Corticospinal Tract Injury Leads to Poor Motor Recovery Immediately After Ischemic Stroke

Corticospinal tract (CST) integrity is an imaging biomarker for predicting upper extremity motor recovery, but data are limited in acute ischemic stroke patients. Our study aimed to assess the impact of CST disruption on upper extremity motor recovery after acute ischemic stroke.

We enrolled patients with upper extremity motor deficits within 7 days of stroke onset. Patients' clinical status was assessed for the upper extremity Fugl-Meyer assessment motor component (UE-FM) within 7 days of stroke and at 15, 30, and 90 days. MRI with tractography was performed within 7 days of stroke. Diffusion tensor images (DTI) were processed to produce maps of fractional anisotropy (FA), apparent diffusion, axial, radial, and mean diffusivity. FA maps were used to assess CST asymmetry index (CST-AI). Fisher's exact tests for categorical variables, two-sample t-tests for normally distributed numerical data, and Wilcoxon rank sums for non-normally distributed numeric data were used.

A total of 21 patients were enrolled in the study with a mean age of 66 (±14) years and median baseline upper extremity motor component score (UE-FM) of 42 (median) [range: 23, 53]. Baseline UE-FM was not predictive of a 10-point change at 90 days (p = 0.4469). CST-AI was predictive of recovery at 15 days (p = 0.0373), and axial diffusivity was predictive of recovery at 90 days (p = 0.0402). All other imaging variables did not predict recovery.

Our data suggest that upper extremity motor recovery after acute ischemic stroke is impacted by CST integrity. Further studies are needed to validate our findings.