A Quantitative Case Study of An Infant Later Diagnosed with Autism: Response Profiles at 1 and 4 Months

Background: Recent studies, especially those investigating infant siblings of children with autism, have begun to identify signs of autism in the first year of life. These findings suggest that signs of risk for autism are more easily identified after 6 months of age than in the first 6 months of life. Here we utilize a quantitative analysis of an infant later diagnosed with autism as an additional method for investigating this disorder in early development. Objectives: To analyze behavioral responses to a neurobehavioral examination at 1 month of age, and the Face to Face/Still Face procedure (FF/SF) at 4 months in an infant later diagnosed with autism. To compare the infant's responses to a large longitudinal cohort in which this infant was followed. Methods: A male child who is followed as part of the Maternal Lifestyle Study (MLS; a longitudinal study of prenatal cocaine exposure and non-exposed controls) was identified as having Autistic Disorder with moderate Intellectual Disability (child was born premature; GA=28 weeks). Data from the NICU Neurobehavioral Scales (NNNS) at 1-month and the FF/SF at 4 months were analyzed. NNNS data from 454 preterm (<36 weeks) infants were submitted to a latent profile analysis, resulting in four independent clusters, 2 of which consisted of infants with poor neurobehavioral profiles (n= 82 and 42) and poor behavioral outcomes at age 7. The FF/SF included 4 episodes: mother interaction, still face, re-engagement, and examiner interaction. Maternal behaviors, infant positive and negative responses, and degree of match between infant and mother were coded. Percentile scores for the autistic infant were calculated for each variable. Results: On the NNNS at 1 month, the child with autism was classified into the first of the poor NNNS clusters. For the FF/SF at 4-months, infant negative displays were not atypical (between 27th – 40th %iles). Social positive displays were in the upper quartile for the initial play and still face episodes, but in the lower quintile (17th %ile) during maternal re-engagement. Social positive displays were in the upper quintile during the stranger interaction. Notably, the mother was reserved and low in positivity during re-engagement (10th %ile), whereas the examiner was enthusiastically positive. Conclusions: These data indicate that early infant signs of autism may be present, but these results underscore the subtlety of the presentation of autism in the first year of life. Findings from the NNNS indicated that the autistic child showed nonspecific but poor neurobehavioral responses at 1 month of age. The FF/SF findings were most notable for low positive displays during re-engagement, but – unexpectedly – a high degree of social positive displays during interactions with an exuberant examiner. These findings point to the importance of careful calibration of behavioral protocols to sensitively identify early signs of autism in infancy. These exploratory data also raise the hypothesis that positive behavioral responses may be elicited in infants with later diagnoses of autism, but that these infants may differ in threshold for response.