Autism spectrum disorders in 24 children who are deaf or hard of hearing

Abstract

Objectives

Approximately 4% of children who are deaf or hard of hearing have co-occurring autism spectrum disorder (ASD). Making an additional diagnosis of ASD in this population can be challenging, given the complexities of determining whether speech/language and social delays can be accounted for by their hearing loss, or whether these delays might be indicative of a comorbid ASD diagnosis. This exploratory study described a population of 24 children with the dual diagnosis of ASD and hearing loss.

Methods

Children completed a comprehensive ASD evaluation using standardized autism diagnostic instruments (Autism Diagnostic Observation Schedule, language and psychological testing). Children with permanent hearing loss who had a developmental evaluation between 2001 and 2011 and were diagnosed with an ASD based on the results of that evaluation were included. Information on communication modality, language and cognitive abilities was collected.

Results

The median age of diagnosis was 14 months (range 1–71) for hearing loss and 66.5 months (range 33–106) for ASD. Only 25% (n = 6) children were diagnosed with ASD ≤48 months of age and 46% by ≤6 years. Twelve (50%) children were diagnosed with ASD, 11 were diagnosed with pervasive developmental disorder not otherwise specified and 1 child had Asperger's. Most (67%) had profound degree of hearing loss. Fourteen (58%) children had received a cochlear implant, while 3 children had no amplification for hearing loss. Nine (38%) of the 24 children used speech as their mode of communication (oral communicators).

Conclusions

Communication delays in children who are deaf or hard of hearing are a serious matter and should not be assumed to be a direct consequence of the hearing loss. Children who received cochlear implants completed a multidisciplinary evaluation including a developmental pediatrician, which may have provided closer monitoring of speech and language progression and subsequently an earlier ASD diagnosis. Because children who are deaf or hard of hearing with ASD are challenging to evaluate, they may receive a diagnosis of ASD at older ages.

Introduction

Autism spectrum disorders (ASD) constitute a group of developmental disorders characterized by impairments in social interaction and communication, and by restricted, repetitive, and stereotyped patterns of behavior [1]. Early identification of children with ASD is critical in their medical management and treatment [2], [3], [4], [5], [6], [7], [8], with screening endorsed as early as 18 months of age [9], [10], [11]. Although symptoms are usually apparent by 3 years of age, most children are not diagnosed with ASD until after age 4 [12]. One of the challenges in identifying children at very young ages relates to an absence of skills (such as eye contact, gestures, pointing, and pretend play) rather than the presence of noticeable features (such as spinning parts of toys, lining up toys, or repeating phrases) [13]. However, parents often do notice developmental problems as early 12 months of age, with concerns of hearing and vision most reported in that first year [14], [15].

With the implementation of universal newborn hearing screening in the United States, the age of identification for hearing loss has significantly decreased [16], [17], [18]. This earlier diagnosis has made the early language acquisition trajectory for young children who are deaf or hard of hearing approach that of hearing children [19]. The dual diagnosis of hearing loss and ASD is important as nearly 40% of children with an identified permanent hearing loss have an additional disability [20]. Among this group of children with different learning patterns, the prevalence estimates of ASD have been reported to be as high as 1.7% [21] to 4% [22]. Since the comorbidity of ASD and hearing loss may significantly complicate language development, early identification of both conditions is of utmost importance to mitigate the effects of the dual diagnosis. Unfortunately, because both hearing loss alone and ASD alone could contribute to communication and social delays, identification of the true dual diagnosis is challenging [23], [24], [25], [26].

The literature on the dual diagnosis of ASD and hearing loss is severely lacking. Thus characterizing this group of children is an appropriate first step to enhance our understanding and build the foundation for improved identification and intervention for their communication needs. The objective of this descriptive or exploratory study was to describe a population of children with the dual diagnosis of permanent hearing loss and ASD in the context of the degree of hearing loss.