Implications of perivascular spaces in amyotrophic lateral sclerosis: clinical significance and structural correlation.

Perivascular space (PVS) dysfunction may potentially contribute to the development and progression of amyotrophic lateral sclerosis (ALS). This study investigated the clinical relevance of PVS dysfunction in ALS. Two PVS parameters were quantified in patients with ALS: (i) the enlarged perivascular space (ePVS) score and (ii) the diffusion tensor image analysis along the perivascular space (DTI-ALPS) index. These parameters were analysed in relation to the clinical, structural and prognostic features of ALS. The study included 55 patients with ALS (33 men; mean age, 61.38 ± 10.95 years). The DTI-ALPS index was markedly reduced in the patients compared to age- and gender-matched controls, and there were no differences in ePVS scores between the two groups. The ePVS total score was positively correlated with the ALS progression, as measured by the monthly change in the revised ALS functional rating scale. The ePVS basal ganglia regional score was inversely correlated with muscle strength. Additionally, both the ePVS score and the DTI-ALPS index were associated with regional grey matter volumes of the superior frontal gyrus and middle frontal gyrus, and the DTI-ALPS index was associated with diffusion parameters of the corticostriatal and corticothalamic tracts. This study underscores the importance of PVS dysfunction in ALS according to the ePVS and a reduced DTI-ALPS index, which were respectively associated with disease progression, neurological deficits, including reduced muscle strength, and cortical and subcortical structural changes.