Abstract 130: Decompression of Corticospinal Tract (CST): An Imaging Biomarker for Post-Stroke Recovery

Abstract

Objective: To investigate the anatomical and physiological impact of intracerebral hemorrhage (ICH) on the mechanical CST distortion measured using serial MRI and its relation to functional recovery. Introduction: ICH causes CST (motor pathway for arm movement) deformation/displacement leading to disruption of brain-arm neuronal communication. Limited knowledge exists about the degree and anatomical disruption of CST and long-term recovery of the arm impairment and how temporal resolution of the hematoma/edema volume impacts recovery. Here we applied serial quantitative MRI to establish an association between the CST displacement (CSTD) and arm recovery. Methods: We imaged 12 patients with subcortical bleed on day-2 and 90, who underwent routine care. Using DTI, the change in CSTD at the level of posterior limb of internal capsule (PLIC) was calculated by the distance shift between the patient's pre (determined a standard brain template, registered to DTI images) and post-ICH CST location. A centroid (the medians of a volume at 3 intersecting coordinates) at each PLICs was determined and the distance between the two centroids was recorded. ICH severity and arm impairment were measured on NIHSS and Fugl-Meyer assessment for Upper Extremity (FM-UE) scores. Results: We enrolled 9M/3F, with an average age of 512.1±8.3y who were serially imaged. The hematoma volume (18.6±28.1 to 4.5±4.9mL) and NIHSS (14.0±5 to 5.0±3) significantly (p<0.05) decreased whereas FM-UE (23.8±19 to 41.5±22) improved. The patient's average CSTD changed from 10.9±4.61 to 5.78±2.2mm over time. The change in CSTD exhibited a negative correlation (R2=0.37) with FM-UE scores. These results are shown in Fig1. Conclusion: In conclusion, we present novel quantitative surrogate imaging markers of CST distortion and its association with recovery after ICH.