Attenuated contact heat-evoked potentials associated with sensory and social-emotional symptoms in individuals with autism spectrum disorder

Abstract

Sensory disturbance is associated with socio-emotional problems in individuals with autism spectrum disorder (ASD). Most studies assess sensory symptoms by self-reports, which are largely limited by the language ability and self-awareness of the individuals. This study aims to investigate sensory disturbance by contact heat-evoked potentials (CHEP) in ASD individuals, and to examine the clinical correlates of CHEP parameters. We compared the CHEP parameters and reported pain between 31 ASD individuals (aged 20.5 ± 5.2 years) and and 22 typically-developing controls (TD, aged 21.4 ± 2.6), and correlated the CHEP parameters with self-reported sensory symptoms and attention/socio-emotional symptoms. We found that ASD individuals showed smaller P2-wave amplitudes than TD, even though they reported a similar level of pain. In TD individuals, a smaller P2-wave amplitude was related to higher scores on 'low registration,' 'attention to detail,' and 'attention switching difficulties.' In ASD individuals, longer N2-wave latency was related to higher scores on 'sensory sensitivity' and socio-emotional problems; while higher reported pain was associated with higher scores on 'low registration,' overall autistic severity, and longer N2-wave latency. Our findings of attenuated CHEP response in ASD, which was associated with sensory symptoms and socio-emotional problems, suggest a potential role for CHEP in studying sensory disturbances in ASD.

Figure 1. Grand average of CHEP waves of the group with autism spectrum disorder (ASD: dark line) and the group with typically-developing participant (TD: light gray line).

The N2-wave and P2-wave were marked. The ASD participant showed a smaller P2-wave amplitude.

Figure 2. Correlations between P2-wave amplitude and Low Registration subscores in individuals with autism spectrum disorders (ASD) and typically-developing controls (TD).

Diagnosis group had a main effect (β = −40.0 ± 13.6, F = 8.59, p = 0.005) with a significant interaction between group and Low Registration (β = 0.91 ± 0.36, F = 6.45, p = 0.015). The results were similar when the seemly outlier of an ASD participant with a very high amplitude was deleted [Diagnosis group main effect (F = 10.04, p = 0.003), interaction term (F = 7.03, p = 0.010)].

Figure 3

Relationship between reported pain intensity on the Verbal Rating Scale and (a) Low Registration subscores (b) Autism Spectrum Quotient (AQ) total scores in individuals with autism spectrum disorders. Reported pain intensity was positively correlated with Low Registration subscores (r_s = 0.46, p = 0.015) and AQ total scores (r_s = 0.52, p = 0.006).

Figure 4. Correlations between N2-wave latency and social emotion problem subscores in individuals with autism spectrum disorders (ASD) and typically-developing controls (TD).

Diagnosis group had a main effect on socio-emotional problems (β = 49.3 ± 18.0, F = 7.48, p = 0.009), and N2-wave latency showed a nominal effect (β = 0.007 ± 0.029, F = 3.91, p = 0.054) with significant group × N2-wave latency interaction (β = −0.086 ± 0.036, F = 5.54, p = 0.023). The results were mildly different when the outlier of a TD participant with a very short latency was deleted [diagnosis main effect (F = 5.57, p = 0.023), N2-wave latency main effect (F = 1.77, p = 0.191), and interaction term (F = 4.28, p = 0.045)]. When ASD and TD were separated, the N2-wave latency was still associated with socio-emotional problems significantly in ASD group (t = −3.28, p = 0.0032) but not in TD group (t = 0.27, p = 0.792).