Model-Based Analyses for the Causal Relationship Between Post-stroke Impairments and Functional Brain Connectivity Regarding the Effects of Kinesthetic Illusion Therapy Combined With Conventional Exercise

I don't know why they don't just call it action observation which is precisely what it is.  But nothing specific found since they are using the weasel words of 'might reflect' and 'may'. So the followup for your doctor and hospital is to get concrete stroke protocols on this created such that; you do this, you get these results.

I guess I've been missing earlier research on this:

What does your doctor know about this?

Acute Effect of Visually Induced Kinesthetic Illusion in Patients with Stroke: A Preliminary Report January 2016

Effect of kinesthetic illusion induced by visual stimulation on muscular output function after short-term immobilization April 2016

 

 The association of motor imagery and kinesthetic illusion prolongs the effect of transcranial direct current stimulation on corticospinal tract excitability April 2016 

Event-related desynchronization possibly discriminates the kinesthetic illusion induced by visual stimulation from movement observation. December 2019

A Case Series Clinical Trial of a Novel Approach Using Augmented Reality That Inspires Self-body Cognition in Patients With Stroke: Effects on Motor Function and Resting-State Brain Functional Connectivity. December 2019

 

Role of kinaesthetic motor imagery in mirror-induced visual illusion as intervention in post-stroke rehabilitation.August 2020

Kinesthetic illusion induced by visual stimulation influences sensorimotor event-related desynchronization in stroke patients with severe upper-limb paralysis: A pilot study 2020

Influence of Visual Stimulation-Induced Passive Reproduction of Motor Images in the Brain on Motor Paralysis After Stroke. June 2021

 

The latest here:

Model-Based Analyses for the Causal Relationship Between Post-stroke Impairments and Functional Brain Connectivity Regarding the Effects of Kinesthetic Illusion Therapy Combined With Conventional Exercise

 

Yu Miyawaki^1,2,3, Masaki Yoneta¹, Megumi Okawada¹, Michiyuki Kawakami¹, Meigen Liu¹ and Fuminari Kaneko^1*

• ¹Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
• ²Neurorehabilitation Research Center, Kio University, Nara, Japan
• ³Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan

Aims: Therapy with kinesthetic illusion of segmental body part induced by visual stimulation (KINVIS) may allow the treatment of severe upper limb motor deficits in post-stroke patients. Herein, we investigated: (1) whether the effects of KINVIS therapy with therapeutic exercise (TherEx) on motor functions were induced through improved spasticity, (2) the relationship between resting-state functional connectivity (rs-FC) and motor functions before therapy, and (3) the baseline characteristics of rs-FC in patients with the possibility of improving their motor functions.

Methods: Using data from a previous clinical trial, three path analyses in structural equation modeling were performed: (1) a mediation model in which the indirect effects of the KINVIS therapy with TherEx on motor functions through spasticity were drawn, (2) a multiple regression model with pre-test data in which spurious correlations between rs-FC and motor functions were controlled, and (3) a multiple regression model with motor function score improvements between pre- and post-test in which the pre-test rs-FC associated with motor function improvements was explored.

Results: The mediation model illustrated that although KINVIS therapy with TherEx did not directly improve motor function, it improved spasticity, which led to ameliorated motor functions. The multiple regression model with pre-test data suggested that rs-FC of bilateral parietal regions is associated with finger motor functions, and that rs-FC of unaffected parietal and premotor areas is involved in shoulder/elbow motor functions. Moreover, the multiple regression model with motor function score improvements suggested that the weaker the rs-FC of bilateral parietal regions or that of the supramarginal gyrus in an affected hemisphere and the cerebellar vermis, the greater the improvement in finger motor function.

Conclusion: The effects of KINVIS therapy with TherEx on upper limb motor function may be mediated by spasticity. The rs-FC, especially that of bilateral parietal regions, might reflect potentials to improve post-stroke impairments in using KINVIS therapy with TherEx.

Introduction

Spasticity is frequently represented as the main symptom of motor deficits accompanied by paralysis, especially in the chronic phase in patients after stroke. The disorganization of afferent signals from peripheries or compensational signals from the brain to the peripheries is thought to cause spasticity. Motor deficits of the upper limb can impair patients’ daily lives after stroke, and solving this problem is important in rehabilitation medicine. We have encountered an event in which spasticity masks potential motor functions as if the cause of spasticity exists in a different system from motor paralysis. In fact, some patients’ motor accuracies improve immediately after the target muscle’s spasm is suppressed by therapy for spasticity, such as reinforced stretching, for a muscle that can interfere with accurate movement.

Spasticity disturbs the skilled and gross motor performance of the upper limbs (Pundik et al., 2019). For these motor deficits, studies have proposed some effective therapies, such as constraint-induced movement therapy (Wolf et al., 2006), mental practice (Page et al., 2007), or robot therapy (Klamroth-Marganska et al., 2014), which can have moderate effects (Pollock et al., 2014). However, these therapies require patients to perform voluntary movements or motor imagery, and severe cases with strong difficulties in such performances are often excluded. Therefore, an effective therapy for severe cases is required, for which a novel therapy utilizing kinesthetic illusion of segmental body part induced by visual stimulation (KINVIS) was proposed (Kaneko et al., 2016a, 2019; Aoyama et al., 2020; Okawada et al., 2020).

KINVIS is defined as the psychological phenomenon in which a resting person feels as if his/her own body part is moving or feels the desire to move a body part while watching a movie of that body part moving (Kaneko et al., 2007). We previously demonstrated that primary motor cortex excitability is enhanced during/after KINVIS (Kaneko et al., 2007, 2016b; Aoyama et al., 2012), as shown in the motor imagery of hand or finger movements without performing a voluntary movement (Kaneko et al., 2003, 2014; Yahagi et al., 1996). Moreover, previous studies revealed that motor-related areas, such as the premotor, superior, or inferior parietal cortex, were activated when experiencing KINVIS more than observing a similar movement (Kaneko et al., 2015; Shibata and Kaneko, 2019). These psychological experiences and neurological effects may contribute to recovering post-stroke motor deficits. For example, mirror therapy (Altschuler et al., 1999) that can induce kinesthetic illusions such as KINVIS has a moderate effect on motor deficits (Dohle et al., 2009; Pollock et al., 2014). In terms of interhemispheric inhibition (Murase et al., 2004; Nowak et al., 2009), it is noteworthy that KINVIS requires no voluntary movements even in a non-paralyzed upper limb. Since the KINVIS paradigm enables a person to passively experience finger or hand movements as a kinesthetic illusion, it has the potential to work as a treatment for severe cases.

Based on these findings, the KINVIS therapy was proposed and a clinical trial was conducted for 10 days (Kaneko et al., 2019). In this trial, 11 patients with a severe paretic upper limb in the chronic phase underwent KINVIS therapy and conventional therapeutic exercise (TherEx). The KINVIS therapy comprised a combination of KINVIS and neuromuscular electrical stimulation (NMES). Participants observed prerecorded finger flexion and extension movements of a virtual upper limb displayed on a monitor parallel to and above their own actual limbs. When participants observed the movements, electrical stimulations on the finger extensor muscles were combined to provide proprioception matched with the visual movements. This therapy was undertaken for 20 min, after which TherEx was performed for 60 min. Before and after this 10-day intervention, upper limb motor functions, spasticity, and resting-state brain functional connectivity (rs-FC) were assessed (i.e., pre- and post-tests). This clinical trial produced two main findings.

First, a previous study (Kaneko et al., 2019) had demonstrated significant improvements in the Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and modified Ashworth Scale (MAS) scores after the interventions (see Supplementary Table 1). Interestingly, the improvement of the MAS score reached a minimum of clinically important differences (i.e., reduction of one or more; Barros Galvão et al., 2014). Given that this trial included only patients in the chronic phase, the natural recovery after stroke may not sufficiently explain these improvements. Although this clinical trial was undertaken only for 10 days, other therapies, such as mirror or robot therapy, require longer-term interventions (e.g., >6 weeks; Page et al., 2007; Dohle et al., 2009; Klamroth-Marganska et al., 2014). According to these facts, the effects of the KINVIS therapy with TherEx might have been observed by bringing out the masked potential functions of paretic upper limbs rather than directly recovering their motor deficits. Patients with severe motor deficits in the chronic phase often have severe spasticity, which can disturb the motor performance. In this trial, all patients had a MAS score of ≥2 (i.e., severe spasticity; Kaneko et al., 2019). Considering that significant improvements in the MAS scores were observed in this trial, the improvements in motor functions might have been induced through improvements in spasticity.

As the other finding, the previous clinical trial demonstrated significant correlations between rs-FC and FMA/ARAT scores (Kaneko et al., 2019). These motor function scores were correlated with the rs-FC between the inferior parietal sulcus in the affected (aIPS) and unaffected (uIPS) hemispheres, between the supramarginal gyrus in the affected hemisphere (aSMG) and the cerebellar vermis, and between the inferior parietal lobule in the unaffected hemisphere (uIPL) and dorsal premotor cortex in the unaffected hemisphere (uPMd). Although the causal relationships of these correlations remain unclear, these rs-FC can help capture characteristics in severe cases who participated in the previous trial (Kaneko et al., 2019). However, the previous study analyzed these correlations independently but did not consider spurious correlations. Because some regions composed of these rs-FC were similar to each other (i.e., parietal regions), the influences of their spurious correlations should be investigated. This investigation may contribute to exploring the characteristics of patients with the possibility of improved motor functions using KINVIS therapy with TherEx.

Taken together, although the KINVIS therapy may allow us to treat severe cases, further analyses of the data from the previous clinical trial (Kaneko et al., 2019) can help unravel the effects of its therapy. These analyses may lead to a hypothesis that should be examined in large-scale future clinical trials. Before proceeding to an ensuing trial, therefore, we sought to address the unresolved issues by performing path analyses in structural equation modeling with data from the previous clinical trial (Kaneko et al., 2019), i.e., reuse of data. First, we conducted a path analysis comprising the mediation model to investigate whether the improvements in upper limb motor functions after KINVIS therapy with TherEx were induced through improvements in spasticity. Second, we performed a path analysis comprising the multiple regression model to investigate the relationship among the three rs-FC (i.e., aIPS-uIPS, aSMG-Vermis, and uIPL-uPMd) and motor functions before intervention and without spurious correlations among them. Finally, we conducted a path analysis comprising the multiple regression model to investigate the baseline characteristics of rs-FC in patients with the possibility of improving their motor functions. This study is expected to help develop a novel treatment for patients with severe motor deficits.

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