Early Predictors of Autism in Young Children Who Are Deaf or Hard of Hearing: Three Longitudinal Case Studies
ABSTRACT
Early assessment data (starting at 9 months) for three children who were deaf or hard of hearing and later diagnosed with autism spectrum disorder (ASD) were analyzed. The results from the MacArthur-Bates Communicative Development Inventories (CDI) Words and Gestures and the Child Development Inventory were used to develop three profiles of children who were deaf or hard of hearing and had ASD. One child lacked expected skills and language at ages 9 and 14 months. Another child lost skills and language after 17 months. The third child had results usually within or above the average range until 3 years of age. However, his age quotient decreased for MacArthurBates CDI: Words and Gestures Words Expressed and the Child Development Inventory: Social to significantly below the normal range. Although it can be difficult to diagnose the co-occurrence of ASD and deafness, there were early warning signs for these children. KEYWORDS: Autism, deaf, hard of hearing, children,
developmental assessment, screening
Learning Outcomes: As a result of this activity, the reader will be able to (1) explain the reasons behind and the importance of autism spectrum disorder (ASD) screenings at multiple sessions; (2) describe three potential profiles for boys who are deaf or hard of hearing and have ASD; (3) discuss the current emphasis on earlier identification of ASD.
1 Department of Speech, Language, and Hearing Sciences, University of Colorado, Boulder, Colorado. Address for correspondence: Elizabeth Cameron Kellogg, M.A., Department of Speech, Language, and Hearing Sciences, 2501 Kittredge Loop Road, 409 UCB, University of Colorado Boulder, CO 80309-0409 (e-mail: elizabeth. [email protected]). Screening, Diagnosing and Implementing Interventions for Children Who Are Deaf or Hard of Hearing
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with Autism Spectrum Disorder; Guest Editors, Christine Yoshinaga-Itano, Ph.D. and Amy Thrasher, M.A., CCC-SLP. Semin Speech Lang 2014;35:276–287. Copyright # 2014 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 5844662. DOI: http://dx.doi.org/10.1055/s-0034-1389100. ISSN 0734-0478.
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Elizabeth Cameron Kellogg, M.A.,1 Amy Thrasher, M.A., CCC-SLP,1 and Christine Yoshinaga-Itano, Ph.D.1
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arly identification of autism spectrum disorder (ASD) is important for both hearing and deaf children. It is difficult to study infants who are later diagnosed with ASD. Retrospective studies often involve home videos, reviewed when the children are older, and parent recall. Prospective studies tend to target high-risk populations, such as the siblings of children diagnosed with ASD.1 The purpose of this unique retrospective study is to develop profiles for three children who were diagnosed as deaf or hard of hearing (D/HH) at birth and then later diagnosed with ASD. In Colorado, children who are identified as D/HH through universal newborn hearing screening programs or in the first 3 years of life are offered an array of family-centered services until age 3. Over 90% of the families choose to participate in the Colorado Home Intervention Program (CHIP).2 CHIP began offering family-centered, family-focused intervention for children who are D/HH in 1969.3 Since the mid 1980s, researchers at the University of Colorado Boulder have investigated the predictors of successful outcomes for infants and toddlers who are D/HH.4 Assessments are a component of CHIP, and data are collected at approximately 6-month intervals. The Child Development Inventory, MacArthur-Bates Communicative Development Inventories (CDI), and analyses of spontaneous language samples are some of the assessments used.4
AUTISM SPECTRUM DISORDER The criteria for diagnosing ASD have changed with the 2013 publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V).5 For a helpful review of the changes and the implications of the criteria under the DSM-V, see Mahjouri and Lord.6 The children in this study were diagnosed with the criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition,7 which includes deficits in verbal and nonverbal communication, deficits in social interaction, and restricted, repetitive, and/or stereotyped behavior, activities and/or interests. For those unfamiliar with ASD, Vernon and Rhodes
wrote an article for the American Annals of the Deaf summarizing ASD and its history.8 In 2014, the Centers for Disease Control published prevalence rates from data collected by the Autism and Developmental Disabilities Monitoring Network in 2010.9 According to the data, 1 in 68 8-year-old children met research criteria for ASD. Currently there is neither a genetic test nor biological marker for ASD.10 Thus, standardized assessments and clinical judgments are used to diagnose ASD. Screeners are often used to refer children for a full ASD evaluation. For a review of early screening tools for ASD at the 18- and 24month pediatric visits, please see Barton et al,10 who stated that early identification and subsequent early intervention are related with positive outcomes in communication, social interaction, and cognitive development and included several supporting studies.10 Currently, there is no study of ASD screening or assessment for children with bilateral permanent hearing loss. Szymanski et al reported that the incidence of autism in a population of children who are D/ HH is 1 in every 59 children, higher than the incidence in the hearing population.11 Vernon and Rhodes cited the importance of a special 2008 edition of Odyssey: New Directions in Deaf Education12 in which mental health specialists in deafness began focusing on the double disability.8 It is also quite difficult to diagnose.13,14 ASD diagnosis is often given later to children who are already identified as D/HH as compared with hearing children.15
METHODS The current study is a retrospective case study of three children identified as infants as being D/ HH. Each child entered the CHIP program when deafness or hearing loss was identified. Several assessments were administered from that point through the age of 3 years. MacArthur-Bates Communicative Development Inventory: Words and Gestures (CDI: WG), MacArthur-Bates Communicative Development Inventory: Words and Sentences (CGI: WS), and Minnesota Child Development Inventory (MCDI) were among those assessments. These children were later diagnosed
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with ASD. The three case study participants were chosen from the group of children in the CHIP database with a diagnosis of ASD due to the consistency of assessments at approximate intervals of 5 to 6 months, starting at least at 9 months old. They each also had at least five assessment sessions total. All of the children live in a Colorado metro area. The histories for each child are reported with the known information. Due to the great variety of expression of characteristics across diagnoses and the variety of intervention, each study is treated as a separate case.
Case A Case A was born to two deaf Caucasian parents. He was diagnosed with a bilateral severe sensorineural hearing loss at birth. He was fitted with hearing aids at 7 months old. Case A’s intervention began at age 2 months old, while he was in the neonatal intensive care unit. His intervention was solely from CHIP and consisted of individual therapy delivered in his home. His therapist used sign and speech, and his parents used only sign with him. As he grew, he learned sign but did not speak.
Case B Case B was born to hearing Caucasian parents. At birth, he was diagnosed with profound bilateral sensorineural hearing loss. He received cochlear implants at 16 months. His intervention began at 18 months or before and included services from CHIP, Listen Foundation, and later a private therapist. At 18 months of age, he received 1 hour a week of in-home intervention, and by 21 months he was receiving an hour of in-home intervention along with an hour of out of the home intervention. His intervention initially consisted of verbal/oral therapy without sign language. By age 26 months, some sign was used. Case B was diagnosed with ASD at age 18 months and with apraxia of speech at age 5 years old.
Case C Case C was born to hearing Caucasian parents. He was diagnosed with a bilateral severe sen-
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sorineural hearing loss at birth. He was fitted with hearing aids at age 2 months. Intervention began at age 2.5 months old and was 90 minutes a week in his home. Auditory/verbal therapy was used. Until age 15 months, case C received intervention services from CHIP only. Around 15 months, he began attending a D/HH group at a major hospital in Colorado. With the addition of the D/HH group at the hospital, he received 5 hours of intervention per week and both American Sign Language and sign language in English order was added to the verbal/auditory approach to communication to become a total communication approach.
Assessment Tools: MacArthur-Bates CDI The MacArthur-Bates CDI is a parent questionnaire about language understanding and production for children as young as 8 months of age. It was developed in 1993 and revised in 2007.16 Since 1993 there have been two scales, CDI: WG for infants from 0;8 to 1;4 and the CDI: WS for toddlers from 1;4 to 2;6. A modified version (indicating says or signs) of the MacArthur-Bates CDI: WG was given to the parents in the CHIP program. The CDI: WG contains two parts with several sections. The first section consists of three questions about the child’s responsiveness to language. In the next section, using a list of 28 items, parents identify phrases the child understands. The third section has two questions about the child’s frequency of imitating words and labeling objects. The following section is a 396-item vocabulary checklist broken into 19 semantic categories. Part II of the questionnaire contains sections about actions and gestures. The subscales of the actions and gestures sections include Games and Routines and Pretending to Be a Parent. The MacArthur-Bates CDI: WG may be particularly beneficial for use with children with ASD due to the inclusion of two areas of concern for children with ASD, vocabulary comprehension and production, as well as the use of early social-communicative behaviors (e.g., imitation, functional and symbolic play, and declarative and imperative gestures).17
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Assessment Tools: Child Development Inventory The MCDI was developed in 1972 and was later updated and renamed the Child Development Inventory in 1992.18 This caregiver questionnaire is normed for children 15 months to 6 years. The Child Development Inventory has 270 items that are answered either yes or no. It measures development in eight areas and overall general development leading to nine scales including Social (40 items) and Self Help (40 items). With nine scales, the Child Development Inventory provides a greater picture of a child than many other toddler and preschool scales and screeners. The scores for the scales are given as developmental ages. There are a few differences between the MCDI and the Child Development Inventory. Ireton explained the Child Development Inventory consists of a more comprehensive set of items in terms of age coverage as well as eliminating “poor items.”18(p.2) The Child Development Inventory also has a more representative and more current norm sample. There is a change in the name of one of the scales; the Personal-Social Scale became the Social Scale. Apuzzo and Yoshinaga-Itano described the Personal-Social scale as measuring personal and social behavior, including independence, imitation, social interaction, and concern for others.19 Ireton described the Social Scale as including interactions with parents, children, and other adults and from individual interaction to group participation.18 The MCDI was used with two of the case study participants (cases B and C) and the Child Development Inventory was used with one (case A). This made comparison of specific items difficult because only 17 out of 40 items corresponded between Personal-Social Scale (MCDI) and the Social Scale (Child Development Inventory). Some of the items for the Self Help Scale were changed and just 25 out of 40 items corresponded. Additionally, age-level information for each item is available in the Child Development Inventory manual and unknown for the MCDI. Thus, the individual items for case A could be organized by age level and only the corresponding items for cases B and C could also be organized by age level.
RESULTS The parents of case A and B filled out the MacArthur-Bates CDI: WG four times between ages 9 months and 27 months. Case C’s parents filled it out three times between the ages of 4 and 15 months. Case C scored in the average range across all domains at age 15 months and thus the MacArthur-Bates CDI: WG was not continued and the MacArthur-Bates CDI: WS was used. Case A and B’s scores fell below the typical range in at least some of the domains at 16 months and the assessment was continued past the normed ages (0;8 to 1;6). The results of the following measures related to the MacArthur-Bates CDI: WG will be presented for each case: age quotient, words produced (expressive vocabulary), total gestures produced, and a subscale of gestures. Age quotient is the developmental age score (derived by the norms from the assessment) divided by the chronological age, multiplied by 100. Over time, age quotients indicate the rate of development. A flat age quotient trajectory indicates a year’s growth in a year’s time. It is expected that the age quotient would stay constant or increase as children increase their communication. Case B’s age quotients for acquiring expressive and receptive vocabulary, phrases, and gestures were fairly consistent in the 40 to 60 range, meaning his development was between 40 and 60% of his chronological age. Case A’s rate of acquiring expressive vocabulary, phrases, and gestures decreased between 9 and 22 months. Between 22 and 32 months, his development was 60% of his chronological age. In many of the categories, he lost skills or words he previously understood and/or produced. For example, for MacArthur-Bates CDI: WG: Gestures: Imitating Other Adult Actions, his raw score dropped from 7 to 3 (with five lost skills and one new skill). Case A also lost skills on the Child Development Inventory: Social and Self Help. The age quotients for expressive vocabulary, phrases understood, and gestures for both cases A and B decreased until they plateaued at either 60 or 40 to 60. Initially they were making less than a year’s growth in a year’s time and then they made a year’s growth in a year’s time but only at lower percentage of development for their chronological age.
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As mentioned earlier, case C scored in the average range for 16 months old and the MacArthur-Bates CDI: WG was no longer given. The MacArthur-Bates CDI: WS was used to continue to measure his expressive vocabulary. For expressive vocabulary, case C began with a quotient of 133 at 9 months. It decreased linearly until it was 67 at 36 months, meaning his expressive vocabulary growth slowed over time. He was not making a year’s growth in a year’s time and his scores fell below the typical range after 21 months. At 3 years, his expressive vocabulary development was at 67% of his chronological age. The children’s scores were compared with the norms of the MacArthur-Bates CDI as well as norms for children who are D/HH and have cognition of greater than or equal to 80. These were used because all three participants had cognition greater than 80. This is relevant because the norms for the total D/HH population tend to be 25th percentile lower than the norms for hearing children because the presence of hearing loss impacts access to language.20 The distribution for children who are D/HH is lower than children in the norming sample for the MacArthur-Bates CDI: WG. Cases A and B were between the 10th and 25th percentiles for the D/HH norms, which is below the 10th percentile for children with normal hearing.
Words Produced Fig. 1 shows an overlay of the total number of words produced from the MacArthur-Bates
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CDI: WG for cases A and B and MacArthur-Bates CDI: WS for case C onto the norms for the children who are D/HH with cognition greater than or equal to 80 (D/HH 80 cognitive development). On Fig. 1, Case C’s trajectory does not match those of the other children in the norm, meaning his age quotient score was decreasing as mentioned above. When case C was compared with his peers who are D/HH 80 cognitive development, his scores were below the 50th percentile. The trajectories of cases A and B’s scores seemed to be linear rather than exponential like those of the children in the 25th percentile.
Gestures Produced Fig. 2 shows an overlap of the total gestures produced by all three cases on top of the total gestures for children who are D/HH 80 cognitive development. At 16 months, case C’s scores were at the 75th percentile for children D/HH 80 cognitive development and close to the mean of the norms for hearing boys. This was not consistent with the results of several researchers who found children with ASD had delayed gestures compared with the control group or the norms.17,22–24 However, this child was at a mild end of the spectrum, and he demonstrated some aboveage-level developmental skills. The researchers did not specify if children diagnosed with what was formerly known as Asperger syndrome were included in their studies.
Figure 1 MacArthur-Bates Communicative Development Inventory: Words and Sentences. Words produced for children who are deaf or hard of hearing with cognition greater than or equal to 80 and case study participants. Adapted from Marion Downs Hearing Center.21
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Figure 2 MacArthur-Bates Communicative Development Inventory: Words and Gestures (CDI: WG),. Total gestures for the children who are deaf or hard of hearing with cognition greater than or equal to 80 and case study participants. Adapted from Marion Downs Hearing Center.21
Fig. 2 shows that when compared with the children who are D/HH 80 cognitive development, case B’s scores were well below the 25th percentile. This would be below the 10th percentile for the norms for hearing children. Case A’s total gestures were just at the 25th percentile at 16 months and subsequently fell below that. Given that at 16 months case B demonstrated 4 out of 18 early gestures and 3 out of 45 late gestures, it is not surprising case B was diagnosed with ASD by 18 months. Although it was not listed on case B’s information sheets, it was likely case B began receiving early ASD intervention. This may explain his dramatic increase in gesture use after 18 months (at 21 months he demonstrated 11 out of 18 early gestures and 21 out of 45 late gestures).
Pretending to Be a Parent MacArthur-Bates CDI: WG Subscale D, Pretending to Be a Parent, is one the subscales for the late gestures section and, in the current study, appeared to be an important and revealing category. This subscale involves children playing parent with a doll or stuffed animal, including such actions as feeding it with a bottle, talking to it, and hugging it. Table 1 presents the entire subscale as well as the norms that indicate by what month 50% of the normed sample demonstrated the skill. Both sexes combined showed four of the items by 16 months. The results for this gesture subscale were not
available for either the D/HH norms or the D/ HH 80 cognitive development norms. However, there was a recent pilot study with 20 children with varying ranges of hearing loss. Table 1 MacArthur-Bates Communicative Development Inventory: Words and Gestures Subscale D: Pretending to Be a Parent Item Number
Item
50% Month
Actual %
1 2
Put to bed Cover with
10 13
52.4 52.1
blanket 3 4
Feed with bottle Feed with spoon
16 16
53.7 50.0
5
Brush/comb
(16)
43.3
6
hair Pat or burp it
(16)
31.3
7
Push in
(16)
41.2
8
stroller/buggy Rock it
(16)
40.3
9
Kiss or hug it
(16)
35.8
10
Try to put shoe/sock/hat
(16)
31.3
on it 11
Wipe its face or hands
(16)
31.8
12
Talk to it
(16)
17.9
13
Try to put a diaper on it
(16)
15.2
Note: Month at which 50% of the children have the skill. Parentheses indicate 50% of the children did not have the skill by age 16 months, the upper limit of the normed age range. Adapted from Fenson et al.25(p.159)
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Those results are discussed in the conclusion. Neither case A nor case B displayed any skills from this category until after 17 months. By 17 months, case C had demonstrated two of them (i.e., brushing/combing its hair and hugging/kissing it). Between 17 and 21 months, case A lost five skills and gained one new one. Case C’s score of two items was within one standard deviation from the average for both sexes combined. Cases A and B were significantly lower. No other children had protocols with no demonstrated skill in Pretending to Be a Parent at 16 months of age. As indicated, two of the three children did acquire some skills after the age of 17 months.
Child Development Inventory: Social Subscale Fig. 3 depicts the age quotients for the Child Development Inventory: Social and the MCDI: Personal-Social. Recall that case A’s assessments included the Child Development Inventory and cases B and C’s assessments included the MCDI. Also, the scales were named differently between the two versions. Additionally, note that case A was not given the Child Development Inventory between 16 and 28 months. Age quotients for all three cases decreased significantly over time. Between 28 and 32 months, case A lost 8 skills, maintained 6, and gained 7, thus his raw score went from 14 to 13. His Social age quotient decreased by 19 points over 16 months. Case B lost four skills between 26 and 31 months, two of which he had reportedly been demonstrating since 21 months. His Personal-Social age
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quotient decreased by 38 points over 20 months. Case C’s Personal-Social age quotient decreased by 39 points over 26 months.
MCDI and Child Development Inventory Self Help Subscale The MCDI and Child Development Inventory Self Help age quotients are depicted in Fig. 4 . Both case A’s and case C’s age quotient decreased. Case C, in particular, was right at the expected age quotient of 100 from 8 months until 21 months when his scores started decreasing steadily to 69 at 36 months. Case B’s age quotient was not as consistent. At 14 months, his age quotient was 86 and his age quotient decreased to 62 at 21 months. He plateaued, and his age quotient was also at 62 at 26 months. Then, at 34 months, his age quotient decreased to 50. Case A’s age quotient was even less consistent. Case A’s age quotient was 75 at 16 months, 61 at 28 months, and 69 at 32 months. The missing data at 21 months would have been interesting to plot because it would have provided additional insight. Case A lost one skill between 16 and 28 months and two skills between 28 and 32 months, which were fewer skills than he lost on the Child Development Inventory: Social Scale. Case B did not lose any skills. Case C lost one skill on this subscale. His caregiver indicated he could do it at the 21- and 27-month dates, but not at the 35-month date.
DISCUSSION By choosing case study participants from the CHIP database, data from assessments
Figure 3 Child Development Inventory: Social and Minnesota Child Development Inventory: Personal-Social age quotient for case study participants.
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Figure 4 Minnesota Child Development Inventory and (Child Development Inventory): Self Help age quotients for case study participants.
beginning as early as 4 months were available to be analyzed for children who were diagnosed early as D/HH and went on to receive a diagnosis of ASD. Among the variety of assessments given by CHIP, the MacArthur-Bates CDI and MCDI/Child Development Inventory were chosen to be analyzed for this study. They are not traditionally used as screeners for ASD, but results from them contribute to the larger picture of the whole child including a possible diagnosis of ASD. Both assessments are appropriate for very young children, with the MacArthur-Bates CDI: WG being normed for the youngest infants, at 8 months.
Social Quotient: Child Development Inventory The most sensitive screen for these three children was the significant decrease over time of the social quotient as measured by the Child Development Inventory. All three children either lost skills or failed to gain new skills over time, resulting in decreases of as much as 20 quotient points in a 6month period. These decreases in quotient from skills within the normal range to skills significantly below a quotient of 80, between a score of 50 and 70, indicate significant delays and warrant serious consideration of a referral for a full diagnostic evaluation for ASD.
Gesture Development Although the MacArthur-Bates CDI: WG has not been used as a screener for ASD, it has been
used to measure communication skills in children with or who were later diagnosed with ASD. Several researchers found delays in gesture for children with ASD, and Mitchell et al suggested delays in gestures may be among the earliest signs of ASD.24 Furthermore, Mitchell et al proposed gesture development was potentially more informative than vocabulary development before 18 months24. Case C was within normal range for gesture development. He was also the only child in the study whose expressive vocabulary was also within the normal range. It is often difficult at a young age to identify a child with hearing loss and a diagnosis of Asperger syndrome or Pervasive Developmental Disorder - Not Otherwise Specified. Children at the milder edge of the spectrum may demonstrate age-appropriate skills on some of the common behaviors associated with ASD. On the other hand, when compared with children who are D/ HH 80 cognitive development, cases A and B were at or below the 25th percentile for total gestures produced. Case A and case B also both had decreased total number of words produced on the MacArthur-Bates CDI: WG and WS as compared with the norms for the children who are D/HH 80 cognitive development and who are hearing. Children who are D/HH have gesture development within the normal range unless they also have significant cognitive or neurologic delays. When a child with normal developmental potential fails to develop symbolic gesture over time, this characteristic is not due to the hearing loss. Referral for a full diagnostic evaluation for ASD should be considered.
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Pretending to Be a Parent In a pilot study, the Pretending to Be a Parent subtest from the MacArthur-Bates CDI: WG was administered to 20 children, 10 children with mild to moderate hearing loss and 10 children with severe to profound hearing loss, at 16 months and 21 months. None of the children had an additional diagnosis of ASD. Overall, there was no difference between the groups by degree of hearing loss for this subtest. At 16 months, the mean for all 20 children was 8.5 items and the mean for 21 months was 11.8 items. At 21 months, cases A and B had still not developed these skills. Case A had six items and case B had four items. This is significantly fewer items than the mean for the children with hearing loss in the pilot study. Failure to develop skills in this particular category raises a red flag when compared with other children who are D/HH. Play involving pretending to be a parent might be related to theory of mind. Theory of mind is the ability to consider someone else’s experience, including their mental states, as separate from one’s own. Many researchers have suggested that people with ASD have deficits in theory of mind.26 Pretending to be a parent involves taking on a role of caregiver to a substitute for oneself. This may be difficult if one has difficulty imagining oneself in another’s place. Some of the other gestures and actions included in the late gestures section of the MacArthur-Bates CDI: WG involve imitating adult actions, which might be an easier cognitive task for children with ASD.
Self Help The results and age quotients for the case study participants from the Child Development Inventory: Self Help subscale scores were quite interesting and not necessarily anticipated. It is expected that children with cognition greater than or equal to 80 will have self help skills within normal limits. The case study participants did not have fine or gross motor deficits and should have been able to perform the necessary actions. The types of items none of the three children acquired by the appropriate age included washes face without help, toilet trained for urine control and bowel movements, and unzips zippers. Although self help skills like
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these are not social in nature, they are learned by imitating a caregiver. Children with ASD might not understand the purpose in learning a skill when someone else will help them with it. They also tend to use adults as tools and the adult is acting as a tool when performing these actions on the child. Additionally, this may be related to deficits in play involving pretending to be a parent. Having cognition greater than or equal to 80 and low scores on the Child Development Inventory: Self Help may indicate the presence of a developmental disorder, such as ASD. Additionally, all three cases had decreasing Self Help age quotients. Case B’s scores began decreasing at his earliest age of assessment with the Child Development Inventory, which was 16 months. Case A was not assessed at 22 months. There was a decrease in his scores between 16 months and 28 months of 14 points. Case C’s scores did not begin decreasing until 21 months and then decreased by 36 points from 21 months to 36 months. Decreasing age quotient scores at any age should result in a referral for a full evaluation.
Overall Profile When examining the data, none of the differences cases A and B exhibited (e.g., words produced compared with the D/HH norms; gestures produced compared with the children who are D/ HH with cognition equal to or greater than 80 norms; potentially pretending to be a parent compared with the D/HH norms; the decreasing age quotients) may be noteworthy by themselves. Yet, the collection of these differences may contribute to a profile of a child with hearing loss that should be referred for further ASD evaluation. The decreased scores are in areas that match expected symptoms for ASD. These data create three profiles of children with hearing loss and ASD. Case B’s scores tended to be lower than case A’s, and case B’s data contained more scores of zeroes around 9 and 14 months. Case B’s absence of comprehending or producing words, phrases, or gestures probably added to other characteristics that led to his ultimate diagnosis of ASD by 18 months old. Although there are certain differences between the profiles of the three case studies, the profiles of all three children indicated significantly
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decreasing developmental age quotients. When this is observed in different developmental areas, a referral for a diagnostic evaluation for ASD should be seriously considered.
Regression of Skills and/or Significant Decrease in Developmental Quotient (Failure to Acquire New Skills) Regression of skills is often considered an early warning sign and, combined with other factors, is a potential indicator for a referral for an ASD evaluation. Landa stated that any child with ASD could regress (when previously acquired skills are diminished or lost), particularly in the expressive language and social-emotional reciprocity areas.27 She reported that regression occurs in 10 to 50% of children with autism, at a mean age of 19 months.27 Due to this regression, experts advocate screening at 18 months and 24 months because lost skills will probably be evident. Case A’s reported lost skills were concerning. They contribute to a profile of a child with hearing loss and ASD. These findings and the decreasing age quotients lead to an endorsement for the use of screening over multiple sessions. This is important because screeners may often be performed only once. Follow-up and subsequent screening and assessment may reveal loss of skills or a decreasing age quotient. Single-instance screening is not sufficient. Identifying the optimal schedule for screening has yet to be determined.
Decrease in Developmental Quotients over Time Developmental age scores proportional to chronological or cognitive age tend to remain relatively stable in early childhood. When significant changes, often as much as a decrease in 20 developmental quotient points, occurs, this decrease should be a red flag and a cause to consider referral for a diagnostic evaluation for ASD. Developmental quotient decrease can occur because of lost skills, but they can also occur because the child is unable to acquire the next level of age-appropriate skills and therefore plateaus in the acquisition of new skills.
Decrease in Developmental Quotient in MacArthur-Bates CDI: Words Produced Although case C had the most language of the three participants, his number of words produced for expressive vocabulary did decrease steadily from the 50th to below the 50th percentile for the norms for the children who are D/HH 80. Otherwise, case C’s scores did not have as many differences from the norms. This is a reminder that a child with ASD may score in the average or above-average range in areas of social communication, play, and selfhelp, at least at some ages. However, his age quotients decreased on several sections of the assessments (e.g., MacArthur-Bates CDI: Words Produced and Child Development Inventory: Social). As mentioned above, age quotients are particularly helpful when measured over time so trajectories can be examined. When screeners and assessments are performed over multiple sessions, age quotients also permit comparison of children to themselves in addition to their typically developing peers, and this indicates their rate of development. Slowed or plateaued development is concerning.
FUTURE RESEARCH Many questions and areas for further research are raised as a result of these case studies. For cases A and B, the MacArthur-Bates CDI: WG appeared sensitive to deficits in their total gestures and, in particular, the number of gestures in the subscale Pretending to Be a Parent. Further research is needed to determine if the MacArthur-Bates CDI: WG can be useful in screening for ASD as early as 9 months. It could become one of the earliest assessments to be sensitive to differences between children with ASD and typically developing children. Unfortunately, there are no normed data past 16 months for MacArthur-Bates CDI: WG for the hearing population. The data for the D/ HH population are just starting to emerge. Not all the items on all the subscales are expected to be demonstrated by 16 months. For those subscales, norms could potentially be developed to see by what point those items might be present. It would be very interesting to see how many of the behaviors for Pretending to Be a Parent hearing boys demonstrate by 27 months.
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Other worthwhile comparisons would include hearing children with ASD, girls who are D/HH with ASD, children with other language delays (both hearing and D/HH). These various comparisons could reveal how particular or general the profiles presented here are. It may be the profiles are only applicable to boys who are D/ HH. If there are similarities between these findings and hearing children with ASD, research within the D/HH population could contribute to the understanding of ASD overall. More assessments found to be sensitive to the differences between children who are typically developing and children with ASD would be beneficial. The more differences identified and the earlier those differences present, the more opportunities there will be for earlier identification. Pretending to be a parent play is part of symbolic and imaginative play. Future research might involve comparing children’s pretending to be a parent play skills to their overall symbolic or imaginative play to see if children’s overall play skills correlate to their pretending to be a parent play skills. Additionally, there are studies examining the relationship of symbolic and imaginative play and theory of mind. Role-playing may be related to precursors for developing theory of mind and pretending to be a parent would be one way to measure role-playing. If a larger sample of the children who are D/HH with ASD were assessed with the Child Development Inventory over a period of time, it would be beneficial to follow them to 72 months because there are norms until age 6 years. It could be determined if the children’s scores continued to fall further behind or if they gained some of the missing skills. As there is currently little to no research comparing Child Development Inventory scores for children with ASD against other groups of children (e. g., those who are typically developing and those with developmental disabilities), that area would be another to pursue. More research is needed to explore the reasons behind the low scores and decreasing age quotients for all three cases on the Child Development Inventory Self Help subscale. Results from the Child Development Inventory: Self Help from larger populations of children with ASD, both children who are D/HH and hearing children, might indicate deficits in self help for some children.
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The Child Development Inventory, in particular the Social and Self Help subscales, may be sensitive to differences between children with ASD and typically developing children. The implications from these case studies may reach beyond the research of D/HH and ASD. The profiles of these case study participants are not unlike profiles of hearing children with ASD. The onset pattern of symptoms is often categorized as either early onset or regressive.1 Children, like case B, with the early onset pattern have differences and/or deficits in several areas, including communication and social interaction. Children with the regressive pattern, like case A, may appear typically developing for a year or longer but then lose previously acquired skills, particularly in the areas of communication and social interaction. If assessments such as the MacArthur-Bates CDI: WG and the Child Development Inventory can help to indicate these patterns, they may be useful in screening both hearing children and children who are D/HH as well. Additionally, screenings at multiple ages for all children would result in a set of age quotient scores, which could be monitored for decline. ACKNOWLEDGEMENTS
This research was supported by the Disability Research and Dissemination Center (DRDC) through its Cooperative Agreement Number 5U01DD001007, from the Association of University Centers on Disabilities, and from the Centers for Disease Control (CDC) and Prevention.
REFERENCES 1. Ozonoff S, Iosif A-M, Baguio F, et al. A prospective study of the emergence of early behavioral signs of autism. J Am Acad Child Adolesc Psychiatry 2010;49(3):256–266, e1–e2 2. Yoshinaga-Itano C. From screening to early identification and intervention: discovering predictors to successful outcomes for children with significant hearing loss. J Deaf Stud Deaf Educ 2003;8(1): 11–30 3. Thomson V. The Colorado Newborn Hearing Screening Project. Am J Audiol 1997;6:74–78 4. Yoshinaga-Itano C. The Colorado journey towards optimal outcomes for children with hearing loss. Perspect Hear Hear Disord Child 2010;20:3–11
This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.
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5. American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, DC: American Psychiatric Association Press; 2013 6. Mahjouri S, Lord CE. What the DSM-5 portends for research, diagnosis, and treatment of autism spectrum disorders. Curr Psychiatry Rep 2012; 14(6):739–747 7. American Psychiatric AssociationDiagnostic and Statistical Manual of Mental Disorders. 4th ed. Text revision (DSM-IV-TR). Washington, DC: American Psychiatric Association Press; 2010 8. Vernon M, Rhodes A. Deafness and autistic spectrum disorders. Am Ann Deaf 2009;154(1):5–14 9. Centers for Disease Control and Prevention. Prevalence of autism spectrum disorder among children aged 8 years: Autism and Developmental Disability Monitoring Network, 11 sites, United States, 2010. CDC MMWR Surveill Summ 2014;63(2):1–21 10. Barton ML, Dumont-Mathieu T, Fein D. Screening young children for autism spectrum disorders in primary practice. J Autism Dev Disord 2012;42(6): 1165–1174 11. Szymanski CA, Brice PJ, Lam KH, Hotto SA. Deaf children with autism spectrum disorders. J Autism Dev Disord 2012;42(10):2027–2037 12. Autism issue: When deafness and autism coexist in children. Odyssey [Special issue] 2008;9(1):1–56 13. Easterbrooks SR, Handley CM. Behavior change in a student with a dual diagnosis of deafness and pervasive developmental disorder: a case study. Am Ann Deaf 2005–2006;150(5):401–407 14. Jure R, Rapin I, Tuchman RF. Hearing-impaired autistic children. Dev Med Child Neurol 1991; 33(12):1062–1072 15. Roper L, Arnold P, Monteiro B. Co-occurrence of autism and deafness: diagnostic considerations. Autism 2003;7(3):245–253 16. Fenson L, Marchman VA, Thal DJ, Dale PS, Reznick J, Bates E. MacArthur-Bates Communicative Development Inventories: User’s Guide and Technical Manual. 2nd ed. Baltimore, MD: Paul H. Brookes Publishing Co.; 2007 17. Luyster R, Lopez K, Lord C. Characterizing communicative development in children referred for autism spectrum disorders using the MacAr-
18. 19.
20.
21.
22.
23.
24.
25.
26.
27.
thur-Bates Communicative Development Inventory (CDI). J Child Lang 2007;34(3):623–654 Ireton H. Child Development Inventory Manual. Minneapolis, MN: Behavior Science Systems; 1992 Apuzzo ML, Yoshinaga-Itano C. Early identification of infants with significant hearing loss and the Minnesota Child Development Inventory. Semin Hear 1995;16:124–139 Beer J, Harris MS, Kronenberger WG, Holt RF, Pisoni DB. Auditory skills, language development, and adaptive behavior of children with cochlear implants and additional disabilities. Int J Audiol 2012;51(6):491–498 Marion Downs Hearing Center. MacArthur Communicative Development Inventory: Words and Gestures. Marion Downs Hearing Center: Our Research. 2011. Available at: http://www.mariondowns.com/macarthur-communicative-development-inventory. Accessed on August 19, 2014 Charman T, Drew A, Baird C, Baird G. Measuring early language development in preschool children with autism spectrum disorder using the MacArthur Communicative Development Inventory (Infant Form). J Child Lang 2003;30(1):213–236 Miniscalco C, Fra¨nberg J, Schachinger-Lorentzon U, Gillberg C. Meaning what you say? Comprehension and word production skills in young children with autism. Res Autism Spectr Disord 2012; 6:204–211 Mitchell S, Brian J, Zwaigenbaum L, et al. Early language and communication development of infants later diagnosed with autism spectrum disorder. J Dev Behav Pediatr 2006;27(2, Suppl): S69–S78 Fenson L, Dale PS, Reznick JS, Bates E, Thal DJ, Pethick SJ. Variability in early communicative development. Monogr Soc Res Child Dev 1994; 59(5):1–173, discussion 174–185 Yirmiya N, Erel O, Shaked M, Solomonica-Levi D. Meta-analyses comparing theory of mind abilities of individuals with autism, individuals with mental retardation, and normally developing individuals. Psychol Bull 1998;124(3):283–307 Landa RJ. Diagnosis of autism spectrum disorders in the first 3 years of life. Nat Clin Pract Neurol 2008;4(3):138–147
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ABSTRACT
Early assessment data (starting at 9 months) for three children who were deaf or hard of hearing and later diagnosed with autism spectrum disorder (ASD) were analyzed. The results from the MacArthur-Bates Communicative Development Inventories (CDI) Words and Gestures and the Child Development Inventory were used to develop three profiles of children who were deaf or hard of hearing and had ASD. One child lacked expected skills and language at ages 9 and 14 months. Another child lost skills and language after 17 months. The third child had results usually within or above the average range until 3 years of age. However, his age quotient decreased for MacArthurBates CDI: Words and Gestures Words Expressed and the Child Development Inventory: Social to significantly below the normal range. Although it can be difficult to diagnose the co-occurrence of ASD and deafness, there were early warning signs for these children. KEYWORDS: Autism, deaf, hard of hearing, children,
developmental assessment, screening
Learning Outcomes: As a result of this activity, the reader will be able to (1) explain the reasons behind and the importance of autism spectrum disorder (ASD) screenings at multiple sessions; (2) describe three potential profiles for boys who are deaf or hard of hearing and have ASD; (3) discuss the current emphasis on earlier identification of ASD.
1 Department of Speech, Language, and Hearing Sciences, University of Colorado, Boulder, Colorado. Address for correspondence: Elizabeth Cameron Kellogg, M.A., Department of Speech, Language, and Hearing Sciences, 2501 Kittredge Loop Road, 409 UCB, University of Colorado Boulder, CO 80309-0409 (e-mail: elizabeth. [email protected]). Screening, Diagnosing and Implementing Interventions for Children Who Are Deaf or Hard of Hearing
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with Autism Spectrum Disorder; Guest Editors, Christine Yoshinaga-Itano, Ph.D. and Amy Thrasher, M.A., CCC-SLP. Semin Speech Lang 2014;35:276–287. Copyright # 2014 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 5844662. DOI: http://dx.doi.org/10.1055/s-0034-1389100. ISSN 0734-0478.
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Elizabeth Cameron Kellogg, M.A.,1 Amy Thrasher, M.A., CCC-SLP,1 and Christine Yoshinaga-Itano, Ph.D.1
E
arly identification of autism spectrum disorder (ASD) is important for both hearing and deaf children. It is difficult to study infants who are later diagnosed with ASD. Retrospective studies often involve home videos, reviewed when the children are older, and parent recall. Prospective studies tend to target high-risk populations, such as the siblings of children diagnosed with ASD.1 The purpose of this unique retrospective study is to develop profiles for three children who were diagnosed as deaf or hard of hearing (D/HH) at birth and then later diagnosed with ASD. In Colorado, children who are identified as D/HH through universal newborn hearing screening programs or in the first 3 years of life are offered an array of family-centered services until age 3. Over 90% of the families choose to participate in the Colorado Home Intervention Program (CHIP).2 CHIP began offering family-centered, family-focused intervention for children who are D/HH in 1969.3 Since the mid 1980s, researchers at the University of Colorado Boulder have investigated the predictors of successful outcomes for infants and toddlers who are D/HH.4 Assessments are a component of CHIP, and data are collected at approximately 6-month intervals. The Child Development Inventory, MacArthur-Bates Communicative Development Inventories (CDI), and analyses of spontaneous language samples are some of the assessments used.4
AUTISM SPECTRUM DISORDER The criteria for diagnosing ASD have changed with the 2013 publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V).5 For a helpful review of the changes and the implications of the criteria under the DSM-V, see Mahjouri and Lord.6 The children in this study were diagnosed with the criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition,7 which includes deficits in verbal and nonverbal communication, deficits in social interaction, and restricted, repetitive, and/or stereotyped behavior, activities and/or interests. For those unfamiliar with ASD, Vernon and Rhodes
wrote an article for the American Annals of the Deaf summarizing ASD and its history.8 In 2014, the Centers for Disease Control published prevalence rates from data collected by the Autism and Developmental Disabilities Monitoring Network in 2010.9 According to the data, 1 in 68 8-year-old children met research criteria for ASD. Currently there is neither a genetic test nor biological marker for ASD.10 Thus, standardized assessments and clinical judgments are used to diagnose ASD. Screeners are often used to refer children for a full ASD evaluation. For a review of early screening tools for ASD at the 18- and 24month pediatric visits, please see Barton et al,10 who stated that early identification and subsequent early intervention are related with positive outcomes in communication, social interaction, and cognitive development and included several supporting studies.10 Currently, there is no study of ASD screening or assessment for children with bilateral permanent hearing loss. Szymanski et al reported that the incidence of autism in a population of children who are D/ HH is 1 in every 59 children, higher than the incidence in the hearing population.11 Vernon and Rhodes cited the importance of a special 2008 edition of Odyssey: New Directions in Deaf Education12 in which mental health specialists in deafness began focusing on the double disability.8 It is also quite difficult to diagnose.13,14 ASD diagnosis is often given later to children who are already identified as D/HH as compared with hearing children.15
METHODS The current study is a retrospective case study of three children identified as infants as being D/ HH. Each child entered the CHIP program when deafness or hearing loss was identified. Several assessments were administered from that point through the age of 3 years. MacArthur-Bates Communicative Development Inventory: Words and Gestures (CDI: WG), MacArthur-Bates Communicative Development Inventory: Words and Sentences (CGI: WS), and Minnesota Child Development Inventory (MCDI) were among those assessments. These children were later diagnosed
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with ASD. The three case study participants were chosen from the group of children in the CHIP database with a diagnosis of ASD due to the consistency of assessments at approximate intervals of 5 to 6 months, starting at least at 9 months old. They each also had at least five assessment sessions total. All of the children live in a Colorado metro area. The histories for each child are reported with the known information. Due to the great variety of expression of characteristics across diagnoses and the variety of intervention, each study is treated as a separate case.
Case A Case A was born to two deaf Caucasian parents. He was diagnosed with a bilateral severe sensorineural hearing loss at birth. He was fitted with hearing aids at 7 months old. Case A’s intervention began at age 2 months old, while he was in the neonatal intensive care unit. His intervention was solely from CHIP and consisted of individual therapy delivered in his home. His therapist used sign and speech, and his parents used only sign with him. As he grew, he learned sign but did not speak.
Case B Case B was born to hearing Caucasian parents. At birth, he was diagnosed with profound bilateral sensorineural hearing loss. He received cochlear implants at 16 months. His intervention began at 18 months or before and included services from CHIP, Listen Foundation, and later a private therapist. At 18 months of age, he received 1 hour a week of in-home intervention, and by 21 months he was receiving an hour of in-home intervention along with an hour of out of the home intervention. His intervention initially consisted of verbal/oral therapy without sign language. By age 26 months, some sign was used. Case B was diagnosed with ASD at age 18 months and with apraxia of speech at age 5 years old.
Case C Case C was born to hearing Caucasian parents. He was diagnosed with a bilateral severe sen-
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sorineural hearing loss at birth. He was fitted with hearing aids at age 2 months. Intervention began at age 2.5 months old and was 90 minutes a week in his home. Auditory/verbal therapy was used. Until age 15 months, case C received intervention services from CHIP only. Around 15 months, he began attending a D/HH group at a major hospital in Colorado. With the addition of the D/HH group at the hospital, he received 5 hours of intervention per week and both American Sign Language and sign language in English order was added to the verbal/auditory approach to communication to become a total communication approach.
Assessment Tools: MacArthur-Bates CDI The MacArthur-Bates CDI is a parent questionnaire about language understanding and production for children as young as 8 months of age. It was developed in 1993 and revised in 2007.16 Since 1993 there have been two scales, CDI: WG for infants from 0;8 to 1;4 and the CDI: WS for toddlers from 1;4 to 2;6. A modified version (indicating says or signs) of the MacArthur-Bates CDI: WG was given to the parents in the CHIP program. The CDI: WG contains two parts with several sections. The first section consists of three questions about the child’s responsiveness to language. In the next section, using a list of 28 items, parents identify phrases the child understands. The third section has two questions about the child’s frequency of imitating words and labeling objects. The following section is a 396-item vocabulary checklist broken into 19 semantic categories. Part II of the questionnaire contains sections about actions and gestures. The subscales of the actions and gestures sections include Games and Routines and Pretending to Be a Parent. The MacArthur-Bates CDI: WG may be particularly beneficial for use with children with ASD due to the inclusion of two areas of concern for children with ASD, vocabulary comprehension and production, as well as the use of early social-communicative behaviors (e.g., imitation, functional and symbolic play, and declarative and imperative gestures).17
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Assessment Tools: Child Development Inventory The MCDI was developed in 1972 and was later updated and renamed the Child Development Inventory in 1992.18 This caregiver questionnaire is normed for children 15 months to 6 years. The Child Development Inventory has 270 items that are answered either yes or no. It measures development in eight areas and overall general development leading to nine scales including Social (40 items) and Self Help (40 items). With nine scales, the Child Development Inventory provides a greater picture of a child than many other toddler and preschool scales and screeners. The scores for the scales are given as developmental ages. There are a few differences between the MCDI and the Child Development Inventory. Ireton explained the Child Development Inventory consists of a more comprehensive set of items in terms of age coverage as well as eliminating “poor items.”18(p.2) The Child Development Inventory also has a more representative and more current norm sample. There is a change in the name of one of the scales; the Personal-Social Scale became the Social Scale. Apuzzo and Yoshinaga-Itano described the Personal-Social scale as measuring personal and social behavior, including independence, imitation, social interaction, and concern for others.19 Ireton described the Social Scale as including interactions with parents, children, and other adults and from individual interaction to group participation.18 The MCDI was used with two of the case study participants (cases B and C) and the Child Development Inventory was used with one (case A). This made comparison of specific items difficult because only 17 out of 40 items corresponded between Personal-Social Scale (MCDI) and the Social Scale (Child Development Inventory). Some of the items for the Self Help Scale were changed and just 25 out of 40 items corresponded. Additionally, age-level information for each item is available in the Child Development Inventory manual and unknown for the MCDI. Thus, the individual items for case A could be organized by age level and only the corresponding items for cases B and C could also be organized by age level.
RESULTS The parents of case A and B filled out the MacArthur-Bates CDI: WG four times between ages 9 months and 27 months. Case C’s parents filled it out three times between the ages of 4 and 15 months. Case C scored in the average range across all domains at age 15 months and thus the MacArthur-Bates CDI: WG was not continued and the MacArthur-Bates CDI: WS was used. Case A and B’s scores fell below the typical range in at least some of the domains at 16 months and the assessment was continued past the normed ages (0;8 to 1;6). The results of the following measures related to the MacArthur-Bates CDI: WG will be presented for each case: age quotient, words produced (expressive vocabulary), total gestures produced, and a subscale of gestures. Age quotient is the developmental age score (derived by the norms from the assessment) divided by the chronological age, multiplied by 100. Over time, age quotients indicate the rate of development. A flat age quotient trajectory indicates a year’s growth in a year’s time. It is expected that the age quotient would stay constant or increase as children increase their communication. Case B’s age quotients for acquiring expressive and receptive vocabulary, phrases, and gestures were fairly consistent in the 40 to 60 range, meaning his development was between 40 and 60% of his chronological age. Case A’s rate of acquiring expressive vocabulary, phrases, and gestures decreased between 9 and 22 months. Between 22 and 32 months, his development was 60% of his chronological age. In many of the categories, he lost skills or words he previously understood and/or produced. For example, for MacArthur-Bates CDI: WG: Gestures: Imitating Other Adult Actions, his raw score dropped from 7 to 3 (with five lost skills and one new skill). Case A also lost skills on the Child Development Inventory: Social and Self Help. The age quotients for expressive vocabulary, phrases understood, and gestures for both cases A and B decreased until they plateaued at either 60 or 40 to 60. Initially they were making less than a year’s growth in a year’s time and then they made a year’s growth in a year’s time but only at lower percentage of development for their chronological age.
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As mentioned earlier, case C scored in the average range for 16 months old and the MacArthur-Bates CDI: WG was no longer given. The MacArthur-Bates CDI: WS was used to continue to measure his expressive vocabulary. For expressive vocabulary, case C began with a quotient of 133 at 9 months. It decreased linearly until it was 67 at 36 months, meaning his expressive vocabulary growth slowed over time. He was not making a year’s growth in a year’s time and his scores fell below the typical range after 21 months. At 3 years, his expressive vocabulary development was at 67% of his chronological age. The children’s scores were compared with the norms of the MacArthur-Bates CDI as well as norms for children who are D/HH and have cognition of greater than or equal to 80. These were used because all three participants had cognition greater than 80. This is relevant because the norms for the total D/HH population tend to be 25th percentile lower than the norms for hearing children because the presence of hearing loss impacts access to language.20 The distribution for children who are D/HH is lower than children in the norming sample for the MacArthur-Bates CDI: WG. Cases A and B were between the 10th and 25th percentiles for the D/HH norms, which is below the 10th percentile for children with normal hearing.
Words Produced Fig. 1 shows an overlay of the total number of words produced from the MacArthur-Bates
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CDI: WG for cases A and B and MacArthur-Bates CDI: WS for case C onto the norms for the children who are D/HH with cognition greater than or equal to 80 (D/HH 80 cognitive development). On Fig. 1, Case C’s trajectory does not match those of the other children in the norm, meaning his age quotient score was decreasing as mentioned above. When case C was compared with his peers who are D/HH 80 cognitive development, his scores were below the 50th percentile. The trajectories of cases A and B’s scores seemed to be linear rather than exponential like those of the children in the 25th percentile.
Gestures Produced Fig. 2 shows an overlap of the total gestures produced by all three cases on top of the total gestures for children who are D/HH 80 cognitive development. At 16 months, case C’s scores were at the 75th percentile for children D/HH 80 cognitive development and close to the mean of the norms for hearing boys. This was not consistent with the results of several researchers who found children with ASD had delayed gestures compared with the control group or the norms.17,22–24 However, this child was at a mild end of the spectrum, and he demonstrated some aboveage-level developmental skills. The researchers did not specify if children diagnosed with what was formerly known as Asperger syndrome were included in their studies.
Figure 1 MacArthur-Bates Communicative Development Inventory: Words and Sentences. Words produced for children who are deaf or hard of hearing with cognition greater than or equal to 80 and case study participants. Adapted from Marion Downs Hearing Center.21
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Figure 2 MacArthur-Bates Communicative Development Inventory: Words and Gestures (CDI: WG),. Total gestures for the children who are deaf or hard of hearing with cognition greater than or equal to 80 and case study participants. Adapted from Marion Downs Hearing Center.21
Fig. 2 shows that when compared with the children who are D/HH 80 cognitive development, case B’s scores were well below the 25th percentile. This would be below the 10th percentile for the norms for hearing children. Case A’s total gestures were just at the 25th percentile at 16 months and subsequently fell below that. Given that at 16 months case B demonstrated 4 out of 18 early gestures and 3 out of 45 late gestures, it is not surprising case B was diagnosed with ASD by 18 months. Although it was not listed on case B’s information sheets, it was likely case B began receiving early ASD intervention. This may explain his dramatic increase in gesture use after 18 months (at 21 months he demonstrated 11 out of 18 early gestures and 21 out of 45 late gestures).
Pretending to Be a Parent MacArthur-Bates CDI: WG Subscale D, Pretending to Be a Parent, is one the subscales for the late gestures section and, in the current study, appeared to be an important and revealing category. This subscale involves children playing parent with a doll or stuffed animal, including such actions as feeding it with a bottle, talking to it, and hugging it. Table 1 presents the entire subscale as well as the norms that indicate by what month 50% of the normed sample demonstrated the skill. Both sexes combined showed four of the items by 16 months. The results for this gesture subscale were not
available for either the D/HH norms or the D/ HH 80 cognitive development norms. However, there was a recent pilot study with 20 children with varying ranges of hearing loss. Table 1 MacArthur-Bates Communicative Development Inventory: Words and Gestures Subscale D: Pretending to Be a Parent Item Number
Item
50% Month
Actual %
1 2
Put to bed Cover with
10 13
52.4 52.1
blanket 3 4
Feed with bottle Feed with spoon
16 16
53.7 50.0
5
Brush/comb
(16)
43.3
6
hair Pat or burp it
(16)
31.3
7
Push in
(16)
41.2
8
stroller/buggy Rock it
(16)
40.3
9
Kiss or hug it
(16)
35.8
10
Try to put shoe/sock/hat
(16)
31.3
on it 11
Wipe its face or hands
(16)
31.8
12
Talk to it
(16)
17.9
13
Try to put a diaper on it
(16)
15.2
Note: Month at which 50% of the children have the skill. Parentheses indicate 50% of the children did not have the skill by age 16 months, the upper limit of the normed age range. Adapted from Fenson et al.25(p.159)
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Those results are discussed in the conclusion. Neither case A nor case B displayed any skills from this category until after 17 months. By 17 months, case C had demonstrated two of them (i.e., brushing/combing its hair and hugging/kissing it). Between 17 and 21 months, case A lost five skills and gained one new one. Case C’s score of two items was within one standard deviation from the average for both sexes combined. Cases A and B were significantly lower. No other children had protocols with no demonstrated skill in Pretending to Be a Parent at 16 months of age. As indicated, two of the three children did acquire some skills after the age of 17 months.
Child Development Inventory: Social Subscale Fig. 3 depicts the age quotients for the Child Development Inventory: Social and the MCDI: Personal-Social. Recall that case A’s assessments included the Child Development Inventory and cases B and C’s assessments included the MCDI. Also, the scales were named differently between the two versions. Additionally, note that case A was not given the Child Development Inventory between 16 and 28 months. Age quotients for all three cases decreased significantly over time. Between 28 and 32 months, case A lost 8 skills, maintained 6, and gained 7, thus his raw score went from 14 to 13. His Social age quotient decreased by 19 points over 16 months. Case B lost four skills between 26 and 31 months, two of which he had reportedly been demonstrating since 21 months. His Personal-Social age
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quotient decreased by 38 points over 20 months. Case C’s Personal-Social age quotient decreased by 39 points over 26 months.
MCDI and Child Development Inventory Self Help Subscale The MCDI and Child Development Inventory Self Help age quotients are depicted in Fig. 4 . Both case A’s and case C’s age quotient decreased. Case C, in particular, was right at the expected age quotient of 100 from 8 months until 21 months when his scores started decreasing steadily to 69 at 36 months. Case B’s age quotient was not as consistent. At 14 months, his age quotient was 86 and his age quotient decreased to 62 at 21 months. He plateaued, and his age quotient was also at 62 at 26 months. Then, at 34 months, his age quotient decreased to 50. Case A’s age quotient was even less consistent. Case A’s age quotient was 75 at 16 months, 61 at 28 months, and 69 at 32 months. The missing data at 21 months would have been interesting to plot because it would have provided additional insight. Case A lost one skill between 16 and 28 months and two skills between 28 and 32 months, which were fewer skills than he lost on the Child Development Inventory: Social Scale. Case B did not lose any skills. Case C lost one skill on this subscale. His caregiver indicated he could do it at the 21- and 27-month dates, but not at the 35-month date.
DISCUSSION By choosing case study participants from the CHIP database, data from assessments
Figure 3 Child Development Inventory: Social and Minnesota Child Development Inventory: Personal-Social age quotient for case study participants.
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Figure 4 Minnesota Child Development Inventory and (Child Development Inventory): Self Help age quotients for case study participants.
beginning as early as 4 months were available to be analyzed for children who were diagnosed early as D/HH and went on to receive a diagnosis of ASD. Among the variety of assessments given by CHIP, the MacArthur-Bates CDI and MCDI/Child Development Inventory were chosen to be analyzed for this study. They are not traditionally used as screeners for ASD, but results from them contribute to the larger picture of the whole child including a possible diagnosis of ASD. Both assessments are appropriate for very young children, with the MacArthur-Bates CDI: WG being normed for the youngest infants, at 8 months.
Social Quotient: Child Development Inventory The most sensitive screen for these three children was the significant decrease over time of the social quotient as measured by the Child Development Inventory. All three children either lost skills or failed to gain new skills over time, resulting in decreases of as much as 20 quotient points in a 6month period. These decreases in quotient from skills within the normal range to skills significantly below a quotient of 80, between a score of 50 and 70, indicate significant delays and warrant serious consideration of a referral for a full diagnostic evaluation for ASD.
Gesture Development Although the MacArthur-Bates CDI: WG has not been used as a screener for ASD, it has been
used to measure communication skills in children with or who were later diagnosed with ASD. Several researchers found delays in gesture for children with ASD, and Mitchell et al suggested delays in gestures may be among the earliest signs of ASD.24 Furthermore, Mitchell et al proposed gesture development was potentially more informative than vocabulary development before 18 months24. Case C was within normal range for gesture development. He was also the only child in the study whose expressive vocabulary was also within the normal range. It is often difficult at a young age to identify a child with hearing loss and a diagnosis of Asperger syndrome or Pervasive Developmental Disorder - Not Otherwise Specified. Children at the milder edge of the spectrum may demonstrate age-appropriate skills on some of the common behaviors associated with ASD. On the other hand, when compared with children who are D/ HH 80 cognitive development, cases A and B were at or below the 25th percentile for total gestures produced. Case A and case B also both had decreased total number of words produced on the MacArthur-Bates CDI: WG and WS as compared with the norms for the children who are D/HH 80 cognitive development and who are hearing. Children who are D/HH have gesture development within the normal range unless they also have significant cognitive or neurologic delays. When a child with normal developmental potential fails to develop symbolic gesture over time, this characteristic is not due to the hearing loss. Referral for a full diagnostic evaluation for ASD should be considered.
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Pretending to Be a Parent In a pilot study, the Pretending to Be a Parent subtest from the MacArthur-Bates CDI: WG was administered to 20 children, 10 children with mild to moderate hearing loss and 10 children with severe to profound hearing loss, at 16 months and 21 months. None of the children had an additional diagnosis of ASD. Overall, there was no difference between the groups by degree of hearing loss for this subtest. At 16 months, the mean for all 20 children was 8.5 items and the mean for 21 months was 11.8 items. At 21 months, cases A and B had still not developed these skills. Case A had six items and case B had four items. This is significantly fewer items than the mean for the children with hearing loss in the pilot study. Failure to develop skills in this particular category raises a red flag when compared with other children who are D/HH. Play involving pretending to be a parent might be related to theory of mind. Theory of mind is the ability to consider someone else’s experience, including their mental states, as separate from one’s own. Many researchers have suggested that people with ASD have deficits in theory of mind.26 Pretending to be a parent involves taking on a role of caregiver to a substitute for oneself. This may be difficult if one has difficulty imagining oneself in another’s place. Some of the other gestures and actions included in the late gestures section of the MacArthur-Bates CDI: WG involve imitating adult actions, which might be an easier cognitive task for children with ASD.
Self Help The results and age quotients for the case study participants from the Child Development Inventory: Self Help subscale scores were quite interesting and not necessarily anticipated. It is expected that children with cognition greater than or equal to 80 will have self help skills within normal limits. The case study participants did not have fine or gross motor deficits and should have been able to perform the necessary actions. The types of items none of the three children acquired by the appropriate age included washes face without help, toilet trained for urine control and bowel movements, and unzips zippers. Although self help skills like
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these are not social in nature, they are learned by imitating a caregiver. Children with ASD might not understand the purpose in learning a skill when someone else will help them with it. They also tend to use adults as tools and the adult is acting as a tool when performing these actions on the child. Additionally, this may be related to deficits in play involving pretending to be a parent. Having cognition greater than or equal to 80 and low scores on the Child Development Inventory: Self Help may indicate the presence of a developmental disorder, such as ASD. Additionally, all three cases had decreasing Self Help age quotients. Case B’s scores began decreasing at his earliest age of assessment with the Child Development Inventory, which was 16 months. Case A was not assessed at 22 months. There was a decrease in his scores between 16 months and 28 months of 14 points. Case C’s scores did not begin decreasing until 21 months and then decreased by 36 points from 21 months to 36 months. Decreasing age quotient scores at any age should result in a referral for a full evaluation.
Overall Profile When examining the data, none of the differences cases A and B exhibited (e.g., words produced compared with the D/HH norms; gestures produced compared with the children who are D/ HH with cognition equal to or greater than 80 norms; potentially pretending to be a parent compared with the D/HH norms; the decreasing age quotients) may be noteworthy by themselves. Yet, the collection of these differences may contribute to a profile of a child with hearing loss that should be referred for further ASD evaluation. The decreased scores are in areas that match expected symptoms for ASD. These data create three profiles of children with hearing loss and ASD. Case B’s scores tended to be lower than case A’s, and case B’s data contained more scores of zeroes around 9 and 14 months. Case B’s absence of comprehending or producing words, phrases, or gestures probably added to other characteristics that led to his ultimate diagnosis of ASD by 18 months old. Although there are certain differences between the profiles of the three case studies, the profiles of all three children indicated significantly
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decreasing developmental age quotients. When this is observed in different developmental areas, a referral for a diagnostic evaluation for ASD should be seriously considered.
Regression of Skills and/or Significant Decrease in Developmental Quotient (Failure to Acquire New Skills) Regression of skills is often considered an early warning sign and, combined with other factors, is a potential indicator for a referral for an ASD evaluation. Landa stated that any child with ASD could regress (when previously acquired skills are diminished or lost), particularly in the expressive language and social-emotional reciprocity areas.27 She reported that regression occurs in 10 to 50% of children with autism, at a mean age of 19 months.27 Due to this regression, experts advocate screening at 18 months and 24 months because lost skills will probably be evident. Case A’s reported lost skills were concerning. They contribute to a profile of a child with hearing loss and ASD. These findings and the decreasing age quotients lead to an endorsement for the use of screening over multiple sessions. This is important because screeners may often be performed only once. Follow-up and subsequent screening and assessment may reveal loss of skills or a decreasing age quotient. Single-instance screening is not sufficient. Identifying the optimal schedule for screening has yet to be determined.
Decrease in Developmental Quotients over Time Developmental age scores proportional to chronological or cognitive age tend to remain relatively stable in early childhood. When significant changes, often as much as a decrease in 20 developmental quotient points, occurs, this decrease should be a red flag and a cause to consider referral for a diagnostic evaluation for ASD. Developmental quotient decrease can occur because of lost skills, but they can also occur because the child is unable to acquire the next level of age-appropriate skills and therefore plateaus in the acquisition of new skills.
Decrease in Developmental Quotient in MacArthur-Bates CDI: Words Produced Although case C had the most language of the three participants, his number of words produced for expressive vocabulary did decrease steadily from the 50th to below the 50th percentile for the norms for the children who are D/HH 80. Otherwise, case C’s scores did not have as many differences from the norms. This is a reminder that a child with ASD may score in the average or above-average range in areas of social communication, play, and selfhelp, at least at some ages. However, his age quotients decreased on several sections of the assessments (e.g., MacArthur-Bates CDI: Words Produced and Child Development Inventory: Social). As mentioned above, age quotients are particularly helpful when measured over time so trajectories can be examined. When screeners and assessments are performed over multiple sessions, age quotients also permit comparison of children to themselves in addition to their typically developing peers, and this indicates their rate of development. Slowed or plateaued development is concerning.
FUTURE RESEARCH Many questions and areas for further research are raised as a result of these case studies. For cases A and B, the MacArthur-Bates CDI: WG appeared sensitive to deficits in their total gestures and, in particular, the number of gestures in the subscale Pretending to Be a Parent. Further research is needed to determine if the MacArthur-Bates CDI: WG can be useful in screening for ASD as early as 9 months. It could become one of the earliest assessments to be sensitive to differences between children with ASD and typically developing children. Unfortunately, there are no normed data past 16 months for MacArthur-Bates CDI: WG for the hearing population. The data for the D/ HH population are just starting to emerge. Not all the items on all the subscales are expected to be demonstrated by 16 months. For those subscales, norms could potentially be developed to see by what point those items might be present. It would be very interesting to see how many of the behaviors for Pretending to Be a Parent hearing boys demonstrate by 27 months.
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Other worthwhile comparisons would include hearing children with ASD, girls who are D/HH with ASD, children with other language delays (both hearing and D/HH). These various comparisons could reveal how particular or general the profiles presented here are. It may be the profiles are only applicable to boys who are D/ HH. If there are similarities between these findings and hearing children with ASD, research within the D/HH population could contribute to the understanding of ASD overall. More assessments found to be sensitive to the differences between children who are typically developing and children with ASD would be beneficial. The more differences identified and the earlier those differences present, the more opportunities there will be for earlier identification. Pretending to be a parent play is part of symbolic and imaginative play. Future research might involve comparing children’s pretending to be a parent play skills to their overall symbolic or imaginative play to see if children’s overall play skills correlate to their pretending to be a parent play skills. Additionally, there are studies examining the relationship of symbolic and imaginative play and theory of mind. Role-playing may be related to precursors for developing theory of mind and pretending to be a parent would be one way to measure role-playing. If a larger sample of the children who are D/HH with ASD were assessed with the Child Development Inventory over a period of time, it would be beneficial to follow them to 72 months because there are norms until age 6 years. It could be determined if the children’s scores continued to fall further behind or if they gained some of the missing skills. As there is currently little to no research comparing Child Development Inventory scores for children with ASD against other groups of children (e. g., those who are typically developing and those with developmental disabilities), that area would be another to pursue. More research is needed to explore the reasons behind the low scores and decreasing age quotients for all three cases on the Child Development Inventory Self Help subscale. Results from the Child Development Inventory: Self Help from larger populations of children with ASD, both children who are D/HH and hearing children, might indicate deficits in self help for some children.
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The Child Development Inventory, in particular the Social and Self Help subscales, may be sensitive to differences between children with ASD and typically developing children. The implications from these case studies may reach beyond the research of D/HH and ASD. The profiles of these case study participants are not unlike profiles of hearing children with ASD. The onset pattern of symptoms is often categorized as either early onset or regressive.1 Children, like case B, with the early onset pattern have differences and/or deficits in several areas, including communication and social interaction. Children with the regressive pattern, like case A, may appear typically developing for a year or longer but then lose previously acquired skills, particularly in the areas of communication and social interaction. If assessments such as the MacArthur-Bates CDI: WG and the Child Development Inventory can help to indicate these patterns, they may be useful in screening both hearing children and children who are D/HH as well. Additionally, screenings at multiple ages for all children would result in a set of age quotient scores, which could be monitored for decline. ACKNOWLEDGEMENTS
This research was supported by the Disability Research and Dissemination Center (DRDC) through its Cooperative Agreement Number 5U01DD001007, from the Association of University Centers on Disabilities, and from the Centers for Disease Control (CDC) and Prevention.
REFERENCES 1. Ozonoff S, Iosif A-M, Baguio F, et al. A prospective study of the emergence of early behavioral signs of autism. J Am Acad Child Adolesc Psychiatry 2010;49(3):256–266, e1–e2 2. Yoshinaga-Itano C. From screening to early identification and intervention: discovering predictors to successful outcomes for children with significant hearing loss. J Deaf Stud Deaf Educ 2003;8(1): 11–30 3. Thomson V. The Colorado Newborn Hearing Screening Project. Am J Audiol 1997;6:74–78 4. Yoshinaga-Itano C. The Colorado journey towards optimal outcomes for children with hearing loss. Perspect Hear Hear Disord Child 2010;20:3–11
This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.
286
5. American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, DC: American Psychiatric Association Press; 2013 6. Mahjouri S, Lord CE. What the DSM-5 portends for research, diagnosis, and treatment of autism spectrum disorders. Curr Psychiatry Rep 2012; 14(6):739–747 7. American Psychiatric AssociationDiagnostic and Statistical Manual of Mental Disorders. 4th ed. Text revision (DSM-IV-TR). Washington, DC: American Psychiatric Association Press; 2010 8. Vernon M, Rhodes A. Deafness and autistic spectrum disorders. Am Ann Deaf 2009;154(1):5–14 9. Centers for Disease Control and Prevention. Prevalence of autism spectrum disorder among children aged 8 years: Autism and Developmental Disability Monitoring Network, 11 sites, United States, 2010. CDC MMWR Surveill Summ 2014;63(2):1–21 10. Barton ML, Dumont-Mathieu T, Fein D. Screening young children for autism spectrum disorders in primary practice. J Autism Dev Disord 2012;42(6): 1165–1174 11. Szymanski CA, Brice PJ, Lam KH, Hotto SA. Deaf children with autism spectrum disorders. J Autism Dev Disord 2012;42(10):2027–2037 12. Autism issue: When deafness and autism coexist in children. Odyssey [Special issue] 2008;9(1):1–56 13. Easterbrooks SR, Handley CM. Behavior change in a student with a dual diagnosis of deafness and pervasive developmental disorder: a case study. Am Ann Deaf 2005–2006;150(5):401–407 14. Jure R, Rapin I, Tuchman RF. Hearing-impaired autistic children. Dev Med Child Neurol 1991; 33(12):1062–1072 15. Roper L, Arnold P, Monteiro B. Co-occurrence of autism and deafness: diagnostic considerations. Autism 2003;7(3):245–253 16. Fenson L, Marchman VA, Thal DJ, Dale PS, Reznick J, Bates E. MacArthur-Bates Communicative Development Inventories: User’s Guide and Technical Manual. 2nd ed. Baltimore, MD: Paul H. Brookes Publishing Co.; 2007 17. Luyster R, Lopez K, Lord C. Characterizing communicative development in children referred for autism spectrum disorders using the MacAr-
18. 19.
20.
21.
22.
23.
24.
25.
26.
27.
thur-Bates Communicative Development Inventory (CDI). J Child Lang 2007;34(3):623–654 Ireton H. Child Development Inventory Manual. Minneapolis, MN: Behavior Science Systems; 1992 Apuzzo ML, Yoshinaga-Itano C. Early identification of infants with significant hearing loss and the Minnesota Child Development Inventory. Semin Hear 1995;16:124–139 Beer J, Harris MS, Kronenberger WG, Holt RF, Pisoni DB. Auditory skills, language development, and adaptive behavior of children with cochlear implants and additional disabilities. Int J Audiol 2012;51(6):491–498 Marion Downs Hearing Center. MacArthur Communicative Development Inventory: Words and Gestures. Marion Downs Hearing Center: Our Research. 2011. Available at: http://www.mariondowns.com/macarthur-communicative-development-inventory. Accessed on August 19, 2014 Charman T, Drew A, Baird C, Baird G. Measuring early language development in preschool children with autism spectrum disorder using the MacArthur Communicative Development Inventory (Infant Form). J Child Lang 2003;30(1):213–236 Miniscalco C, Fra¨nberg J, Schachinger-Lorentzon U, Gillberg C. Meaning what you say? Comprehension and word production skills in young children with autism. Res Autism Spectr Disord 2012; 6:204–211 Mitchell S, Brian J, Zwaigenbaum L, et al. Early language and communication development of infants later diagnosed with autism spectrum disorder. J Dev Behav Pediatr 2006;27(2, Suppl): S69–S78 Fenson L, Dale PS, Reznick JS, Bates E, Thal DJ, Pethick SJ. Variability in early communicative development. Monogr Soc Res Child Dev 1994; 59(5):1–173, discussion 174–185 Yirmiya N, Erel O, Shaked M, Solomonica-Levi D. Meta-analyses comparing theory of mind abilities of individuals with autism, individuals with mental retardation, and normally developing individuals. Psychol Bull 1998;124(3):283–307 Landa RJ. Diagnosis of autism spectrum disorders in the first 3 years of life. Nat Clin Pract Neurol 2008;4(3):138–147
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