Abstract WP199: Change of Corticospinal Tract Integrity and 6-month Motor Outcome After Stroke: DTI Study

Abstract

Objective: Corticospinal tract (CST) changes with time after stroke. However, few studies have investigated longitudinal change of CST and its relationship with motor outcomes. Primary goal of this study is to investigate the changes of CST after stroke using diffusion tensor image (DTI) and the relationship between CST changes and functional motor outcome in upper and lower extremities at 6 months after onset of stroke. Methods: We collected data from STroke Outcome Prediction (STOP) database that is prospective data collecting system for functional recovery prediction after stroke based on neuroimaging study. Fifty-five patients with first-ever stroke who performed functional assessment and underwent DTI at 30 days and 6 months poststroke were included. Clinical evaluation included Fugl-Meyer Assessment (FMA), Manual Function Test (MFT), Berg Balance Scale (BBS), and Functional Ambulation Category (FAC). DTI parameters were fiber number (FN), average fiber length (AL), fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), radial diffusivity (RD), laterality index (LI) and delta (Δ) changes of these values. Also type of CST by diffusion tensor tractography was included for analysis. Results: FA decreased and diffusivity indices (AD, MD, RD) increased in ipsilesional hemisphere; Decrease of FA and increase of RD were also noted in contralesional side. Type of CST were changed in 19 patients (34.6%). Spearman correlation analysis showed strong correlations between DTI values (FN, AL, FA, RD) and motor outcomes (FMA, MFT, BBS, FAC) at 30 days and 6 months. However, ΔFA or ΔRD did not show significant correlation with Δ changes of motor outcomes. In the CART analysis, overall prediction accuracy of DTI parameters for 6-month motor outcome ranged from 81.8 to 90.9 %. Conclusion: The integrity of CST changed not only on the lesion side but also on contralesional side. Integrity of CST using DTI at early phase of rehabilitation is useful to predict 6-month motor outcome after stroke. Acknowledgement: No potential conflict of interests relevant to this article were reported. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2019R1A2C2003020).