White matter changes in reward circuits of amyotrophic lateral sclerosis: a fixel-based study of appetite loss

These findings highlight white matter fibre alterations in both motor and non-motor circuits in ALS. Although direct associations with appetite and metabolism were not observed, the results provide evidence of structural degeneration within reward- and behaviour-related pathways. Taken together, these findings reinforce that ALS is not confined to motor pathways but represents a multisystem neurodegenerative disease with both motor and extra-motor network involvement, offering important insights for future research into disease mechanisms and therapeutic targets.