The Role of the World Health Organization's International Classification of Functioning, Health and Disability in Models of Infant Cochlear Implant Management

Abstract

Newborn hearing screening has led to the early diagnosis of hearing loss in neonates and early device fitting is common, based primarily on electrophysiologic and radiologic information, with some supplementary behavioral measures. Such early fitting of hearing devices, in particular cochlear implants (CIs), has been beneficial to the majority of children implanted under the age of 12 months who meet the cochlear implant candidacy criteria. Comorbidities are common in children with hearing loss, although they may not be evident in neonates and may not emerge until later in infants. Evidence suggests that the child's outcomes are strongly influenced by a range of environmental factors including emotional and social support from the immediate and extended family. Consequently, such factors are important in service planning and service delivery for babies and children receiving CIs. The World Health Organization's International Classification of Functioning, Health and Disability (ICF) can provide a framework to facilitate the holistic management of pediatric cochlear implant recipients. The ICF also can be used to map the progress of recipients over time to highlight emerging issues that require intervention. This article will discuss our preliminary use of the ICF to establish clinical practice; develop advocacy skills among clients and their families; identify eligibility for services such as support in educational settings; enable access to modes of service delivery such as telepractice; provide a conceptual framework for policy and program development for pediatric cochlear implant recipients (i.e., in both disability and health services); and, most importantly, establish a clear pathway for the longitudinal management of the cochlear implant in a child's future. It is anticipated that this model will be applied to other populations receiving cochlear implants through our program.

Learning Outcomes: As a result of this activity, the participant will be able to (1) apply the World Health Organization (WHO) International Classification of Functioning, Health and Disability (ICF) model to plan and monitor the pediatric cochlear implant journey; (2) develop a working knowledge of the application of WHO qualifiers to establish a preoperative baseline and ongoing monitoring following cochlear implantation; (3) describe the ICF characteristics that underpin the pediatric cochlear implant journey; (4) identify the additional considerations that may occur in children who undertake the cochlear implant journey; and (5) apply the WHO's ICF to modify intervention and support as required throughout the pediatric journey.

Following the introduction of newborn hearing screening in Australia, early cochlear implantation (CI), before the age of 12 months, is linked with a trajectory toward normal language development.^{1 2 3} The common motivator for CI in young children is to facilitate educational and social participation, that is, to maximize opportunities for them to access the standard developmental pathway of age-equivalent hearing peers through the acquisition of spoken language. To achieve this, a multidisciplinary family-centered approach to intervention is recommended, where professionals from various sectors, including health, community, and education, work with the family and build upon their strengths to optimize outcomes for the child.^{4 5} Holistic management of each child is conducted in partnership with his or her family or caregivers and other key stakeholders using individualized goals and care plans and these underpin the CI journey.

There are four key components of the CI journey, irrespective of age, that continue throughout the lifetime of a CI recipient as can be seen in Fig. 1.

Figure 1.

The cochlear implantation (CI) model.

Following identification of hearing loss, the preoperative evaluation of suitability and preparation for a CI is followed by surgery, then an acute phase of device programming and intervention is implemented. An ongoing cycle of management continues for device checks and programming, auditory training, and assessment to ensure recipients reach and maintain their optimal potential. Device reviews and assessment intervals vary within a range from 3 to 12 months, tailored according to each individual's needs.⁶ A battery of procedures involving a range of stakeholders focusing on audition, social skills, communication, quality of life, cognition, and vision is recommended throughout the CI journey to achieve a holistic approach.⁷

A common platform for classification of function that can be used across all sectors and stakeholders in the CI journey is provided by the World Health Organization (WHO) International Classification of Functioning, Health and Disability (ICF). The inclusion of the brief ICF core set for hearing loss and the ICF: Children & Youth version (ICF-CY) can be used for infant CI recipients, their family, and professionals within the CI program and between other organizations involved in the WHO ICF platform.^{8 9} This encompasses both the health-related and developmental issues typical for these children, particularly those with considerations in addition to deafness. The WHO ICF framework can be used to facilitate a holistic CI journey for an infant, which incorporates qualifiers that are readily understood and applicable to all major stakeholders involved.

This article will describe the use of the WHO ICF in defining the limitations, impairment, and barriers in body structure and body function, activity and participation, and environmental and personal factors that exist for an infant undertaking the CI journey. WHO qualifiers rate the degree of the problem, limitations, or impairment identified using the CI test battery to determine suitability or candidacy for a CI and for ongoing monitoring. Three case studies encompassing the first 2 years of an infant's CI journey will demonstrate the value of the WHO ICF to identify the barriers and facilitators and the factors that underpin the derivation of specific goals and strategies enabling activity and participation and improved body function over time.

How to Use the ICF in the Cochlear Implant Journey for Infants

In a CI journey, body structure, body function, activity and participation, and environmental and personal factors are assessed and qualified using the WHO ICF qualifiers defined by WHO in 2013. As shown in Table 1, qualifiers of function range from 0 (q0: no problem or impairment) to 4 (q4: complete problem or impairment). Qualifier 8 (q8) indicates there is no specific problem; qualifier 9 (q9) is used when it is not applicable to qualify the function.

Table 1. WHO ICF Qualifiers (2013).

Qualifier	Problem (impairment, restriction, limitation, barrier)	Percent problem
0	No	0–4%
1	Mild	5–24%
2	Moderate	25–49%
3	Severe	50–95%
4	Complete	96–100%
8	Not specified
9	Not applicable

Abbreviations: ICF, International Classification of Functioning, Health and Disability; WHO, World Health Organization.

Application of these qualifiers within the CI journey utilizes procedures outlined in Table 2. Where indicated, procedures are only required preoperatively, and other procedures are used at regular intervals postoperatively, until more age-appropriate materials are available.

Table 2. WHO ICF in the Infant CI Journey.

Assessments Tools	Explanation	No Problem (rating of 0)	“Problem” in Infant CI Population (Ratings 1–4 as per Table 1)
Body structure: inner ear, brain
MRI (preoperative only)	MRI of cochlear and vestibular structures, auditory nerve presence and structure, and the brain, in particular auditory cortex of brain performed prior to cochlear implantation to establish anatomical structure	q0: presence and no visible abnormalities of cochlear or vestibular structure, auditory nerve, and auditory cortex	q1: abnormality of vestibule (e.g., large vestibular aqueduct syndrome), presence and no visible abnormalities of cochlear, auditory nerve and auditory cortex q2: abnormal morphology of cochlear, presence and no visible abnormality of vestibule, auditory nerve and auditory cortex q3: abnormal morphology or absence of auditory nerve, presence and no visible abnormality of cochlear, vestibule or auditory cortex q4: abnormal morphology of cochlear, abnormal morphology or absence of auditory nerve, no visible abnormality of vestibule and cortex
Genetic testing	Blood tests to determine if hearing loss has genetic causality; indicative of structural cause of hearing loss; recessive genetic mostly from Connexin 26; other genetic causality nonsyndromal or syndromal	q0: no evidence of genetic abnormality	q1: no evidence of genetic abnormality, however evidence of abnormal inner hair cell structure based on function q2: Connexin 26 associated with abnormal structure of inner hair cell q3: otoferlin associated with auditory neuropathy spectrum disorder q4: presence of syndromal genetics with additional considerations (e.g., Ushers vision; CHARGE [heart, vision])
Body function: hearing function, perception, attention, memory, voice and sound production, motor function
Otoacoustic emissions	Objective test using either TEOAEs or DPOAEs to verify cochlea function of inner and outer hair cells	q0: TEOAE and DPOAE responses within the normal range	q1–q4: absence of response on OAE could suggest any level of hearing loss from mild through to severe or profound; cannot provide information on neural involvement
ABR (preoperative only)	Objective test provides information about transmission of auditory signal from the cochlear nerve through to inferior colliculus brainstem to determine integrity of the auditory pathway	q0–q5: clear waveforms measured within a 5.5-ms time frame indicative of normal transmission of sound through the auditory pathway to upper level of the brainstem	q1–q3: waveforms present when auditory signal is elevated above the normal level; level that auditory signal is present will indicate if there is a mild degree of impairment (1) or a severe degree of impairment (3) q4: Abnormal, and or absent waveforms indicative of severe to profound sensorineural hearing loss
AABR (preoperative only)	Screening ABR using automated equipment presents click stimuli at 35-dB nHL at a rate of 30–37/s; failure to respond leads to more comprehensive testing	q0: presence of responses at screening level	q1–q4: absence of response on AABR could suggest any level of hearing loss from mild through to severe or profound
Transtympanic ABR16 (preoperative only)	Use of electrical current presented using a needle electrode via the tympanic membrane direct to the round window niche, to stimulate the cochlear nerve and auditory brainstem; elicits waves 1–5 as per the acoustic ABR; used to emulate the cochlear implant	q0: five clear waveforms measured within a 4.5-ms time frame indicative of normal transmission of sound through the auditory pathway to upper level of the brainstem	q1–q3: varying degrees of presence and morphology of waveforms indicative of a mild (1), moderate (2) or severe (3) barrier to transmission of electrical current through the auditory nerve along the brainstem q4: absence of any waveforms indicates transmission of electrical current through cochlear nerve and brainstem could be problematic; may be a contraindication to cochlear implantation
Electrocochleography17 (preoperative only)	Objective evaluation of frequency specific hearing thresholds using an electrode placed on the round window niche	q0: cochlear microphonic and action potential measured indicating auditory thresholds within the normal range on individual ears for click and frequency specific (500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz) at 20 dBn	q1–q4: auditory stimuli required to elicit a response with click and/or frequency specific stimuli suggested auditory thresholds from mild (1) through to severe (3) or profound (4) degree of impairment
Cortical auditory evoked potentials18	Objective evaluation of auditory cortical function (i.e., the thalamocortical portion of the auditory cortex); testing performed with and without hearing devices on to determine device effectiveness	q0: presence of waveforms indicative of normal cortical function when speech stimuli /ma/, /ta/, /ga/ is presented at soft (50 dB), loud (70 dB), and conversational (60 dB) levels of speech	With hearing aids on q1: response to all speech stimuli at soft levels q2: response to speech stimuli at conversational speech levels q3: some response to one or two of the speech stimuli at loud levels q4: no response to any stimuli presented
Unaided audiogram—pure tone assessment (individual ears and/or bilateral)	Frequency-specific behavioral evaluation to determine degree of hearing loss; detection of all sounds across frequencies testing Depending on age of child, testing methodology will use either behavioral observational audiometry (or visual reinforced orientation audiometry	q0: Responses obtained for each ear and/or bilaterally when stimuli is presented at 20-dB HL or softer	Responses present when auditory signal is elevated above the normal level; level that auditory signal is present will indicate if there is a mild (q1), moderate (q2), severe (q3), or profound (q4) degree of impairment
Aided audiogram (individual ears and/or bilateral)		q0: If child is using hearing devices, responses obtained for each ear and/or bilaterally when stimuli is presented at 20-dB HL or softer is consistent with hearing devices removing barriers to hearing—no problem with accessing sound across speech spectrum	Hearing devices not sufficient to provide access within the normal range of hearing; level that auditory signal is present will indicate if there is a mild (q1), moderate (q2),severe (q3), or profound (q4) degree of impairment
Ling 6 sound assessment19	Phonemes representing the speech spectrum ar, ee, oo, s, sh, m presented at 1 m from child at 65 dBA requiring a detection or identification response when testing each ear separately and or bilaterally; can be performed with or without hearing devices on	q0: detection of all sounds at normal conversational speech level 65 dBA for each ear separately and bilaterally from 1 m	Using hearing devices: q1: able to detect all sounds but s q2: able to detect all vowels and m q3: able to detect broad vowel ar and m q4: unable to detect any of the 6 sounds presented
Activity and participation: use of communication devices, listening, vocalizations and words, communication, interactions, and relationships; fine and gross motor movements (e.g., maintaining head control)
Infant Monitor of Vocal Production23 24	Interview style rating of infant's vocal competence between 1 and 24 mo of age; can be used following hearing device fitting to verify if child has sufficient access to sound to facilitate speech development	q0: age-appropriate progression of vocal competence	q1: minor delay in development of vocal competence q2: moderate delay in development of vocal competence q3: severe delay in development of vocal competence q4: no progression of vocal competence between test intervals
Rossetti Infant Toddler Language Scale25	Questionnaire to evaluate communication development from birth to 3 y of age at 3-mo intervals	q0: age-appropriate development of pragmatics, gesture, play, language comprehension, and language expression, interaction, and attachment	q1: minor delay in development of one or more areas of development q2: moderate delay q3: severe delay q4: no progression
Parent Evaluation of Aural/Oral performance of Children (PEACH21)	Functional questionnaire using interview of parents to evaluate auditory and oral performance of infants and children in quiet and noisy listening conditions	q0: score consistent with normal-hearing peers aged between 1 and 50 mo	q1: score 1 standard deviation below child's mean for listening in noise q2: score 1 standard deviation below child's mean for both noise and quiet q3: score 2 standard deviations below the mean for child's age q4: score 3 standard deviations below the mean for child's age
Data logging	Information collected by hearing device to provide summary of events including duration of use, number of activations of device, times device is removed, and range of listening environments to reflect noise and speech levels	q0: hearing device retained and used for all waking hours with maximum speech input when in quiet listening environments	q1: device used all waking hours, some difficulty with retention q2: device used most waking hours, some retention difficulties, and/or less than optimal acoustic environment and input q3: device used some waking hours, retention difficulties, and/or poor acoustic environment and input q4: limited (<0.5 h) or no device usage during waking hours and/or extensive exposure to noise with limited speech input
Environmental and personal factors: immediate and extended family, attitudes of family, social and professional support
Attachment27	Rating of parent's ability to perceive and be responsive to their child's needs	q0: Secure attachment of family and child—family responses quickly, sensitively and consistently to child's needs	q1 (attachment 3—avoidant): distant and disengaged q2 (attachment 2—ambivalent): inconsistent sometimes sensitive sometimes neglectful q3 (attachment 1—disorganized): extreme, erratic, frightened or frightening, passive or intrusive
MFRS26	Rating of parent's participation with intervention program on a 5-point scale from Ideal (5) through to limited participation (1)	q0: Ideal family participation (rating of 5 on MFRS)	q1 (MFRS 4): good participation q2 (MFRS 3): average participation q3 (MFRS 2): below average participation q4 (MFRS 1): limited participation

Abbreviations: AABR, automated auditory brainstem response; ABR, auditory brainstem response; CHARGE, coloboma, heart defect, atresia choanae, retarded growth and development, genital abnormality, and ear abnormality; CI, cochlear implantation; DPOAE, distortion product otoacoustic emission; HL, hearing level; ICF, International Classification of Functioning, Health and Disability; MFRS, Moeller Family Rating Scale; MRI, magnetic resonance imaging; nHL, normal Hearing Level; OAE, otoacoustic emission; TEOAE, transient-evoked otoacoustic emission; WHO, World Health Organization.

Body Structure

The presence of normal anatomical (the cochlea or part thereof) and neural structures (the auditory nerve) is required for a cochlear implant to achieve good hearing function. If the structure of the external ear is affected, otologic issues may be obvious at birth. Other otologic considerations are often diagnosed quite early following newborn hearing screening whereby radiologic testing, magnetic resonance imaging (MRI), is typically performed to determine the integrity of the auditory nerve, the hearing structures, and the brain.¹⁰ Abnormalities of the cochlear structure, the vestibules (inner ear), and the auditory nerve are commonly reviewed and, where these are detected, families are counseled on potential outcomes based on similar clinical data sets that have been collected within individual clinical settings. Profiles of children with similar otologically complex cases are reviewed and discussed with families and the scope of potential outcomes discussed.

Otologic considerations include large vestibular aqueduct syndrome (LVAS), which has the following qualifiers: mild problem (q1), common cochlear cavities (q2), auditory nerve abnormalities (q3), or any combination of these (q4). Outcomes reported in the published literature for each of these considerations are used for counseling and preparing families and children for expectations following CI.^{3 11} Generally, outcomes of children with LVAS are consistent with the broader population of children receiving cochlear implants.¹¹ Outcomes of children with abnormalities of cochlear structure are more variable depending on the degree of abnormality. For example, those with common cavities of the cochlea may receive more limited auditory benefit than those who have more complete cochlear development.¹¹ True auditory neuropathy cases with compromised or absent nerves will have auditory outcomes that are less than optimal than their peers without otologic complexities.³

Causal and associated factors such as cerebral palsy, and syndromes linked with deafness such as CHARGE (coloboma, heart defect, atresia choanae, retarded growth and development, genital abnormality, and ear abnormality) are generally identified at around the time of birth or potentially prenatally. Pediatricians or otologists may refer families for genetic testing to isolate the underlying cause of deafness, which can determine the body structure abnormalities. For example, approximately a third of recessive genetic deafness is linked to Connexin 26 (q3), which is linked with impaired function of the inner hair cells of the cochlea, or through identification of the otoferlin gene (q4), which is indicative of auditory neuropathy spectrum disorder.^{12 13}

Qualification of body structure requires consideration of the radiologic findings and, if available, genetic information. Throughout the CI journey, body structure will remain at the same qualification rating. For example, a child with LVAS (q1) who has been identified with Connexin 26 (q3) will remain at q2—an average of the qualifier ratings; whereas a child with the otoferlin gene and abnormalities of the auditory nerve and cochlear will remain at q4. The cochlear implant does not restore body structure; it potentially restores body function. However, the degree of the impairment of the body structure is an important consideration in counseling families regarding potential outcomes, and ensuring that the appropriate goals and supports are established.

Body Function

Children with severe to profound deafness have limitations with their hearing function and perception, and potentially this can impact auditory attention, auditory memory, and voice and sound production. In some children, other considerations related to body function, such as autism, dyspraxia, cognitive disorders, auditory processing difficulties, behavioral or emotional issues and combinations of these, may become evident over time. It is not uncommon that children with physical and cognitive considerations in addition to deafness have more than one comorbidity.¹⁴

A battery of procedures enables qualification of body function of an infant to determine CI suitability and for ongoing monitoring. In most parts of Australia, this begins when the child has newborn hearing screening at 2 days old. Screening tests for hearing function include otoacoustic emissions and automated auditory brainstem response testing.¹⁵ Failure on either or both of these procedures leads to comprehensive audiological testing, which occurs within 3 weeks of the initial identification. A battery of diagnostic audiological tests including tympanometry, repeat otoacoustic emissions, and auditory brainstem response (ABR) using clicks and tone bursts.

In addition, some CI centers conduct a battery of objective electrophysiologic tests performed while the child is asleep or under a general anesthetic, including electrocochleography, acoustic ABR and transtympanic electrical ABR (TT-EABR).¹⁶ These procedures evaluate the integrity of the auditory pathway and can estimate frequency-specific hearing levels,¹⁷ and the use of TT-EABR can provide evidence of whether electrical current generated at the level of the cochlea can be transmitted through the brainstem, as would be expected with a cochlear implant. This testing when combined with other aspects of the preoperative test battery provides information that can assist in counseling of families about possible outcomes with a cochlear implant in relation to body structure and body function such as the neural integrity and possible hearing function.

Unaided cortical auditory evoked potential testing using speech stimuli /m/, /t/, /g/ at 55, 65, and 75 dB provide information about the function of the auditory cortex.¹⁸ This test is usually repeated when the infant is fitted with hearing aids to determine whether the signal from the hearing device is sufficient for providing access to the speech spectrum for hearing function and perception (q0 or q1). Cortical auditory evoked potentials provide objective feedback on whether hearing devices need to be adjusted or transitioned to a CI to facilitate body function.

Behavioral speech perception testing is performed through the Ling 6 sound test. Six phonemes are presented in randomized order. The phonemes represent the speech spectrum: ar, oo, ee, s, sh, and m.¹⁹ This evaluation can be used with infants, children, and adults. The test is presented live voice with intensity measured via a sound-level meter at conversational speech levels (65 dBA). Sounds are presented at 1 m and then 3 m from the child. Behavioral observational audiometry is used to measure response patterns to these sounds for infants and young children including eye widening, head turns, or changes in sucking. As children become older, use of toys, or objects that can be associated with the sound, provide rewards and precede the use of conditioned response procedures to conduct this test. Separate ear measures are recommended to determine access to the speech spectrum for individual ears.²⁰ A qualifier of 0 requires responses at levels on average at 25-dB sound pressure level indicating ability to hear soft speech.

Other behavioral procedures such as audiometry in the free field using warbled pure tones sounds across the frequencies of 250 to 4,000 Hz may be used to verify access to sound. However, this is age dependent, with more reliance on objective testing and functional questionnaires for infants.

The body function qualifier is derived from reviewing the range of tests performed. Typically, a child being considered for CI would have a body function qualifier of q3 or q4. Following CI and intervention, the objective is that the child attain a body function qualifier of q0 or q1 where there is mild or no impairment evident while using the device.

Activity and Participation

Children with severe to profound deafness have potential limitations in their activity and participation in particular listening, vocalizations and words, communication, interactions, and relationships. Facilitators for activity and participation may be the use of devices including hearing aids or cochlear implants. However, use of these can be limited by developmental issues and fine and gross motor movements (e.g., maintaining head control). The test battery for activity and participation includes questionnaires and interviews such as the Parent Evaluation of Aural/Oral performance of Children (PEACH), Infant Monitor of Vocal Production (IMP), AND Rossetti Infant Toddler Language Scale. Each of these tools are used at regular intervals with infants to monitor progress over time.

Functional questionnaires such as the PEACH evaluate auditory and oral performance of infants and children in quiet and noisy listening conditions.²¹ The PEACH can be used with infants as young as 1 month of age to school age. Normative data on children without hearing loss enable comparisons to be made indicating whether auditory and oral performance is within the normal range (i.e., with 2 standard deviations). The PEACH has good internal consistency, with reliability of 0.88, and the test–retest correlation of 0.93.²²

An interview-style rating, the IMP enables monitoring of children's vocalizations from 1 month through to 24 months of age.²³ The IMP has been used to monitor vocalizations of children following fitting of hearing devices, with a slowing of vocal competence suggesting that the hearing device may be inadequate for the child to access sound for their speech development.²⁴

Scales such as the Rossetti Infant Toddler Language scale provide information on communication development including interaction attachment, pragmatics, gesture, play, language comprehension, and language expression.²⁵ The scale can be administered to parents of infants and toddlers from birth to 3 years at 3-month intervals. This enables regular review of communication development so that ICF qualifiers can be adjusted accordingly.

Use of data logging on hearing devices provide a summary of events such as duration of use, the number of times the hearing device comes off, the range of listening environments the child has been exposed to (for example, music, speech, AND noise), and the intensity of sound in the child's environment. Data logging has been a regular feature in hearing instruments and was recently introduced into CI technology in 2012. Monitoring of device use can ensure that issues with retention are addressed as is common in young infants, and that there is a consistency of device use, which is required for access to sound. Overall, the qualifier for activity and participation requires consideration of outcomes on this battery of procedures as outlined in Table 2. Prior to DI it would be expected that there would be severe (q3) or total (q4) limitation of activity and participation. Over time, it would be expected that with appropriate intervention and supports in place these limitations would be removed (q0) or significantly reduced (q1).

Environmental and Personal Factors

The impact of environmental and personal factors as barriers and facilitators of goal achievement can be rated on scales of family participation.^{26 27} Attachment reflects whether parents are able to perceive a child's needs and whether they feel emotionally close to the child. Landy observed that the impact of the immediate family's responsiveness to a child is reflected in the child's general state of being and explains why the child behaves in a particular way.²⁷ Attachment was one of the variables identified in a recent study evaluating parental stress following CI.²⁸ The proportion of primary caregivers who achieved clinically significant scores on the Parenting Stress Index related to attachment was significantly lower than would be expected in the normative population when children were aged 5 and 8 years old,²⁹ despite significantly higher proportions of primary caregivers achieving clinically significant scores on other domains including depression, isolation, competency, and role restriction.²⁸ However, given that these measures were made when the children were older, it is anticipated the age of the children at testing missed the critical early infant toddler developmental phase when some parents of deaf children, particularly those with comorbidities, demonstrate disorganized or ambivalent attachment styles (Rennie M, Bernardo S, Little C, Evans D, unpublished observations, 2015).

The importance of environmental factors such as the immediate family are reinforced by Moeller, who demonstrated that parent participation was positively correlated with outcomes in early intervention programs.²⁶ Parents may experience depression, anxiety, anger, or grief, which can impact their ability to provide the scaffold needed to support their child. Collaboration with families to support, empower, and enable positive interactions with their child and to emphasize their strengths has been linked with improvements in language following CI. Higher parent involvement was significantly correlated with increased child cognitive ability.²⁸

Environmental and personal factors including immediate and extended family as well as other stakeholders including health professionals and social supports can either be facilitators toward achieving goals (q0 or q1) or could prevent or hinder a child's progress (q3 or q4).

Case Studies Demonstrating the Use of ICF in Cochlear Implant Journey with Infants

The following three cases show the use of the WHO ICF for the evaluation and monitoring of infants receiving a cochlear implant. All children were identified with a hearing loss at 2 days of age, and subsequent testing confirmed a bilateral sensorineural hearing loss within 3 weeks of life. All children were referred to the national provider of audiological services to have hearing aids fitted, based on the information provided through their diagnostic audiological testing. Hearing aids were fitted to all within the age of 9 weeks. Each family contacted early intervention services and began researching CI within a few days of their child's diagnosis.

Typically, if the multidisciplinary team members including the immediate family, extended family, and health and educational professionals work together toward common objectives and there are no emerging comorbidities or unforeseen barriers, movement through the model should predominantly be on target. It is anticipated that by 12 months post-CI the child who received a cochlear implant below the age of 12 months and did not have any comorbidities in addition to deafness would have full-time use of their cochlear implant, have spontaneous changes in their vocalizations, spontaneously alert to their name and environmental sounds, show evidence of deriving meaning from many speech and environmental sounds, and have a major improvement in language.³⁰ Children with additional considerations have also demonstrated significant progress, albeit on a slower trajectory, and may take a period of up to 3 years post-CI to make similar gains to children with no comorbidities.³¹ Children with delays in implantation (beyond 12 months) may experience delays in their speech and language development.³²

Case 1: William—A Typical Journey

William had a pediatric examination soon after birth and there were no comorbidities evident (Fig. 2). After his hearing loss was confirmed, as per protocol, a social worker was engaged to counsel William's family about their options. The parents were committed and diligent in hearing aid use; however, until William was able to sit up and had improved head control, keeping the hearing aids on was problematic.

Figure 2.

Case study 1 (William, a typical CI journey). Overall goal: Use of the cochlear implant to provide access to sound to assist in language development.

There was no family history of hearing loss. William's family lived in an outer urban area, close to integrated cochlear implant and early intervention services. There were no financial pressures evident. Extended family support, through both paternal and maternal grandparents, was available as required to assist William's parents. The immediate and extended family members were able to work as part of the multidisciplinary team, which, in their case, included a social worker, audiologist, speech pathologist, educational consultant, and ear, nose, and throat surgeon.

Goals and objectives for William and his family were derived after meeting with other families, making use of online resources, and meeting with members of the multidisciplinary team.

A body structure qualifier of 2 (q2) was rated as radiologic investigations revealed the auditory nerve was present, the cochlea was structurally normal, and there were no evident abnormalities of the vestibule or brain. Genetic testing was negative for Connexin 26, known to be involved in both dominant and recessive forms of sensorineural deafness.³³

Environmental and personal factors including immediate and extended family as well as other stakeholders including health professionals and social supports were all identified as being facilitators toward achieving goals. That is, an attachment rating of 4 and participation rating of 5 showed there was no problem (q0).

William's CI candidacy evaluation using the test battery outlined in Table 2 resulted in categories of body function along with activity and participation presenting as a total problem (q4).

Three months after implantation, William's CI program on his speech processor was stable. William continued to attend individual early intervention sessions weekly, and his parents were involved with a parent-to-parent network. William's parents and other family members provided consistent support. His expanded prelinguistic skills and age-appropriate development of early vocalizations were measured through the IMP and the Rossetti Infant Toddler Language Scales. William was making good progress from his preoperative evaluation baseline; however, his auditory and speech production skills were not age-appropriate as measured on checklists implemented as part of the CI test battery (such as the Rossetti and PEACH).

He responded to many sounds in his environment, including speech, and was beginning to vocalize more, which was reflected in the shift from his activity and participation qualifiers from 4 to 3. However, his body function was impacted by some problems with device retention with qualifiers remaining at q3.

Twelve months after his CI, use of data logging on his speech processor showed improved device use due to improved retention (q1). His auditory and speech production skills were approximating an age-appropriate range. His vocalizations and performance on the Rossetti indicated a 3- to 6-month delay (q1).The PEACH showed age-appropriate outcomes (q0). William responded to warbled pure tone sounds in the free field across the frequencies of 250 to 8,000 Hz at levels on average at 25-dB sound pressure level indicating ability to hear soft speech (q1). This finding was confirmed by his responses to phoneme detection and identification testing using the Ling sounds, where all phonemes across the speech spectrum were detected and those sounds within his phonemic repertoire were repeated (q0). Data logging showed device use for ∼10 hours per day (q0). William was enrolled in the local playgroup with other community children and began music appreciation classes. He made excellent progress and qualifiers shifted to q1 (slight problem) for body function, as well as for activity and participation. Environmental and personal factors continued to act as facilitators throughout William's progress as the family adjusted to the diagnosis of deafness, the cochlear implants, and associated habilitation. The family was positive at almost all stages of the journey and worked proactively with the transdisciplinary team.

Two years after his CI, William achieved age-appropriate scores and his activity and participation were no longer limited (q0). Ongoing 6-month monitoring using the WHO ICF platform was continued to ensure William moved through his developmental stages without limitations in his body function and activity and participation.

Case 2: Leo—Total Limitation of Body Structure (q4)

Leo's case study (Fig. 3) demonstrates the integration of ICF model into the management of an otologically complex case with CHARGE syndrome (total impairment of body structure, q4). The wide range of possible longitudinal outcomes of children with CHARGE was used as the basis of counseling for this case.³⁴

Figure 3.

Case study 2 (Leo, total limitation in body structure). Overall goal: Use of cochlear implant to provide access to sound to assist in language development.

Leo was diagnosed with CHARGE syndrome soon after birth (q4). A bilateral profound hearing loss was confirmed when Leo was 4 weeks old. An MRI showed absent auditory nerves bilaterally and bilateral dysplastic cochleae, more evident on the left side than on the right (body structure q4). Leo was fitted with hearing aids at 6 weeks of age. Leo showed some responses to sounds presented at very loud levels when wearing his hearing aids, particularly through the right ear. A repeat MRI showed the presence of very fine auditory nerve fibers. Middle ear effusion was present, particularly in the left ear, which impacted hearing aid use as using the earmold with the hearing aid he was prone to infection. Leo had heart surgery scheduled at 6 months. Leo had a percutaneous endoscopic gastrostomy so that fluids could be directed to his stomach for feeding, because he was unable to eat orally. Vision was monitored as part of the CHARGE syndrome and there were no abnormalities found. Motor milestones were delayed at the time of his evaluation for CI suitability at the age of 8 months. Leo lived at home with his parents and had no siblings. His parents wanted bilateral CIs so that Leo could have the best possible access to sound to develop communication.

Leo received a right cochlear implant at 9 months of age. At the time of CI surgery, the TT-EABR electrophysiologic test performed on the left ear showed potential viability of the left auditory nerve. He received a left cochlear implant at 11 months of age. No further heart surgeries were required. Middle ear effusion had resolved. Contrary to the initial MRI results, the auditory nerves were able to process information from each ear.

By 3 months after his initial CI, Leo was starting to approximate age-appropriate vocalizations; however, his PEACH scores and Rossetti remained severely delayed (q3). His motor milestones were ∼3 months delayed. Data logging showed intermittency of device use due to retention issues, which were addressed through use of a cap over his speech processors (q3). Leo had elevated levels on his aided audiogram (responses at 30 to 50 dB across all frequencies in each year) (q2). Detection responses were consistent on the Ling sounds for all phonemes except s and sh, which were inconsistent (q2). Device programming was therefore scheduled more regularly to monitor this. Body function had progressed to q2, and activity and participation made marginal progress to q3.

His CI programming was scheduled at 3-month intervals given the questionable integrity of the auditory nerve. Leo, his mother, and his grandfather attended weekly individual and group sessions, which were scheduled to continue until he reached preschool. Sessions incorporated goals for physiotherapy and occupational therapy as well as communication and audition consistent with a multidisciplinary approach.

Environmental and personal factors including family involvement and participation were ranked at q0 as the parents managed and coordinated his intervention, which involved many medical, allied health, and educational professionals. The extended family, mainly his grandfather, was actively involved in either supporting Leo directly or providing support to the immediate family.

At the beginning of the cochlear implant journey, Leo had total limitations of body function (q4) and activity and participation (q4). Twelve months after implantation, severe problems remained for body function (q2) and activity and participation (q2), and environmental and personal factors (q0) continued to facilitate his journey.

Two years after his first cochlear implant, Leo had mild limitations to body function (q1) and activity and participation (q1) due to continued improvements in his development and function, but still not approximating the age-appropriate level. This was anticipated given the existence of his additional considerations. Leo was able to eat a normal diet independently. Although otologic considerations have been addressed in Leo's case study, the importance of continued monitoring of body function with activity and participation to monitor vision, cognitive, communication, and physical development would be required longitudinally (Fig. 4).

Figure 4.

Case study 3 (Jack, total limitation in environmental and personal factors). Overall goal: Use of cochlear implant to provide access to sound to assist in language development.

Case 3: Jack—Environmental and Personal Factors (q4)

In case 3, Jack's parents were congenitally deaf. They were bilingual with primary use of Auslan. Jack's father received a cochlear implant as an adult and used his device intermittently. Soon after birth, Jack had an MRI that was normal, and the gene Connexin 26 was identified (body structure, q2). A multidisciplinary review meeting was held with the surgeon, immediate family, extended family, health professionals, and early intervention team following candidacy evaluation. Jack's parents consented to bilateral simultaneous cochlear implants. It was agreed the extended family would be actively engaged with the immediate family and professional supports in working toward goals for device use and for spoken language development. Home visits by the transdisciplinary team were agreed upon to ensure good access to his service (environmental and personal factors, q1).

Jack's mother was very unwell leading up to the surgery, which occurred when Jack was 9 months old. Soon after DI, it was discovered that Jack had low muscle tone and was failing to meet his developmental milestones for sitting and walking. His parents felt that Jack's motor development should take precedence over the CI follow-up, and although acknowledging the need for consistent device use in team meetings with an Auslan interpreter present, Jack's parents opted not to use the CI and focus primarily on physiotherapy and occupational therapy. The barriers for environmental and personal factors emerged for the immediate and extended family (q4). Jack had sporadically attended early intervention, owing to the mother's continuing illness and conflicting appointments for physiotherapy and occupational therapy. Arrangements were made for home visits, but they were commonly canceled by the immediate family. Jack was only seen twice in the 3-month period following device activation instead of the scheduled 12 appointments. Family participation was quite poor, and the mother presented as having ambivalent attachment as she was “inconsistent, sometimes sensitive, sometimes neglectful” consistent with an attachment rating of 1 (q4).

At his 3-month postoperative review, Jack had made minimal progress with his hearing function as measured on the PEACH, and his vocalizations and communication showed only minimal improvement on the IMP and the Rossetti scales (q4). His bilateral aided thresholds on the free field audiogram, and detection of the Ling sounds with individual ears indicated Jack had good access to the speech spectrum (q1), showing improvements for body function overall (q1). However, his activity and participation remained at q4. Although he had access to sound, he had not integrated the signal from the cochlear implant to develop hearing function, listening, and communication. His responses indicated sound detection only because intermittent device use precluded him from a consistent auditory signal, making it difficult for him to learn how to develop the meaning attached to the sound he was detecting.

Integration of listening and communication goals into his other therapies was discussed, but this did not occur because his devices were not being used consistently. The situation was compounded by the fact that Jack had poor head control, and device retention was problematic. Retention options were tried and effective retention devices were provided, but the family continued to contend that device retention was a barrier to device use.

The use of the WHO ICF with Jack and his family demonstrated that there was no or minimal change in the activity and participation qualifiers between the preoperative and the postoperative interval. Environmental and personal factors emerged as a barrier that had not been evident at the preoperative phase (q4).

This prompted the need for a review of the service delivery model that was being used. Access to sessions and participation in sessions was a factor impacting on outcomes.

At 3 months post-DI, telepractice was introduced as an option of service delivery to this family using an iPad (Apple, Cupertino, CA) for videoconferencing through an interpreter. This was increasingly accepted by the immediate family as a regular service model for habilitation and counseling, which served to build trust in the transdisciplinary team. Once this platform had been established, device programming with the educational consultant in the child's home as a facilitator resulted in increased use of the cochlear implant. The educational consultant set up the equipment for mapping in the child's home, and the audiologist used remote mapping procedures as described by Psarros and Van Wanrooy to access the computer and perform testing and make adjustments to Jack's speech processors.³⁵

Telepractice has become an integral part of the cochlear implant journey for clients where geographic, socioeconomic, psychosocial, and mobility issues prevent the client from traveling to a clinic.³⁶ To facilitate service delivery, telepractice for remote cochlear implant programming and habilitation and rehabilitation is routine in many centers, particularly in Australia. For example, larger cochlear implant centers may have up to 4,000 cochlear implant recipients with ∼30% living remote to their nearest clinic and as a result utilizing therapy and audiological services through outreach clinics and telepractice.³⁷ Difficulty accessing therapy following CI was cited by Morettin et al as a barrier to children achieving optimal outcomes and this can be mitigated by telepractice.³⁸ A blend of telepractice with clinic-based service delivery can improve a client's access to services.³⁸

One year after the device was implanted, Jack began to increase device compliance and data logging showed increases in average use from 30 minutes up to 2 hours and eventually 4 hours per day. The goal of device use in all waking hours was not achieved, but some progress was made (q3). His PEACH, IMP, and Rossetti scores showed minimal progress; however, they demonstrated a clear delay in his development for communication and audition resulting in improvements of activity and participation (q3). By the 2-year review, further progress had been made in activity and participation (q2) with the gap toward the goal of age-appropriateness closing slightly in his communication development.

None of the goals were achieved as indicated by “ − ”on all areas of function. There was a minor shift as shown in environmental and personal factors (q2). However, the fact that participation and attachment remained as barriers may have been addressed by ensuring that concepts and messages and perceptions being conveyed through interpreters were clear and consistent. Introduction to other deaf parents of children with cochlear implants to provide societal support was recommended to the parents at various stages throughout the case management but was not accepted. This may have provided the social framework and support to possibly facilitate better acceptance of the cochlear implant.

A major contributor of the slow progress was assumed to result from the demonstrated issues with attachment and family participation. For reasons that were not clear, paternal extended family were not included in the ongoing support and management, precluding possible positive family participation.

With some improvements in his motor development, there was a small increase in device usage. Improvements in device usage and activity and participation also could be due to the variation of the service delivery model to include telepractice. Telepractice provided a consistent platform for service delivery and enabled regular appointments to be kept; in particular, it facilitated the programming of the device in the home environment. Continued monitoring of the overall goal to achieve use of the CI to provide access to sound to assist in language development was yet to be achieved. The support required to facilitate the removal of problems impacting on body structure, body function, and activity and participation could integrate the use of telepractice and a blend of service delivery models.

Case Study Summary

All of these cases commenced their journey at the same point in the child's lifetime. However, the factors affecting their journey differed. although William had a typical journey, the presence of body structure issues impacted on Leo's journey, and Jack had limitations in his environmental and personal factors, which in turn impacted on his activity and participation. The use of the WHO ICF enabled the stakeholders to objectively review the areas where scaffolds and supports were required with regular monitoring and reviewing, ensuring that appropriate action was taken to remove barriers for limitations. In Leo's case, the supports required were provided by integration of additional health professionals and otologic investigations. In Jack's case, a shift in the model of service delivery was implemented following the identification of difficulties with the environmental and personal factors. As with Leo, a slower trajectory was followed, but the areas impacting as identified by the WHO ICF enabled a more tailored and holistic approach be negotiated to remove the barriers required to achieve function.

The qualifiers provide a clear profile of existing limitations and removal or addition of these as a child travels along the stages of CI. As these case studies show, regular review of goals and progress is required to ensure that the WHO ICF platform can successfully engage all stakeholders in the CI journey.