Deaf and Hard-of-Hearing Children and Autism Spectrum Disorder: Screening, Assessment, and Diagnosis

The issue

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Autism Spectrum Disorder (ASD) is a life-long neuro-developmental disorder that impacts social, communicative, and behavioral functioning.  According to the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5), the standard classification system used in the United States for diagnosing psychiatric disorders, ASD is characterized by persistent deficits in: 1) social communication and social interaction (i.e., social-emotional reciprocity, nonverbal communicative behaviors used for social interaction, and understanding of relationships); and 2) restricted, repetitive patterns of behavior, interest or activities. To date, estimates of the rate of ASD in deaf and hard of hearing (DHH) children have been similar, if not higher, than those of their hearing counterparts.   Many problems exist, however, regarding how to best screen, assess and diagnose DHH children.

What we know

The American Academy of Pediatrics (AAP) has created  a user-friendly list of  early signs of ASD, available through its https://www.healthychildren.org website.  The site advises parents to trust their instincts and consult their pediatrician should they have any concerns regarding their child’s development.  While many of the red flags listed apply to both hearing and DHH children (i.e., limited or inconsistent eye contact,  poor joint attention, poor pretend play skills, rocking, lining up toys, etc.), several early signs may apply to typically-developing DHH children (i.e., language delays with consequent social communication delays).  A further complication for parents is the fact that some these “red flags” apply only at certain ages and can vary in severity. ASD clinical red flags specific to DHH children have included: persistent gesture use despite instruction in a sign language (e.g., American Sign Language), poor use of facial aspects of the sign language, palm (sign handshape) reversals, gaps in language acquisition, and delays beyond expected for hearing loss, difficulty understanding deaf cultural norms, etc.  For children whose parents choose spoken language only, however, many of these indicators do not readily apply and may make it more difficult for parents to distinguish ASD behaviors from behaviors associated with a poor match in communication mode.

The AAP recommends formalized screening for ASD at the 18- and 24-month well-child checks.  The Modified Checklist for Autism in Toddlers-Revised (MCHAT-R), a brief, parent-report tool that distinguishes children between 16 and 30 months of age who are at risk for ASD versus those who are not,  is a common tool used within pediatric practices.   Per the AAP, children who screen positive on the MCHAT-R should be referred for a diagnostic assessment to determine whether a DSM-5 diagnosis of ASD is warranted.   Researchers have criticized many of the ASD screening tools for lacking sensitivity, missing up to 50% of DHH children who also have an ASD.  While research on DHH-specific screening tools is underway, none yet has been validated for use with DHH children.

National best standards endorse either a physician or a clinical psychologist making an ASD diagnosis. The process of diagnosing ASD requires not only an assessment of DSM-5 symptoms, but also an assessment of related medical and psychiatric disorders, intellectual functioning, and language levels. Additionally, the clinician must be able to specify the severity levels of the child’s social communication deficits, as well as restricted interests/repetitive behaviors.   For DHH children, several diagnostic challenges exist including lack of standardized assessment tools for DHH children, diagnostic overshadowing (that is behaviors associated with being DHH masking ASD symptoms), and a limited number of providers who are trained in ASD and who understand the needs of DHH children. For children who primarily use sign language, use of interpreters may also be problematic because the interpreter 1) may lack training in recognizing atypical language features,  2) may disrupt rapport necessary for assessing social reciprocity, and  3) may not fully understand his/her role in the process.

What we don’t know

Presently, we don’t know the prevalence of ASD among DHH children, and little empirical data are available on the screening, assessment, and diagnosis of ASD in this population. Both screening and diagnostic tools typically used for children suspected of having ASD have not been validated on DHH children.  For example, gold standard diagnostic tools such as the Autism Diagnostic Schedule-2 and the Autism Diagnostic Interview–Revised have yet to be adapted for DHH children.

Implications

In the absence of validated tools, best practice relies on educated clinical opinion based on interpretation of data gathered from multiple sources.  Additionally, experts recommend referring a child who has some red flags of ASD and yet passes the ASD screening to have a comprehensive ASD assessment.

Posted on July 7, 2016 by
Debra Zand
St. Louis University School of Medicine
Dzand {at} slu.edu

Katherine Pierce
St. Louis University School of Medicine
Kjpierce (at} slu.edu

Heidi Sallee
St. Louis University School of Medicine
Salleehm {at} slu.edu