Feasibility and Safety of Transcranial Focused Ultrasound on Language Impairment in a Patient with Autism Spectrum Disorder: A Case Report.

BACKGROUND

Autism spectrum disorder (ASD) is defined by persistent difficulties with social communication and language, and a subset of children stay minimally verbal despite intensive interventions. The left amygdala and ventral-anterior superior temporal sulcus (STSva) form a key circuit for social-language integration, but how transcranial focused ultrasound (tFUS) might modulate in minimally verbal ASD has not been explored.

CASE PRESENTATION: An 11-year-old minimally verbal ASD boy received 4 weeks of sequential tFUS stimulation (0.5 MHz). The treatment targeted the left amygdala and STSva, five times per week. Outcome assessments included the Mandarin Clinical Evaluation of Language for Preschoolers' Core Scale (MCELP-CS), Autism Behavior Checklist (ABC), and functional near-infrared spectroscopy (fNIRS) at pre-tFUS, post-tFUS, and a 4-week follow-up. The boy tolerated the intervention well, with no adverse events. Significant improvements in key language skills (vocabulary naming +10%, sentence structure imitation +22%) and reduced ASD symptoms (ABC language -40%, social interaction -26%) were observed post-tFUS and sustained at follow-up. fNIRS confirmed altered cortical activation and reorganized functional connectivity in language-related brain regions.

CONCLUSION

This single-case observational report describes acceptable tolerance to sequential tFUS targeting the left amygdala-STSva circuit in a minimally verbal child with ASD, alongside concomitant behavioural and neuroimaging changes. These preliminary observations provide descriptive, hypothesis-generating data for this circuit-directed intervention strategy and highlight the necessity of larger controlled trials to further evaluate its potential clinical utility.