"Non Invasive Tools for Early Detection of Autism Spectrum Disorders"

Background: Autism spectrum disorders (ASDs) are often not diagnosed until children reach 3-4 years of age. So far, the study of the early symptoms of ASDs is mainly based on retrospective analysis of home videotapes, usually recorded during children's first birthday party, or prospective studies of infant siblings of children with ASDs using the Autism Observation Scale for Infants, which measures visual attention, response to name, social babbling, eye contact and sensory behaviors. Neither home video analysis nor high risk infants studies, detected consistent abnormalities before 1 year of age. Early identification of young children with ASDs, possibly through a set of behavioral and neurophysiological indexes, is crucial in light of findings indicating that early intervention is much more effective than interventions starting in later childhood.

Objectives:  Aim of our study is to identify early diagnostic markers through the assessment of neurobiological and developmental patterns in infant siblings of children with ASDs. We focused on age-specific motor (general movements analysis) and vocal repertoires (infant crying analysis), which are known to be later impaired in ASD children and that have been found altered in other neurodevelopmental disorders. General movements and cry analyses are of great relevance since they provide information concerning both development and integrity of the central nervous system and are completely non-invasive and easy to perform.

Methods: Recruiting of full term infants without genetic/neurological abnormalities  and younger siblings of children diagnosed with ASDs; assessment of normative values for vocal, motor parameters and neuropsychological markers. Infant spontaneous movements and crying will be video- and audio-recorded at home in presence of a primary caregiver in the first six months of age. Subsequently, their neuropsychological and language development will be evaluated (AOSI, ADOS-T, Griffiths Mental Developmental Scales-ER; Peabody Motor Development Scale; MacArthur and First Year Inventory).

Results: So far, we recruited 80 full term infants and 14 high risk infants. Analysis of infant crying revealed that high risk infants have a lower frequency of fundamental frequency and of the two resonance frequencies F1 and F2 as compared to full term subjects. General movements analysis, an effective tool in predicting abnormal outcome in infants at risk for neurological development, revealed an unusual motor pattern in infants at high risk. Specifically, only 5 out of 14 high risk infants reached the maximum motor optimality score during the writhing movement period (10 days and 6 weeks) and 7 out of 14 infants during the fidgety period (12 weeks). Five high risk infants showed no responses to name, deficits in emotion recognition, and poor motor development.

Conclusions: Our preliminary results showed the importance of monitoring high-risk infant development during the first six months of life and suggest the usefulness of these non-invasive tools to identify early diagnostic markers. However, the sample size, primarily of high risk subjects, needs to be increased.