Interlimb neural coupling: Implications for poststroke hemiparesis

Abstract

Interlimb coordination is essential to perform goal-directed daily tasks and purposeful locomotion. The coordination occurs due to spatiotemporal coupling of movements, which also comprises interactions in segmental kinematics, joint dynamics, and muscle activity. Neuroanatomical and neurophysiological linkages at the spinal and brain level are responsible for the coordination. The linkage is termed "neural coupling". According to the task demand, the coupling may occur between two upper limbs or two lower limbs or all four limbs. Central pattern generators play a key role in interlimb coordination by regulating the rhythmic upper and lower limb movements. Neuroanatomically, multiple areas of both cerebral hemispheres via the corpus callosum interact and control the bimanual upper limb movements. There is an interhemispheric synchronization and disinhibition to control the coupled bimanual upper and lower limb movements. Movement of the upper limb also enhances neuromuscular recruitment of the lower limb. In stroke, bimanual motor impairments exist in the form of asymmetry and reduced coordination, which may be related to weakness of the ipsilateral body side lesser than the contralateral side. The aim of the present review was to understand the interlimb coordination and neural coupling and its implication in stroke rehabilitation. The review suggests incorporating the movements of bilateral upper and lower limbs either simultaneously or consecutively for hemiparetic subjects. Further, the conventional and contemporary rehabilitation methods need to be reconsidered while utilizing the coupling concept.

The Difference of Neural Networks between Bimanual Antiphase and In-Phase Upper Limb Movements: A Preliminary Functional Magnetic Resonance Imaging Study

“…Both in-phase and antiphase movements require synchronization between the two sides of the upper limbs, but the antiphase movements additionally need contralateral movement suppression and the independence of the two movements [35]. There is an interhemispheric synchronization and disinhibition to control the coupled bimanual upper limb movement [4]. These studies [10, 56, 57] showed that the CMA suppresses the intrinsically favored coordination tendencies and facilitates less familiar bimanual movements; because of that, the CMA appears to play a more generic role related to cognitive control and response inhibition [34].…”

“…Most daily movements require certain degree of collaboration between the upper limbs [1–3]; interlimb coordination is important for performing goal-oriented daily movements [4]. Bimanual movements, which are more abundant than unimanual movements [3], are effective instruments to investigate motor dysfunctions in general and the underlining mechanisms of asymmetry and lateralization following neurodegenerative disorders and other neurological diseases [3, 5, 6].…”

“…One example of such bimanual movement is the simultaneous (in-phase) or alternative (antiphase) flexion and extension elbow movement used in our study. In-phase bimanual models are more precise and stable than antiphase models at any time [4, 8, 9], while the antiphase models are increasingly destabilized at high frequencies, even resulting in a transition to the more stable models [10]. On the other hand, control of such bimanual coordination tasks is often disrupted in patients suffering from brain pathologies.…”

Correlation between mobility assessed by the Modified Rivermead Mobility Index and physical function in stroke patients

“…Coordination is closely correlated with the degrees of motor recovery and rehabilitation27 ) . Adequate coordination of the lower limbs is essential for performing daily tasks and purposeful locomotion28 ) . Therefore, enhancing the coordination of the lower limb may improve post-stroke outcomes29 ) .…”

A Review of Robot-Assisted Lower-Limb Stroke Therapy: Unexplored Paths and Future Directions in Gait Rehabilitation

“…In the context of hemiparetic gait rehabilitation, the study of interlimb coordination mechanisms might be of great significance. In fact, it has been shown that neural coupling exists in poststroke patients as it does in healthy subjects (Arya and Pandian, 2014) and for the upper limbs as well (Yoon et al, 2010). In studies with poststroke subjects with hemiparesis, it was found that neural decoupling between the lower limbs perturbs the paretic lower limb function (Kautz and Patten, 2005).…”