Functional Rehabilitation of Social Communication in Young Children with Autism: Clinical and Neurobiological Correlates

Background:  

Based on the neurodevelopemental theory of autism, the exchange and development therapy (EDT) is applied in very young children, when the neural plasticity is greater. The EDT consists in the early and harmonious re-education of the basic neurophysiologic functions; the development of which leads to the development of more complex functions. Previous studies have confirmed the efficiency of the EDT, showing a decrease of the inappropriate behaviours and an increase in cognitive and social abilities. However, the cerebral correlates that underlie these improvements have never been studied.

Objectives:  

The aim of the current study was to investigate the evolution of two neurophysiological markers (ocular exploration, electrophysiological responses to face) before and after the EDT and to test whether these are related to clinical improvements.

Methods:  

Six children with a diagnosis of autism (ASD) according to the DSM-IV criteria and assessed with ADOS and/or ADI (mean age = 4 years 10 months) were involved in an EDT during two years. Clinical and neurophysiological evaluations were assessed three times during the follow up: before the beginning T0, one year after T1 and two years after T2. Socio-emotional abilities and autistic behaviours were measured using SCEB (Social Cognitive Evaluation Battery; Adrien,2007) and BSE-R (Behavioural Summarized Evaluation scale revised; Barthélémy et al., 1997). Using an eye-tracking method, the visual exploration of face was investigated and visual ERPs (P1, N170) were recorded during an implicit emotional task. A group of typically developing children (TD) matched by chronological age also participated to the eye-tracking and ERPs recordings.

Results:  

ASDs displayed strongly abnormal pattern of face exploration (children with ASDs looked less at the eye region compared to TD children) and visual ERPs in response to face (P1 and N170 were delayed and smaller in ASD) confirming that these processes, involved in social adaptation, were affected in our sample at T0. Moreover one year after the beginning of the therapy, improvements are observed in both socio emotional and cognitive area especially in affective relation. During this first year of therapy, the time spent on the eyes increased, suggesting a normalization of the ocular strategy used to explore faces. However, the electrophysiological indices appeared to be affected by the EDT only during the second year. The amplitude of P1 and N170 increased and the topographical analysis revealed a normalization of the N170.

Conclusions:  

Both clinical and neurophysiological markers appeared to be affected by the EDT. Although these data are only preliminary, they are very encouraging and suggest an effect of therapy on brain development in agreement with the principles of the EDT.