Early corticospinal tract sub-pathway lesion load and integrity predict post-stroke motor outcomes

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Corticospinal tract (CST) damage predicts post-stroke motor deficits.
• The role of CST sub-pathways from non-primary motor areas is not fully understood.

Purpose of the Study:

• To investigate if CST sub-pathway microstructural integrity and lesion load (LL) at 2 weeks predict motor outcomes at 2, 6, and 12 weeks post-stroke.

Main Methods:

• Diffusion spectrum imaging (DSI) quantified CST integrity.
• Structural MRI measured CST lesion load (LL).
• Stepwise multiple linear regression analyzed predictive values.

Main Results:

• CST integrity and LL were key determinants of motor deficit at 2 weeks.
• CST-LL from non-M1 areas (PMd, S1) were dominant predictors of motor outcomes at 6 and 12 weeks, explaining up to 79.5% of variance.

Conclusions:

• Dorsal premotor cortex (PMd) tract integrity and non-M1 CST lesion load are promising biomarkers for post-stroke motor impairment.
• Non-M1 tracts, especially PMd, are crucial for motor function and potential intervention targets.