The relationship between corticospinal tract and the affected lower limb function and walking ability in subacute...

[Purpose] The relationship between corticospinal tract (CST) integrity and upper limb motor function after stroke is well studied, but its association with lower limb motor function remains unclear. In addition, the analysis by type of stroke are remains insufficient. This study examined the relationship between CST integrity, lower limb motor function, and walking ability in subacute stroke patients, considering type of stroke. [Participants and Methods] In this study, 27 patients with cerebral infarction and 13 patients with intracerebral hemorrhage were included. Diffusion tensor imaging (DTI) assessed CST integrity using the fractional anisotropy ratio (rFA) at the cerebral peduncle. Motor function was evaluated with the Fugl-Meyer Assessment of Lower Extremity (FMA-LE), the affected-side muscle strength with a handheld dynamometer, and walking ability with Functional Ambulation Categories (FAC). Group differences between types of stroke and correlations between rFA and motor function were analyzed. [Results] Patients with intracerebral hemorrhage had significantly lower rFA. rFA correlated with FMA-LE and lower limb muscle strength, except for hip extensors. Walking ability was also associated with rFA and FAC. [Conclusion] CST integrity as assessed by DTI was associated with motor function of the affected-side lower limb and walking ability in subacute stroke patients and warrant further study.