Superficial white matter microstructural impairments correlate with functional alterations and disease severity in early-stage ALS

Motivation: To systematically investigate the alterations of superficial white matter (SWM) in ALS. Goal(s): We aimed to assess SWM microstructural changes and their associations with neural dysfunction and disease severity in ALS. Approach: SWM microstructural impairments were evaluated through neurite orientation dispersion and density imaging. Functional disturbances within cortical regions corresponding to compromised SWM were measured by regional homogeneity (ReHo) . Disease severity was assessed using the revised ALS Functional Rating Scale (ALSFRS-R). Results: ALS patients exhibited alternations in NDI value and ReHo value in specific SWM regions. Furthermore, cortical ReHo alterations mediated the relationship between SWM NDI value and the ALSFRS-R score. Impact: Focusing on SWM evaluation offers a new perspective on the interaction between structural and functional disruptions in ALS, highlighting a crucial neurobiological substrate related to disease progression.