The neural basis of constraint-induced movement therapy

Modified constraint-induced movement therapy enhances cortical plasticity in a rat model of traumatic brain injury: a resting-state functional MRI study

Modified constraint-induced movement therapy (mCIMT) has shown beneficial effects on motor function improvement after brain injury, but the exact mechanism remains unclear. In this study, amplitude of low frequency fluctuation (ALFF) metrics measured by resting-state functional magnetic resonance imaging was obtained to investigate the efficacy and mechanism of mCIMT in a control cortical impact (CCI) rat model simulating traumatic brain injury. At 3 days after control cortical impact model establishment, we found that the mean ALFF (mALFF) signals were decreased in the left motor cortex, somatosensory cortex, insula cortex and the right motor cortex, and were increased in the right corpus callosum. After 3 weeks of an 8-hour daily mCIMT treatment, the mALFF values were significantly increased in the bilateral hemispheres compared with those at 3 days postoperatively. The mALFF signal values of left corpus callosum, left somatosensory cortex, right medial prefrontal cortex, right motor cortex, left postero dorsal hippocampus, left motor cortex, right corpus callosum, and right somatosensory cortex were increased in the mCIMT group compared with the control cortical impact group. Finally, we identified brain regions with significantly decreased mALFF values at 3 days postoperatively. Pearson correlation coefficients with the right forelimb sliding score indicated that the improvement in motor function of the affected upper limb was associated with an increase in mALFF values in these brain regions. Our findings suggest that functional cortical plasticity changes after brain injury, and that mCIMT is an effective method to improve affected upper limb motor function by promoting bilateral hemispheric cortical remodeling. mALFF values correlate with behavioral changes and can potentially be used as biomarkers to assess dynamic cortical plasticity after traumatic brain injury.

Case Report: True Motor Recovery of Upper Limb Beyond 5 Years Post-stroke

Most of motor recovery usually occurs within the first 3 months after stroke. Herein is reported a remarkable late recovery of the right upper-limb motor function after a left middle cerebral artery stroke. This recovery happened progressively, from two to 12 years post-stroke onset, and along a proximo-distal gradient, including dissociated finger movements after 5 years. Standardized clinical assessment and quantified analysis of the reach-to-grasp movement were repeated over time to characterize the recovery. Twelve years after stroke onset, diffusion tensor imaging (DTI), functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation (TMS) analyses of the corticospinal tracts were carried out to investigate the plasticity mechanisms and efferent pathways underlying motor control of the paretic hand. Clinical evaluations and quantified movement analysis argue for a true neurological recovery rather than a compensation mechanism. DTI showed a significant decrease of fractional anisotropy, associated with a severe atrophy, only in the upper part of the left corticospinal tract (CST), suggesting an alteration of the CST at the level of the infarction that is not propagated downstream. The finger opposition movement of the right paretic hand was associated with fMRI activations of a broad network including predominantly the contralateral sensorimotor areas. Motor evoked potentials were normal and the selective stimulation of the right hemisphere did not elicit any response of the ipsilateral upper limb. These findings support the idea that the motor control of the paretic hand is mediated mainly by the contralateral sensorimotor cortex and the corresponding CST, but also by a plasticity of motor-related areas in both hemispheres. To our knowledge, this is the first report of a high quality upper-limb recovery occurring more than 2 years after stroke with a genuine insight of brain plasticity mechanisms.

Management of Post-Facelift Facial Paralysis With Botulinum Toxin Type A

BACKGROUND

Facial nerve injury after facelift is rare; hence, its treatment is poorly established. Botulinum toxin type A (BTXA) can be employed to resolve the asymmetry. To our knowledge, there is no protocol in the literature about the best timing for this treatment, injection sites, or recommended dose.

OBJECTIVES

The authors sought to propose a protocol to guide the management of asymmetries post-facelift.

METHODS

Fifteen patients with post-rhytidectomy facial palsies were treated in the non-paralyzed side with BTXA. After analysis of the smile deviation vectors, it is possible to identify the muscles that should be treated. The dose varied from 1 to 2 volume-unit per point. Patients were examined after 15 days for outcomes evaluation and touch-up if needed. Patients were re-treated after 5 to 6 months in case of asymmetry recurrence.

RESULTS

Symmetry was achieved in all cases. Six patients had definitive nerve lesions and required treatment every 6 months after the first session. Five patients had lesions affecting the upper third of the face; 4 of them were definitive nerve lesions. Two of the 4 patients who were treated less than 2 weeks after surgery recovered early from the post-facelift paralysis and developed reversed asymmetry due to the BTXA. In 7 patients, the post-facelift asymmetry was due to neuropraxis: the recovery from the nerve injury and BTXA treatment occurred symmetrically on both sides of the face in the following months after 1 single session.

CONCLUSIONS

Asymmetries post-facelift were successfully managed with the proposed protocol. The best time for injection was 2 to 4 weeks after surgery.

LEVEL OF EVIDENCE: 4

From Hemispheric Asymmetry through Sensorimotor Experiences to Cognitive Outcomes in Children with Cerebral Palsy

Recent neuroimaging studies allowed us to explore abnormal brain structures and interhemispheric connectivity in children with cerebral palsy (CP). Behavioral researchers have long reported that children with CP exhibit suboptimal performance in different cognitive domains (e.g., receptive and expressive language skills, reading, mental imagery, spatial processing, subitizing, math, and executive functions). However, there has been very limited cross-domain research involving these two areas of scientific inquiry. To stimulate such research, this perspective paper proposes some possible neurological mechanisms involved in the cognitive delays and impairments in children with CP. Additionally, the paper examines the ways motor and sensorimotor experience during the development of these neural substrates could enable more optimal development for children with CP. Understanding these developmental mechanisms could guide more effective interventions to promote the development of both sensorimotor and cognitive skills in children with CP.

Contralesional plasticity following constraint-induced movement therapy benefits outcome: contributions of the intact hemisphere to functional recovery

Stroke is a leading cause of death and disability worldwide. A common, chronic deficit after stroke is upper limb impairment, which can be exacerbated by compensatory use of the nonparetic limb. Resulting in learned nonuse of the paretic limb, compensatory reliance on the nonparetic limb can be discouraged with constraint-induced movement therapy (CIMT). CIMT is a rehabilitative strategy that may promote functional recovery of the paretic limb in both acute and chronic stroke patients through intensive practice of the paretic limb combined with binding, or otherwise preventing activation of, the nonparetic limb during daily living exercises. The neural mechanisms that support CIMT have been described in the lesioned hemisphere, but there is a less thorough understanding of the contralesional changes that support improved functional outcome following CIMT. Using both human and non-human animal studies, the current review explores the role of the contralesional hemisphere in functional recovery of stroke as it relates to CIMT. Current findings point to a need for a better understanding of the functional significance of contralesional changes, which may be determined by lesion size, location, and severity as well stroke chronicity.

Neural mechanisms underlying the Rubber Hand Illusion: A systematic review of related neurophysiological studies

INTRODUCTION

Many researchers took advantage of the well-established rubber hand illusion (RHI) paradigm to explore the link between the sense of body ownership and the different brain structures and networks. Here, we aimed to review the studies that have investigated this phenomenon by means of neurophysiological techniques.

METHODS

The MEDLINE, accessed by Pubmed and EMBASE electronic databases, was searched using the medical subject headings: "Rubber hand illusion" AND "Transcranial magnetic stimulation (TMS)" OR "Evoked potentials (EP)" OR "Event related potentials (ERP)" OR "Electroencephalography (EEG)".

RESULTS

Transcranial magnetic stimulation studies revealed a significant excitability drop in primary motor cortex hand circuits accompanying the disembodiment of the real hand during the RHI experience and that the perceived ownership over the rubber hand is associated with normal parietal-motor communication. Moreover, TMS provided causal evidence that the extrastriate body area is involved in the RHI and subsequently in body representation, while neuromodulation of ventral premotor area and the inferior parietal lobe did not result in an enhancement of embodiment. EP and ERP studies suggest that pre-existing body representations may affect larger stages of tactile processing and support predictive coding models of the functional architecture of multisensory integration in bodily perceptual experience. High-frequency oscillations on EEG play a role in the integrative processing of stimuli across modalities, and EEG activity in γ band activity in the parietal area reflects the visuotactile integration process. EEG studies also revealed that RHI is associated with the neural circuits underlying motor control and that premotor areas play a crucial role in mediating illusory body ownership.

CONCLUSION

Neurophysiological studies shed new light on our understanding of the different aspects that contribute to the formation of a coherent self-awareness in humans.

The Delta-Subunit Selective GABA A Receptor Modulator, DS2, Improves Stroke Recovery via an Anti-inflammatory Mechanism

Inflammatory processes are known to contribute to tissue damage in the central nervous system (CNS) across a broad range of neurological conditions, including stroke. Gamma amino butyric acid (GABA), the main inhibitory neurotransmitter in the CNS, has been implicated in modulating peripheral immune responses by acting on GABA _A receptors on antigen-presenting cells and lymphocytes. Here, we investigated the effects and mechanism of action of the delta-selective compound, DS2, to improve stroke recovery and modulate inflammation. We report a decrease in nuclear factor (NF)-κB activation in innate immune cells over a concentration range in vitro. Following a photochemically induced motor cortex stroke, treatment with DS2 at 0.1 mg/kg from 1 h post-stroke significantly decreased circulating tumor necrosis factor (TNF)-α, interleukin (IL)-17, and IL-6 levels, reduced infarct size and improved motor function in mice. Free brain concentrations of DS2 were found to be lower than needed for robust modulation of central GABA _A receptors and were not affected by the presence and absence of elacridar, an inhibitor of both P-glycoprotein and breast cancer resistance protein (BCRP). Finally, as DS2 appears to dampen peripheral immune activation and only shows limited brain exposure, we assessed the role of DS2 to promote functional recovery after stroke when administered from 3-days after the stroke. Treatment with DS2 from 3-days post-stroke improved motor function on the grid-walking, but not on the cylinder task. These data highlight the need to further develop subunit-selective compounds to better understand change in GABA receptor signaling pathways both centrally and peripherally. Importantly, we show that GABA compounds such as DS2 that only shows limited brain exposure can still afford significant protection and promote functional recovery most likely via modulation of peripheral immune cells and could be given as an adjunct treatment.

Immediate effect of a wearable foot drop stimulator to prevent foot drop on the gait ability of patients with hemiplegia after stroke

The purpose of this study was to compare the effects of a foot drop stimulator (FDS) and ankle-foot orthosis (AFO) on the gait ability of patients with hemiplegia after stroke. This study recruited 10 patients with hemiplegia after stroke. All patients performed gait under two conditions (AFO and FDS gait). Gait parameters were measured with the GAITRite® system to analyze the spatial and temporal parameters of the patients' gaits. No significant differences in cadence, velocity, swing time, stance time, or step length of the affected or less-affected limbs were found between the two conditions (all, p > .05). These findings demonstrate that AFO and FDS have a similar effect on the gait ability of patients with hemiplegia after stroke.

Clinical factors associated with the development of nonuse learned after stroke: a prospective study

Background: Upper extremity impairment is present in most of people with stroke. The use of the affected upper extremity can be impacted not only by physical impairment but also by abehavioral phenomenon called learned nonuse. Objective: The aim of this study was to evaluate which clinical factors in the acute phase are associated with the development of learned nonuse in the upper extremity after stroke. Methods: This cohort study included 38 patients with ischemic stroke. Hospital discharge data were collected for clinical aspects, scales of severity, incapacity and autonomy, as well as for neuromuscular and sensory evaluations. At 90 days after hospital discharge, the score on the Motor Activity Log scale for detecting learned nonuse was obtained, and life quality was evaluated by the EuroQol. The individuals with and without learned nonuse were compared by attest for univariate analysis, and ageneralized linear model was employed to find possible predictors, which were considered significant p <0.05. Results: In the statistical model, age (p= .006), severity at discharge (p= .036), handgrip strength (p= .000), altered sensitivity (p= .011), incapacity at discharge (p= .009) and autonomy at discharge (p= .011) were found to be associated with learned nonuse. In relation to quality of life, mobility, personal care, usual activities, anxiety, depression and perception had lower mean values in the learned nonuse group. Conclusion: Age, severity of stroke, incapacity and neuromuscular and sensory compromises are associated with upper extremity learned nonuse in stroke patients.

Contralateral Botulinum Toxin Improved Functional Recovery after Tibial Nerve Repair in Rats

BACKGROUND

There is clinical and experimental evidence that botulinum toxin applied to the healthy side of patients with facial paralysis positively affects functional recovery of the paralyzed side. The authors created an experimental model to study the effects of botulinum toxin injection in the gastrocnemius muscle contralateral to the side of tibial nerve lesion/repair in rats.

METHODS

Fifty rats were allocated into five groups: group I, control; group II, tibial nerve section; group III, tibial nerve section and immediate neurorrhaphy; group IV, tibial nerve section, immediate neurorrhaphy, and botulinum toxin injected into the contralateral gastrocnemius muscle; and group V, botulinum toxin injected into the gastrocnemius muscle and no surgery. Assessment tools included a walking track, electromyography, gastrocnemius muscle weight measurement, and histologic analysis of the nerve.

RESULTS

Paralysis in group V was transient, with function returning to normal at 8 weeks. At 12 weeks, group V had lower latency levels. At week 12, group IV showed higher functional outcomes and amplitude levels than group III, and lower muscle atrophy on the side injected with botulinum toxin compared with group V.

CONCLUSION

Transient paralysis of the contralateral gastrocnemius muscle by botulinum toxin type A improved functional recovery in rats that underwent section and repair of the tibial nerve.

Improved quality of life following constraint-induced movement therapy is associated with gains in arm use, but not motor improvement

BACKGROUND

Constraint-induced movement therapy (CI therapy) is one of few treatments for upper extremity (UE) hemiparesis that has been shown to result in motor recovery and improved quality of life in chronic stroke. However, the extent to which treatment-induced improvements in motor function versus daily use of the more affected arm independently contribute to improved quality of life remains largely unexplored.

OBJECTIVE

The objective of this study is to identify whether motor function or daily use of a hemiparetic arm has a greater influence on quality of life after CI therapy.

METHODS

Two cohorts of participants with chronic stroke received either in-person CI therapy (n = 29) or video-game home-based CI therapy (n = 16). The two cohorts were combined and the motor-related outcomes (Wolf Motor Function Test, Action Research Arm Test, Motor Activity Log [MAL]) and quality of life (Stroke-Specific Quality of Life) were jointly modeled to assess the associations between outcomes.

RESULTS

The only outcome associated with improved quality of life was the MAL. Improvements in quality of life were not restricted to motor domains, but generalized to psychosocial domains as well.

CONCLUSIONS

Results suggest that improved arm use during everyday activities is integral to maximizing quality of life gains during motor rehabilitation for chronic post-stroke UE hemiparesis. In contrast, gains in motor function were not associated with increases in quality of life. These findings further support the need to implement techniques into clinical practice that promote arm use during daily life if improving quality of life is a main goal of treatment. ClinicalTrials.gov Registration Numbers: NCT01725919 and NCT03005457.

Losing my hand. Body ownership attenuation after virtual lesion of the primary motor cortex

A fundamental component of the self-awareness is the sensation that we are acting with our own body. Thus, a coherent sense of self implies the existence of a tight link between the sense of body ownership and the motor system. Here, we investigated this issue by taking advantage of a well-known experimental manipulation of body ownership, i.e., the rubber hand illusion (RHI), during which the subjects perceive a fake hand as part of their own body. To test the effect of the motor system down-regulation on the RHI susceptibility, we designed a sham-controlled study, where the primary motor cortex (M1) excitability was modulated by off-line low-frequency repetitive transcranial magnetic stimulation (rTMS). After rTMS (real or sham), subjects underwent the RHI either on the right hand, contralateral to the inhibited hemisphere (Experiment 1), or on the left hand, ipsilateral to the inhibited hemisphere (Experiment 2). Only in Experiment 1, the procedure strengthened the illusory experience, as proved by a significant increase, in rTMS compared to Sham, of both subjective (Embodiment/Disembodiment Questionnaires) and objective (Proprioceptive Drift) RHI measures. This evidence demonstrates that, when the M1 activity is down-regulated, the sense of body ownership is attenuated and the subjects become more prone to incorporate an alien body part. This, in turn, supports the existence of a mutual interaction between the sense of body ownership and the motor system, shedding new light on the construction of a coherent sense of self as an acting body.

Withdrawn: Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence

Vidal AC, Banca P, Pascoal AG, Cordeiro G, Sargento-Freitas J, Gouveia A and Castelo-Branco M. Bilateral versus ipsilesional corticosubcortical activity patterns in stroke show hemispheric dependence. Int J Stroke. Epub ahead of print 5 April 2018. DOI: https://doi.org/10.1177/1747493018767164. Ahead of Print article withdrawn by publisher. Due to an administrative error, this article was accidentally published Online First and in Volume 12 Issue 1 with different DOIs. Vidal AC, Banca P, Pascoal AG, Cordeiro G, Sargento-Freitas J, Gouveia A and Castelo-Branco M. Bilateral versus ipsilesional corticosubcortical activity patterns in stroke show hemispheric dependence. Int J Stroke. Epub ahead of print 5 April 2018. The correct and citable version of the article remains: Vidal AC, Banca P, Pascoal AG, Cordeiro G, Sargento-Freitas J, Gouveia A and Castelo-Branco M. Bilateral versus ipsilesional corticosubcortical activity patterns in stroke show hemispheric dependence. Int J Stroke 2017; 12(1): 71–83. DOI: https://doi.org/10.1177/1747493016672087.

Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence

Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients, bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contrast, ipsilesional patterns have been linked with better motor outcomes. Aim We investigated the pathophysiology of hemispheric interactions during limb movement without and with contralateral restraint, to mimic the effects of constraint-induced movement therapy. We used neuroimaging to probe brain activity with such a movement-dependent interhemispheric modulation paradigm. Methods We used an fMRI block design during which the plegic/paretic upper limb was recruited/mobilized to perform unilateral arm elevation, as a function of presence versus absence of contralateral limb restriction ( n = 20, with balanced left/right lesion sites). Results Analysis of 10 right-hemispheric stroke participants yielded bilateral sensorimotor cortex activation in all movement phases in contrast with the unilateral dominance seen in the 10 left-hemispheric stroke participants. Superimposition of contralateral restriction led to a prominent shift from activation to deactivation response patterns, in particular in cortical and basal ganglia motor areas in right-hemispheric stroke. Left-hemispheric stroke was in general characterized by reduced activation patterns, even in the absence of restriction, which induced additional cortical silencing. Conclusion The observed hemispheric-dependent activation/deactivation shifts are novel and these pathophysiological observations suggest short-term neuroplasticity that may be useful for hemisphere-tailored neurorehabilitation.

Efficacy of Modified Constraint Induced Movement Therapy in the Treatment of Hemiparetic Upper Limb in Stroke Patients: A Randomized Controlled Trial

INTRODUCTION

Paretic upper limb in stroke patients has a significant impact on the quality of life. Modified Constraint Induced Movement Therapy (mCIMT) is one of the treatment options used for the improvement of the function of the paretic limb.

AIM

To investigate the efficacy of four week duration mCIMT in the management of upper extremity weakness in hemiparetic patients due to stroke.

MATERIALS AND METHODS

Prospective single blind, parallel randomized controlled trial in which 30 patients received conventional rehabilitation programme (control group) and 30 patients participated in a mCIMT programme in addition to the conventional rehabilitation programme (study group). The mCIMT included three hours therapy sessions emphasizing the affected arm use in general functional tasks, three times a week for four weeks. Their normal arm was also constrained for five hours per day over five days per week. All the patients were assessed at baseline, one month and three months after completion of therapy using Fugl-Meyer Assessment (FMA) score for upper extremity and Motor Activity Log (MAL) scale comprising of Amount of Use (AOU) score and Quality of Use (QOU) score.

RESULTS

All the 3 scores improved significantly in both the groups at each follow-up. Post-hoc analysis revealed that compared to conventional rehabilitation group, mCIMT group showed significantly better scores at 1 month {FMA1 (p-value <0.0001, es0.2870), AOU1 (p-value 0.0007, es0.1830), QOU1 (p-value 0.0015, es0.1640)} and 3 months {FMA3 (p-value <.0001, es0.4240), AOU3 (p-value 0.0003, es 0.2030), QOU3 (p-value 0.0008, es 0.1790)}.

CONCLUSION

Four weeks duration for mCIMT is effective in improving the motor function in paretic upper limb of stroke patients.

Influence of Perspective of Action Observation Training on Residual Limb Control in Naïve Prosthesis Usage

Prior work in amputees and partial limb immobilization have shown improved neural and behavioral outcomes in using their residual limb with prosthesis when undergoing observation-based training with a prosthesis-using actor compared to an intact limb. It was posited that these improvements are due to an alignment of user with the actor. It may be affected by visual angles that allow emphasis of critical joint actions which may promote behavioral changes. The purpose of this study was to examine how viewing perspective of observation-based training effects prosthesis adaptation in naïve device users. Twenty nonamputated prosthesis users learned how to use an upper extremity prosthetic device while viewing a training video from either a sagittal or coronal perspective. These views were chosen as they place visual emphasis on different aspects of task performance to the device. The authors found that perspective of actions has a significant role in adaptation of the residual limb while using upper limb prostheses. Perspectives that demonstrate elbow adaptations to prosthesis usage may enhance the functional motor outcomes of action observation therapy. This work has potential implications on how prosthetic device operation is conveyed to persons adapting to prostheses through action observation based therapy.

Change in Movement-Related Cortical Potentials Following Constraint-Induced Movement Therapy (CIMT) After Stroke

Abstract. Patients with chronic stroke were given Constraint-Induced Movement Therapy (CIMT) over an intensive two-week course of treatment. The intervention resulted in a large improvement in use of the more-affected upper extremity in the laboratory and in the real-world environment. High-resolution electroencephalography (EEG) showed that the treatment produced marked changes in cortical activity that correlated with the significant rehabilitative effects. Repetitive unilateral self-paced voluntary movements showed a large increase after treatment in the amplitudes of the late components of the Bereitschaftspotential (BP) both in the hemisphere contralateral to the more-affected arm and in the ipsilateral hemisphere. Simultaneous electromyographic recordings (EMG) and other aspects of the data indicate that the emergence of the movement-related neural source in the healthy hemisphere was not due to mirror movements of the non-test hand and that the increase in BP amplitudes was not the result of an increase in the force or effort of the response pre- to post-treatment. The results are consistent with the rehabilitation treatment having produced a use-dependent cortical reorganization and is a case where the physiological data interdigitates with and provides additional credibility to the clinical data.

Influence of Corticospinal Tracts from Higher Order Motor Cortices on Recruitment Curve Properties in Stroke

BACKGROUND

Recruitment curves (RCs) acquired using transcranial magnetic stimulation are commonly used in stroke to study physiologic functioning of corticospinal tracts (CST) from M1. However, it is unclear whether CSTs from higher motor cortices contribute as well.

OBJECTIVE

To explore whether integrity of CST from higher motor areas, besides M1, relates to CST functioning captured using RCs.

METHODS

RCs were acquired for a paretic hand muscle in patients with chronic stroke. Metrics describing gain and overall output of CST were collected. CST integrity was defined by diffusion tensor imaging. For CST emerging from M1 and higher motor areas, integrity (fractional anisotropy) was evaluated in the region of the posterior limb of the internal capsule, the length of CST and in the region of the stroke lesion.

RESULTS

We found that output and gain of RC was related to integrity along the length of CST emerging from higher motor cortices but not the M1.

CONCLUSIONS

Our results suggest that RC parameters in chronic stroke infer function primarily of CST descending from the higher motor areas but not M1. RCs may thus serve as a simple, in-expensive means to assess re-mapping of alternate areas that is generally studied with resource-intensive neuroimaging in stroke.

Neuromechanical principles underlying movement modularity and their implications for rehabilitation

Neuromechanical principles define the properties and problems that shape neural solutions for movement. Although the theoretical and experimental evidence is debated, we present arguments for consistent structures in motor patterns, i.e., motor modules, that are neuromechanical solutions for movement particular to an individual and shaped by evolutionary, developmental, and learning processes. As a consequence, motor modules may be useful in assessing sensorimotor deficits specific to an individual and define targets for the rational development of novel rehabilitation therapies that enhance neural plasticity and sculpt motor recovery. We propose that motor module organization is disrupted and may be improved by therapy in spinal cord injury, stroke, and Parkinson's disease. Recent studies provide insights into the yet-unknown underlying neural mechanisms of motor modules, motor impairment, and motor learning and may lead to better understanding of the causal nature of modularity and its underlying neural substrates.

Enhanced task-oriented training in a person with dementia with Lewy bodies

Despite the inevitable loss of function seen in people with progressive dementias, interventions for reversing or minimizing functional loss are understudied. Research supports task-oriented training, but practical gaps in how to best evaluate clients for this training and how to implement it in clinical settings may be thwarting translation to occupational therapy practice. We structured an intervention model called STOMP (Skill-building through Task-Oriented Motor Practice) using a unique blend of task-oriented training and motor-learning principles. In this article, we describe through a case study the process and outcome of using STOMP to improve functional skills in a woman with moderate dementia with Lewy bodies. Our findings suggest that STOMP has the potential to serve as a structure for the evaluation and treatment of occupational performance deficits in people with dementia and that this model warrants further investigation.

Modulation of cortical interhemispheric interactions by motor facilitation or restraint

Cortical interhemispheric interactions in motor control are still poorly understood and it is important to clarify how these depend on inhibitory/facilitatory limb movements and motor expertise, as reflected by limb dominance. Here we addressed this problem using functional magnetic resonance imaging (fMRI) and a task involving dominant/nondominant limb mobilization in the presence/absence of contralateral limb restraint. In this way we could modulate excitation/deactivation of the contralateral hemisphere. Blocks of arm elevation were alternated with absent/present restraint of the contralateral limb in 17 participants. We found the expected activation of contralateral sensorimotor cortex and ipsilateral cerebellum during arm elevation. In addition, only the dominant arm elevation (hold period) was accompanied by deactivation of ipsilateral sensorimotor cortex, irrespective of presence/absence of contralateral restraint, although the latter increased deactivation. In contrast, the nondominant limb yielded absent deactivation and reduced area of contralateral activation upon restriction. Our results provide evidence for a difference in cortical communication during motor control (action facilitation/inhibition), depending on the “expertise” of the hemisphere that controls action (dominant versus nondominant). These results have relevant implications for the development of facilitation/inhibition strategies in neurorehabilitation, namely, in stroke, given that fMRI deactivations have recently been shown to reflect decreases in neural responses.

Cortical reorganization after hand immobilization: the beta qEEG spectral coherence evidences

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes.

Cortical reorganization after hand immobilization: the beta qEEG spectral coherence evidences

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes.

Beneficial effects of minocycline and botulinum toxin-induced constraint physical therapy following experimental traumatic brain injury

BACKGROUND

Effective recovery from functional impairments caused by traumatic brain injury (TBI) requires appropriate rehabilitation therapy. Multiple pathways are involved in secondary injury and recovery suggesting a role for multimodal approaches.

OBJECTIVE

Here, we examined the efficacy of the anti-inflammatory agent minocycline and botulinum toxin (botox)-induced limb constraint with structured physical therapy, delivered alone or in combination, after a severe TBI produced by a controlled cortical impact in rats.

METHODS

Minocycline was administered at 25 mg/kg daily for 2 weeks beginning 1 day after TBI or sham surgery. For constraint/physical therapy, botox-type A was injected into the nonaffected forearm muscle 1 day after injury and 2 weeks of physical therapy commenced at 5 days after injury. Functional evaluations were conducted 8 weeks after injury.

RESULTS

Minocycline, either as a monotherapy or as combination treatment with botox/physical therapy significantly reduced impairments of spatial learning and memory in the water maze test, whereas botox/physical therapy reduced forelimb motor asymmetry and improved manual dexterity in the cylinder and vermicelli handling tests, A synergistic effect between the 2 treatments was observed when rats performed tasks requiring dexterity. Inflammation was attenuated in the peri-contusion cortex and hippocampus in all TBI groups receiving mono or combination therapies, though there was no significant difference in lesion size among groups.

CONCLUSION

These data provide a rationale for incorporating anti-inflammatory treatment during rehabilitation therapy.

Plasticity in the Injured Brain

Changes in brain circuits occur within specific paradigms of action in the adult brain. These paradigms include changes in behavioral activity patterns, alterations in environmental experience, and direct brain injury. Each of these paradigms can produce axonal sprouting, dendritic morphology changes, and alterations in synaptic connectivity. Activity-, experience-, and injury-dependent plasticity alter neuronal network function and behavioral output, and in the case of brain injury, may produce neurological recovery. The molecular substrate for adult neuronal plasticity overlaps in these three paradigms in key signaling pathways. These common pathways for adult plasticity suggest common mechanisms for activity-, experience-, and injury-dependent plasticity. These common pathways may also interact to enhance or impede each other during adult recovery of function after injury. This review focuses on common molecular changes evoked during the process of adult neuronal plasticity, with a focus on neural repair in stroke.

Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia

Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusion. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia.

Influence of constraint-induced movement therapy upon evoked potentials in rats with cerebral infarction

Constraint-induced movement therapy (CIMT) is an effective treatment promoting motor recovery of upper extremity function in stroke patients. The objective of the present study was to determine the effect of CIMT on the evoked potentials in rats with focal cerebral cortical ischemia induced by endothelin-1 (ET-1). Thirty rats were randomly assigned to the sham, infarct or CIMT groups. ET-1 was injected stereotaxically into the forelimb area of the cerebral cortex in the dominant hemisphere. Custom-made constraint jackets were applied to limit movement of the unaffected forelimb in the CIMT group. Motor and sensory function of the forelimb was evaluated by a pellet retrieval task and forearm asymmetry test. Electrophysiologic changes were evaluated by motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs). The location and extent of cerebral ischemia were confirmed and compared histologically. The CIMT group showed better recovery in the pellet retrieval task. Forelimb use was more symmetrical in the CIMT group. The waveform of the SEP was reversed and delayed in the infarct group, but it was preserved in the CIMT group with amplitude decrease only. The estimated volume of infarction was smaller in the CIMT group, although statistically not significant. The results demonstrate that CIMT can promote recovery of motor function in focal cerebral cortical infarcts, and that recovery may be related to reorganization of the cerebral neuronal network in the somatosensory pathway.

Emerging therapies in neurorehabilitation

Just as advancing technology has furthered our understanding of how the nervous system recovers, technology also enables the development of novel approaches to treatment. Because nervous system disease and injury often lead to severely impaired function, patients and families are willing to try anything, so therapies are often adopted with little evidence that they actually work. Evidence shows that comprehensive rehabilitation programs produce better outcomes, but it is still not understood what components of these multifaceted programs are critical to their success. Functional neuroimaging and other modalities now allow monitoring of neurophysiologic changes that can be paired with assessments detailing clinical changes, furthering our understanding of the factors that influence the recovery process. This article discusses several novel and emerging therapies in neurorehabilitation as well as recent multistudy reviews of selected treatments.

Exploring the efficacy of constraint in animal models of stroke: meta-analysis and systematic review of the current evidence

BACKGROUND

Constraint-induced movement therapy (CIMT) is used to counteract learned nonuse observed following stroke in humans and has been shown to improve function. Variations of CIMT used in animal models of stroke have the potential to inform and improve our understanding of this intervention.

OBJECTIVE

To conduct a systematic review of studies investigating constraint in experimental stroke. The authors aimed to assess the quality and establish the efficacy of constraint on neurobehavior, cognitive function, infarct size, and stress and mortality and to determine the optimal dose or time to administration.

METHODS

Systematic review with meta-analysis was used. Data were analyzed using DerSimonian and Laird weighted-mean-difference random effects meta-analysis.

RESULTS

The quality scores of the 8 articles (15 studies) included were moderate (median 5/10; interquartile range, 4.8-6.0). There was a trend for animals with constraint to have worse neurobehavioral scores (-10% worse; 95% confidence interval [CI] = -20 to 0; P = .06). Infarct volumes were not significantly different between groups (-3% larger with constraint; 95% CI = -15 to 9; P = .63). Cognitive function was significantly better after constraint, although this estimate was based on only 28 animals from 2 studies. Insufficient data prevented analysis of the effect of constraint on stress and mortality.

CONCLUSIONS

This meta-analysis showed no benefit of constraint on neurobehavioral scores, which is at odds with some human studies. Animal models may help us efficiently explore the biological basis of rehabilitation interventions; however, review of the data in this study raise uncertainty about its effectiveness in humans.

Reduced-intensity modified constraint-induced movement therapy versus conventional therapy for upper extremity rehabilitation after stroke: a multicenter trial

BACKGROUND

Constraint-induced movement therapy (CIMT) is a rehabilitation approach for arm paresis consisting of an intensive schedule of treatment (6 h/d). The high demand of resources for CIMT is a critical issue for its implementation in the Italian health system.

OBJECTIVE

To compare the effects of a reduced-intensity modified CIMT (mCIMT) program that included splinting the unaffected arm for 12 hours daily with the effects of a conventional rehabilitation program for arm paresis in patients with stroke.

METHODS

Sixty-six participants with hemiparesis (3-24 months poststroke) who could extend the wrist and several fingers at least 10° were randomly assigned to mCIMT or conventional rehabilitation. Each group underwent 10 (2 h/d) treatment sessions (5 d/wk for 2 weeks). Patients were assessed with the Wolf Motor Function Test (WMFT-FA and WMFT-T), the Motor Activity Log (MAL-AOU and MAL-QOM), and the Ashworth Scale before and after treatment and 3 months later.

RESULTS

Between-groups analysis showed that the mCIMT group overall had greater improvement than the control group in terms of the WMFT-FA (P = .010), MAL-AOU (P < .001), and MAL-QOM (P < .001). Differences between groups were significant both after treatment (P < .01) and at the 3-month follow-up (P < .01), although 40% of participants did not complete the 3-month assessment. Furthermore, the mCIMT group showed a greater decrease of Ashworth Scale score than the control group at 3 months (P = .021).

CONCLUSION

Two hours of CIMT may be more effective than conventional rehabilitation in improving motor function and use of the paretic arm in patients with chronic stroke.

Effects of sling and voluntary constraint during constraint-induced movement therapy for the arm after stroke: a randomized, prospective, single-centre, blinded observer rated study

OBJECTIVE

To determine whether a combination of constraint-induced movement therapy and physiotherapy in stroke patients using different constraint regimens (sling versus voluntary constraint) changes or reduces motor deficits, the amount of functional use of the arm and whether the effects of treatment continue after 12 months.

DESIGN

Forty-seven stroke patients were stratified and randomly divided into intensive physiotherapy programmes focused on regaining arm functions.

SETTING

Neurorehabilitation Unit of IInd Department of Neurology at Institute of Psychiatry and Neurology in Warsaw.

SUBJECT

Patients were randomly allocated to: the sling-constraint group (n = 24) or to the voluntary-constraint group (n = 23).

INTERVENTIONS

Massed practice with the paretic arm (5 hours/day for 15 consecutive working days). Sling-constraint group had their arm immobilized in a hemi-sling during therapy. In addition, individual, 1-hour physiotherapy sessions were conducted in both groups.

MAIN MEASURES

Rivermead Motor Assessment (RMA) Arm scale, (0-15), Motor Activity Log - Quality of Movement (MAL-QOM) (0-5 for 30 daily tasks).

RESULTS

There was no significant difference between groups after therapy (MAL-QOM mean change for sling group 0.78, SD = 0.46 and for voluntary-constraint group 0.84, SD = 0.48; P = 0.687). All treated patients retained mean gains in real-world arm use (MAL-QOM) mean scores after 12 months follow-up compared with posttreatment values but there was no significant difference between groups (comparison of estimated mean change of MAL-QOM stated 0.23. 95% confidence interval = -0.04-0.50).

CONCLUSION

Voluntary activity constraint in the intact arm is equivalent to sling, standard constraint during massed practice of paretic arm.

Recovery from ischemia in the middle-aged brain: a nonhuman primate model

Studies of recovery from stroke mainly utilize rodent models and focus primarily on young subjects despite the increased prevalence of stroke with age and the fact that recovery of function is more limited in the aged brain. In the present study, a nonhuman primate model of cortical ischemia was developed to allow the comparison of impairments in young and middle-aged monkeys. Animals were pretrained on a fine motor task of the hand and digits and then underwent a surgical procedure to map and lesion the hand-digit representation in the dominant motor cortex. Animals were retested until performance returned to preoperative levels. To assess the recovery of grasp patterns, performance was videotaped and rated using a scale adapted from human occupational therapy. Results demonstrated that the impaired hand recovers to baseline in young animals in 65-80 days and in middle-aged animals in 130-150 days. However, analysis of grasp patterns revealed that neither group recover preoperative finger thumb grasp patterns, rather they develop compensatory movements.

Perisynaptic GABA Receptors The Overzealous Protector

An attempt to find pharmacological therapies to treat stroke patients and minimize the extent of cell death has seen the failure of dozens of clinical trials. As a result, stroke/cerebral ischemia is the leading cause of lasting adult disability. Stroke-induced cell death occurs due to an excess release of glutamate. As a consequence to this, a compensatory increased release of GABA occurs that results in the subsequent internalization of synaptic GABA(A) receptors and spillover onto perisynaptic GABA(A) receptors, resulting in increased tonic inhibition. Recent studies show that the brain can engage in a limited process of neural repair after stroke. Changes in cortical sensory and motor maps and alterations in axonal structure are dependent on patterned neuronal activity. It has been assumed that changes in neuronal excitability underlie processes of neural repair and remapping of cortical sensory and motor representations. Indeed, recent evidence suggests that local inhibitory and excitatory currents are altered after stroke and modulation of these networks to enhance excitability during the repair phase can facilitate functional recovery after stroke. More specifically, dampening tonic GABA inhibition can afford an early and robust improvement in functional recovery after stroke.

Unidirectional rotations produce asymmetric changes in horizontal VOR gain before and after unilateral labyrinthectomy in macaques

Unilateral vestibular lesions cause marked asymmetry in the horizontal vestibulo-ocular reflex (VOR) during rapid head rotations, with VOR gain being lower for head rotations toward the lesion than for rotations in the opposite direction. Reducing this gain asymmetry by enhancing ipsilesional responses would be an important step toward improving gaze stability following vestibular lesions. To that end, there were two goals in this study. First, we wanted to determine whether we could selectively increase VOR gain in only one rotational direction in normal monkeys by exposing them to a training session comprised of a 3-h series of rotations in only one direction (1,000°/s² acceleration to a plateau of 150°/s for 1 s) while they wore 1.7 × magnifying spectacles. Second, in monkeys with unilateral vestibular lesions, we designed a paradigm intended to reduce the gain asymmetry by rotating the monkeys toward the side of the lesion in the same way as above but without spectacles. There were three main findings (1) unidirectional rotations with magnifying spectacles result in gain asymmetry in normal monkeys, (2) gain asymmetry is reduced when animals are rotated towards the side of the labyrinthectomy via the ipsilesional rotation paradigm, and (3) repeated training causes lasting reduction in VOR gain asymmetry.

Chronic electrical stimulation of the intact corticospinal system after unilateral injury restores skilled locomotor control and promotes spinal axon outgrowth

Injury to the brain or spinal cord usually preserves some corticospinal (CS) connections. These residual circuits sprout spontaneously and in response to activity-based treatments. We hypothesized that augmenting activity in spared CS circuits would restore the skilled motor control lost after injury and augment outgrowth of CS terminations in the spinal cord. After selective injury of one half of the CS tract (CST) in the rat, we applied 10 d of electrical stimulation to the forelimb area of motor cortex of the spared half and tested motor performance for 30 d. Rats with injury and CST stimulation showed substantial improvements in skilled paw placement while walking over a horizontal ladder. By the end of the testing period, the walking errors of the previously impaired forelimb in rats with injury and stimulation returned to baseline, while the errors remained elevated in rats with injury only. Whereas the time to perform the task returned to normal in all animals, the pattern of errors returned to normal only in the stimulated group. Electrical stimulation also caused robust outgrowth of CST axon terminations in the ipsilateral spinal cord, the side of impairment, compared with rats with injury only. The outgrowth was directed to the normal gray matter territory of ipsilateral CST axon terminations. Thus, stimulation of spared CS circuits induced substantial axon outgrowth to the largely denervated side of the spinal cord and restored normal motor control in the previously impaired limbs.