Investigating Resting-State Brain Activity in Adolescents with High-Functioning Autism Spectrum Disorder: Linking Fractional Amplitude of Low-Frequency Fluctuation to Clinical Symptoms

The study aimed to investigate the alterations in spontaneous brain activity, as measured by fractional amplitude of low-frequency fluctuation (fALFF), in adolescents with high-functioning autism spectrum disorder (HFASD) and to explore the relationship between these alterations and the severity of autistic symptoms. We recruited 58 adolescents with HFASD and 66 typically developing (TD) controls, matched for age, gender, and full-scale intelligence quotient (FSIQ). Group-level analysis was conducted to identify variances in fALFF between individuals with autism spectrum disorder (ASD) and TD controls. The assessment of symptom severity in individuals with ASD was conducted utilizing the Autism Behavior Checklist (ABC). A voxel-wise correlation analysis was performed to investigate the relationships between symptom severity and the fALFF mapping in individuals with ASD, specifically in cerebral regions exhibiting ReHo abnormalities. Compared to TD controls, adolescents with HFASD showed reduced fALFF in several brain regions, including the bilateral inferior parietal lobule (IPL), right precuneus, right postcentral gyrus, bilateral middle temporal gyrus, and left cingulate gyrus. Positive correlations were observed between fALFF values in the left IPL and the Relating, Sensory, and total scores of the Autism Behavior Checklist (ABC) scale, while fALFF values in the left postcentral gyrus showed positive correlations with the Social self-help scores. These findings suggest that modifications in local spontaneous brain activity within these regions may be associated with the symptomatology of ASD, potentially enhancing our understanding of the neural mechanisms underlying the symptoms of ASD and facilitating earlier identification and improved treatment strategies.