Validation of the Com Deall Developmental Checklist and the Com Deall Oro-Motor Assessment in Normative and Autistic Populations in India: Linking Motor, Cognitive, and Speech and Language Skills

Background:  The many tools globally available for assessment of autism spectrum conditions lack culturally specific adaptations and norms. Whereas social cognitive impairments were once assumed to be primary, early signs of motor speech impairment have gained importance in explaining uneven language profiles in non-verbal autistic children. Motor deficits in children with ASD range from motor delay and motor asymmetries to oro-motor impairments, as well as praxis of limb movements and speech movements. These basic traits of motor dysfunction and dyspraxia correlate with the severity of autism's more immediately apparent, more diagnostic, and more debilitating social communicative deficits, and can impair the later development of social communication and language. Especially because remediation of these basic motor deficits can benefit later communicative development, validated, culturally appropriate, and economically accessible tools are needed to quantify the effects of intervention.

Objectives:  To validate against international norms the Com DEALL Developmental Checklist (CDDC) and the Com DEALL Oro-Motor Assessment (CDOMA), low-cost instruments indigenously developed, normed, and tested in India. These culturally adapted and economically accessible test-retest measures assess autistic skills and deficits in motor and particularly oral motor development, receptive and expressive language, and adaptive skills, at baseline and during intervention.

Methods:  CDDC and CDOMA were cross-validated against the Mullen Scales of Early Learning (MSEL) and the Verbal Motor Production Assessment for Children (VMPAC), respectively, in 60 children with ASD attending the Com DEALL programme and 155 typically developing children. All subscales of all tests were assayed for correlation against each other, exploratory factor analysis was applied for each diagnostic group separately, and a linear discriminant between groups was constructed with leave-one-out validation for each test separately.

Results:  All subscales common to MSEL and CDDC correlated with each other, although correlations with MSEL gross motor and visual reception diminished with age. Nearly all VMPAC subscales correlated with the CDOMA Tongue Movement subscale and most strongly with the CDOMA Speech subscale. The CDDC correctly classified 96.3% of the participants into ASD and age-matched typical groups, with leave-one-out cross-validation; controls were classified more accurately (99.2%) than children with ASD (86.7%). The CDOMA correctly classified 85.8%, controls again more accurately (99.2%) than children with ASD (60%). Cognitive and social skills segregated with language in typical development, but with motor skills in ASD.

Conclusions:  Whereas the factor structure of oro-motor assessments in the typical group describes the type of motor or cognitive control assayed (motor control versus sequence maintenance) independently of the complexity of speech production (sounds versus words versus sentences), in the autistic group the variance between factors is a matter of complexity of production, cutting across type of control. These results validate CDDC and CDOMA, suggest a link between autistic motor and cognitive control, and suggest that autistic speech impairment is complexity-specific.