Cortical mapping of active and passive upper limb training in stroke patients and healthy people: A functional near-infrared spectroscopy study

Active exercise for upper limb training has been widely used to improve hemiplegic upper limb function, and its effect may be boosted by extrinsic visual feedback. The passive movement of the hemiplegic upper limb is also commonly used. We conducted a functional near-infrared spectroscopy experiment to compare cortical activation during the following three conditions: active left upper limb movement (on the hemiplegic sides in stroke patients), with or without extrinsic motor performance visual feedback (LAV, LAnV), and passive left upper limb movement (hemiplegic sides in stroke patients) (LP) in stroke patients and healthy controls. Twenty patients with right hemispheric stroke and 20 healthy controls were recruited for this study. Hemodynamic changes were detected during left upper limb movements (on the hemiplegic sides in stroke patients) under the above three conditions in the sensorimotor cortex (SMC), supplementary motor area (SMA), and premotor cortex (PMC). There was no significant difference in the level of cortical activation between patients with stroke and healthy subjects during the three conditions. Both the LAV and LAnV induced significantly higher activation in the contralateral SMA and PMC than in the LP. Extrinsic visual feedback led to additional activation in the contralateral PMC and SMA, but this was not statistically significant. Our study indicates that active upper-limb movement appears to induce higher cortical activation than that elicited by passive movement in both stroke patients and the healthy population. Extrinsic motor performance in the form of visual feedback provided during active movement may facilitate sensorimotor areas over the contralateral hemisphere.