ABSTRACT
BACKGROUND: It is difficult to diagnose autism spectrum disorder (ASD) in people with a combination of intellectual and sensory disabilities because of overlap in behaviour. The ASD typical behaviours of people with combined intellectual and sensory disabilities are often caused by their disabilities and not by ASD. Current diagnostic tools are inadequate to differentiate between people with and without ASD when they have these combined disabilities, because tools lack norms for this population or are subjective, indirect or unable to adapt to the variety of disabilities that these people may have. Because giving a correct diagnosis is necessary for treatment and support, a new observational tool was developed to diagnose ASD in people with multiple disabilities, observation of autism in people with sensory and intellectual disabilities (OASID). METHOD: Observation of autism in people with sensory and intellectual disabilities was tested on 18 participants with moderate to profound intellectual disabilities, one or dual sensory impairment, with and without ASD. Two independent experts diagnosed these participants as well in order to test the psychometric properties and differentiating abilities of OASID. RESULTS: Observation of autism in people with sensory and intellectual disabilities showed high inter-rater reliability, internal consistency of scales and content and construct validity. OASID could differentiate people with and without ASD without overlap. CONCLUSIONS: Observation of autism in people with sensory and intellectual disabilities could differentiate people with intellectual disabilities combined with sensory impairments, who clearly had or did not have signs of ASD. People with unclear signs of ADS scored in between those two groups with regard to their OASID scores. Psychometric properties of OASID are promising.
Subject(s)
Autism Spectrum Disorder/diagnosis , Blindness/diagnosis , Deafness/diagnosis , Intellectual Disability/diagnosis , Psychiatric Status Rating Scales/standards , Psychometrics/instrumentation , Adolescent , Adult , Autism Spectrum Disorder/epidemiology , Blindness/epidemiology , Child , Comorbidity , Deafness/epidemiology , Diagnosis, Differential , Female , Humans , Intellectual Disability/epidemiology , Male , Middle Aged , Young AdultABSTRACT
BACKGROUND: In persons with deafblindness, it is hard to distinguish autism spectrum disorders from several deafblind specific behaviours caused by the dual sensory impairments, especially when these persons are also intellectually disabled. As a result, there is an over-diagnosis of autism in persons who are deafblind leading to unsuitable interventions. METHODS: Autism as specified by the DSM-IV was studied in 10 persons with congenital deafblindness with profound intellectual disabilities. Behaviours of people with deafblindness and autism (n = 5) and of people with deafblindness without autism (n = 5) were observed in a semi-standardised assessment. RESULTS: All people with deafblindness showed impairments in social interaction, communication and language. In contrast to persons without autism, people with deafblindness and autism showed significantly more impairments in reciprocity of social interaction, quality of initiatives to contact and the use of adequate communicative signals and functions. No differences between the groups were found for quantity and persistence of stereotyped behaviour, quality of play and exploration and adequate problem-solving strategies. CONCLUSIONS: This study indicates that there are some possibilities to differentiate autism from behaviours specific for deafblindness. It also confirms the large overlap in overt behaviours between people with deafblindness and persons with autism.
Subject(s)
Autistic Disorder/diagnosis , Autistic Disorder/psychology , Deaf-Blind Disorders/diagnosis , Deaf-Blind Disorders/psychology , Intellectual Disability/diagnosis , Intellectual Disability/psychology , Adolescent , Adult , Child , Child, Preschool , Communication , Consensus , Diagnosis, Differential , Exploratory Behavior , Female , Humans , Interpersonal Relations , Language Development Disorders/diagnosis , Language Development Disorders/psychology , Male , Personality Assessment , Play and Playthings , Problem Solving , Stereotyped Behavior , Young AdultABSTRACT
The Sonksen Picture Guide to Visual Function (SPGVF) assesses a person's ability to discriminate pictures of everyday objects. Sonksen added the SPGVF to tests of visual acuity, because real objects, miniatures, and pictures are the main learning medium for young children. In earlier studies correlations have been found between visual acuity and responses to the SPGVF. However, to date no studies have used visually impaired children. In the study reported here, the associations between performance on the SPGVF task, visual acuity and contrast sensitivity were investigated. Participants were 17 visually impaired and 29 children without disabilities, 4--6 years of age. The results showed that visual acuity was more important for picture recognition than contrast sensitivity. Contrast thresholds < 3.33% implied that not all SPGVF-pictures could be recognized. The visually impaired children in the current study showed shorter mean identification distances than the normally sighted children in the original Sonksen and Macrae study.
