Evaluation of sympathetic sudomotor responses to auditory stimuli in children with autism spectrum disorders

Abstract

Aim and Objective: Autism spectrum disorder (ASD) being a complex neurological and developmental disorder is also associated with autonomic nervous system dysfunction. Sudomotor nerve function is one highly sensitive index of sympathetic cholinergic activity and can be evaluated by measuring sympathetic skin response (SSR) to various stimuli. Studies reporting SSR to auditory stimulus among ASDs are limited and to the extent of our knowledge not assessed in the Indian scenario. The objective of the study was to assess and compare sympathetic sudomotor activity by evaluating SSR to auditory stimuli in children with and without ASDs. Materials and Methods: A total of eighty individuals were enrolled in the study, including forty children with ASD and forty typically developing (TD) children. SSR to auditory stimulus was assessed using a digitized data acquisition unit in a soundproof room, maintained at 23°C. SSR indices such as latent period (s), amplitude (mv), and habituation were analyzed and compared using appropriate statistical tests between the groups. P < 0.05 was considered statistically significant. Results: Habituation for SSR was statistically significantly lower ( P < 0.001) in children with ASD (0.43 [0.21, 0.61]) compared to TD children (0.78 [0.65, 0.95]). Latent period was also statistically significantly higher in children with ASD (1.67 [1.37, 2.02]) compared to TD children (1.41 [1.2, 1.72]). However, there was no significant difference in amplitude values between the groups. Conclusions: Children with ASDs exhibited slower habituation of SSR to auditory stimuli compared to healthy controls. This slower habituation process might be due to the persistent predominant state of sympathetic nerves, which, in turn, contributes to the atypical emotional and behavioral traits prevailing in ASDs.

Autism Spectrum Disorder and auditory sensory alterations: a systematic review on the integrity of cognitive and neuronal functions related to auditory processing

“…Impairments at the level of emotional perception can be related to internal distractions or overload of sensory information that hinder social communication. Studies using sympathetic skin response show that children diagnosed with ASD exhibit delayed habituation to auditory stimuli (Bharath et al 2021 ). The predominant state of sympathetic nerves can affect the predisposition to filter and perceive cues, and also influence anxiety levels or valence of social cues.…”

Electrodermal activity spectral and nonlinear analysis – potential biomarkers for sympathetic dysregulation in autism

“…In this context, the autonomic nervous system (ANS) plays a crucial role in the control of the physiological, emotional/ cognitive and behavioural state during social interaction. Recently, scientists' interest in detecting relationships between autonomic dysfunction and ASD has been growing, but the exact pathomechanisms leading to autonomic abnormalities in ASD are still unclear (Bal et al 2010;Ming et al 2011;Plus 2019;Bharath et al 2020). Moreover, the existing findings on the ASD-linked sympathetic regulation reflected by EDA are controversial, such as increased, i.e.…”

“…Moreover, the existing findings on the ASD-linked sympathetic regulation reflected by EDA are controversial, such as increased, i.e. associated with more social impairments (O'Haire et al 2015;Neuhaus et al 2016;Fenning et al 2017), unaltered (Kong et al 2021), decreased (linked with augmented externalizing behaviour complications in ASD children) (Bujnakova et al 2016;Baker et al 2018), or slower habituation of sympathetic skin response to auditory stimuli indicating a persistent predominant state of sympathetic activity in autism (Bharath et al 2020). Furthermore, Baker et al (2015) found positive associations of EDA and interpersonal variability (i.e.…”