fMRI changes in kids after a concussion; could TMS help?

Concussions in children are far more than just a bump on the head—they can trigger subtle yet significant changes in brain function that may linger long after the visible symptoms fade. A recent prospective, longitudinal study sheds new light on how pediatric concussion disrupts functional brain network connectivity over time.

In this large-scale study, researchers tracked 385 children with concussion and 198 with mild orthopedic injuries (used as a control group) across five pediatric hospitals in Canada. Each child underwent high-resolution fMRI scans shortly after injury and again at either three or six months. The focus was on resting-state functional connectivity (FC)—how different regions of the brain communicate when the brain is not engaged in a specific task.

While within-network connectivity remained largely intact, disruptions in between-network connectivity emerged over time in the concussion group. Key findings included:

– Reduced connectivity between the visual and ventral attention networks across all time points after concussion.

– Lower connectivity between the visual and default mode networks, specifically at six months post-injury.

– Age-dependent differences in connectivity between the frontoparietal and ventral attention networks at three months: younger children showed reduced connectivity, while older children showed increased connectivity.

– Sex- and symptom-related differences in attention network connectivity, with girls without persisting symptoms showing higher connectivity between dorsal and ventral attention networks than those with lingering symptoms.

These findings point to long-term changes in how different brain networks interact after pediatric concussion, even after most children appear clinically recovered. It suggests that functional connectivity may be a sensitive biomarker of lasting brain changes—possibly outlasting observable symptoms.

This study provides crucial evidence that brain network changes can persist for months after a concussion, particularly between regions responsible for attention, vision, and executive function. These disruptions are influenced by age, sex, and whether or not symptoms persist, highlighting the complexity of brain recovery in children.

The authors did not discuss potential therapies, but transcranial magnetic stimulation (TMS) is a potential treatment that could normalize the disrupted networks. It is a non-invasive neuromodulation technique that uses magnetic pulses to stimulate specific brain regions. Already FDA-approved for conditions like depression and anxiety in adults, TMS is gaining interest for its potential in treating brain network dysfunctions after a concussion and other neurological disorders. We use it primarily for refractory chronic migraines but also persistent post-concussion symptoms.