In a small randomized trial, preschoolers with autism who received 12 weeks of gentle, low-frequency TMS improved more on core symptoms than children who received a sham treatment. Brain scans taken before and after offered clues about why.
| Study at a glance | |
|---|---|
| Published | BMC Pediatrics, August 2026 |
| Study type | Randomized controlled trial |
| Participants | 34 children with autism, ages 2–6 (32 completed) |
| Treatment | 12 weeks of 1 Hz rTMS to the left prefrontal cortex, vs. sham |
| Main finding | Greater improvement on three autism symptom scales with active TMS |
What the study is about
Autism spectrum disorder (ASD) shapes how children communicate, connect with others, and respond to the world around them. The preschool years are a window when the brain is especially adaptable, which is why early support matters so much.
A research team in China asked two questions. Could repetitive transcranial magnetic stimulation (rTMS), added to standard rehabilitation, ease core autism symptoms in very young children? And if so, what was it actually changing in the brain?
Why they did it
Much of the earlier rTMS research in autism involved older children, teens, and adults, and few studies looked directly at how the brain responds during treatment. Understanding the “how” matters: it can show whether a treatment is working through a meaningful pathway and help predict who is most likely to benefit.
The team targeted the left dorsolateral prefrontal cortex (DLPFC), a region near the front of the brain involved in planning, attention, and self-control. They used low-frequency (1 Hz) stimulation, which tends to calm activity in the area being stimulated.
What they did
Thirty-four children ages 2 to 6 were randomly assigned to one of two groups:
- Active TMS (17 children): 12 weeks of low-frequency rTMS over the left DLPFC, plus conventional rehabilitation.
- Sham (17 children): sham stimulation, which mimics the experience of treatment without delivering active stimulation.
Thirty-two children completed the study. Before and after treatment, the researchers measured symptoms with four widely used tools: the Childhood Autism Rating Scale (CARS), the Autism Behavior Checklist (ABC), the Repetitive Behavior Scale–Revised (RBS-R), and the Autism Treatment Evaluation Checklist (ATEC). Each child also had a resting-state fMRI scan, which maps brain activity while a person is at rest.
What it showed
- Symptoms improved more with active TMS. Children in the TMS group improved significantly more than the sham group on the CARS, RBS-R, and ATEC.
- Brain activity shifted. After treatment, the TMS group showed more activity in the right caudate nucleus, right angular gyrus, and left anterior cingulate gyrus. These regions are involved in attention, behavioral control, and pulling information together. Activity decreased in several regions toward the back of the brain.
- One region tracked with symptoms. Changes in the right angular gyrus were significantly linked to scores on the ATEC, ABC, and CARS.
The authors concluded that the treatment appeared safe and effective for this age group.
Why it matters
This study does more than ask “did it work?” By pairing symptom scores with brain scans, it starts to explain how TMS may help: by strengthening activity in regions that support thinking and self-regulation.
The researchers also suggest the right angular gyrus and right caudate nucleus could serve as biomarkers, measurable signals that show whether treatment is taking effect. If confirmed, markers like these could one day help clinicians personalize treatment and spot early on which children are responding.
What to keep in mind
- It’s a small study. With 32 children completing it, the results need to be confirmed in larger trials.
- We don’t yet know how long the benefits last. Children were assessed right after the 12-week course.
- TMS was an add-on, not a replacement. Children in the active group also received conventional rehabilitation. Behavioral and developmental therapies remain the foundation of autism care.
- This is investigational. TMS is not FDA-cleared for autism. Families interested in research options should talk with their child’s care team.
The bottom line
For preschoolers with autism, low-frequency TMS to the prefrontal cortex showed early promise for improving core symptoms, along with measurable changes in brain activity. It’s an encouraging first step, and a reason to watch for larger studies.
At Junction Brain Health, we follow TMS research closely so our patients, families, and referring providers know where the field is heading. Have questions about TMS? Contact our team.
Source: Li Z, Lv J, Lu F, Yang Y, He Y, Zhu M. Effects of rTMS intervention on resting-state functional brain activity in children with autism spectrum disorders: a resting-state fMRI study. BMC Pediatrics. 2026;26(1).
Link to Study: https://pubmed.ncbi.nlm.nih.gov/42723030/