ENIGMA pediatric msTBI: Preliminary results from meta-analysis of diffusion MRI

Traumatic brain injury (TBI) is a major public health issue around the world. Pediatric TBI patients are at risk of long-term disabilities, as a brain injury sustained during development can affect on-going maturational processes. The white matter (WM) in particular is vulnerable, as myelination continues into the third decade of life and beyond, and poor myelination of tracts can result in decreased integration within brain networks. In addition, variability and heterogeneity are hallmarks of TBI, e.g., injury-related variables and symptoms. These issues combined with small sample sizes limit the power and generalizability of individual studies. In the present study, we employed a meta-analytic approach, combining data across 4 pediatric TBI samples resulting in 104 TBI (75M/29F) and 114 control participants (70M/44F) between 7-18 years, using harmonized processing and analysis as part of the ENIGMA consortium (Enhancing NeuroImaging Genetics through Meta-Analysis). We report lower fractional anisotropy (FA) values in TBI patients across several post-injury windows, particularly in central WM tracts. Within the TBI patient group, we also report marginally significant results of lower FA in younger TBI patients, patients scanned closer to time of injury, and female patients. Although this meta-analytic approach yielded the largest sample size reported yet in pediatric moderate/severe TBI (msTBI) neuroimaging, our trends indicate that larger sample sizes are needed in further studies. As additional cohorts join the ENIGMA Pediatric moderate/severe TBI (msTBI) effort, more robust effects will be revealed.