Serial treatments of primed low-frequency rTMS in stroke: characteristics of responders vs. nonresponders

Evaluation of Contralateral Limb Cross Education and High-Frequency Repetitive Transcranial Magnetic Stimulation on Functional Indices of the Affected Upper Limb in Subacute Phase of Stroke

Background

Stroke is one of the causes of long-term morbidity. Despite rehabilitation strategies, most survivors live with motor deficits in the upper limbs.

Objectives

The aim of the study was to compare the effect of contralateral cross education (CE) and high-frequency repetitive magnetic stimulation (HF-rTMS) on the function of upper extremity in subacute phase of stroke.

Methods

Forty patients were randomly assigned into 4 groups. Group "A" received physical therapy (PT) for 10 sessions, 3 times per week. Group "B" received PT and HF-rTMS as follows: stimulation of 20 Hz for 5 s, intertrain interval for 50 s, 20 trains, 2000 pulses at 90% resting motor threshold, and conventional PT. Group "C" was treated with CE and PT. In group "D," HF-rTMS, CE, and PT were administered.

Results

Significant differences were found in the Fugl-Meyer scale between "A" and "C" (P = 0.01), "A" and "D" (P = 0.02), and "B" and "C" groups (P = 0.01). In the box-block test, there were significant differences between "A" and "B" (P = 0.01), "A" and "C" (P < 0.001), "B" and "D" (P = 0.001), and "B" and "C" groups (P = 0.01). Statistical differences were observed in grip strength between "A" and "B" (P = 0.01) and "A" and "C" groups (P = 0.02).

Conclusions

It is suggested that clinicians select the therapeutic methods in line with their expected goal. When the goal is to improve upper extremity function, CE+PT could be more effective than HF-rTMS+PT. Also, CE+PT and HF-rTMS+PT were more effective than CE+HF-rTMS+PT at improving grip strength. Therefore, combining several methods would not always lead to better results.

Repetitive Transcranial Magnetic Stimulation of Primary Motor Cortex for stroke upper limb motor sequelae rehabilitation: A systematic review

BACKGROUND: Repetitive Transcranial Magnetic Stimulation (rTMS) over the primary motor cortex (M1) has been used to treat stroke motor sequelae regulating cortical excitability. Early interventions are widely recommended, but there is also evidence showing interventions in subacute or chronic phases are still useful. OBJECTIVE: To synthetize the evidence of rTMS protocols to improve upper limb motor function in people with subacute and/or chronic stroke. METHODS: Four databases were searched in July 2022. Clinical trials investigating the effectiveness of different rTMS protocols on upper limb motor function in subacute or chronic phases post-stroke were included. PRISMA guidelines and PEDro scale were used. RESULTS: Thirty-two studies representing 1137 participants were included. Positive effects of all types of rTMS protocols on upper limb motor function were found. These effects were heterogeneous and not always clinically relevant or related to neurophysiological changes but produced evident changes if evaluated with functional tests. CONCLUSION: rTMS interventions over M1 are effective for improving upper limb motor function in people with subacute and chronic stroke. When rTMS protocols were priming physical rehabilitation better effects were achieved. Studies considering minimal clinical differences and different dosing will help to generalize the use of these protocols in clinical practice.

Effects of transcranial magnetic stimulation in modulating cortical excitability in patients with stroke: a systematic review and meta-analysis

Background

Transcranial magnetic stimulation (TMS) has attracted plenty of attention as it has been proved to be effective in facilitating motor recovery in patients with stroke. The aim of this study was to systematically review the effects of repetitive TMS (rTMS) and theta burst stimulation (TBS) protocols in modulating cortical excitability after stroke.

Methods

A literature search was carried out using PubMed, Medline, EMBASE, CINAHL, and PEDro, to identify studies that investigated the effects of four rTMS protocols—low and high frequency rTMS, intermittent and continuous TBS, on TMS measures of cortical excitability in stroke. A random-effects model was used for all meta-analyses.

Results

Sixty-one studies were included in the current review. Low frequency rTMS was effective in decreasing individuals’ resting motor threshold and increasing the motor-evoked potential of the non-stimulated M1 (affected M1), while opposite effects occurred in the stimulated M1 (unaffected M1). High frequency rTMS enhanced the cortical excitability of the affected M1 alone. Intermittent TBS also showed superior effects in rebalancing bilateral excitability through increasing and decreasing excitability within the affected and unaffected M1, respectively. Due to the limited number of studies found, the effects of continuous TBS remained inconclusive. Motor impairment was significantly correlated with various forms of TMS measures.

Conclusions

Except for continuous TBS, it is evident that these protocols are effective in modulating cortical excitability in stroke. Current evidence does support the effects of inhibitory stimulation in enhancing the cortical excitability of the affected M1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-022-00999-4.

Predicting Individual Treatment Response to rTMS for Motor Recovery After Stroke: A Review and the CanStim Perspective

Background

Rehabilitation is critical for reducing stroke-related disability and improving quality-of-life post-stroke. Repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique used as stand-alone or adjunct treatment to physiotherapy, may be of benefit for motor recovery in subgroups of stroke patients. The Canadian Platform for Trials in Non-Invasive Brain Stimulation (CanStim) seeks to advance the use of these techniques to improve post-stroke recovery through clinical trials and pre-clinical studies using standardized research protocols. Here, we review existing clinical trials for demographic, clinical, and neurobiological factors which may predict treatment response to identify knowledge gaps which need to be addressed before implementing these parameters for patient stratification in clinical trial protocols.

Objective

To provide a review of clinical rTMS trials of stroke recovery identifying factors associated with rTMS response in stroke patients with motor deficits and develop research perspectives for pre-clinical and clinical studies.

Methods

A literature search was performed in PubMed, using the Boolean search terms stroke AND repetitive transcranial magnetic stimulation OR rTMS AND motor for studies investigating the use of rTMS for motor recovery in stroke patients at any recovery phase. A total of 1,676 articles were screened by two blinded raters, with 26 papers identified for inclusion in this review.

Results

Multiple possible factors associated with rTMS response were identified, including stroke location, cortical thickness, brain-derived neurotrophic factor (BDNF) genotype, initial stroke severity, and several imaging and clinical factors associated with a relatively preserved functional motor network of the ipsilesional hemisphere. Age, sex, and time post-stroke were generally not related to rTMS response. Factors associated with greater response were identified in studies of both excitatory ipsilesional and inhibitory contralesional rTMS. Heterogeneous study designs and contradictory data exemplify the need for greater protocol standardization and high-quality controlled trials.

Conclusion

Clinical, brain structural and neurobiological factors have been identified as potential predictors for rTMS response in stroke patients with motor impairment. These factors can inform the design of future clinical trials, before being considered for optimization of individual rehabilitation therapy for stroke patients. Pre-clinical models for stroke recovery, specifically developed in a clinical context, may accelerate this process.

Resting motor threshold in the course of hand motor recovery after stroke: a systematic review

Background

Resting motor threshold is an objective measure of cortical excitability. Numerous studies indicate that the success of motor recovery after stroke is significantly determined by the direction and extent of cortical excitability changes. A better understanding of this topic (particularly with regard to the level of motor impairment and the contribution of either cortical hemisphere) may contribute to the development of effective therapeutical strategies in this cohort.

Objectives

This systematic review collects and analyses the available evidence on resting motor threshold and hand motor recovery in stroke patients.

Methods

PubMed was searched from its inception through to 31/10/2020 on studies investigating resting motor threshold of the affected and/or the non-affected hemisphere and motor function of the affected hand in stroke cohorts.

Results

Overall, 92 appropriate studies (including 1978 stroke patients and 377 healthy controls) were identified. The analysis of the data indicates that severe hand impairment is associated with suppressed cortical excitability within both hemispheres and with great between-hemispheric imbalance of cortical excitability. Favorable motor recovery is associated with an increase of ipsilesional motor cortex excitability and reduction of between-hemispheric imbalance. The direction of change of contralesional motor cortex excitability depends on the amount of hand motor impairment. Severely disabled patients show an increase of contralesional motor cortex excitability during motor recovery. In contrast, recovery of moderate to mild hand motor impairment is associated with a decrease of contralesional motor cortex excitability.

Conclusions

This data encourages a differential use of rehabilitation strategies to modulate cortical excitability. Facilitation of the ipsilesional hemisphere may support recovery in general, whereas facilitation and inhibition of the contralesional hemisphere may enhance recovery in severe and less severely impaired patients, respectively.

Effects of coupling inhibitory and facilitatory repetitive transcranial magnetic stimulation on motor recovery in patients following acute cerebral infarction

BACKGROUND

The treatment for patients suffering from motor dysfunction following stroke using continuous repetitive transcranial magnetic stimulation (rTMS) has the potential to be beneficial for recovery. However, the impact of explicit results on the coupling of various rTMS protocols on motor treatment in patients following acute cerebral infarction remain unexplored.

OBJECTIVE

The current study aims to design a sham-controlled randomized report to explore the capability of consecutive suppressive-facilitatory rTMS method to increase the motor results following acute stroke.

METHODS

A hundred ischemic stroke patients suffering from motor disorder were randomly assigned to obtain 4 week sessions of (1)10 Hz over the ipsilesional primary motor cortex (M1) and next 1 Hz over the contralesional M1; (2) contralesional sham stimulation and next ipsilesional real 10 Hz; (3) contralesional real 1 Hz rTMS and next ipsilesional sham stimulation; or (4) bilateral sham-control procedures. At 24 hours before and after the intervention, we obtained cortical excitability data from study subjects. At baseline, after treatment and 3 months follow up, we additionally evaluated patients with the clinical assessments.

RESULTS

At post-intervention, group A showed greater motor improvements in FMA, FMA-UL, NIHSS, ADL and mRS values than group B, group C and group D, that were continued for at least 3 months after the completion of the treatment time. Specifically, it is shown in the cortical excitability study that the motor-evoked potential (MEP) amplitude and resting motor threshold (rMT) more significantly improved in group A than other groups. The improvement in motor function and change in motor cortex excitability exhibit a significant correlation in the affected hemisphere. The combined 1 Hz and 10 Hz stimulation treatment showed a synergistic effect.

CONCLUSIONS

Facilitatory rTMS and coupling inhibitory produced extra satisfactory results in facilitating the motor's recovery in the subacute and acute phase following stroke compared to that acquired from alone single-course modulation.

Virtual Reality Meets Non-invasive Brain Stimulation: Integrating Two Methods for Cognitive Rehabilitation of Mild Cognitive Impairment

Mild cognitive impairment (MCI) refers to a subtle, general cognitive decline with a detrimental impact on elderlies' independent living and quality of life. Without a timely diagnosis, this condition can evolve into dementia over time, hence the crucial need for early detection, prevention, and rehabilitation. For this purpose, current neuropsychological interventions have been integrated with (i) virtual reality, which immerses the user in a controlled, ecological, and safe environment (so far, both virtual reality-based cognitive and motor rehabilitation have revealed promising positive outcomes); and (ii) non-invasive brain stimulation, i.e., transcranial magnetic or electric brain stimulation, which has emerged as a promising cognitive treatment for MCI and Alzheimer's dementia. To date, these two methods have been employed separately; only a few studies (limited to motor rehabilitation) have suggested their integration. The present paper suggests to extend this integration to cognitive rehabilitation as well as to provide a multimodal stimulation that could enhance cognitive training, resulting in a more efficient rehabilitation.

The effects of five sessions of continuous theta burst stimulation over contralesional sensorimotor cortex paired with paretic skilled motor practice in people with chronic stroke

BACKGROUND

In individuals with chronic stroke, impairment of the paretic arm may be exacerbated by increased contralesional transcallosal inhibition (TCI). Continuous theta burst stimulation (cTBS) can decrease primary motor cortex (M1) excitability and TCI. However, contralesional cTBS shows inconsistent effects after stroke. Variable effects of cTBS could stem from failure to pair stimulation with skilled motor practice or a focus of applying cTBS over M1.

OBJECTIVE

Here, we investigated the effects of pairing cTBS with skilled practice on motor learning and arm function. We considered the differential effects of stimulation over two different brain regions: contralesional M1 (M1c) or contralesional primary somatosensory cortex (S1c).

METHODS

37 individuals with chronic stroke participated in five sessions of cTBS and paretic arm skilled practice of a serial targeting task (STT); participants received either cTBS over M1c or S1c or sham before STT practice. Changes in STT performance and Wolf Motor Function Test (WMFT) were assessed as primary outcomes. Assessment of bilateral corticospinal, intracortical excitability and TCI were secondary outcomes.

RESULTS

cTBS over sensorimotor cortex did not improve STT performance and paretic WMFT-rate beyond sham cTBS. TCI was reduced bi-directionally following the intervention, regardless of stimulation group. In addition, we observed an association between STT performance change and paretic WMFT-rate change in the M1c stimulation group only.

CONCLUSIONS

Multiple sessions of STT practice can improve paretic arm function and decrease TCI bilaterally, with no additional benefit of prior cTBS. Our results suggest that improvement in STT practice following M1c cTBS scaled with change in paretic arm function in some individuals. Our results highlight the need for a better understanding of the mechanisms of cTBS to effectively identify who may benefit from this form of brain stimulation.

White Matter Biomarkers Associated with Motor Change in Individuals with Stroke: A Continuous Theta Burst Stimulation Study

Continuous theta burst stimulation (cTBS) is a form of noninvasive repetitive brain stimulation that, when delivered over the contralesional hemisphere, can influence the excitability of the ipsilesional hemisphere in individuals with stroke. cTBS applied prior to skilled motor practice interventions may augment motor learning; however, there is a high degree of variability in individual response to this intervention. The main objective of the present study was to assess white matter biomarkers of response to cTBS paired with skilled motor practice in individuals with chronic stroke. We tested the effects of stimulation of the contralesional hemisphere at the site of the primary motor cortex (M1c) or primary somatosensory cortex (S1c) and a third group who received sham stimulation. Within each stimulation group, individuals were categorized into responders or nonresponders based on their capacity for motor skill change. Baseline diffusion tensor imaging (DTI) indexed the underlying white matter microstructure of a previously known motor learning network, named the constrained motor connectome (CMC), as well as the corticospinal tract (CST) of lesioned and nonlesioned hemispheres. Across practice, there were no differential group effects. However, when categorized as responders vs. nonresponders using change in motor behaviour, we demonstrated a significant difference in CMC microstructural properties (as measured by fractional anisotropy (FA)) for individuals in M1c and S1c groups. There were no significant differences between responders and nonresponders in clinical baseline measures or microstructural properties (FA) in the CST. The present study identifies a white matter biomarker, which extends beyond the CST, advancing our understanding of the importance of white matter networks for motor after stroke.

Stepping Up to Rethink the Future of Rehabilitation: IV STEP Considerations and Inspirations

BACKGROUND AND PURPOSE

The IV STEP conference challenged presenters and participants to consider the state of science in rehabilitation, highlighting key area of progress since the previous STEP conference related to prediction, prevention, plasticity, and participation in rehabilitation.

KEY POINTS

Emerging from the thought-provoking discussions was recognition of the progress we have made as a profession and a call for future growth. In this summary article, we present a recap of the key points and call for action. We review the information presented and the field at large as it relates to the 4 Ps: prediction, prevention, plasticity, and participation.

RECOMMENDATIONS FOR PRACTICE

Given that personalized medicine is an increasingly important approach that was clearly woven throughout the IV STEP presentations, we took the liberty of adding a fifth "P," Personalized, in our discussion of the future direction of the profession.

Video evidence of improved hand function following repetitive transcranial magnetic stimulation combined with physical therapy in stroke: a case report

In a 46‐year‐old female 6 months poststroke who presented with minimal paretic hand function, repetitive transcranial magnetic stimulation (rTMS), and exercises considerably improved her function beyond that accomplished with conventional rehabilitation. However, intermittent rTMS (2 sessions/week) was required to sustain the benefits. Research is required to determine the critical frequency of intermittent rTMS needed to sustain functional gains long term.

Combined rTMS and virtual reality brain-computer interface training for motor recovery after stroke

OBJECTIVE

Combining repetitive transcranial magnetic stimulation (rTMS) with brain-computer interface (BCI) training can address motor impairment after stroke by down-regulating exaggerated inhibition from the contralesional hemisphere and encouraging ipsilesional activation. The objective was to evaluate the efficacy of combined rTMS  +  BCI, compared to sham rTMS  +  BCI, on motor recovery after stroke in subjects with lasting motor paresis.

APPROACH

Three stroke subjects approximately one year post-stroke participated in three weeks of combined rTMS (real or sham) and BCI, followed by three weeks of BCI alone. Behavioral and electrophysiological differences were evaluated at baseline, after three weeks, and after six weeks of treatment.

MAIN RESULTS

Motor improvements were observed in both real rTMS  +  BCI and sham groups, but only the former showed significant alterations in inter-hemispheric inhibition in the desired direction and increased relative ipsilesional cortical activation from fMRI. In addition, significant improvements in BCI performance over time and adequate control of the virtual reality BCI paradigm were observed only in the former group.

SIGNIFICANCE

When combined, the results highlight the feasibility and efficacy of combined rTMS  +  BCI for motor recovery, demonstrated by increased ipsilesional motor activity and improvements in behavioral function for the real rTMS  +  BCI condition in particular. Our findings also demonstrate the utility of BCI training alone, as shown by behavioral improvements for the sham rTMS  +  BCI condition. This study is the first to evaluate combined rTMS and BCI training for motor rehabilitation and provides a foundation for continued work to evaluate the potential of both rTMS and virtual reality BCI training for motor recovery after stroke.

Non-Invasive Brain Stimulation in Children With Unilateral Cerebral Palsy: A Protocol and Risk Mitigation Guide

Non-invasive brain stimulation has been increasingly investigated, mainly in adults, with the aims of influencing motor recovery after stroke. However, a consensus on safety and optimal study design has not been established in pediatrics. The low incidence of reported major adverse events in adults with and without clinical conditions has expedited the exploration of NIBS in children with paralleled purposes to influence motor skill development after neurological injury. Considering developmental variability in children, with or without a neurologic diagnosis, adult dosing and protocols may not be appropriate. The purpose of this paper is to present recommendations and tools for the prevention and mitigation of adverse events (AEs) during NIBS in children with unilateral cerebral palsy (UCP). Our recommendations provide a framework for pediatric NIBS study design. The key components of this report on NIBS AEs are (a) a summary of related literature to provide the background evidence and (b) tools for anticipating and managing AEs from four international pediatric laboratories. These recommendations provide a preliminary guide for the assessment of safety and risk mitigation of NIBS in children with UCP. Consistent reporting of safety, feasibility, and tolerability will refine NIBS practice guidelines contributing to future clinical translations of NIBS.

Interhemispheric Pathways Are Important for Motor Outcome in Individuals with Chronic and Severe Upper Limb Impairment Post Stroke

Background

Severity of arm impairment alone does not explain motor outcomes in people with severe impairment post stroke.

Objective

Define the contribution of brain biomarkers to upper limb motor outcomes in people with severe arm impairment post stroke.

Methods

Paretic arm impairment (Fugl-Meyer upper limb, FM-UL) and function (Wolf Motor Function Test rate, WMFT-rate) were measured in 15 individuals with severe (FM-UL ≤ 30/66) and 14 with mild–moderate (FM-UL > 40/66) impairment. Transcranial magnetic stimulation and diffusion weight imaging indexed structure and function of the corticospinal tract and corpus callosum. Separate models of the relationship between possible biomarkers and motor outcomes at a single chronic (≥6 months) time point post stroke were performed.

Results

Age (ΔR²0.365, p = 0.017) and ipsilesional-transcallosal inhibition (ΔR²0.182, p = 0.048) explained a 54.7% (p = 0.009) variance in paretic WMFT-rate. Prefrontal corpus callous fractional anisotropy (PF-CC FA) alone explained 49.3% (p = 0.007) variance in FM-UL outcome. The same models did not explain significant variance in mild–moderate stroke. In the severe group, k-means cluster analysis of PF-CC FA distinguished two subgroups, separated by a clinically meaningful and significant difference in motor impairment (p = 0.049) and function (p = 0.006) outcomes.

Conclusion

Corpus callosum function and structure were identified as possible biomarkers of motor outcome in people with chronic and severe arm impairment.

Stepping Up to Rethink the Future of Rehabilitation: IV STEP Considerations and Inspirations

BACKGROUND AND PURPOSE

The IV STEP conference challenged presenters and participants to consider the state of science in rehabilitation, highlighting key area of progress since the previous STEP conference related to prediction, prevention, plasticity, and participation in rehabilitation.

KEY POINTS

Emerging from the thought-provoking discussions was recognition of the progress we have made as a profession and a call for future growth. In this summary article, we present a recap of the key points and call for action. We review the information presented and the field at large as it relates to the 4 Ps: prediction, prevention, plasticity, and participation.

RECOMMENDATIONS FOR PRACTICE

Given that personalized medicine is an increasingly important approach that was clearly woven throughout the IV STEP presentations, we took the liberty of adding a fifth "P," Personalized, in our discussion of the future direction of the profession.

Using theoretical models from adult stroke recovery to improve use of noninvasive brain stimulation for children with congenital hemiparesis

Noninvasive brain stimulation has been widely used for adults with stroke to improve upper limb motor function. A recent study by Kirton and colleagues (Kirton A, Ciechanski P, Zewdie E, Andersen J, Nettel-Aguirre A, Carlson H, Carsolio L, Herrero M, Quigley J, Mineyko A, Hodge J, Hill M. Neurology 88: 259-267, 2017) applied noninvasive brain stimulation to children with congenital hemiparesis but found no significant effect of noninvasive brain stimulation on motor function. Here, we explore theories about cortical reorganization in both adult and children with hemiparesis and discuss how to improve the approaches of noninvasive brain stimulation to generate optimal motor improvement and development for children with congenital hemiparesis.

Importance and Difficulties of Pursuing rTMS Research in Acute Stroke

Although much research has been done on repetitive transcranial magnetic stimulation (rTMS) in chronic stroke, only sparse research has been done in acute stroke despite the particularly rich potential for neuroplasticity in this stage. We attempted a preliminary clinical trial in one active, high-quality inpatient rehabilitation facility (IRF) in the -United States. But after enrolling only 4 patients in the grant period, the study was stopped because of low enrollment. The purpose of this paper is to offer a perspective describing the important physiologic rationale for including rTMS in the early phase of stroke, the reasons for our poor patient enrollment in our attempted study, and recommendations to help future studies succeed. We conclude that, if scientists and clinicians hope to enhance stroke outcomes, more attention must be directed to leveraging conventional rehabilitation with neuromodulation in the acute phase of stroke when the capacity for neuroplasticity is optimal. Difficulties with patient enrollment must be addressed by reassessing traditional inclusion and exclusion criteria. Factors that shorten patients' length of stay in the IRF must also be reassessed at all policy-making levels to make ethical decisions that promote higher functional outcomes while retaining cost consciousness.

N-of-1 Trial in Person with Pontine Stroke Receiving Repetitive Transcranial Magnetic Stimulation to Improve Hand Function

Stroke characteristics vary widely between individuals making it difficult to assess the value of stroke rehabilitation interventions. To eliminate inter-subject variability, this study used an N-of-1 randomized, controlled design to explore the efficacy of repetitive transcranial magnetic stimulation (rTMS) in one unique individual with pontine stroke. We hypothesized that five days of active 6-Hz primed, low-frequency rTMS to the contralesional primary motor area (M1), combined with finger movement tracking training, would accomplish greater gains in hand function than sham rTMS combined with tracking training. We assessed hand function (Box and Block test and finger tracking test), cortical activation (laterality index during functional magnetic resonance imaging), and cortical excitability (interhemispheric inhibition testing (IHI) with transcranial magnetic stimulation (TMS)). Diffusion tensor imaging (DTI) assessed the integrity of his corticospinal tracts at baseline. Results showed no improvement in the Box and Block or finger tracking tests, unreliable IHI findings, and no change in laterality index following active rTMS. DTI suggested truncation of the left corticospinal tract (CST) at the pons. His non-dexterous hand movements combined with no elicitable motor evoked potentials with TMS to ipsilesional M1 and his DTI findings lead us to speculate a reticulospinal mechanism for preserving his rudimentary paretic hand control. We conclude that rTMS combined with tracking training was not effective in the absence of CST pathways and that research is needed to confirm markers of reticulospinal function in humans as an alternative to defective CST function.

Repetitive Transcranial Magnetic Stimulation/Behavioral Intervention Clinical Trial: Long-Term Follow-Up of Outcomes in Congenital Hemiparesis

OBJECTIVE

The purpose of this study was to examine long-term outcomes of nonpharmacological intervention in children and adolescents with stroke utilizing repetitive transcranial magnetic stimulation (rTMS) to the primary motor cortex combined with constraint- induced movement therapy (CIMT) to improve motor function in the paretic hand. Outcome measures included function, satisfaction, and medical status review.

METHODS

Fourteen of the original 19 participants (74%) from our rTMS/CIMT clinical trial (real rTMS+CIMT, n = 8; and sham rTMS+CIMT, n = 6) were evaluated. The median age of the subjects at follow up was 13.4 years (range 11-20 years old, 50% male). Median time to follow-up was 47.5 months (range 21-57 months). Descriptive statistics were conducted using frequencies and counts. Motor performance was measured using the Assisting Hand Assessment (AHA) and Canadian Occupational Performance Measure (COPM). Satisfaction was reported with use of the COPM and TMS Tolerance Survey. Open-ended interview was conducted for feedback on study experience and subjective perspectives of current functional status.

RESULTS

Overall, seven of eight individuals who received real rTMS and five of six individuals who received sham rTMS maintained or improved AHA scores. Six of 14 participants reported new onset of co-occurring conditions (four individuals in the real rTMS group, two individuals in the sham rTMS group). The majority (86%) of participants reported study satisfaction. Review of medical status revealed co-occurring conditions including: Epilepsy, obsessive-compulsive disorder, anxiety, depression, unspecified mood disorder, and undiagnosed inattentiveness.

CONCLUSIONS

Long-term outcomes of rTMS/CIMT in pediatric stroke were investigated. Variability in performance and unattributed symptoms were noted. Considering the prevalence of co-occurring conditions in children and adolescents with stroke, new-onset symptoms were not attributed to original intervention. With the small sample size, the impact of rTMS on long-term outcomes cannot be fully determined from these data. Characterizing long-term outcomes through performance, participant perspectives, and medical status allows comprehensive assessment of rTMS/CIMT intervention efficacy.

Depressive symptoms influence use of feedback for motor learning and recovery in chronic stroke

PURPOSE

Sensorimotor impairments and depressive symptoms (PSD) influence arm motor recovery post-stroke. Feedback provision improves upper limb motor learning in patients with chronic stroke but factors including PSD may affect ability to use feedback. We evaluated the influence of PSD on the ability to use auditory feedback for upper limb recovery and motor learning in patients with chronic stroke.

METHODS

Participants (n = 24) practiced 72 pointing movements/session (6 targets, 12 sessions, randomized) with auditory feedback on movement speed and trunk displacement. The presence of PSD (Beck's Depression Inventory; BDI-II) was assessed at pre-intervention (PRE). Arm motor impairment (Fugl-Meyer Assessment, shoulder horizontal adduction, shoulder flexion, elbow extension ranges, trunk displacement) and arm use (Motor Activity Log) were assessed at PRE, immediately after (POST) and retention (3 mos; RET). Participants were divided into two groups based on BDI-II scores: ≥ 14/63 (DEP group; n = 8; score: 20.5 ± 7.5) and ≤ 13/63 (no PSD (ND) group; n = 16; score: 5.0 ± 3.8). Changes in impairment and arm use levels were assessed (mixed-model ANOVAs).

RESULTS

All participants improved arm use. DEP had lower Fugl-Meyer scores, used more compensatory trunk displacement and had lower shoulder horizontal adduction range compared to ND.

CONCLUSION

The presence of PSD diminished the ability to use auditory feedback for arm motor recovery and motor learning.

Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol

Background

Perinatal stroke occurs in more than 1 in 2,500 live births and resultant congenital hemiparesis necessitates investigation into interventions which may improve long-term function and decreased burden of care beyond current therapies (http://www.cdc.gov/ncbddd/cp/data.html). Constraint-Induced Movement Therapy (CIMT) is recognized as an effective hemiparesis rehabilitation intervention . Transcranial direct current stimulation as an adjunct treatment to CIMT may potentiate neuroplastic responses and improve motor function. The methodology of a clinical trial in children designed as a placebo-controlled, serial –session, non-invasive brain stimulation trial incorporating CIMT is described here. The primary hypotheses are 1) that no serious adverse events will occur in children receiving non-invasive brain stimulation and 2) that children in the stimulation intervention group will show significant improvements in hand motor function compared to children in the placebo stimulation control group.

Methods/design

A randomized, controlled, double-blinded clinical trial. Twenty children and/or young adults (ages 8–21) with congenital hemiparesis, will be enrolled. The intervention group will receive ten 2-hour sessions of transcranial direct current stimulation combined with constraint-induced movement therapy and the control group will receive sham stimulation with CIMT. The primary outcome measure is safety assessment of transcranial direct current stimulation by physician evaluation, vital sign monitoring and symptom reports. Additionally, hand function will be evaluated using the Assisting Hand Assessment, grip strength and assessment of goals using the Canadian Occupational Performance Measure. Neuroimaging will confirm diagnoses, corticospinal tract integrity and cortical activation. Motor cortical excitability will also be examined using transcranial magnetic stimulation techniques.

Discussion

Combining non-invasive brain stimulation and CIMT interventions has the potential to improve motor function in children with congenital hemiparesis beyond each intervention independently. Such a combined intervention has the potential to benefit an individual throughout their lifetime.

Trial registration

Clinicaltrials.gov, NCT02250092Registered 18 September 2014

A Review of Transcranial Magnetic Stimulation and Multimodal Neuroimaging to Characterize Post-Stroke Neuroplasticity

Following stroke, the brain undergoes various stages of recovery where the central nervous system can reorganize neural circuitry (neuroplasticity) both spontaneously and with the aid of behavioral rehabilitation and non-invasive brain stimulation. Multiple neuroimaging techniques can characterize common structural and functional stroke-related deficits, and importantly, help predict recovery of function. Diffusion tensor imaging (DTI) typically reveals increased overall diffusivity throughout the brain following stroke, and is capable of indexing the extent of white matter damage. Magnetic resonance spectroscopy (MRS) provides an index of metabolic changes in surviving neural tissue after stroke, serving as a marker of brain function. The neural correlates of altered brain activity after stroke have been demonstrated by abnormal activation of sensorimotor cortices during task performance, and at rest, using functional magnetic resonance imaging (fMRI). Electroencephalography (EEG) has been used to characterize motor dysfunction in terms of increased cortical amplitude in the sensorimotor regions when performing upper limb movement, indicating abnormally increased cognitive effort and planning in individuals with stroke. Transcranial magnetic stimulation (TMS) work reveals changes in ipsilesional and contralesional cortical excitability in the sensorimotor cortices. The severity of motor deficits indexed using TMS has been linked to the magnitude of activity imbalance between the sensorimotor cortices. In this paper, we will provide a narrative review of data from studies utilizing DTI, MRS, fMRI, EEG, and brain stimulation techniques focusing on TMS and its combination with uni- and multimodal neuroimaging methods to assess recovery after stroke. Approaches that delineate the best measures with which to predict or positively alter outcomes will be highlighted.

A Comparison of Primed Low-frequency Repetitive Transcranial Magnetic Stimulation Treatments in Chronic Stroke

BACKGROUND

Preceding low-frequency repetitive transcranial magnetic stimulation (rTMS) with a bout of high-frequency rTMS called priming potentiates the after-effects of the former in healthy adults. The utility of primed rTMS in stroke remains under-explored despite its theoretical benefits in enhancing cortical excitability and motor function.

OBJECTIVE

To ascertain the efficacy of priming in chronic stroke by comparing changes in cortical excitability and paretic hand function following three types of primed low-frequency rTMS treatments.

METHODS

Eleven individuals with chronic stroke participated in this repeated-measures study receiving three treatments to the contralesional primary motor cortex in randomized order: 6 Hz primed 1 Hz rTMS, 1 Hz primed 1 Hz rTMS, and sham 6 Hz primed active 1 Hz rTMS. Within- and between-treatment differences from baseline in cortical excitability and paretic hand function from baseline were analyzed using mixed effects linear models.

RESULTS

6 Hz primed 1 Hz rTMS produced significant within-treatment differences from baseline in ipsilesional cortical silent period (CSP) duration and short-interval intracortical inhibition. Compared to 1 Hz priming and sham 6 Hz priming of 1 Hz rTMS, active 6 Hz priming generated significantly greater decreases in ipsilesional CSP duration. These heightened effects were not observed for intracortical facilitation or interhemispheric inhibition excitability measures.

CONCLUSION

Our findings demonstrate the efficacy of 6 Hz primed 1 Hz rTMS in probing homeostatic plasticity mechanisms in the stroke brain as best demonstrated by differences CSP duration and SICI from baseline. Though 6 Hz priming did not universally enhance cortical excitability across measures, our findings pose important implications in non-invasive brain stimulation application in stroke rehabilitation.