Posts Tagged chronic
[Abstract + References] Electromyographic indices of muscle fatigue of a severely paralyzed chronic stroke patient undergoing upper limb motor rehabilitation
[ARTICLE] Whole-Body Vibration in Horizontal Direction for Stroke Rehabilitation: A Randomized Controlled Trial – Full Text
As most of the existing whole-body vibration (WBV) training programs provide vertical or rotatory vibration, studies on the effects of horizontal vibration have rarely been reported. The present study was conducted to investigate the effect of WBV in the horizontal direction on balance and gait ability in chronic stroke survivors.
This study was designed as a randomized controlled trial. Twenty-one stroke survivors were randomly allocated into 2 groups (whole-body vibration group [n=9] and control group [n=12]). In the WBV group, WBV training in the horizontal direction was conducted for 6 weeks, and a conventional rehabilitation for 30 min, 3 days per week for a 6-week period, was conducted in both the WBV and control groups. Outcome variables included the static balance and gait ability measured before training and after 6 weeks.
On comparing the outcome variables before and after training in the WBV group, significant differences were observed in the cadence and single support time of gait ability. However, there were no significant differences in other variables, including velocity, step length, stride length, and double support time. In addition, after training, no significant differences in all variables were observed between the 2 groups.
The results of this study suggest that WBV training in the horizontal direction has few positive effects on balance and gait function in chronic stroke survivors. However, further investigation is needed to confirm this.
Stroke survivors suffer from central nervous system damage, with sensory and motor system damage, which leads to consequences such as decreased control of muscle tone, delay in muscle contraction, and absence of selective movement [1,2]. In addition, stroke survivors have unstable balance and poor gait ability, which naturally limits their activities of daily living and participation in the community, while losing independence [2,3]. Consequently, the first priority for stroke survivors is recovery of independent activities, and for this, the recovery of balance in a standing posture and gait abilities is essential.
For functional recovery of stroke survivors, various methods have been suggested , and whole-body vibration (WBV) is a relatively novel form of exercise intervention that could improve functional recovery . WBV involves the use of a vibrating platform in a static position or while performing dynamic movements. In previous studies, it was suggested that WBV training could improve physical functions. Castrogiovanni et al.  reported that a multi-component training, including aerobic activity and other types of training (resistance and/or strength exercises), is the best kind of exercise for improving bone mass and bone metabolism in elderly people and especially in osteopenic and osteoporotic women. With regard to whole-body vibration training, studies have suggested that it could be a valid method. Pichler et al.  reported that mechanical stimulation such as treadmill and vibration stimulation training inhibits the activity of RANKL in osteoporosis. In addition, Musumeci et al.  suggested that, in certain diseases such as osteoporosis, mechanical stimulation including treadmill and vibration platform training could be a possible therapeutic treatment. Based on their results, they proposed the hypothesis that physical activity could also be used as a therapeutic treatment for cartilage diseases such as osteoarthritis. Van Nes et al.  introduced WBV as a means of somatic sensory stimulation for functional recovery of stroke survivors. They also reported that somatosensory stimulation through WBV can significantly improve muscle performance, balance, and daily activities. Balance, defined as the ability to maintain the center of pressure (COP) on the support surface in given circumstances, can be held through adjusted harmony of visual, vestibular, and somatic sensory system , and vibration stimulation is reported to cause small changes in the skeletal muscle length of the human body and affect the motor neurons to facilitate activation of the spinal reflexes through short spindle-motor neuron connections .
Balance is a major component required for controlling or maintaining the COP in mobility and locomotion in which the support surface changes . The information on changes of the support surface along with the biomechanic information needed for movement control is passed on to the central nervous system by muscle spindles, Golgi tendon organs, and joint receptors in the proprioception sense; thus, they have a very important role in controlling balance [13,14]. In addition, Muller and Redfern  performed a comparative analysis of the latency of beginning muscle activity by measuring electromyogram (EMG) activation degree of muscle strength of the lower extremities caused by movement of the COP while the support surface moved back and forth. Consequently, the latency of activation of the tibialis anterior muscle was rapid on the support surface moving forward and that of the soleus muscle was rapid when moving backward. Given these reports, for recovery of balance ability, the horizontal vibration in all directions might be needed more than the vertical or rotatory vibration provided by the original WBV training. Additionally, our bodies maintain standing posture using ankle strategy, hip strategy, or both . The ankle strategy, which is the postural control strategy that starts first in postural sway, enables immediate recovery of standing balance through ankle joint muscle contraction . Horizontal vibration, therefore, may significantly activate not only stimulation of somatosensory, but also ankle strategy or hip strategy.
However, since most of the existing WBV training programs provide only vertical or rotatory vibrations, studies on effects of horizontal vibrations have been rarely reported. Accordingly, the present study examined the effects of horizontal WBV in an antero-posterior or medio-lateral direction on balance and gait abilities of stroke survivors.[…]
[Abstract] Improvement of Upper Limb Motor Control and Function After Competitive and Noncompetitive Volleyball Exercises in Chronic Stroke Survivors: A Randomized Clinical Trial.
To investigate the effects of competitive and noncompetitive volleyball exercises on the functional performance and motor control of the upper limbs in chronic stroke survivors.
Randomized clinical trial.
Outpatient rehabilitation center.
Chronic stroke survivors (N=48).
Participants were randomly assigned to competitive (n=16) or noncompetitive (n=16) volleyball exercise groups (60min/d volleyball exercise+30min/d traditional rehabilitation, 3d/wk for 7wk) and control group (n=16).
MAIN OUTCOME MEASURES:
Reach and grasp motor control measures were evaluated through kinematic analysis. Functional outcomes were assessed via Motor Activity Log, Wolf Motor Function Test (WMFT), Box and Block Test, and Wrist Position Sense Test.
Significant improvement of functional performance was observed in both competitive (P<.0001) and noncompetitive volleyball exercise groups (P<.01), but not in the control group (P>.05), with the exception of WMFT score. Volleyball training, in general, resulted in more efficient spatiotemporal control of reach and grasp functions, as well as less dependence on feedback control as compared to the control group. Moreover, the competitive volleyball exercise group exhibited greater improvement in both functional performance and motor control levels.
Volleyball team exercises, especially in a competitive format, resulted in enhancing the efficacy of the preprogramming and execution of reach and grasp movements, as well as a shift from feedback to feedforward control of the affected upper limb in chronic stroke survivors. This may well be a potential underlying mechanism for improving functional performance.
A new video game-led training device called a myoelectric computer interface (MyoCI), invented by Northwestern Medicine scientists, is enabling severely impaired stroke survivors to regain function in their arms after sometimes decades of immobility.
When integrated with a customized video game, the device helped retrain stroke survivors’ arm muscles into moving more normally. Most of the 32 study participants experienced increased arm mobility and reduced arm stiffness while using it, and retained their arm function a month after finishing the training, according to a study published recently in Neurorehabilitation and Neural Repair.
Many stroke survivors can’t extend their arm forward with a straight elbow because the muscles act against one another in abnormal ways, called “abnormal co-activation” or “abnormal coupling.”
The Northwestern device identifies which muscles are abnormally coupled and retrains the muscles into moving normally by using their electrical muscle activity (called electromyogram, or EMG) to control a cursor in a customized video game. The more the muscles decouple, the higher the person’s score, a media release from Northwestern University explains.
“We gamified the therapy into an ’80s-style video game,” says senior author Dr Marc Slutzky, associate professor of neurology and of physiology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine neurologist. “It’s rather basic graphics by today’s standards, but it’s entertaining enough.”
“The beauty of this is even if the benefit doesn’t persist for months or years, patients with a wearable device could do a ‘tune-up’ session every couple weeks, months or whenever they need it,” adds Slutzky, whose team designed the original device. “Long-term, I envision having flexible, fully wireless electrodes that an occupational therapist could quickly apply in their office, and patients could go home and train by themselves.”
Slutzky also is studying this method on stroke patients in the hospital, starting within a week of their stroke.
Abnormal coupling of muscles leaves many stroke patients with a bent elbow, which makes it difficult to benefit from typical task-based stroke-rehabilitation therapies, such as training on bathing, getting dressed and eating.
Only about 30% of stroke patients in the United States receive therapy after their initial in-patient rehabilitation stay, often because their injury is too severe to benefit from standard therapy, it costs too much, or they’re too far from a therapist. This small, preliminary study lays the groundwork for inexpensive, wearable, at-home therapy options for severely impaired stroke survivors, the release continues.
“We’re still in the very early stages, but I’m hopeful this may be an effective new type of stroke therapy,” Slutzky states. “The goal is to one day let patients buy the training device inexpensively, potentially without even needing insurance and use it wirelessly in their home.”
Patients in the study were severely impaired – could only slightly move their arm and extend their elbow – and had had their stroke at least 6 months prior to beginning the study. The average patient was more than 6 years out from their stroke, and some were decades out.
After Slutzky’s intervention, study participants could, on average, extend their elbow angle by 11 degrees more than before the intervention, which was a pleasant surprise, Slutzky comments.
This type of treatment only requires a small amount of muscle activation, which is advantageous for severely impaired stroke patients who typically can’t move enough to even begin standard physical therapy. It also gives feedback to the patient if they’re activating their muscles properly.
To identify which muscles were abnormally coupled, study participants attempted to reach out to multiple different targets while the scientists recorded the electrical activity in eight of their arm muscles using electrodes attached to the skin. For example, the biceps and anterior deltoid muscles in the arm often activated together in stroke participants, while they normally shouldn’t.
Then, to retrain the muscles into moving normally (ie, without abnormally co-activating), the participants used their electrical muscle activity to control a cursor in a customized video game. The two abnormally coupled muscles moved the cursor in either horizontal or vertical directions, in proportion to their EMG amplitude, the release continues.
For example, if the biceps would contract in isolation, the cursor would move up. If the anterior muscles would contract in isolation, the cursor would move to the side. But if the muscles would contract together, the cursor would move diagonally.
The goal was to move the cursor only vertically or horizontally – not diagonally – to acquire targets in the game. To get a high score, participants had to learn to decouple the abnormally coupled muscles.
Muscles tend to produce more electrical muscle activity when contracting isometrically (without moving) compared to when moving the arm freely, but the ultimate goal of this training is to enable home use. One goal of this study was to see if participants could benefit without restraining the arm as much as with restraining the arm.
Participants were broken into three groups: 60 minutes of training with their arm restrained; 90 minutes of training with their arm restrained; and 90 minutes of training without arm restraints. Overall, arm function improved substantially, in all groups and there was no significant difference between the three groups, the release concludes.
[Source(s): Northwestern University, News-Medical Life Sciences]
[ARTICLE] Boosting robot-assisted rehabilitation of stroke hemiparesis by individualized selection of upper limb movements – a pilot study – Full Text
Intensive robot-assisted training of the upper limb after stroke can reduce motor impairment, even at the chronic stage. However, the effectiveness of practice for recovery depends on the selection of the practised movements. We hypothesized that rehabilitation can be optimized by selecting the movements to be practiced based on the trainee’s performance profile.
We present a novel principle (‘steepest gradients’) for performance-based selection of movements. The principle is based on mapping motor performance across a workspace and then selecting movements located at regions of the steepest transition between better and worse performance.
To assess the benefit of this principle we compared the effect of 15 sessions of robot-assisted reaching training on upper-limb motor impairment, between two groups of people who have moderate-to-severe chronic upper-limb hemiparesis due to stroke. The test group (N = 7) received steepest gradients-based training, iteratively selected according to the steepest gradients principle with weekly remapping, whereas the control group (N = 9) received a standard “centre-out” reaching training. Training intensity was identical.
Both groups showed improvement in Fugl-Meyer upper-extremity scores (the primary outcome measure). Moreover, the test group showed significantly greater improvement (twofold) compared to control. The score remained elevated, on average, for at least 4 weeks although the additional benefit of the steepest-gradients -based training diminished relative to control.
This study provides a proof of concept for the superior benefit of performance-based selection of practiced movements in reducing upper-limb motor impairment due to stroke. This added benefit was most evident in the short term, suggesting that performance-based steepest-gradients training may be effective in increasing the rate of initial phase of practice-based recovery; we discuss how long-term retention may also be improved.
Upper-limb (UL) motor impairment is a common outcome of stroke that can severely hamper basic daily living activities [1, 2, 3]. Training-based therapy can promote recovery with the outcome depending on the intensity and duration of the intervention [4, 5, 6]. Robot-assisted training allows intense practice without increasing the individual’s dependence on a therapist and can improve clinical scores of UL motor capacity [7, 8, 9]. However, the effects are usually small and provide limited improvement in motor function, especially in more severe hemiparesis [6, 7, 10, 11, 12]. Identifying training methods that can boost outcome is thus vital. Considering the extent of effort and sophistication invested in robot-assisted technology (e.g. [13, 14]) perhaps it is time to focus on how to optimise its utility (in terms of training principles). Recent attempts have focussed on creating training scenarios which are more engaging or which simulate daily living activities. However, the evidence for the added benefit of this approach is mixed . Another approach is to individualize the difficulty of the practised task (e.g. [16, 17]). This is based on the idea that motor improvement depends on the ability to ‘make sense’ of information related to performance , and postulates that matching the challenge (difficulty) level of the training task to the current ability of the trainee would optimise motor learning . Individualizing task difficulty is commonly achieved by adjusting the parameters controlling task demands (e.g. movement speed or distance; or amount of assistance) across a pre-selected standard set of movements, to match the ability of the individual. Yet, so far there is little evidence for the added benefit of this approach for UL motor recovery. Hence, individually adjusting the task difficulty level might –by itself – not suffice for boosting UL rehabilitation outcome.
To apply our method we first developed a novel principle of mapping of robot-assisted reaching performance across two dimensions of target location and movement direction , informing us about postural and movement-related aspects of motor control, respectively—key factors in the planning and execution of reaching movements [23, 24, 25]. The performance maps then served to select movement sets for training, based on our “steepest gradients” principle. To test our hypothesis–namely, training based on that principle would lead to superior recovery–we compared the outcome of 15 sessions of robot-assisted training between two groups of people who have severe-to-moderate chronic UL hemiparesis due to stroke, differing only in the selection of trained movement. In one group the selection was based on the steepest performance gradients principle (updated weekly) whereas the other group was trained with a fixed set of centre-out reaching movements regardless of participant’s performance profile, as commonly used in robot-assisted UL therapy .[…]
Continue —-> Boosting robot-assisted rehabilitation of stroke hemiparesis by individualized selection of upper limb movements – a pilot study | Journal of NeuroEngineering and Rehabilitation | Full Text
[Abstract] Robot-Assisted Reach Training With an Active Assistant Protocol for Long-Term Upper Extremity Impairment Poststroke: A Randomized Controlled Trial.
To assess whether robot-assisted reach training (RART) with an active assistant protocol can improve upper extremity function and kinematic performance in chronic stroke survivors.
This study was conducted as a randomized controlled trial.
National rehabilitation center.
Chronic stroke survivors (N=38) were randomized into 2 groups: a robot-assisted reach training with assist-as-needed (RT-AAN) group and a robot-assisted reach training with guidance force (RT-G) group.
The RT-AAN group received robot-assisted reach training with an assist-as-needed mode for 40 minutes per day, 3 times per week over a 6-week period, and the RT-G group participated in the RART with a guidance mode for 40 minutes per day, 3 times per week over a 6-week period.
MAIN OUTCOME MEASURES:
Upper extremity functions were measured with Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Box and Block Test. In addition, movement velocities were measured as an index for upper extremity kinematic performances in 6 directions.
Both groups showed significant improvements in FMA, ARAT, and kinematics (movement velocity) in all directions (targets 1-6, P<.05). However, the RT-AAN group showed significantly more improvement than the RT-G group in FMA and ARAT (P<.05).
RART with an active assistant protocol showed improvements of upper extremity function and kinematic performance in chronic stroke survivors. In particular, assist-as-needed robot control was effective for upper extremity rehabilitation. Therefore robot-assisted training may be suggested as an effective intervention to improve upper extremity function in chronic stroke survivors.
Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
[Abstract] Effect of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors: a randomized controlled trial
BACKGROUND: When solely mirror therapy is applied for a long period of time, spatial perception and attention to the damaged side may decrease, and the effect of mirror therapy may be limited. To overcome this limitation, it has recently been suggested that the combination of mirror therapy with mirror treatment is effective.
AIM: The aim of this study was to investigate the effects of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors.
DESIGN: A randomized controlled trial.
SETTING: Rehabilitation center.
POPULATION: Thirty stroke survivors were randomly assigned to two groups: the experimental group (n = 15) and the control group (n = 15).
METHODS: Participants of the experimental group received afferent electrical stimulation with mirror therapy, and participants of the control group received sham afferent electrical stimulation with sham mirror therapy for 60 minutes per day, 5 days per week, for 4 weeks. Motor function was measured using a handheld dynamometer and the Modified Ashworth Scale, balance was measured using the Berg Balance Scale, and gait was assessed using the GAITRite at baseline and after 4 weeks.
RESULTS: The experimental group showed significant differences in muscle strength, Modified Ashworth Scale, and Berg Balance Scale results, and velocity, cadence, step length, stride length, and double support time of their gait (p <0.05) in the pre-post intervention comparison. Significant differences between the two groups in muscle strength, Berg Balance Scale, gait velocity, step length, and stride length (p <0.05) were found.
CONCLUSIONS: Mirror therapy with afferent electrical stimulation may effectively improve muscle strength and gait and balance abilities in hemiplegic stroke survivors.
CLINICAL REHABILITATION IMPACT: Afferent electrical stimulation combined with mirror therapy can be used as an effective intervention to improve lower limb motor function, balance, and gait in chronic stroke survivors in clinical settings.
via Effect of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors: a randomized controlled trial – European Journal of Physical and Rehabilitation Medicine 2019 Mar 22 – Minerva Medica – Journals
[ARTICLE] Guided Self-rehabilitation Contract vs conventional therapy in chronic stroke-induced hemiparesis: NEURORESTORE, a multicenter randomized controlled trial – Full Text
After discharge from hospital following a stroke, prescriptions of community-based rehabilitation are often downgraded to “maintenance” rehabilitation or discontinued. This classic therapeutic behavior stems from persistent confusion between lesion-induced plasticity, which lasts for the first 6 months essentially, and behavior-induced plasticity, of indefinite duration, through which intense rehabilitation might remain effective. This prospective, randomized, multicenter, single-blind study in subjects with chronic stroke-induced hemiparesis evaluates changes in active function with a Guided Self-rehabilitation Contract vs conventional therapy alone, pursued for a year.
One hundred and twenty four adult subjects with chronic hemiparesis (> 1 year since first stroke) will be included in six tertiary rehabilitation centers. For each patient, two treatments will be compared over a 1-year period, preceded and followed by an observational 6-month phase of conventional rehabilitation. In the experimental group, the therapist will implement the diary-based and antagonist-targeting Guided Self-rehabilitation Contract method using two monthly home visits. The method involves: i) prescribing a daily antagonist-targeting self-rehabilitation program, ii) teaching the techniques involved in the program, iii) motivating and guiding the patient over time, by requesting a diary of the work achieved to be brought back by the patient at each visit. In the control group, participants will benefit from conventional therapy only, as per their physician’s prescription.
The two co-primary outcome measures are the maximal ambulation speed barefoot over 10 m for the lower limb, and the Modified Frenchay Scale for the upper limb. Secondary outcome measures include total cost of care from the medical insurance point of view, physiological cost index in the 2-min walking test, quality of life (SF 36) and measures of the psychological impact of the two treatment modalities. Participants will be evaluated every 6 months (D1/M6/M12/M18/M24) by a blinded investigator, the experimental period being between M6 and M18. Each patient will be allowed to receive any medications deemed necessary to their attending physician, including botulinum toxin injections.
This study will increase the level of knowledge on the effects of Guided Self-rehabilitation Contracts in patients with chronic stroke-induced hemiparesis.
The most common motor deficit following stroke is spastic hemiparesis . More than 90% of patients with hemiparesis recover some lower limb function after a stroke, but rarely with a level of ease or speed that would allow for independent and comfortable ambulation in everyday life, outdoors in particular [1, 2, 3]. In the upper limb, the proportion of patients that recover daily use of the arm is estimated between 10 and 30% [4, 5, 6, 7, 8]. Consequently, around half of stroke survivors do not resume professional activities, and two thirds remain chronically disabled .
In parallel, most patients in chronic stages have their rehabilitation discontinued or converted into “maintenance” therapy, as professionals often estimate that they might no longer progress [7, 10, 11, 12, 13, 14, 15]. Others benefit from reinduction periods, prescribed according to subjective or ill-defined criteria. It has not been demonstrated that this conventional rehabilitation system now fits current knowledge on behavior-induced brain plasticity and on the potential for motor recovery in chronic spastic paresis [16, 17, 18]. Indeed, a significant body of evidence demonstrates that high intensity of rehabilitation (the opposite of “maintenance therapy”) correlates with motor function improvement in chronic stages [16, 19, 20]. One way to achieve sufficient amounts of physical treatment might be to adequately guide and motivate the patient into practicing self-rehabilitation [18, 20]. It has been confirmed that programs of exercises given by the therapist to be performed at home are appreciated by patients not only for the structure they give to everyday life, but also as they represent in themselves a source of motivation and hope, particularly when these programs are associated with ongoing professional support [21, 22].
We hypothesize that there is confusion between the lesion-induced plasticity of the central nervous system – essentially during the first 6 months post-lesion – and the behavior-induced plasticity, which lasts indefinitely [16, 17, 23, 24, 25, 26, 27]. The latter justifies initiatives to organize chronic and intense physical rehabilitation work [17, 18, 23, 24, 25, 26, 27, 28]. Even though previous, short-term open studies evaluating self-rehabilitation programs in spastic hemiparesis suggested the possibility of functional improvement, to our knowledge there are no large-scale prospective randomized controlled protocols that test the effectiveness of long term self-rehabilitation programs in spastic hemiparesis as against conventional rehabilitation systems, especially in chronic stages [29, 30, 31, 32, 33, 34, 35, 36].
Technically, which home rehabilitation exercises might be recommended? From a neurophysiological point of view, muscle overactivity chronologically emerges as the third fundamental feature of motor impairment that begins in the subacute phase in hemiparesis, following paresis and soft tissue contracture that appear in the acute phase [37, 38, 39]. One recognizable form of muscle overactivity is spasticity (hyper-reflectivity to phasic stretch), which is potentiated by muscle shortening [37, 38]. Hypersensitivity to stretch in an antagonist muscle also impedes voluntary motoneurone recruitment for the agonist muscle, a phenomenon called “stretch-sensitive paresis” . As none of the three fundamental mechanisms of motor impairment (paresis, muscle shortening, and muscle overactivity) is distributed symmetrically between agonists and antagonists, there are force imbalances around joints, hindering active movements and deforming body postures . Each of these three mechanisms of impairment, particularly the two most important, which are muscle shortening and muscle overactivity, can be specifically targeted with local treatment, muscle by muscle, aiming to rebalance forces, joint by joint . For the less overactive muscles around each joint, an intensive motor training will aim to break the vicious cycle Paresis-Disuse-Paresis . For their shortened and more overactive antagonists most importantly, a daily program of self-stretch postures at high load combined with a program of maximal amplitude rapid alternating movements, potentially associated with botulinum toxin injections, will aim to increase muscle extensibility and reduce cocontraction, breaking the vicious cycle: Muscle shortening-Overactivity-Muscle shortening [28, 42, 43] (www.i-gsc.com). Significant preliminary results obtained using prescription and teaching of self-rehabilitation programs within a Guided Self-rehabilitation Contract (GSC) led us to hypothesize that this method practiced over the long term might enhance active motor function in chronic hemiparesis beyond 1 year following stroke [18, 44, 45, 46, 47, 48].
From a social point of view, stroke is the leading cause of acquired disability in Western countries. For the Steering Committee on Stroke Prevention and Management in France, the yearly cost of stroke is €5.9 billions, the cost of care in medical and social facilities is €2.4 billions and the cost of daily allowances and disability pensions is €125.8 millions . Additionally, several studies have shown that indirect costs were proportional to direct costs . Stroke thus accounts for a large share of health expenditures. In that regard as well, devising a feasible and effective guided self-rehabilitation program might offer financial advantages for our health systems.[…]
[ARTICLE] Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial – Full Text
A recent study has demonstrated that a turning-based treadmill program yields greater improvements in gait speed and temporal symmetry than regular treadmill training in chronic stroke patients. However, it remains unknown how this novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in chronic stroke patients. The purpose of this study was to examine how a novel type of gait training, which is an unfamiliar but effective task for people with chronic stroke, enhances brain reorganization.
Subjects in the experimental and control groups received 30 min of turning-based treadmill training and regular treadmill training, respectively. Cortico-cortical connectivity and cortico-muscular connectivity during walking and gait performance were assessed before and after completing the 12-session training.
Eighteen subjects (n = 9 per group) with a mean age of 52.5 ± 9.7 years and an overground walking speed of 0.61 ± 0.26 m/s consented and participated in this study. There were significant group by time interactions for gait speed, temporal gait symmetry, and cortico-cortical connectivity as well as cortico-muscular connectivity in walk-related frequency (24–40 Hz) over the frontal-central-parietal areas. Compared with the regular treadmill training, the turning-based treadmill training resulted in greater improvements in these measures. Moreover, the increases in cortico-cortical connectivity and cortico-muscular connectivity while walking were associated with improvements in temporal gait symmetry.
Our findings suggest this novel turning-based treadmill training is effective for enhancing brain functional reorganization underlying cortico-cortical and corticomuscular mechanisms and thus may result in gait improvement in people with chronic stroke.
A recent study suggested that chronic stroke patients maintain the capacity to increase synchronization of neural activity between different brain regions as measured by EEG connectivity. These changes of functional connectivity in the motor cortex through neurofeedback correlate with improvements in motor performance . Previously, we demonstrated that a novel specific training, the turning-based treadmill program, yielded greater improvements in gait speed and temporal symmetry than regular treadmill training for people with chronic stroke . We presumed the turning-based treadmill training, which is a challenging and unfamiliar training task for chronic stroke patients, may facilitate brain reorganization and behavioral recovery . Thus, we sought to understand how such novel gait training promotes brain reorganization in this study.
An EEG-based method has the advantage of real-time recording during walking due to the relative ease of data acquisition. As indicated by the authors of the first study to use an EEG signal recorded during walking, the power increases within numerous frequency bands (3–150 Hz) in the sensorimotor cortex and is more pronounced during the end of the stance phase of walking . Source localization EEG analysis revealed the importance of the primary somatosensory, somatosensory association, primary motor and cingulate cortex in gait control . Focal lesions due to stroke may not only affect the functional connectivity of cortical areas  but also impede the neural transmission of descending motor pathways . Based on spectral analysis, the direct relationship of cortical activities with peripheral movements is still unknown. Accordingly, an analysis of EEG-EMG coherence recorded during treadmill walking was done by Petersen et al. , who demonstrated that cortical activity in the primary motor cortex within the gamma band (24–40 Hz) was transmitted via the corticospinal tract to the leg muscles during the swing phase of walking. In addition, a recent study confirmed the strong correlation between kinematic errors of the lower extremities and fronto-centroparietal connectivity during gait training and post-training in healthy subjects . However, it remains unknown how novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in individuals with chronic stroke. Therefore, the aims of the current study were to explore the effects of the turning-based treadmill training, a novel gait training program, on cortico-cortical connectivity and corticomuscular connectivity and to investigate the relationship between connectivity changes and gait performance in chronic stroke patients.[…]
Continue —> Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial | Journal of NeuroEngineering and Rehabilitation | Full Text