317 Automated Diffusion Tensor Tractography: Quantitative Tract Counts Predict 90-Day Change in Motor Function by Baseline Deficit in Acute Ischemic Stroke Patients Undergoing Mechanical Thrombectomy

Abstract

INTRODUCTION: Ischemic stroke causes persistent motor deficits in roughly half of survivors. Although mechanical thrombectomy (MT) optimizes stroke outcomes, not all patients improve. Commercially available diffusion tensor tractography (DTT) software increases access to robust tractometric software. Automation and seamless clinical integration of diffusion tensor imaging (DTI) and tractography protocols standardizes data acquisition in high-throughput and high-resolution manners. METHODS: Between June 2020 and 2021, a total of 28 patients with M1 and M2 ischemic strokes underwent a standardized DTT protocol following MT. Patients were stratified by their baseline deficits, defined as the averaged upper and lower extremity motor testing scores at the time of initial presentation (MTS severe = 0, intermediate = 0.5–3.5, and mild = 4+). Multivariable linear regression analysis included demographics, clinical characteristics, and tractometrics of the lesioned CST with MTS at 90-days as the outcome. RESULTS: There were 12 patients with severe, 12 with intermediate, and 4 with mild baseline deficits. Stratification by baseline deficits revealed no significant difference between mean effected tract counts (5.20, 5.08, and 5.78 in the severe, intermediate, and mild groups, respectively, p = 0.377). When controlling for demographics and clinical characteristics, baseline deficits (β = -0.838, SE = 0.913, p < 0.001) and effected mean tract count (β = 1.755, SE = 0.407, p = 0.001) of the CST significantly predicted the change in MTS at 90-day follow-up (adjusted R2 = 0.727 p = 0.002). CONCLUSIONS: Our study suggests automated tractometrics predict the change in motor function at 90 days when controlling for the patient’s baseline motor deficit. Although larger cohort studies should be conducted, commercially available DTI software could yield novel avenues into rehabilitation optimization for post-stroke patients with persistent motor deficits.