1.10 THALAMIC METABOLITE LEVELS AND SENSORY PROCESSING IN TWINS WITH AUTISM SPECTRUM DISORDER

Objectives

Sensory processing abnormalities are commonly reported in individuals with ASD, and nearly all sensory systems are filtered through the thalamus. The goal of this investigation was to examine neurochemical profiles of the thalamus in twins with and without ASD to determine whether or not thalamic perturbations are related to sensory processing abnormalities.

Methods

Data were acquired from participants in a neuroimaging study of same-sex twin pairs with and without ASD. Sensory processing abnormalities were assessed with the Sensory Profile Caregiver Questionnaire (SPQ), and metabolites of interest were acquired with a magnetic resonance spectroscopy chemical shift imaging slab that covered the left and right thalami. Independent sample t tests were used to compare differences between individuals from each ASD twin pair exhibiting the highest symptom

Results

Compared with control subjects (N = 29), individuals with ASD (N = 43) exhibited greater multisensory processing abnormalities [t(70) = 6.60, P < 0.001], and lower N-acetyl-aspartate (NAA) levels in the left thalamus [t(70) = 3.036, P = 0.003], which were significantly correlated (r = 0.39, P = 0.001). Monozygotic twins discordant for ASD (N = 3) did not exhibit a significant difference in multisensory processing, whereas dizygotic (DZ) twins discordant for ASD (N = 10) exhibited greater

Conclusions

The present study provides further evidence of a relationship between thalamic perturbations and sensory processing abnormalities in individuals with ASD. Reduced neuronal viability in the thalamus in individuals with ASD may confer increased risk for sensory processing abnormalities. Finally, further examination of thalamic abnormalities in twins will help shed light on the heritability of sensory processing-related alterations in ASD.

ASD ND TWINS