cases, the speech audiograms confirmed the diagnosis.
N. Saravanappa et al.
Since the beginning of January 1999, otoacoustic emission testing has been used to evaluate the diagnosis of pseudohypacusis. The number of children seen in our department during 1999—2000 was approximately 3000. During the period 1999—2000, 19 children showed evidence of pseudohypacusis. In 12 children, otoacoustic emission testing confirmed the diagnosis of pseudohypacusis. Repeat pure-tone audiometry showed normal hearing thresholds in five children and two children required speech audiogram. Only three children had brainstem evoked response audiometry, where it was necessary to confirm the diagnosis enabling our team to explain the diagnosis to the children and their parents. Auditory brainstem response testing was used mainly to obtain objective estimation of the true thresholds in a few difficult cases where children and their parents did not agree with simple audiological tests. In most cases (12 out of 19), explaining to children and parents regarding the results of otoacoustic emissions resulted in improvement in hearing and disappearance of the condition. Informing the child and their parents about the inconsistent results on pure-tone audiometry and explaining to them about the objective testing of hearing by otoacoustic emissions helped in treating pseudohypacusis.
4. Discussion The prevalence of pseudohypacusis is estimated at 1.35% based on a study involving 4720 patients [6]. However, the true prevalence may be higher as pseudohypacusis goes unrecognised in many cases [3]. Children may present with pseudohypacusis regardless of age, sex, mental status or social background. The peak incidence is reported to be between 10 and 12 years of age, with girls presenting more often than boys [5]. In children diagnosed with pseudohypacusis, the hearing loss usually comes on suddenly, usually associated with an identifiable conflict with the parents or teachers. In one series, there was a preceding history of trauma in a significant number (33%) of paediatric patients presenting with non-organic hearing loss [7]. This clearly shows that the diagnosis of pseudohypacusis should be considered even when a strong clinical history supporting a hearing loss is present, as it has been reported that patients with pseudohypacusis have been given tertiary referrals to a cochlear implant program for assessment [8]. The problem of pseudohypacusis may range in severity from an exaggeration of a genuine hearing loss to a feigned hearing loss where none exists. In some cases, pseudohypacusis may indicate underlying problems that
Diagnostic tools in pseudohypacusis in children
merit detailed investigation and treatment [4]. In a study by Brooks and Geoghegan, where 38 patients who had been diagnosed as having non-organic hearing loss were reviewed, five had concurrent speech problems and five had associated psychiatric problems [4]. In most cases, pseudohypacusis can be diagnosed by using conventional audiological procedures. However, the diagnosis of pseudohypacusis may be a challenging task in a few cases. A wide variety of subjective and objective tests have been suggested for evaluating and diagnosing pseudohypacusis, including the Lombard test, Stengers test, the Doerfler-Stewart test and lengthened off-time Bekesy audiometry [3,9]. Pure-tone audiometry and speech audiometry are the standard subjective tests for assessment of the degree and nature of hearing loss. Objectively, in persons who have normal hearing, the acoustic reflex is usually elicited at hearing thresholds ranging from 70 to 95 dB. Although middle ear reflex measurements could be used to exclude pseudohypacusis, these measurements do not give exact information about auditory sensitivity. Hosoi et al. reported that suggestion audiometry, where it is suggested to the patient that hearing will be improved as a result of the test procedure, could be useful for the detection of non-organic hearing loss and suggestion speech audiometry could be used for the determination of true hearing levels [10]. With advancements in technology, several advanced electrophysiological and audiological tests have been used in diagnosing pseudohypacusis, which include brainstem evoked response audiometry [11,12] and electrocochleography [8,9]. Auditory brainstem response is widely used for measuring true hearing thresholds in suspected cases of pseudohypacusis [13]. However, it lacks simplicity and convenience and is also relatively expensive. Otoacoustic emissions, described by Kemp, are an excellent way for assessing the cochlear function [14]. Otoacoustic emission testing is a non-invasive, objective diagnostic technique, which is gaining popularity as an aid in the detection and assessment of pseudohypacusis [15,16]. Evoked OAEs are primarily generated by the outer hair cells in the cochlea. These low-level sounds can be recorded in the external auditory canal after appropriate stimulation. More clinically useful are transient evoked OAEs and distortion product OAEs. Transient evoked OAEs are preferred over distortion product OAEs as transient evoked OAEs are generated from a large portion of the basilar membrane and are influenced by the status of the whole cochlea. Evoked otoacoustic emissions testing can provide objective information to aid in the detection and quantification of pseudohypacusis [15].
1237
Testing of evoked otoacoustic emissions can be used initially to confirm the hearing status in patients with pseudohypacusis [6]. Evoked otoacoustic emissions can be recorded in nearly all ears with normal or near normal hearing. The recording of normal evoked otoacoustic emissions usually confirms normal middle ear and cochlear function, thereby ruling out a moderate to severe hearing loss and the presence of conductive components. Qiu et al. found that evoked otoacoustic emissions were the most rapid, economical and objective method, which confirmed the diagnosis of hearing loss in 78.1% of cases in their reported series [6]. Otoacoustic emissions testing was found to be diagnostically useful in determining normal peripheral auditory function thereby resolving some of the dilemmas encountered, while facing children with suspected pseudohypacusis [17]. The presence of transient evoked OAEs can be equated to hearing thresholds equal to or better than 20 dB [18]. However, in a few rare cases, evoked otoacoustic emissions may be present in spite of a severe to profound hearing loss [19]. Conversely, there may be normal audiometric thresholds in the absence of transient evoked OAEs and this is indicative of subclinical cochlear damage. Such a situation is usually encountered in adult patients with noise induced hearing loss [20]. Several authors recommend the use of transient evoked otoacoustic emissions for diagnosing pseudohypacusis [15,21,22]. Balatsouras et al. suggest that it is worth performing tympanometry alongside transient evoked otoacoustic emissions [22]. We believe that otoacoustic emissions testing is quicker, less subjective compared to speech audiometry and also not dependant on comprehension as with speech audiometry. In some cases, it also alleviates the need for repeat pure-tone audiometry at a later date to confirm the diagnosis; thereby the audiologist’s time can be used more constructively. Treatment of pseudohypacusis may range from no interference to psychotherapy [5]. If there are any suspicions of underlying psychological conflict that must be identified and treated as pseudohypacusis is considered to be a psychogenic disorder in a few children [1,3,5]. It is important not to confront the child and at all times, the child must be treated as if the hearing difficulty is real [3]. Explaining to the child and their parents about the inconsistent results in pure-tone audiometry and the objective measurement of otoacoustic emissions usually helps in alleviating the condition as is evident by our experience. Both the child and their parents should be reassured strongly that the hearing loss will get better. When the correct diagnosis of pseudohypacusis is made, the treatment is relatively simple
1238
with reassurance, explanation and encouragement [23,24].
5. Conclusions Pseudohypacusis should be relatively easy to diagnose in children because of the problems they have in producing inter- and intra-test consistency. Simple audiological tests such a repeat pure-tone audiometry, impedance testing and speech audiometry are usually sufficient to diagnose pseudohypacusis. However, speech audiometry is time consuming and like pure-tone audiometry still subjective. With the availability of otoacoustic emission testing, pseudohypacusis in children can be diagnosed easily and quickly. Otoacoustic emissions provide the clinician with a sensitive way of determining normal hearing thresholds, preventing unnecessary intervention, but alerting the ENT surgeon to the possible presence of any underlying psychological disturbance or malingering. Brainstem evoked response audiometry is necessary only in very few cases. We believe that pseudohypacusis remains an under diagnosed condition in children but that, once suspected, the diagnosis can be quickly established using available audiological tests. Once the diagnosis is made, children with pseudohypacusis can be effectively managed with reassurance and encouragement.
References [1] J.P. Pracey, R.M. Walsh, G.A. Mepham, D.A. Bowdler, Childhood pseudohypacusis, Int. J. Pediatr. Otorhinolaryngol. 37 (1996) 143—149. [2] R. Carhart, Testing for malingering, Trans. Am. Acad. Ophthalmol. Otolaryngol. 65 (1961) 437. [3] J.P. Pracey, D.A. Bowdler, Pseudohypacusis in children, Clin. Otolaryngol. 21 (1996) 383—384. [4] D.N. Brooks, P.M. Geoghegan, Non-organic hearing loss in young persons: transient episode or indicator of deep-seated difficulty, Br. J. Audiol. 26 (1992) 347—350. [5] D.A. Bowdler, J. Rogers, The management of pseudohypacusis in school-age children, Clin. Otolaryngol. 14 (1989) 211—215. [6] W.W. Qiu, S.S. Yin, F.J. Stucker, L.W. Welsh, Current evaluation of pseudohypacusis: strategies and classification, Ann. Otol. Rhinol. Laryngol. 107 (1998) 638—647.
N. Saravanappa et al.
[7] D. Radkowski, S. Cleveland, E.M. Friedman, Childhood pseudohypacusis in patients with high risk for actual hearing loss, Laryngoscope 108 (1998) 1534—1538. [8] P.D.R. Spraggs, M.J. Burton, J.M. Graham, Nonorganic hearing loss in cochlear implant candidates, Am. J. Otol. 15 (5) (1994) 652—657. [9] W.F. Rintelnann, S.A. Schwann, B.W. Blakley, Pseudohypacusis, Otolaryngol. Clin. North Am. 24 (1991) 381—390. [10] H. Hosoi, Y. Tsuta, K. Murata, H. Levitt, Suggestion audiometry for non-organic hearing loss (pseudohypacusis) in children, Int. J. Paediatr. Otorhinolaryngol. 47 (1999) 11— 21. [11] M. Hyde, P. Alberti, N. Matsumoto, Y.L. Li, Auditory evoked potentials in audiometric assessment of compensation and medico legal patients, Ann. Otol. Rhinol. Laryngol. 95 (1986) 514—519. [12] H. Sohmer, M. Feinmesser, L. Bauberger-Tell, E. Edelstein, Cochlear, brainstem, and cortical evoked responses in nonorganic hearing loss, Ann. Otol. Rhinol. Laryngol. 86 (1977) 227—234. [13] J.W. Sanders, B.B. Lazenby, Auditory brainstem response measurement in the assessment of pseudohypacusis, Am. J. Otol. 4 (1983) 292—299. [14] D.T. Kemp, S. Ryan, P. Bray, A guide to the effective use of otoacoustic emissions, Ear Hear 11 (1990) 92—105. [15] F.E. Musiek, S.P. Bornstein, W.F. Rintelmann, Transient evoked otoacoustic emissions and pseudohypacusis, J. Am. Acad. Audiol. 6 (1995) 293—301. [16] J.D. Durrant, R.K. Kesterson, D.B. Kamerer, Evaluation of the non-organic hearing loss suspect, Am. J. Otol. 18 (1997) 361—367. [17] M. Baldwin, P. Watkin, The clinical application of oto-acoustic emissions in paediatric audiological assessment, J. Laryngol. Otol. 106 (1992) 301—306. [18] M.P. Gorga, S.T. Neely, B.M. Bergman, K.L. Beauchaine, J.R. Kaminiske, J. Peters, L. Schulte, W. Jesteadt, A comparison of transient evoked and distortion product emissions in normal hearing and hearing impaired subjects, J. Acous. Soc. Am. 94 (1993) 2639—2648. [19] W.W. Qiu, F.J. Stucker, G.M. Waguespack, Evoked otoacoustic emissions in evaluation of central auditory impairment, J. Audiol. Med. 5 (1996) 119—129. [20] D. Prasher, W. Sulkowski, The role of otoacoustic emissions in screening and evaluation of noise damage, Int. J. Occup. Med. Environ. Health 12 (1999) 183—192. [21] K.J. Kvaerner, B. Engdahl, J. Aursnes, A.R. Arnesen, I.W. Mair, Transient-evoked otoacoustic emissions–—helpful tool in the detection of pseudohypacusis, Scand. Audiol. 25 (3) (1996) 173—177. [22] D.G. Balatsouras, A. Kaberos, S. Korres, D. Kandiloros, E. Ferekidis, C. Economou, Detection of pseudohypacusis: a prospective, randomised study of the use of otoacoustic emissions, Ear Hear 24 (2003) 518—527. [23] M. Yoshida, A. Hoguchi, T. Uemura, Functional hearing loss in children, Int. J. Paediatr. Otorhinolaryngol. 17 (1989) 287— 295. [24] Q. Andaz, T. Heyworth, S. Rowe, Non-organic hearing loss in children: a 2-year study, ORL; J. Otorhinolaryngolog. Relat. Spec. 57 (1) (1995) 33—35.
www.elsevier.com/locate/ijporl
Diagnostic tools in pseudohypacusis in children N. Saravanappa, G.A. Mepham, D.A. Bowdler * Department of Otorhinolaryngology and Head & Neck Surgery, University Hospital Lewisham, Lewisham High Street, London SE13 6LH, UK Received 11 June 2003; received in revised form 28 February 2005; accepted 1 March 2005
KEYWORDS Pseudohypacusis; Functional hearing loss; Otoacoustic emissions
Summary Pseudohypacusis is the term used for a non-organic or functional hearing loss. The mainstay of diagnosis is a lack of consistency in audiological testing. It is usually easier to diagnose in children than in adults, as children are less able to reproduce consistently erroneous results on repeated testing. Nevertheless, the diagnosis is often missed in children, probably due to a lack of awareness of the condition. In a previous study from our department, we highlighted the usefulness of speech audiometry in establishing the diagnosis. However, with the advent of otoacoustic emissions testing, we have changed the emphasis of our testing protocol. Using otoacoustic emissions, the diagnosis of pseudohypacusis can be established quickly and easily. # 2005 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Pseudohypacusis has been defined as functional or non-organic hearing loss that cannot be explained on the basis of an organic condition [1]. Carhart first described the term pseudphypacusis in 1961 to describe a condition in which a person presents with a hearing loss, which is not consistent with clinical or audiometric findings [2]. Other terminologies used include psychogenic hearing loss, functional hearing loss and malingering. In most cases of childhood pseudohypacusis, it may be difficult to know the exact reason for such a presentation. An adult presenting with pseudohypacusis usually presents for financial rewards or to * Corresponding author. Tel.: +44 208 3333 191; fax: +44 208 3333 188. E-mail address: [email protected] (D.A. Bowdler).
evade taking up responsibilities. However, this is not the case in children. Most cases of childhood pseudohypacusis are identified due to a failed hearing test at school. Until such an event, even the parents may not be aware that their child has a non-organic loss. As a whole, pseudohypacusis in children has a higher prevalence than is suspected in the population [3] and this condition is frequently misdiagnosed or missed in children [1,3]. The hearing loss in a small minority of children may be part of a formalised conversion disorder, which is a psychological defence mechanism wherein subconscious emotional conflict is translated into physical disability. In such cases, hearing loss is one of several neurological symptoms associated with conversion disorders. However, hearing loss may not be associated with childhood hysteria at all [1,3]. Whatever the underlying cause, it is important to have a high index of suspicion in order to make an
0165-5876/$ — see front matter # 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2005.03.039
1236
early diagnosis [3]. The mainstay of diagnosis is a lack of consistency in audiological testing. It is usually easier to diagnose in children than in adults, as children are less able to produce consistently erroneous results on repeated testing. However, the diagnosis is often missed in children, largely due to a lack of awareness of the condition. In some children, non-organic hearing loss may indicate underlying problems, which merit detailed investigation and treatment [4]. Having established the diagnosis of psudohypacusis, the treatment may range from simple observation to psychotherapy and counselling [5].
2. Patients and methods The aim of this study was to analyse the changing trends in establishing the diagnosis of pseudohypacusis in our department and to stress the importance of the role of otoacoustic emissions (OAE) testing in establishing the diagnosis. This study was conducted as a retrospective case-notes review. Approximately, 3000—3500 new children are seen in our department annually. The number of children diagnosed with pseudohypacusis per year is around 10—20. The clinical notes of children diagnosed of pseudohypacusis over a 4-year period (1997—2000) were reviewed and the data collected on the type of investigations performed to confirm the diagnosis. This was compared with the results of a previous study from our department (1995—1996). This study was aimed at analysing the changing trends in establishing the diagnosis of pseudohypacusis. For testing otoacoustic emissions, we use OAE Echoport ILO288 system from Otodynamics, which was used to record the transient evoked acoustic emissions.
3. Results During 1997—1998, 31 children between the ages of 5 and 16 years (mean of 12) were diagnosed with pseudohypacusis. Repeat pure-tone audiogram showed normal hearing in 22 cases and confirmed diagnosis. Three children required speech audiogram to rule out any organic cause. The remaining six children underwent brainstem evoked response audiometry, which confirmed the presence of wave V at threshold of 20 dB or less. In a previous study (1995—1996) from our department [1], all children suspected of having pseudohypacusis based on pure-tone audiometry underwent speech audiometry. In 90% of cases, the speech audiograms confirmed the diagnosis.
N. Saravanappa et al.
Since the beginning of January 1999, otoacoustic emission testing has been used to evaluate the diagnosis of pseudohypacusis. The number of children seen in our department during 1999—2000 was approximately 3000. During the period 1999—2000, 19 children showed evidence of pseudohypacusis. In 12 children, otoacoustic emission testing confirmed the diagnosis of pseudohypacusis. Repeat pure-tone audiometry showed normal hearing thresholds in five children and two children required speech audiogram. Only three children had brainstem evoked response audiometry, where it was necessary to confirm the diagnosis enabling our team to explain the diagnosis to the children and their parents. Auditory brainstem response testing was used mainly to obtain objective estimation of the true thresholds in a few difficult cases where children and their parents did not agree with simple audiological tests. In most cases (12 out of 19), explaining to children and parents regarding the results of otoacoustic emissions resulted in improvement in hearing and disappearance of the condition. Informing the child and their parents about the inconsistent results on pure-tone audiometry and explaining to them about the objective testing of hearing by otoacoustic emissions helped in treating pseudohypacusis.
4. Discussion The prevalence of pseudohypacusis is estimated at 1.35% based on a study involving 4720 patients [6]. However, the true prevalence may be higher as pseudohypacusis goes unrecognised in many cases [3]. Children may present with pseudohypacusis regardless of age, sex, mental status or social background. The peak incidence is reported to be between 10 and 12 years of age, with girls presenting more often than boys [5]. In children diagnosed with pseudohypacusis, the hearing loss usually comes on suddenly, usually associated with an identifiable conflict with the parents or teachers. In one series, there was a preceding history of trauma in a significant number (33%) of paediatric patients presenting with non-organic hearing loss [7]. This clearly shows that the diagnosis of pseudohypacusis should be considered even when a strong clinical history supporting a hearing loss is present, as it has been reported that patients with pseudohypacusis have been given tertiary referrals to a cochlear implant program for assessment [8]. The problem of pseudohypacusis may range in severity from an exaggeration of a genuine hearing loss to a feigned hearing loss where none exists. In some cases, pseudohypacusis may indicate underlying problems that
Diagnostic tools in pseudohypacusis in children
merit detailed investigation and treatment [4]. In a study by Brooks and Geoghegan, where 38 patients who had been diagnosed as having non-organic hearing loss were reviewed, five had concurrent speech problems and five had associated psychiatric problems [4]. In most cases, pseudohypacusis can be diagnosed by using conventional audiological procedures. However, the diagnosis of pseudohypacusis may be a challenging task in a few cases. A wide variety of subjective and objective tests have been suggested for evaluating and diagnosing pseudohypacusis, including the Lombard test, Stengers test, the Doerfler-Stewart test and lengthened off-time Bekesy audiometry [3,9]. Pure-tone audiometry and speech audiometry are the standard subjective tests for assessment of the degree and nature of hearing loss. Objectively, in persons who have normal hearing, the acoustic reflex is usually elicited at hearing thresholds ranging from 70 to 95 dB. Although middle ear reflex measurements could be used to exclude pseudohypacusis, these measurements do not give exact information about auditory sensitivity. Hosoi et al. reported that suggestion audiometry, where it is suggested to the patient that hearing will be improved as a result of the test procedure, could be useful for the detection of non-organic hearing loss and suggestion speech audiometry could be used for the determination of true hearing levels [10]. With advancements in technology, several advanced electrophysiological and audiological tests have been used in diagnosing pseudohypacusis, which include brainstem evoked response audiometry [11,12] and electrocochleography [8,9]. Auditory brainstem response is widely used for measuring true hearing thresholds in suspected cases of pseudohypacusis [13]. However, it lacks simplicity and convenience and is also relatively expensive. Otoacoustic emissions, described by Kemp, are an excellent way for assessing the cochlear function [14]. Otoacoustic emission testing is a non-invasive, objective diagnostic technique, which is gaining popularity as an aid in the detection and assessment of pseudohypacusis [15,16]. Evoked OAEs are primarily generated by the outer hair cells in the cochlea. These low-level sounds can be recorded in the external auditory canal after appropriate stimulation. More clinically useful are transient evoked OAEs and distortion product OAEs. Transient evoked OAEs are preferred over distortion product OAEs as transient evoked OAEs are generated from a large portion of the basilar membrane and are influenced by the status of the whole cochlea. Evoked otoacoustic emissions testing can provide objective information to aid in the detection and quantification of pseudohypacusis [15].
1237
Testing of evoked otoacoustic emissions can be used initially to confirm the hearing status in patients with pseudohypacusis [6]. Evoked otoacoustic emissions can be recorded in nearly all ears with normal or near normal hearing. The recording of normal evoked otoacoustic emissions usually confirms normal middle ear and cochlear function, thereby ruling out a moderate to severe hearing loss and the presence of conductive components. Qiu et al. found that evoked otoacoustic emissions were the most rapid, economical and objective method, which confirmed the diagnosis of hearing loss in 78.1% of cases in their reported series [6]. Otoacoustic emissions testing was found to be diagnostically useful in determining normal peripheral auditory function thereby resolving some of the dilemmas encountered, while facing children with suspected pseudohypacusis [17]. The presence of transient evoked OAEs can be equated to hearing thresholds equal to or better than 20 dB [18]. However, in a few rare cases, evoked otoacoustic emissions may be present in spite of a severe to profound hearing loss [19]. Conversely, there may be normal audiometric thresholds in the absence of transient evoked OAEs and this is indicative of subclinical cochlear damage. Such a situation is usually encountered in adult patients with noise induced hearing loss [20]. Several authors recommend the use of transient evoked otoacoustic emissions for diagnosing pseudohypacusis [15,21,22]. Balatsouras et al. suggest that it is worth performing tympanometry alongside transient evoked otoacoustic emissions [22]. We believe that otoacoustic emissions testing is quicker, less subjective compared to speech audiometry and also not dependant on comprehension as with speech audiometry. In some cases, it also alleviates the need for repeat pure-tone audiometry at a later date to confirm the diagnosis; thereby the audiologist’s time can be used more constructively. Treatment of pseudohypacusis may range from no interference to psychotherapy [5]. If there are any suspicions of underlying psychological conflict that must be identified and treated as pseudohypacusis is considered to be a psychogenic disorder in a few children [1,3,5]. It is important not to confront the child and at all times, the child must be treated as if the hearing difficulty is real [3]. Explaining to the child and their parents about the inconsistent results in pure-tone audiometry and the objective measurement of otoacoustic emissions usually helps in alleviating the condition as is evident by our experience. Both the child and their parents should be reassured strongly that the hearing loss will get better. When the correct diagnosis of pseudohypacusis is made, the treatment is relatively simple
1238
with reassurance, explanation and encouragement [23,24].
5. Conclusions Pseudohypacusis should be relatively easy to diagnose in children because of the problems they have in producing inter- and intra-test consistency. Simple audiological tests such a repeat pure-tone audiometry, impedance testing and speech audiometry are usually sufficient to diagnose pseudohypacusis. However, speech audiometry is time consuming and like pure-tone audiometry still subjective. With the availability of otoacoustic emission testing, pseudohypacusis in children can be diagnosed easily and quickly. Otoacoustic emissions provide the clinician with a sensitive way of determining normal hearing thresholds, preventing unnecessary intervention, but alerting the ENT surgeon to the possible presence of any underlying psychological disturbance or malingering. Brainstem evoked response audiometry is necessary only in very few cases. We believe that pseudohypacusis remains an under diagnosed condition in children but that, once suspected, the diagnosis can be quickly established using available audiological tests. Once the diagnosis is made, children with pseudohypacusis can be effectively managed with reassurance and encouragement.
References [1] J.P. Pracey, R.M. Walsh, G.A. Mepham, D.A. Bowdler, Childhood pseudohypacusis, Int. J. Pediatr. Otorhinolaryngol. 37 (1996) 143—149. [2] R. Carhart, Testing for malingering, Trans. Am. Acad. Ophthalmol. Otolaryngol. 65 (1961) 437. [3] J.P. Pracey, D.A. Bowdler, Pseudohypacusis in children, Clin. Otolaryngol. 21 (1996) 383—384. [4] D.N. Brooks, P.M. Geoghegan, Non-organic hearing loss in young persons: transient episode or indicator of deep-seated difficulty, Br. J. Audiol. 26 (1992) 347—350. [5] D.A. Bowdler, J. Rogers, The management of pseudohypacusis in school-age children, Clin. Otolaryngol. 14 (1989) 211—215. [6] W.W. Qiu, S.S. Yin, F.J. Stucker, L.W. Welsh, Current evaluation of pseudohypacusis: strategies and classification, Ann. Otol. Rhinol. Laryngol. 107 (1998) 638—647.
N. Saravanappa et al.
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