Age Impacts Long-Term Connectivity Changes Caused by a Traumatic Brain Injury

While alterations in resting-state functional connectivity (rsFC) often occur in the acute and chronic phases after an individual suffers from a traumatic brain injury (TBI), there is little data assessing the long-term changes in rsFC.

A team, led by Nicola L. de Souza, School of Graduate Studies, Biomedical Sciences, Rutgers Biomedical and Health Sciences, examined how rsFC might change for individuals who suffered a brain injury over a longer duration of time.

The researchers obtained resting-state functional magnetic resonance imaging scans from the Federal Interagency Traumatic Brain Injury Research Informatics Systems.The research team examined 39 patients who primarily suffered from a mild traumatic brain injury. Each participant completed a rsfMRI scan during the sub-acute phase of around 10 days post injury, as well as during the long-term period of approximately 18 months post injury.

The investigators looked at changes in voxel-based rsFC from anterior medical prefrontal cortex (aMPFC) and posterior cingulate cortex (PCC) seeds in the default mode network (DMN) between the 2 phases.

They also examined the effect of age at the time of injury on the long-term rsFC.

The study authors discovered that increased rsFC from the aMPFC and the PCC to frontal and temporal regions was identifiable at approximately 18 months post brain injury. Widespread increases in rsFC from the aMPFC and between the PCC and frontal regions were shown for younger patients at the time of injury.

However, there were limited increases of rsFC noted at the 18-month mark for the older participants in the study.

“Long-term increases in rsFC were found following TBI, but age at the time of injury was associated with distinct rsFC profiles suggesting that younger patients show greater increases in rsFC over time,” the authors wrote.

Recently, researchers found a majority of younger individuals are symptom-free and fully recovered 1 year post-concussion.

Still, those with repeat concussion had worse outcomes and delays in returning to normal school routines and sports.

The findings suggested the need for education strategies to potentially reduce parental anxiety following a pediatric concussion. Such strategies should be implemented into standardized care at the time of initial assessment to normalize outcome expectations. Further, clinicians, parents, and youth should consider the overall risks and benefits of resuming at-risk activities before medical clearance is granted.

A majority of youth experiences a significant reduction in all symptoms one-year post-concussion (P <.001). Headache was the most common residual symptom at one-year (26% in the repeat concussion subgroup vs 13% in those without; difference, 14% [95% CI, 1-34]; P=.024). Following headache, the most common symptoms were fatigue, difficulty remembering, irritability, and feeling more emotional.

The study, “Effect of age at time of injury on long-term changes in intrinsic functional connectivity in traumatic brain injury,” was published online in Brain Injury.