Pain-related white-matter changes following mild traumatic brain injury: A longitudinal diffusion tensor imaging pilot study

Post-traumatic headache (PTH) is a common consequence of mild traumatic brain injury (mTBI), significantly impacting an individual's quality of life and rehabilitation. However, the underlying neuropathogenesis of PTH remains poorly understood. This study utilized diffusion tensor imaging (DTI) to detect microstructural brain alterations in mTBI participants with or at risk of developing PTH. The current study investigated associations between early DTI metrics (1-month postinjury), pain sensitivity (quantitative sensory tests), and psychological assessments (1-month and 6-months postinjury) to identify differences between mTBI (n=12) and healthy controls (HC; n=10). Abnormalities in mean axial diffusivity in the forceps major were observed in mTBI relative to HCs at 1-month postinjury (p=0.02). Within the mTBI group, DTI metrics at 1-month postinjury were significantly associated (p<0.05) with pain-related measures and psychological outcomes at 6-months postinjury. Notably, the associations between early DTI metrics and later pain-related measures exhibited significant group differences in right sagittal stratum (p<0.01), white matter tract in left insula (p<0.04), and left superior longitudinal fasciculus (p<0.05). In conclusion, these findings indicate that DTI metrics can be used to predict pain and psychological measures in mTBI, suggesting an important role of white matter microstructure in PTH following mTBI.