Progressive choroid plexus enlargement across disease stages in patients with sporadic amyotrophic lateral sclerosis

BACKGROUND: The choroid plexus (CP), a key structure involved in cerebrospinal fluid homeostasis and glymphatic function, is increasingly recognized as an interface for neuroimmune communication. Recent studies have identified CP abnormalities as potential neuroimaging markers in several neurodegenerative disorders, including sporadic amyotrophic lateral sclerosis (sALS). However, whether CP enlargement occurs early and progresses across clinical stages or over time in patients with sALS remains unclear. Given the role of the CP in peripheral-central nervous system immune crosstalk, the association between neuroinflammation and CP abnormalities in sALS also requires clarification. In this prospective study, we used structural MRI to examine cross-sectional and longitudinal CP volume changes in patients with sALS and to evaluate their associations with CSF inflammatory markers. METHODS: This prospective study included 161 newly diagnosed patients with sALS who underwent genetic testing and structural MRI, and 64 healthy controls (HCs) who underwent structural MRI. Disease stage in patients with sALS was assessed using the King's staging system. Longitudinal MRI was performed in a subset of 42 patients, of whom 38 also underwent baseline CSF inflammatory protein assessment. RESULTS: Compared with HCs, patients with sALS at all King's stages showed significantly larger CP volumes after Bonferroni correction (all p < 0.05). CP volumes were significantly greater in patients at King's stage 3 than in those at King's stage 1 or stage 2 after Bonferroni correction (all p < 0.05). In the longitudinal subgroup, CP volume increased significantly from baseline to follow-up. Multivariable analysis showed that higher CSF CHIT1 and IL-6 levels were independently associated with larger CP volume in patients with sALS (β = 0.348-0.456; p < 0.01). CONCLUSIONS: Our findings provide evidence that CP enlargement occurs early and progresses across disease stages and over time in patients with sALS. Higher CSF CHIT1 and IL-6 levels were associated with larger CP volume, supporting a potential link between neuroinflammation and CP abnormalities in sALS. These findings support CP enlargement as a promising neuroimaging marker for monitoring disease progression and neuroinflammatory processes in patients with sALS.