Cerebro-cerebellar structure-function coupling's role in motor recovery after infarction

To investigate the pathway-specific structure-function coupling induced by focal subcortical infarction and its influence on clinical symptoms.

In this prospective study, 50 patients with unilateral subcortical infarction and motor impairment and 50 matched controls underwent resting state fMRI, DTI, and Fugl-Meyer-Assessment lower-extremity (FMA-LE) at 7-14- and 30-days post-infarction. To analyze the pathway-specific structure-function coupling, we evaluated the association between structural integrity of the corticospinal tract (CST), dentate thalamocortical tract (DTCT), cortico-pontocerebellar tract (CPCT), and dorsal spinocerebellar tract (DSCT) and functional connectivity (FC) of corresponding subregions. Moderation analysis assesses whether the structure-function coupling pathway moderates FMA-LE.

At baseline, patients exhibited significantly lower structural integrity of DTCT, DSCT, and CST than controls. We found structure-function couplings in the three motor pathways of the cerebro-cerebellar circuit: (1) contralesional thalamus to ipsilesional cerebellum-crus_2 with dentate thalamocortical tract (DTCT), (2) contralesional thalamus to cerebellum vermis_10 with dorsal spinocerebellar tract (DSCT), (3) ipsilesional precentral gyrus to frontal medial gyrus with CST. The baseline DSCT structural integrity specificity modulates the relationship between FC and FMA-LE over 30 days.

We observed that cerebro-cerebellar circuit structure-function coupling after infarction, based on its anatomy and mapped to motor function (with DSCT as the key pathway mediating/moderating prognosis), serves as a potent biomarker for lower limb prognosis and a basis for precise rehabilitation.