Ionic and Microstructural Alterations in the Corticospinal Tract in SPG4: Insights from Sodium Imaging

Motivation: Hereditary spastic paraplegia (HSP-SPG4) is characterized by corticospinal tract (CST) degeneration, but current MRI techniques lack sensitivity for early ionic disturbances. There is a need for non-invasive biomarkers to detect these changes and monitor disease progression. Goal(s): To evaluate sodium MRI as a non-invasive tool for detecting ionic disturbances in the CST of HSP-SPG4 patients. Approach: 15 patients and 15 controls underwent 3T-MRI with T1-weighted imaging, DTI, and sodium MRI. Sodium concentration and diffusion metrics were analyzed along the CST. Results: Increased sodium concentrations in the CST correlated with disease duration, suggesting sodium MRI as a potential biomarker for disease monitoring. Impact: This study demonstrates the potential of sodium MRI as a non-invasive biomarker for early detection of ionic disturbances in HSP-SPG4, enabling improved monitoring of disease progression. It opens avenues for exploring targeted therapies and differentiating HSP-SPG4 from other neurodegenerative disorders.