Relationship Between Gastrointestinal Disorder and GSR Indicators of Stress In Autism Spectrum Disorders

Background: There appears to be a high prevalence of gastrointestinal (GI) problems in children with autism spectrum disorders (ASD) (e.g., Williams et al., 2010), and evidence suggests that the response to stress in ASD is augmented (Corbett et al., 2008).  Additionally, an association exists between stress and GI disorders (e.g., Suarez et al., 2010).  However, despite this knowledge, the relationship between stress indices and GI disturbances has not been explored in ASD.

Objectives: We sought to examine the relationship between the response to stressful stimuli in children with ASD both with and without gastrointestinal disorders or significant GI symptomatology. We hypothesized that the response to stress in children and adolescents with ASD with a GI disorder or significant GI symptomatology would be higher than those with ASD alone. Galvanic skin response (GSR), a measurement of eccrine gland activity, was used as an indicator of sympathetic nervous system activation for a baseline condition as well as in response to auditory and vibrotactile stimulation as well as cold temperature.

Methods: Children and adolescents with an ASD diagnosis with a comorbid GI disorder or significant GI symptomatology, as assessed by the Autism Treatment Network Gastrointestinal Questionnaire, and those with ASD without a GI diagnosis or significant GI symptomatology had GSR data recorded from the distal phalanxes of their index and middle fingers for a baseline condition as well as independent conditions of auditory, vibrotactile, and cold temperature stimulation.

Results: Mean GSR was significantly higher for the ASD GI group for the cold pressor task, and maximum amplitude GSR was significantly higher for the ASD GI group for the cold pressor task.  Trends toward significance were noted for  the baseline and vibrotactile conditions.

Conclusions: Preliminary results from our pilot study suggest that physiological response to sensory stimuli in the domain of cold temperature stimulation may differ in those with ASD with a GI disorder or significant GI symptomatology relative to those with ASD alone.  Although our data indicate differences in physiological responding among the groups, a larger sample size is needed to determine if the effects can be substantiated.  Identifying the aspects contributing to GI problems in ASD will be important for optimizing future treatment strategies.