Posts Tagged Motor function

[ARTICLE] Effects of somatosensory electrical stimulation on motor function and cortical oscillations – Full Text

Abstract

Background

Few patients recover full hand dexterity after an acquired brain injury such as stroke. Repetitive somatosensory electrical stimulation (SES) is a promising method to promote recovery of hand function. However, studies using SES have largely focused on gross motor function; it remains unclear if it can modulate distal hand functions such as finger individuation.

Objective

The specific goal of this study was to monitor the effects of SES on individuation as well as on cortical oscillations measured using EEG, with the additional goal of identifying neurophysiological biomarkers.

Methods

Eight participants with a history of acquired brain injury and distal upper limb motor impairments received a single two-hour session of SES using transcutaneous electrical nerve stimulation. Pre- and post-intervention assessments consisted of the Action Research Arm Test (ARAT), finger fractionation, pinch force, and the modified Ashworth scale (MAS), along with resting-state EEG monitoring.

Results

SES was associated with significant improvements in ARAT, MAS and finger fractionation. Moreover, SES was associated with a decrease in low frequency (0.9-4 Hz delta) ipsilesional parietomotor EEG power. Interestingly, changes in ipsilesional motor theta (4.8–7.9 Hz) and alpha (8.8–11.7 Hz) power were significantly correlated with finger fractionation improvements when using a multivariate model.

Conclusions

We show the positive effects of SES on finger individuation and identify cortical oscillations that may be important electrophysiological biomarkers of individual responsiveness to SES. These biomarkers can be potential targets when customizing SES parameters to individuals with hand dexterity deficits. Trial registration: NCT03176550; retrospectively registered.

Background

Despite recent advances in rehabilitation, a substantial fraction of stroke patients continue to experience persistent upper-limb deficits [1]. At best, up to 1 out of 5 patients will recover full arm function, while 50% will not recover any functional use of the affected arm. [2] Improvement in upper limb function specifically depends on sensorimotor recovery of the paretic hand [3]. Yet, there remains a lack of effective therapies readily available to the patient with acquired brain injury for recovery of hand and finger function; a systematic review found that conventional repetitive task training may not be consistently effective for the upper extremity [4]. It is thus critical to explore inexpensive and scalable approaches to restore hand and finger dexterity, reduce disability and increase participation after stroke and other acquired brain injuries.

Sensory threshold somatosensory electrical stimulation (SES) is a promising therapeutic modality for targeting hand motor recovery [5]. It is known to be a powerful tool to focally modulate sensorimotor cortices in both healthy and chronic stroke participants [5678]. Devices such as transcutaneous nerve stimulation (TENS) units can deliver SES and are commercially available, inexpensive, low risk, and easily applied in the home setting [9]. Previous studies have demonstrated short-term and long-term improvements in hand function after SES [5101112131415]. However, the effect of SES on regaining the ability to selectively move a given digit independently from other digits (i.e. finger fractionation) has not been investigated. Poor finger individualization is an important therapeutic target because it is commonly present even after substantial recovery and may account for chronic hand dysfunction [16]. Further, it is unclear if SES is associated with compensatory or restorative mechanisms. Prior studies have largely relied on relatively subjective clinical evaluations of impairment, such as the Fugl-Meyer Assessment, or timed and task-based assessments, such as the Jebson-Taylor Hand Function Test. Biomechanical analyses, on the other hand, can provide important objective and quantitative evidence of improvement in neurologic function and normative motor control [1718]. Therefore, we aimed to determine not only the functional effects, but also the kinematic effects, of SES on chronic hand dysfunction.

Simultaneously, it should be noted that although SES can potentially be an effective therapy, not all individuals who are administered SES experience positive effects. While improvement levels as high as 31–36% compared to baseline function have been reported, [1119] about half of one cohort demonstrated minimal or no motor performance improvement after a single session of SES [15]. One method to shed more light on this discrepancy is to identify neurophysiological biomarkers associated with motor responses to SES. Neurophysiological biomarkers are increasingly used to predict treatment effects [2021]. Although some studies have examined biomarkers associated with treatment-induced motor recovery, to our knowledge none have been performed for SES [2223]. A recent study using electroencephalography (EEG) found that changes in patterns of connectivity predicted motor recovery after stroke [24]. At present, little is known about the effect of peripheral neuromodulation on EEG activity, how existing neural dynamics interacts with peripheral stimulation, and whether this interaction is associated with improvements in motor function. Associating EEG activity with treatment response may also provide mechanistic insight regarding the effects of SES on neural plasticity. EEG activity can also potentially be used as a cost-effective real-time metric of the time-varying efficacy of SES. This novel application of EEG information may help tailor treatment efforts while reducing the variability in outcome.

The main goal of this pilot study was to evaluate both changes in finger fractionation in response to SES and identify the associated neural biomarkers through analyses of EEG dynamics. Outcomes from this study have potential in designing targeted SES therapy based on neural biomarkers to modulate and improve hand function after acquired brain injury such as stroke (e.g. enrollment in long-term studies of the efficacy of SES).

 

Continue —>  Effects of somatosensory electrical stimulation on motor function and cortical oscillations | Journal of NeuroEngineering and Rehabilitation | Full Text

Fig. 1a Schematic representation of the method used for calculating the FCI. The participant is instructed to flex only the index finger as much as possible without flexing the other digits. b FCI is defined mathematically as the angle traversed by the middle finger (digit A) divided by the angle tranversed by the index finger (digit B) relative to the horizontal starting position. c Statistically significant change in mean fractionation from baseline to immediately after peripheral nerve stimulation. Fractionation improvement is indicated by a decrease in finger coupling index (FCI)

 

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Movement Therapy of the Upper Extremities with a Robotic Ball in Stroke Patients: Results of a Randomized Controlled Crossover Study – Full Text

Abstract

Background Stroke is associated with motor impairments of the upper extremities. The defining goal of rehabilitation is independent execution of activities of daily living. New therapy procedures use different hardware components to implement digital therapy contents. These can be useful complements to established therapy protocols.

Objectives The aim of this study was to examine the effect of movement therapy with a robotic ball on motor function parameters in stroke patients.

Materials and Methods 25 patients (60.0±10.0 years, 172.5±13.8 cm, 79.5±13.8 kg, 89.8±72.6 months post-stroke) took part in this crossover study. The intervention and control periods comprised 12 weeks each. Training with the robotic ball was done in addition to standard therapy two times a week for 45 min each. Different game activities were carried out with the help of a tablet and a smartphone.

Results Isometric grip strength improved by 4.5±3.6 kg (p=0.000), and unilateral dexterity increased by 7.5±6.3 successful tries (p=0.000) in the round block test. The self-reported disabilities of the arm, shoulder and hand were assessed using the QuickDASH questionnaire and showed improvements by 12.4±13.0 points (p=0.001).

Conclusions Additional therapy using the robotic ball improved upper extremity motor function and self-perceived health status in chronic stroke patients. However, performance stagnated when standard therapy was implemented alone. Moderately affected patients seem to benefit the most. The presence of very severe motor or cognitive symptoms led, in part, to some dropouts. The results need to be verified using larger patient populations.

Introduction

In Germany, up to 75% of the approx. 196,000 initial and 66,000 repeated strokes are survived [1] [2] [3] [4]. For the affected patients, it is often the trigger for persistent physical limitations, which in 85% of the cases are manifested by the cardinal symptom of spastic or flaccid hemiparesis of the upper extremities. Restriction or even loss of function of the hand and arm drastically impacts the daily life of the affected individual [1] [5] [6] [7]. Demographic change has increased the incidence of stroke. Improved acute care has enabled more people to survive the event, resulting in a greater number of patients and a growing demand for therapy [1] [2] [6]. Reduced range of motion, pain, sensory disturbances and increased muscle tone are characteristic patient symptoms [8] [9]. Loss of arm function is the consequence in about half of stroke cases [8], unlike rehabilitation of independent mobility, which can be achieved in up to 85% of patients [10]. Consequently, relatively less time is devoted to recovery of hand and arm function [11]. In addition to effects on motor function there are often psychological and social consequences [12]. A variety of physical activity measures should contribute to the compensation and restoration of skills and abilities [13] [14]. Since it is still possible to make progress even weeks after a stroke, it is imperative to develop more effective therapeutic methods, especially in the case of sustained loss of upper extremity function [8]. Thus the severity and location of the cerebral insult as well as comorbidities are decisive for the further rehabilitation process [15] [16]. The success of Constraint-induced Movement Therapy (CIMT) [7] [17] [18] [19] [20] [21] [22] [23] [24] demonstrates the necessity and possible benefit of using the upper extremities during training and everyday life.

In this context as well as due to innovative developments in technology-supported concepts and components [25] [26] [27] [28] [29] [30] in the field of stroke rehabilitation such as exergaming, [31] [32] [33] [34] the “Sphero 2.0” robotic ball was reviewed in combination with game-playing applications as a supplemental therapeutic activity [35]. The potential benefit for stroke patients regarding improving motor parameters has been documented in review articles on technology-supported therapeutic measures [36] [37]. Hardware and software components from the entertainment industry or telecommunications are used to develop new therapy activities. There are examples of the Microsoft Kinect webcam used in stroke rehabilitation [30] [38] [39] [40] [41] [42] [43] [44] as well as for game consoles such as the Nintendo Wii [45] [46] [47], Sony Playstation [48] or Microsoft XBox [44]. In addition, smartphones [34], tablets [49] [50] [51] [52] or virtual reality goggles [53] are being used to employ generally commercially available games with potential therapeutic benefits, or to use their sensor systems for movement detection and control. Therapeutic content can be found in commercial video games such as Wii Sports [54] or Kinect Sports [44] as well as games programmed specifically for therapeutic applications [42] [55]. Their common element is the required use of the affected body half to achieve the respective game objective. The activity can reflect daily activities such as grasping and moving a glass [56], cooking [38], or striking selected piano keys [38] [49]. […]

Continue —> Thieme E-Journals – Neurology International Open / Full Text

Fig. 2 The “Sphero 2.0” robotic ball by Orbotix (Boulder, CO, USA).

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[WEB SITE] VR on par with traditional rehab in restoring motor function in stroke patients

 - Stroke, endovascular. neuroimaging, neuro
Using virtual reality training to restore motor function after a stroke is just as effective as traditional physical therapy, reports a new study published in the medical journal Neurology.

Danish first author Iris Brunner, PhD, and colleagues evaluated a pool of 120 stroke patients, all of whom had experienced a stroke within 12 weeks of the study’s baseline and were having difficulty restoring full function in their upper extremities. The group was split in half, with one cohort randomized to virtual reality rehabilitation training and the other randomized to conventional therapy. All results were stratified based on the severity of hand paresis, muscle weakness and wrist and arm strength.

Study patients participated in a minimum of 16 hour-long therapy sessions over the course of four weeks, Brunner and co-authors wrote. Process was measured through the primary outcome measure, the Action Research Arm Test, and secondary outcome measures like the Box and Blocks Test and Functional Independence Measure.

Those randomized to virtual reality training used a screen and gloves with sensors to navigate a variety of games that incorporated arm, hand and finger movements, according to the research. The virtual reality system isn’t immersive, Brunner said in a release from the American Academy of Neurology (AAN)—goggles aren’t a part of the system yet.

“We can only speculate whether using virtual reality goggles or other techniques to create a more immersive experience would increase the effect of the training,” she said.

High-tech goggles or not, virtual reality patients seemed to see the same benefits as those who underwent traditional physical and occupational therapy.

“Both groups had substantial improvement in their functioning, but there was no difference between the two groups in the results,” Brunner said. “These results suggest that either type of training could be used, depending on what the patient prefers.”

Patients in virtual reality therapy improved 12 points from the study’s baseline to the postintervention assessment, the authors wrote, and improved 17 points from baseline to a three-month follow-up. Similarly, participants randomized to conventional therapy improved 13 and 17 points, respectively.

Though additional upper extremity virtual reality training didn’t top traditional methods as a rehab alternative, Brunner and colleagues wrote the new technique could be an alternative or supplement to traditional rehabilitation.

“Virtual reality training may be a motivating alternative for people to use as a supplement to their standard therapy after a stroke,” Brunner said in the AAN release. “Future studies could also look at whether people could use virtual reality therapy remotely from their homes, which could lessen the burden and cost of traveling to a medical center for standard therapy.”

 

via VR on par with traditional rehab in restoring motor function in stroke patients | Cardiovascular Business

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[Abstract+References] Longitudinal Structural and Functional Differences Between Proportional and Poor Motor Recovery After Stroke

Background. Evolution of motor function during the first months after stroke is stereotypically bifurcated, consisting of either recovery to about 70% of maximum possible improvement (“proportional recovery, PROP”) or in little to no improvement (“poor recovery, POOR”). There is currently no evidence that any rehabilitation treatment will prevent POOR and favor PROP. Objective. To perform a longitudinal and multimodal assessment of functional and structural changes in brain organization associated with PROP. Methods. Fugl-Meyer Assessments of the upper extremity and high-density electroencephalography (EEG) were obtained from 63 patients, diffusion tensor imaging from 46 patients, at 2 and 4 weeks (T0) and at 3 months (T1) after stroke onset. Results. We confirmed the presence of 2 distinct recovery patterns (PROP and POOR) in our sample. At T0, PROP patients had greater integrity of the corticospinal tract (CST) and greater EEG functional connectivity (FC) between the affected hemisphere and rest of the brain, in particular between the ventral premotor and the primary motor cortex. POOR patients suffered from degradation of corticocortical and corticofugal fiber tracts in the affected hemisphere between T0 and T1, which was not observed in PROP patients. Better initial CST integrity correlated with greater initial global FC, which was in turn associated with less white matter degradation between T0 and T1. Conclusions. These findings suggest links between initial CST integrity, systems-level cortical network plasticity, reduction of white matter atrophy, and clinical motor recovery after stroke. This identifies candidate treatment targets.

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via Longitudinal Structural and Functional Differences Between Proportional and Poor Motor Recovery After StrokeNeurorehabilitation and Neural Repair – Adrian G. Guggisberg, Pierre Nicolo, Leonardo G. Cohen, Armin Schnider, Ethan R. Buch, 2017

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[Abstract] The Use of Repetitive Transcranial Magnetic Stimulation for Stroke Rehabilitation: A Systematic Review

Objectives

Stroke is a leading cause of disability. Alternative and more effective techniques for stroke rehabilitation have been sought to overcome limitations of conventional therapies. Repetitive transcranial magnetic stimulation (rTMS) arises as a promising tool in this context. This systematic review aims to provide a state of the art on the application of rTMS in stroke patients and to assess its effectiveness in clinical rehabilitation of motor function.

Methods

Studies included in this review were identified by searching PubMed and ISI Web of Science. The search terms were (rTMS OR “repetitive transcranial magnetic stimulation”) AND (stroke OR “cerebrovascular accident” OR CVA) AND (rehab OR rehabilitation OR recover*). The retrieved records were assessed for eligibility and the most relevant features extracted to a summary table.

Results

Seventy out of 691 records were deemed eligible, according to the selection criteria. The majority of the articles report rTMS showing potential in improving motor function, although some negative reports, all from randomized controlled trials, contradict this claim. Future studies are needed because there is a possibility that a bias for non-publication of negative results may be present.

Conclusions

rTMS has been shown to be a promising tool for stroke rehabilitation, in spite of the lack of standard operational procedures and harmonization. Efforts should be devoted to provide a greater understanding of the underlying mechanisms and protocol standardization.

Source: The Use of Repetitive Transcranial Magnetic Stimulation for Stroke Rehabilitation: A Systematic Review – ScienceDirect

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[ARTICLE] Including a Lower-Extremity Component during Hand-Arm Bimanual Intensive Training does not Attenuate Improvements of the Upper Extremities: A Retrospective Study of Randomized Trials – Full Text

Hand-Arm Bimanual Intensive Therapy (HABIT) promotes hand function using intensive practice of bimanual functional and play tasks. This intervention has shown to be efficacious to improve upper-extremity (UE) function in children with unilateral spastic cerebral palsy (USCP). In addition to UE function deficits, lower-extremity (LE) function and UE–LE coordination are also impaired in children with USCP. Recently, a new intervention has been introduced in which the LE is simultaneously engaged during HABIT (Hand-Arm Bimanual Intensive Therapy Including Lower Extremities; HABIT-ILE). Positive effects of this therapy have been demonstrated for both the UE and LE function in children with USCP. However, it is unknown whether the addition of this constant LE component during a bimanual intensive therapy attenuates UE improvements observed in children with USCP. This retrospective study, based on multiple randomized protocols, aims to compare the UE function improvements in children with USCP after HABIT or HABIT-ILE. This study included 86 children with USCP who received 90 h of either HABIT (n = 42) or HABIT-ILE (n = 44) as participants in previous studies. Children were assessed before, after, and 4–6 months after intervention. Primary outcomes were the ABILHAND-Kids and the Assisting Hand Assessment. Secondary measures included the Jebsen-Taylor Test of Hand Function, the Pediatric Evaluation of Disability Inventory [(PEDI); only the self-care functional ability domain] and the Canadian Occupational Performance Measure (COPM). Data analysis was performed using two-way repeated-measures analysis of variance with repeated measures on test sessions. Both groups showed similar, significant improvements for all tests (test session effect p < 0.001; group × test session interaction p > 0.05) except the PEDI and COPM. Larger improvements on these tests were found for the HABIT-ILE group (test session effect p < 0.001; group × test session interaction p < 0.05). These larger improvements may be explained by the constant simultaneous UE–LE engagement observed during the HABIT-ILE intervention since many daily living activities included in the PEDI and the COPM goals involve the LE and, more specifically, UE–LE coordination. We conclude that UE improvements in children with USCP are not attenuated by simultaneous UE–LE engagement during intensive intervention. In addition, systematic LE engagement during bimanual intensive intervention (HABIT-ILE) leads to larger functional improvements in activities of daily living involving the LE.

Introduction

Cerebral palsy (CP) is the most common cause of pediatric motor disability with a prevalence ranging from 2 to 3.6 out of 1,000 children in western countries (12). Motor disorders are often accompanied by sensation, perception, cognition, behavior, communication, and epilepsy disorders (1). Although the lesions are established from birth and are non-progressive, the motor impairments experienced by children with CP affect their autonomy and functional outcomes during their life-span. Moreover, motor symptoms such as impaired ability to walk may worsen during development (3).

One of the most disabling long-term functional deficits in children with unilateral spastic cerebral palsy (USCP) is impaired manual dexterity, i.e., impaired skilled hand movements and precision grip abilities (4). Upper-extremity (UE) impairments may affect functional independence, especially for activities of daily living requiring bimanual coordination (e.g., buttoning one’s shirt). It is now well known that intensive interventions based on motor skill learning principles and goal-directed training are effective for improving UE function in children with USCP (5). Constraint-Induced Movement Therapy (CIMT) was the first intensive intervention adapted to children with USCP (6). CIMT was first designed for adults with stroke and subsequently adapted to children with USCP showing improvements in hand function (5). Taking advantage of the key ingredient of CIMT (intensive practice with the affected UE), Charles and Gordon developed an alternative intensive bimanual approach termed “Hand-Arm Bimanual Intensive Therapy” (HABIT) (7). HABIT was developed with recognition that the combined use of both hands was necessary to increase functional independence in children with USCP (7). Focusing on improving bimanual coordination through structured play and functional activities during HABIT demonstrated efficacy to improve UE function in children with USCP (5).

Both HABIT and CIMT focus only on the UE of children with USCP. Though the lower extremity (LE) is generally less affected than UE in children with USCP, impairments observed in the affected LE range from an isolated equine ankle to hip flexion and adduction with a fixed knee (8). Children with USCP are then unable to achieve postural symmetry while standing, systematically presenting with an overload on one bodyside (8). They also frequently encounter limitations in walking abilities (3). Besides the LE impairments, UE–LE coordination is often impaired in children with USCP (910). This coordination is frequently used in daily living activities (e.g., walking while carrying an object in the hand, climbing stairs while using the railing). A program that simultaneously trains the UE and LE in children with USCP is thus of interest since the UE impairments in children with CP remain stable through time (11) while walking and other LE abilities may decline during development (3). In 2014, taking advantage of the key ingredients in HABIT (intensive bimanual practice), Bleyenheuft and Gordon developed a new intervention focusing on both the UE and LE entitled “Hand-Arm Bimanual Intensive Therapy Including Lower Extremities” (HABIT-ILE) (12). Positive effects of this therapy focusing on both the UE and LE through structured play and functional activities have been demonstrated both for the UE and the LE of children with USCP (13) as well as, more recently, for children with bilateral CP (14). However, it is unknown whether the introduction of a systematic LE engagement in addition to a bimanual intervention may lead to attenuated improvements in UE compared to traditional HABIT due to shifts in attention (multitasking). This retrospective study aimed to compare changes in the UE of children with USCP undergoing 90 h of intensive bimanual intervention either with (HABIT-ILE) or without (HABIT) a LE component. We hypothesized that the introduction of systematic LE training simultaneously added to the bimanual training would lead to reduced improvements in the UE during HABIT-ILE compared to traditional HABIT. […]

Continue —> Frontiers | Including a Lower-Extremity Component during Hand-Arm Bimanual Intensive Training does not Attenuate Improvements of the Upper Extremities: A Retrospective Study of Randomized Trials | Neurology

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[ARTICLE] Transcranial direct current stimulation as a motor neurorehabilitation tool: an empirical review – Full Text

Abstract

The present review collects the most relevant empirical evidence available in the literature until date regarding the effects of transcranial direct current stimulation (tDCS) on the human motor function. tDCS in a non-invasive neurostimulation technique that delivers a weak current through the brain scalp altering the cortical excitability on the target brain area. The electrical current modulates the resting membrane potential of a variety of neuronal population (as pyramidal and gabaergic neurons); raising or dropping the firing rate up or down, depending on the nature of the electrode and the applied intensity. These local changes additionally have shown long-lasting effects, evidenced by its promotion of the brain-derived neurotrophic factor. Due to its easy and safe application and its neuromodulatory effects, tDCS has attracted a big attention in the motor neurorehabilitation field among the last years. Therefore, the present manuscript updates the knowledge available about the main concept of tDCS, its practical use, safety considerations, and its underlying mechanisms of action. Moreover, we will focus on the empirical data obtained by studies regarding the application of tDCS on the motor function of healthy and clinical population, comprising motor deficiencies of a variety of pathologies as Parkinson’s disease, stroke, multiple sclerosis and cerebral palsy, among others. Finally, we will discuss the main current issues and future directions of tDCS as a motor neurorehabilitation tool.

Background

The central nervous system (CNS) works thanks to the communication between more than 100,000 millions of neurons, whose activity and networking is modulated by chemical and electrical processes [1]. Across history, humans have been trying to alter the electrical brain processes to enhance human’s brain function, for the treatment of psychopathologies and for a better understanding of the brain physiology. For example, in the antiquity, modulation of the electrical processes of the brain started with the use of electrical impulses of torpedo fishes applied directly on the CNS, for therapeutic purposes [2]. In 1746, Musschenbroek (1692–1761) used Leyde jars and electrostatic devices to treat neuralgia, contractures and paralysis. The discovery of biometallic electricity and the invention of the voltaic battery augmented the interest in the therapeutic effects of galvanism. Afterwards, Duchenne de Boulogne (1806–1875) upgraded the electrotherapy with volta and magnetofaradaic apparatuses. Fortunately, in the past Century, the technological advances and its integration in health sciences have let us go from uncontrolled and unsafe interventions with side effects to well-controlled, more effective and safe stimulation devices [3].

Currently, the most used stimulation devices can be divided into invasive techniques, such as deep brain stimulation (DBS), and non-invasive brain stimulation (NiBS) techniques, whose most representative methods are transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) [4].

Although results are variable [5], DBS has reported positive results over the motor function, especially on the motor symptoms of Parkinson’s disease. However, DBS is a technique that needs the implantation of the electrodes on the stimulated area, which is associated with the typical risk derived from surgery, as infections. Therefore, there is an increasing tendence on the search for non-invasive brain stimulation techniques, which can modulate the motor function avoiding those risks.

Hence, NiBS are characterized for its easy and safe use and relatively cheap price, demonstrating also successful results in the treatment of neurological and psychiatric alterations [4]. In the last decades, TMS has been the most researched and developed neuromodulation technique. TMS generates fast changes in the magnetic field delivering electrical currents through the brain, allowing the specific modulation of the cortical excitability through the initiation of action potentials [6]. Multiple studies have already shown its efficacy and safe use for the treatment of multiple pathologies [7], serving also as a useful tool for the functional location of brain areas, especially regarding the motor cortex [8, 9]. However, TMS requires the participation of the participant, and due to its functioning, it is difficult to perform a sham condition, which is highly desirable especially in the research field. In addition, TMS produces in most of the cases undesirable side-effects, as headache [10].

Therefore, the tDCS technique is attracting a strong interest in the neuroscience research field. tDCS has supposed a revolution in the last 15 years of research, solving most of the disadvantages of TMS [10]. tDCS is a neuromodulation tool consisting on a battery connected to two electrodes, the anode and cathode, which are placed directly over the brain scalp and over extracephalic regions. The current flows between both electrodes and induces the depolarization or hyperpolarization of the membrane of the underlying neurons, which depends of the anodal or cathodal nature of the electrode [11], altering the neuronal excitability resulting in the modification of the brain activity [12]. This device is completely portable, as it is provided by built-in rechargeable battery with duration of approximately 6 h stimulation time at 1 mA (0.5–1.5 W of power consumption), and needs approximately 7 h for complete recharging. In addition, including battery, it has a weight of 0.8 kg. Its portability is one of the biggest advantages of tDCS in the context of NiBS. Therefore, tDCS can be considered as a suitable complementary technique on motor rehabilitation therapy, allowing its application in different contexes, during the motor training and even combined with aerobic exercise [13, 14].

This non-invasive brain manipulation has opened the doors for a variety of potential treatments for the major neurological and psychiatry diseases [15], as depression [16], schizophrenia [17], Obsessive–Compulsive disorder [18] and addictions [19], among others.

However, motor functions are the major target for clinical and non-clinical studies regarding tDCS, serving mainly as a potential tool in post-stroke rehabilitation [20], but also in pathologies like Parkinson’s disease [21]. In addition, numerous studies have shown that tDCS produces changes in the brain plasticity processes, generating long-lasting effects that enhances even further its applicability in the neurorehabilitation field [22, 23].

The purpose of this review is to assess the current and future stage of tDCS regarding its use on the human motor function, identifying the empirical cues that point out its benefits as well as its potential limitation, providing a comprehensive framework for designing future research in the field of brain stimulation with tDCS and human motor rehabilitation. The present review is divided in four parts. The first part is based on a detailed definition on what we know about tDCS, the protocols of montage and parameters of stimulation, comprising the mechanisms of action of tDCS, what differs tDCS from other non-invasive neuromodulation techniques, and the main need to-know safety standards. Given the conciseness of this first part, we will present the recent studies focusing exclusively on the empirical data obtained from the use of tDCS in the human motor function, regarding, in the second part, healthy humans; in the third part, its clinical application on deteriorated human motor functions across different pathologies as Parkinson disease, stroke and cerebral palsy. Finally, in the fourth part of this review, we will discuss the main current issues of tDCS applied on the human motor function.[…]

Continue —> Transcranial direct current stimulation as a motor neurorehabilitation tool: an empirical review | BioMedical Engineering OnLine | Full Text

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[Abstract] Computer-aided prediction of extent of motor recovery following constraint-induced movement therapy in chronic stroke

Abstract

Constraint-induced movement therapy (CI therapy) is a well-researched intervention for treatment of upper limb function. Overall, CI therapy yields clinically meaningful improvements in speed of task completion and greatly increases use of the more affected upper extremity for daily activities. However, individual improvements vary widely. It has been suggested that intrinsic feedback from somatosensation may influence motor recovery from CI therapy. To test this hypothesis, an enhanced probabilistic neural network (EPNN) prognostic computational model was developed to identify which baseline characteristics predict extent of motor recovery, as measured by the Wolf Motor Function Test (WMFT). Individual characteristics examined were: proprioceptive function via the brief kinesthesia test, tactile sensation via the Semmes-Weinstein touch monofilaments, motor performance captured via the 15 timed items of the Wolf Motor Function Test, stroke affected side. A highly accurate predictive classification was achieved (100% accuracy of EPNN based on available data), but facets of motor functioning alone were sufficient to predict outcome. Somatosensation, as quantified here, did not play a large role in determining the effectiveness of CI therapy.

Source: Computer-aided prediction of extent of motor recovery following constraint-induced movement therapy in chronic stroke – ScienceDirect

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[CORDIS Project] Motor Recovery with Paired Associative Stimulation (RecoveriX) – European Commission

Motor Recovery with Paired Associative Stimulation (RecoveriX)

Objective

Source: European Commission : CORDIS : Projects and Results : Motor Recovery with Paired Associative Stimulation (RecoveriX)

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[ARTICLE] AExaCTT – Aerobic Exercise and Consecutive Task-specific Training for the upper limb after stroke: Protocol for a randomised controlled pilot study – Full Text

Abstract

Motor function may be enhanced if aerobic exercise is paired with motor training. One potential mechanism is that aerobic exercise increases levels of brain-derived neurotrophic factor (BDNF), which is important in neuroplasticity and involved in motor learning and motor memory consolidation. This study will examine the feasibility of a parallel-group assessor-blinded randomised controlled trial investigating whether task-specific training preceded by aerobic exercise improves upper limb function more than task-specific training alone, and determine the effect size of changes in primary outcome measures. People with upper limb motor dysfunction after stroke will be allocated to either task-specific training or aerobic exercise and consecutive task-specific training. Both groups will perform 60 hours of task-specific training over 10 weeks, comprised of 3 × 1 hour sessions per week with a therapist and 3 × 1 hours of home-based self-practice per week. The combined intervention group will also perform 30 minutes of aerobic exercise (70–85%HRmax) immediately prior to the 1 hour of task-specific training with the therapist. Recruitment, adherence, retention, participant acceptability, and adverse events will be recorded. Clinical outcome measures will be performed pre-randomisation at baseline, at completion of the training program, and at 1 and 6 months follow-up. Primary clinical outcome measures will be the Action Research Arm Test (ARAT) and the Wolf Motor Function Test (WMFT). If aerobic exercise prior to task-specific training is acceptable, and a future phase 3 randomised controlled trial seems feasible, it should be pursued to determine the efficacy of this combined intervention for people after stroke.

1. Introduction

1.1. Background

Currently 440,000 persons after stroke live in community settings in Australia [1]. Many with stroke experience chronic disability and although two-thirds receive care each day [1], the majority still have unmet needs [2]. Upper limb dysfunction is a persistent and disabling problem present in 69% of persons after stroke in Australia [3]. Upper limb dysfunction is a major contributor to poor well-being and quality-of-life [4]; [5]; [6] ;  [7]. Unsurprisingly, advancing treatments for upper limb recovery is a top ten research priority for persons after stroke and their carers [8].

In Australia, 87% of persons with stroke-attributable upper limb impairments receive task-specific training [3]. Task-specific training is a progressive training strategy that utilises practice of goal-directed, real-world, context-specific tasks that are intrinsically and/or extrinsically meaningful to the person, to enable them to undertake activities of daily living [9] and may improve upper limb motor function after stroke [9]; [10] ;  [11].

Improvements in motor function coincide with structural and functional reorganisation of the brain [12]; [13]; [14] ;  [15]. The brain’s ability to undergo these changes is denoted as neuroplasticity. Capitalisation and enhancement of neuroplasticity in peri-infarct and non-primary motor regions may promote recovery via an increased response to motor training and other neurorehabilitative interventions [16]; [17] ;  [18].

Many studies show that aerobic exercise (prolonged, rhythmical activity using large muscle groups to increase heart rate) enhances neuroplasticity [19], grey matter volume, white matter integrity [20]; [21] ;  [22] and brain activation [23]; [24] ;  [25]. Furthermore increasing evidence indicates that lower limb aerobic exercise increases upper limb motor function. A single bout of aerobic cycling exercise can improve long-term retention of a motor skill in healthy individuals [26], regardless of whether performed immediately before or after motor training [27].

Aerobic exercise increases BDNF [28]. Improvements in motor skill learning and memory induced by aerobic exercise have been associated with increased peripheral blood concentrations of BDNF [26]. BDNF is involved with neurogenesis [29] and neuroprotection [30] in the human brain [31], thereby playing an important role in stroke recovery, including facilitating functional upper limb motor rehabilitation [32].

In chronic stroke, an 8-week programme of lower extremity endurance cycling enhanced upper extremity fine motor control [33]. Also, a single bout of aerobic treadmill exercise improved grasp function of the hemiparetic hand [34]. As aerobic exercise alone can enhance motor function after stroke, motor learning in stroke rehabilitation may be facilitated if aerobic exercise is paired with motor training [35] ;  [36].

1.2. Aims and objectives

The aims of this study are to 1) assess the feasibility of conducting a randomised controlled trial to compare the effects of task-specific training preceded by aerobic exercise to task-specific training alone on upper limb motor function after stroke; and 2) calculate the effect size of changes in primary clinical outcome measures to evaluate proof-of-concept and inform calculation of sample size for a future phase III trial. This includes investigating potential neural correlates of exercise-induced motor function changes using peripheral blood serum BDNF measurement and multi-modal MRI.

2. Methods

2.1. Study design

This is a parallel-group assessor-blinded randomised controlled pilot study (Fig. 1). One group will undertake task-specific training alone and the other group will undertake 30 minutes of aerobic cycling exercise prior to their task-specific training. The interventions will be delivered by a therapist 3 days per week for 10 weeks. Both groups will be provided with an individually-prescribed task-specific training programme to practice at home for 60 minutes, 3 times per week. Assessments will be conducted at baseline, within 1 week from the end of intervention, and 1 and 6 months following the end of the intervention period. Ethics approval has been obtained from the Hunter New England Human Research Ethics Committee (14/12/10/4.07) and registered with the University of Newcastle Human Research Ethics Committee (H-2015-0105). The study is registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12616000848404).

Continue —>  AExaCTT – Aerobic Exercise and Consecutive Task-specific Training for the upper limb after stroke: Protocol for a randomised controlled pilot study

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