Induction of central nervous system plasticity by repetitive transcranial magnetic stimulation to promote sensorimotor recovery in incomplete spinal cord injury

Effect of Intermittent Theta Burst Stimulation Dual-Target Stimulation on Lower Limb Function in Patients with Incomplete Spinal Cord Injury: A Randomized, Single-Blind, Sham-Controlled Study

OBJECTIVE

To explore the influence of intermittent theta burst stimulation (iTBS) dual-target stimulation on lower limb function in patients with incomplete spinal cord injury (iSCI).

METHODS

A randomized, single -blind, sham-controlled trial was used in this study. Thirty iSCI patients with lower limb dysfunction meeting the inclusion criteria were randomly divided into a sham group and an iTBS group, with 15 cases in each group. The iTBS group received conventional rehabilitation therapy combined with iTBS dual-target stimulation on the central cerebral sulcus and the nerve root of the spinal cord injury segment. The sham group was treated with conventional rehabilitation therapy combined with iTBS dual-target sham stimulation therapy. Comprehensive functional assessment was performed on all patients before treatment, on the day 3 and day 21 of treatment. The main evaluation indicators were as follows: amplitude and latency of motor-evoked potential (MEP) in the anterior tibial muscles of both lower limbs, latency of sensory-evoked potential (SEP) of both lower limbs, knee flexor strength and knee extensor strength, lower extremity motor score (LEMS), lower extremity sensory score, spinal cord independence measure (SCIM) score, and gait parameters (stride speed, stride frequency, stride length, and ground reaction force).

RESULTS

On day 21 of treatment, in the iTBS group, the MEP amplitude of the anterior tibial muscles increased, the latency of MEP shortened, knee flexor strength and knee extensor strength increased, and the LEMS and SCIM score of both lower limbs increased. In addition, there were statistically significant differences in the muscle strength of the knee flexion muscle, knee extensor muscle, MEP amplitude, LEMS, and SCIM between the 2 groups (P < 0.05). Among the 10 patients who could walk with an assisted walker, the step length and step frequency of the iTBS group were increased compared with the sham group after treatment (P < 0.01), and the ground reaction force was increased (P < 0.05). There was no significant difference in the lower extremity sensory score of the lower limbs between the 2 groups (P > 0.05).

CONCLUSIONS

ITBS dual-target stimulation can significantly improve the motor function of both lower limbs in patients with iSCI but does not significantly improve the sensory function of both lower limbs. Therefore, this treatment mode may participate in the reconstruction and repair of some nerve circuits in patients with iSCI. In addition, iTBS dual-target stimulation can improve the ability of iSCI patients to perform daily living.

Model-based analysis of the acute effects of transcutaneous magnetic spinal cord stimulation on micturition after spinal cord injury in humans

AIM

After spinal cord injuries (SCIs), patients may develop either detrusor-sphincter dyssynergia (DSD) or urinary incontinence, depending on the level of the spinal injury. DSD and incontinence reflect the loss of coordinated neural control among the detrusor muscle, which increases bladder pressure to facilitate urination, and urethral sphincters and pelvic floor muscles, which control the bladder outlet to restrict or permit bladder emptying. Transcutaneous magnetic stimulation (TMS) applied to the spinal cord after SCI reduced DSD and incontinence. We defined, within a mathematical model, the minimum neuronal elements necessary to replicate neurogenic dysfunction of the bladder after a SCI and incorporated into this model the minimum additional neurophysiological features sufficient to replicate the improvements in bladder function associated with lumbar TMS of the spine in patients with SCI.

METHODS

We created a computational model of the neural circuit of micturition based on Hodgkin-Huxley equations that replicated normal bladder function. We added interneurons and increased network complexity to reproduce dysfunctional micturition after SCI, and we increased the density and complexity of interactions of both inhibitory and excitatory lumbar spinal interneurons responsive to TMS to provide a more diverse set of spinal responses to intrinsic and extrinsic activation of spinal interneurons that remains after SCI.

RESULTS

The model reproduced the re-emergence of a spinal voiding reflex after SCI. When we investigated the effect of monophasic and biphasic TMS at two frequencies applied at or below T10, the model replicated the improved coordination between detrusor and external urethral sphincter activity that has been observed clinically: low-frequency TMS (1 Hz) within the model normalized control of voiding after SCI, whereas high-frequency TMS (30 Hz) enhanced urine storage.

CONCLUSION

Neuroplasticity and increased complexity of interactions among lumbar interneurons, beyond what is necessary to simulate normal bladder function, must be present in order to replicate the effects of SCI on control of micturition, and both neuronal and network modifications of lumbar interneurons are essential to understand the mechanisms whereby TMS reduced bladder dysfunction after SCI.

Beneficial Effect of Repetitive Transcranial Magnetic Stimulation Combined With Physiotherapy After Cervical Spondylotic Myelopathy Surgery

PURPOSE

Cervical spondylotic myelopathy (CSM) is one of the most notable causes of spinal cord impairment among elderly people worldwide. Little is written about the influence of postoperative rehabilitation on recovery of function in patients with CSM. In this study, we assessed the combined effects of repetitive transcranial magnetic stimulation (rTMS) combined with physiotherapy and physiotherapy alone on motor and sensory improvement assessed after spinal cord decompression in patients with CSM.

METHODS

This prospective study comprised 52 patients with CSM; they were divided into two randomized groups after spinal cord decompression. The first group (group Ι) includes 26 patients, received a combination of rTMS and physiotherapy. The second group (group ΙΙ) of 26 patients underwent only physiotherapy. The neurologic assessment measures, including American Spinal Cord Injury Association score, modified Japanese Orthopaedic Association score, Ashworth scale, and Nurick grade, were recorded before and after rehabilitation interventions for each patient.

RESULTS

According to the neurologic assessment measures, physiotherapy with/without rTMS after surgical decompression corresponded to significant improvement of motor function ( P < 0. 01) without significant restoration of sensory function ( P > 0. 01). Recovery rates of motor function were significantly better in group Ι than in group ΙΙ ( P < 0. 01). There was no significant difference between two groups with respect to age ( P = 0.162) and sex ( P = 1.00).

CONCLUSIONS

Although physiotherapy with/without rTMS improves motor function recovery after CSM surgery, rTMS in combination with physiotherapy leads to a more rapid motor function recovery than physiotherapy alone.

Effects of central-peripheral FMS on urinary retention after spinal cord injury: a pilot randomized controlled trial protocol

Background

Urinary retention is a common complication of spinal cord injury (SCI), which can seriously affect the quality of life of patients. Function magnetic stimulation (FMS) has been widely used in the recovery of neurological function in various diseases, but its application in urinary retention after SCI remains unclear. Therefore, we would like to conduct a pilot randomized controlled trial (RCT) to observe the feasible effect of FMS on urinary retention after SCI, to explore its mechanism of action.

Method/design

This is a single-center pilot RCT, which 60 patients with urinary retention after SCI will be selected, numbered in chronological order of hospitalization, and randomly divided into 4 groups using the random number table method, Groups A (control group), Group B, Group C, and Group D; Each group will receive the same conventional rehabilitation treatment. The whole intervention period 2 weeks and will be evaluated before and after treatment to collect data on residual bladder volume, functional near-infrared spectroscopy (fNIRS), changes in voiding condition, changes in surface electromyography (SEMG) values of pelvic floor muscle and quality of life scores (QoL).

Study hypothesis

We hypothesized that FMS for the treatment of urinary retention after SCI would have a significant clinical feasible effect;and that peripheral combined with central FMS would be more effective than single-site FMS for the treatment of urinary retention after SCI.

Objective

(1) To illustrate the clinical effectiveness of FMS in the treatment of urinary retention after SCI and to provide a new treatment modality for the patients; (2) Comparison of the differences in the efficacy of central and peripheral single FMS and combined central and peripheral FMS in the treatment of urinary retention after SCI; (3) To explore the central control mechanisms of bladder function recovery after SCI in conjunction with changes in fNIRS.

Trial registration

This study has been ethically approved by the Scientific and Ethics Committee of the First Affiliated Hospital of Gannan Medical university with approval number (LLSC-2022112401). It has been registered with the China Clinical Trials Registry with the registration number: ChiCTR2200067143.

The effect of high-frequency repetitive transcranial magnetic stimulation on motor recovery and gait parameters in chronic incomplete spinal cord injury: A randomized-controlled study

Objectives

This study aims to examine the effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) on gait parameters and lower extremity motor recovery in a more specific sample of individuals with chronic and traumatic incomplete spinal cord injury (iSCI).

Patients and methods

This double-blind, sham-controlled, randomized study included a total of 28 individuals (20 males, 8 females; mean age: 35.7±12.1 years; range, 18 to 45 years) with chronic (>1 year) traumatic iSCI. The participants were randomly allocated to either sham rTMS group (n=14) or real rTMS group (n=14). We compared the groups based on the lower extremity motor scores (LEMS), the temporal-spatial gait measurements using three-dimensional gait analysis, the Walking Index for SCI-II (WISCI-II), and 10-m walking test at baseline, three weeks (post-treatment) and five weeks (follow-up) after the treatment.

Results

The real rTMS group revealed a significant improvement in walking speed, LEMS score, and 10-m walking test after the treatment compared to baseline (p=0.001, p=0.002, and p=0.023, respectively). Changes in the LEMS score were significantly increased in the real rTMS group compared to the sham group at both three and five weeks (p=0.001 and p=0.001, respectively). No significant difference was observed in the other variables between the groups (p>0.05).

Conclusion

Our study findings support the therapeutic effectiveness of rTMS on motor recovery in chronic iSCI. The rTMS can be used as an adjuvant therapy to conventional physiotherapy in the rehabilitation of patients with iSCI.

Effect of transcranial magnetic stimulation on functional outcome in patients with incomplete spinal cord injury: A randomized controlled study

Background. Incomplete spinal cord injury is a common disorder leading to sensory or motor function loss. Objective. This study aimed to investigate the effect of repetitive transcranial magnetic stimulation therapy (rTMS) on functional outcome in patients with incomplete spinal cord injury. Design. A prospective randomized controlled trial. Setting. Agouza Rehabilitation Hospital Out clinic. Methods. Forty male patients with chronic traumatic incomplete spinal cord injury aging from 25 to 45years. Patients were randomly divided into two equal groups (group A and group B).Group A was the study group that received rTMS in addition to designed physical therapy program including BWST training and Group B was the control group that received the same designed physical therapy program including BWST training. The functional gait was assessed using walking index for spinal cord injury (WISCI II) and gait speed was assessed using 10 m walk test. Measurements were performed before and after treatment and three months after end of the treatment as follow up. Results. There was a statistically significant improvement in WISCI II and 10m walk test at post treatment and follow up compared with that pre-treatment in study group (P < 0.05). There was no statistically significant improvement in all outcome variables at post treatment and follow up compared with that pretreatment in control group (P > 0.05).There was a statistically significant improvement in patients who received rTMS with BWST compared with patients received BWST only in WISCI II and 10 m walk test at post treatment (p = 0.01 and p = 0.001 respectively) compared to pre treatment. The gained effect was lost at follow up measurement compared to post treatment in WISCI II and the gained effect was maintained at follow up measurement compared to post treatment in 10m walk test score. Conclusion. It was proven that rTMS add a valuable effect for restoring function in patients with incomplete spinal cord injury, particularly in cases when the effect of BWST has reached a plateau.

The Role of Transcranial Magnetic Stimulation, Peripheral Electrotherapy, and Neurophysiology Tests for Managing Incomplete Spinal Cord Injury

Efforts to find therapeutic methods that support spinal cord functional regeneration continue to be desirable. Natural recovery is limited, so high hopes are being placed on neuromodulation methods which promote neuroplasticity, such as repetitive transcranial magnetic stimulation (rTMS) and electrical stimulation used as treatment options for managing incomplete spinal cord injury (iSCI) apart from kinesiotherapy. However, there is still no agreement on the methodology and algorithms for treatment with these methods. The search for effective therapy is also hampered by the use of different, often subjective in nature, evaluation methods and difficulties in assessing the actual results of the therapy versus the phenomenon of spontaneous spinal cord regeneration. In this study, an analysis was performed on the database of five trials, and the cumulative data are presented. Participants (iSCI patients) were divided into five groups on the basis of the treatment they had received: rTMS and kinesiotherapy (N = 36), peripheral electrotherapy and kinesiotherapy (N = 65), kinesiotherapy alone (N = 55), rTMS only (N = 34), and peripheral electrotherapy mainly (N = 53). We present changes in amplitudes and frequencies of the motor units’ action potentials recorded by surface electromyography (sEMG) from the tibialis anterior—the index muscle for the lower extremity and the percentage of improvement in sEMG results before and after the applied therapies. The increase in values in sEMG parameters represents the better ability of motor units to recruit and, thus, improvement of neural efferent transmission. Our results indicate that peripheral electrotherapy provides a higher percentage of neurophysiological improvement than rTMS; however, the use of any of these additional stimulation methods (rTMS or peripheral electrotherapy) provided better results than the use of kinesiotherapy alone. The best improvement of tibialis anterior motor units’ activity in iSCI patients provided the application of electrotherapy conjoined with kinesiotherapy and rTMS conjoined with kinesiotherapy. We also undertook a review of the current literature to identify and summarise available works which address the use of rTMS or peripheral electrotherapy as neuromodulation treatment options in patients after iSCI. Our goal is to encourage other clinicians to implement both types of stimulation into the neurorehabilitation program for subjects after iSCI and evaluate their effectiveness with neurophysiological tests such as sEMG so further results and algorithms can be compared across studies. Facilitating the motor rehabilitation process by combining two rehabilitation procedures together was confirmed.

Safety and effects of a therapeutic 15 Hz rTMS protocol administered at different suprathreshold intensities in able-bodied individuals

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) remains a promising strategy for neurorehabilitation. The stimulation intensity (SI) influences the aftereffects observed. Here, we examined whether single sessions of a 15 Hz rTMS protocol, administered at suprathreshold SI, can be safely administered to able-bodied (AB) individuals. Six right-handed men were included in this pilot study. HF-rTMS was delivered over the right M1, in 10 trains of 75 biphasic stimuli at 15 Hz, at 105-120% of the individual resting motor threshold (RMT). To assess safety, electromyography (EMG) was monitored to control for signs of spread of excitation and brief EMG burst (BEB) after stimulation. Additionally, TMS side effects questionnaires and the numeric rating scale (NRS) were administered during each session. We assessed corticospinal excitability (CSE) and motor performance changes with measures of resting (rMEP) and active (aMEP) motor evoked potential and grip strength and box and blocks test (BBT) scores, respectively. Overall, the sessions were tolerated and feasible without any pain development. However, EMG analysis during 15 Hz rTMS administration revealed increased BEB frequency with SI. Statistical models revealed an increase of CSE at rest (rMEP) but not during active muscle contraction (aMEP). No linear relationship was observed between 15 Hz rTMS SI and rMEP increase. No significant changes were highlighted for motor performance measures. Although feasible and tolerable by the AB individuals tested, the results demonstrate that when administered at suprathreshold intensities (≥ 105% RMT) the 15 Hz rTMS protocol reveals signs of persistent excitation, suggesting that safety precautions and close monitoring of participants should be performed when testing such combinations of high-intensity and high-frequency stimulation protocols. The results also give insight into the nonlinear existent relationship between the SI and HF-rTMS effects on CSE.NEW & NOTEWORTHY The results of this pilot study show the effects of a therapeutically promising 15 Hz repetitive transcranial magnetic stimulation (rTMS) protocol, administered at different suprathreshold intensities in able-bodied individuals. Although tolerable and feasible with a neuromodulatory potential, 15 Hz rTMS might result in persistent excitability that needs to be closely monitored if administered at suprathreshold stimulation intensity. These results reaffirm the importance of feasibility studies, especially in translational animal-to-human research.

Effect of transcutaneous posterior tibial nerve stimulation and repetitive transcranial magnetic stimulation on neurogenic overactive bladder symptoms in female patients with multiple sclerosis: The study protocol of a randomized controlled study

INTRODUCTION

Neurogenic bladder is frequently seen in patients with multiple sclerosis (MS). Electrical stimulation methods (neuromodulation) can be used for patients that have persistent symptoms despite pharmacological treatment. This study aims to compare the effects of two different neuromodulation techniques used in the treatment of neurogenic bladder.

METHODS AND ANALYSIS

This is a single-center randomized controlled trial for MS patients with neurogenic bladder. Patients determined to be eligible according to the study criteria will be randomized into two treatment groups: the transcutaneous posterior tibial nerve stimulation (PTNS) and repetitive transcranial magnetic stimulation (rTMS) groups. Each group will include eight patients. The patients will be treated for a total of 10 sessions for two consecutive weeks. The pressure-flow study will be used to compare the initial and final urodynamic results as the primary outcome. All the participants will fill in a 3-day bladder diary before and after the treatments in each group. Patients will also be asked to complete specific questionnaires for incontinence and quality of life (QOL): Overactive Bladder Questionnaire-V8 score (OAB-V8), Incontinence Severity Index (ISI), Incontinence Quality of Life Scale score (I-QOL), International Incontinence Questionnaire (ICIQ-SF) score, and International Consultation on Incontinence Questionnaire-Female Lower Urinary Tract Symptoms (ICIQ-FLUTS) score) as the secondary outcomes.

ETHICS AND DISSEMINATION

An ethical approval number was obtained from the Non-Invasive Clinical Research Ethics Committee of Istanbul Medipol University (ethical approval number: 768). Support was received within the scope of the Istanbul Medipol University Scientific Research Project with project number 2020-2017. The result of this study will be published in a peer-reviewed journal.

TRIAL REGISTRATION

NCT05312138.

High-Frequency rTMS Combined with Task-Specific Hand Motor Training Modulates Corticospinal Plasticity in Motor Complete Spinal Cord Injury: A case report

Since its first use in spinal cord injury (SCI) in the early 2000s [1], high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) demonstrated a capacity to modulate corticospinal excitability (CSE) and motor performance. Studies focused on individuals with incomplete SCI. Here, we examined the feasibility of a 15-day therapeutic stimulation protocol combining HF-rTMS with task-specific motor training targeting the weaker hand in an individual with early chronic complete SCI. In this case report, we present evidence of progressive increase of CSE at rest and during muscle activation, and decreased cortical inhibition, associated with a trend toward improvement in pinch function of the weaker hand. These promising findings need to be confirmed in a larger population. Clinical Relevance- These preliminary results are promising and demonstrate the importance of a large number of training session repetitions to induce consistent changes relevant to the recovery after a complete SCI.

Spinal Cord Injury and Loss of Cortical Inhibition

After spinal cord injury (SCI), the destruction of spinal parenchyma causes permanent deficits in motor functions, which correlates with the severity and location of the lesion. Despite being disconnected from their targets, most cortical motor neurons survive the acute phase of SCI, and these neurons can therefore be a resource for functional recovery, provided that they are properly reconnected and retuned to a physiological state. However, inappropriate re-integration of cortical neurons or aberrant activity of corticospinal networks may worsen the long-term outcomes of SCI. In this review, we revisit recent studies addressing the relation between cortical disinhibition and functional recovery after SCI. Evidence suggests that cortical disinhibition can be either beneficial or detrimental in a context-dependent manner. A careful examination of clinical data helps to resolve apparent paradoxes and explain the heterogeneity of treatment outcomes. Additionally, evidence gained from SCI animal models indicates probable mechanisms mediating cortical disinhibition. Understanding the mechanisms and dynamics of cortical disinhibition is a prerequisite to improve current interventions through targeted pharmacological and/or rehabilitative interventions following SCI.

Stimulation Parameters Used During Repetitive Transcranial Magnetic Stimulation for Motor Recovery and Corticospinal Excitability Modulation in SCI: A Scoping Review

There is a growing interest in non-invasive stimulation interventions as treatment strategies to improve functional outcomes and recovery after spinal cord injury (SCI). Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulatory intervention which has the potential to reinforce the residual spinal and supraspinal pathways and induce plasticity. Recent reviews have highlighted the therapeutic potential and the beneficial effects of rTMS on motor function, spasticity, and corticospinal excitability modulation in SCI individuals. For this scoping review, we focus on the stimulation parameters used in 20 rTMS protocols. We extracted the rTMS parameters from 16 published rTMS studies involving SCI individuals and were able to infer preliminary associations between specific parameters and the effects observed. Future investigations will need to consider timing, intervention duration and dosage (in terms of number of sessions and number of pulses) that may depend on the stage, the level, and the severity of the injury. There is a need for more real vs. sham rTMS studies, reporting similar designs with sufficient information for replication, to achieve a significant level of evidence regarding the use of rTMS in SCI.

Advances in targeting central sensitization and brain plasticity in chronic pain

Maladaptation in sensory neural plasticity of nociceptive pathways is associated with various types of chronic pain through central sensitization and remodeling of brain connectivity. Within this context, extensive research has been conducted to evaluate the mechanisms and efficacy of certain non-pharmacological pain treatment modalities. These include neurostimulation, virtual reality, cognitive therapy and rehabilitation. Here, we summarize the involved mechanisms and review novel findings in relation to nociceptive desensitization and modulation of plasticity for the management of intractable chronic pain and prevention of acute-to-chronic pain transition.

Effects of Chronic High-Frequency rTMS Protocol on Respiratory Neuroplasticity Following C2 Spinal Cord Hemisection in Rats

Simple Summary

High spinal cord injuries (SCIs) are known to lead to permanent diaphragmatic paralysis, and to induce deleterious post-traumatic inflammatory processes following cervical spinal cord injury. We used a noninvasive therapeutic tool (repetitive transcranial magnetic stimulation (rTMS)), to harness plasticity in spared descending respiratory circuit and reduce the inflammatory processes. Briefly, the results obtained in this present study suggest that chronic high-frequency rTMS can ameliorate respiratory dysfunction and elicit neuronal plasticity with a reduction in deleterious post-traumatic inflammatory processes in the cervical spinal cord post-SCI. Thus, this therapeutic tool could be adopted and/or combined with other therapeutic interventions in order to further enhance beneficial outcomes.

Abstract

High spinal cord injuries (SCIs) lead to permanent diaphragmatic paralysis. The search for therapeutics to induce functional motor recovery is essential. One promising noninvasive therapeutic tool that could harness plasticity in a spared descending respiratory circuit is repetitive transcranial magnetic stimulation (rTMS). Here, we tested the effect of chronic high-frequency (10 Hz) rTMS above the cortical areas in C2 hemisected rats when applied for 7 days, 1 month, or 2 months. An increase in intact hemidiaphragm electromyogram (EMG) activity and excitability (diaphragm motor evoked potentials) was observed after 1 month of rTMS application. Interestingly, despite no real functional effects of rTMS treatment on the injured hemidiaphragm activity during eupnea, 2 months of rTMS treatment strengthened the existing crossed phrenic pathways, allowing the injured hemidiaphragm to increase its activity during the respiratory challenge (i.e., asphyxia). This effect could be explained by a strengthening of respiratory descending fibers in the ventrolateral funiculi (an increase in GAP-43 positive fibers), sustained by a reduction in inflammation in the C1–C3 spinal cord (reduction in CD68 and Iba1 labeling), and acceleration of intracellular plasticity processes in phrenic motoneurons after chronic rTMS treatment. These results suggest that chronic high-frequency rTMS can ameliorate respiratory dysfunction and elicit neuronal plasticity with a reduction in deleterious post-traumatic inflammatory processes in the cervical spinal cord post-SCI. Thus, this therapeutic tool could be adopted and/or combined with other therapeutic interventions in order to further enhance beneficial outcomes.

Effects of cortical intermittent theta burst stimulation combined with precise root stimulation on motor function after spinal cord injury: a case series study

Activation and reconstruction of the spinal cord circuitry is important for improving motor function following spinal cord injury. We conducted a case series study to investigate motor function improvement in 14 patients with chronic spinal cord injury treated with 4 weeks of unilateral (right only) cortical intermittent theta burst stimulation combined with bilateral magnetic stimulation of L3-L4 nerve roots, five times a week. Bilateral resting motor evoked potential amplitude was increased, central motor conduction time on the side receiving cortical stimulation was significantly decreased, and lower extremity motor score, Berg balance score, spinal cord independence measure-III score, and 10 m-walking speed were all increased after treatment. Right resting motor evoked potential amplitude was positively correlated with lower extremity motor score after 4 weeks of treatment. These findings suggest that cortical intermittent theta burst stimulation combined with precise root stimulation can improve nerve conduction of the corticospinal tract and lower limb motor function recovery in patients with chronic spinal cord injury.

Noninvasive Neuromodulation Techniques in Difficult Tracheostomy Weaning of Patients With Spinal Cord Injury: Report of Two Cases

High spinal cord injured patients (SCI) are susceptible to respiratory muscle impairments. Transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) may influence the diaphragm's central control, but until now they are not described as a therapeutic resource for difficult weaning. We present two case reports of SCI patients (P1 and P2) with long-term tracheostomy (>40 days) and hospital stay (>50 days). In association with respiratory exercise, P1 received a combined application of anodal tDCS over the supplementary motor area plus sensory PES in the thoracic-abdominal muscles, and P2 received isolated excitatory PES in the abdominal muscles, applied daily except on weekends. Maximum inspiratory/expiratory pressure, peak cough flow, diaphragm excursion, and thickening fraction were measured in the first and last days of the protocol. Both patients had improvements, with clinical impact such as cough effectiveness, decannulated after 15 applications of stimulation. Augmentation of neural respiratory drive and corticospinal excitability is suggested.

A novel paired associative stimulation protocol with a high-frequency peripheral component: A review on results in spinal cord injury rehabilitation

In recent decades, a multitude of therapeutic approaches has been developed for spinal cord injury (SCI), but few have progressed to regular clinical practice. Novel non-invasive, cost-effective, and feasible approaches to treat this challenging condition are needed. A novel variant of paired associative stimulation (PAS), high-PAS, consists of non-invasive high-intensity transcranial magnetic stimulation (TMS) and non-invasive high-frequency electrical peripheral nerve stimulation (PNS). We observed a therapeutic effect of high-PAS in 20 patients with incomplete SCI with wide range of injury severity, age, and time since injury. Tetraplegic and paraplegic, traumatic, and neurological SCI patients benefited from upper- or lower-limb high-PAS. We observed increases in manual motor scores (MMT) of upper and lower limbs, functional hand tests, walking tests, and measures of functional independence. We also optimized PAS settings in several studies in healthy subjects and began elucidating the mechanisms of therapeutic action. The scope of this review is to describe the clinical experience gained with this novel PAS approach. This review is focused on the summary of our results and observations and the methodological considerations for researchers and clinicians interested in adopting and further developing this new method.

Enhancement of Neural Stem Cell Proliferation in Rats with Spinal Cord Injury by a Combination of Repetitive Transcranial Magnetic Stimulation (rTMS) and Human Umbilical Cord Blood Mesenchymal Stem Cells (hUCB-MSCs)

BACKGROUND This study was designed to explore the combined effects of repetitive transcranial magnetic stimulation (rTMS) and human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) transplantation on neural stem cell proliferation in rats with spinal cord injury (SCI). MATERIAL AND METHODS SCI was induced in 90 rats by laminectomy at T10. Fifteen rats each were treated with 0.5 Hz rTMS or 10 Hz rTMS or underwent hUCB-MSC transplantation; 15 each were treated with 0.5 Hz rTMS+hUCB-MSCs or 10 Hz rTMS+hUCB-MSCs; and 15 were untreated (control group). The Basso, Beattie, and Bresnahan (BBB) scores and motor evoked potentials (MEPs) were measured, and all rats underwent biotin dextran-amine (BDA) tracing of the corticospinal tract (CST). The levels of expression of neural stem cell proliferation related proteins, including BrdU, nestin, Tuj1, Ng2+ and GFAP, were measured, and the levels of bFGF and EGF determined by Western blotting. RESULTS BBB scores and MEPs were increased after rTMS and hUCB-MSC transplantation, while histologically determined SCI-induced neuron apoptosis was attenuated. The numbers of BDA-positive fibers and Brdu-, nestin- and Tuj1-positive cells were markedly increased and the numbers of Ng2+- and GFAP-positive cells were markedly decreased following treatment with rTMS alone or rTMS plus hUCB-MSC transplantation. The levels of expression of bFGF and EGF were significantly upregulated following rTMS treatment and hUCB-MSC transplantation. Higher performance was observed after combined treatment with rTMS and hUCB-MSC transplantation than after either alone. CONCLUSIONS The combination of rTMS treatment and hUCB-MSC transplantation could attenuate SCI-induced neural stem cell apoptosis and motor dysfunction in rats.

Efficacy of biofeedback, repetitive transcranial magnetic stimulation and pelvic floor muscle training for female neurogenic bladder dysfunction after spinal cord injury: a study protocol for a randomised controlled trial

INTRODUCTION

Neurogenic bladder dysfunction is prevalent in female patients with spinal cord injury (SCI), and previous guidelines have recommended pelvic floor muscle training (PFMT) for first-line conservative treatment. However, the actual regimen of PFMT varies widely and the single treatment does not satisfy the need of some patients. Therefore, this study aims to provide a detailed rationale and methodology for comparing the effectiveness of PFMT, biofeedback and repetitive transcranial magnetic stimulation (rTMS) as adjunct treatments for neurogenic bladder dysfunction.

METHODS AND ANALYSIS

This trial is a single-centre randomised controlled trial for female patients with urinary incontinence (UI) in phase of chronic SCI. Eligible participants will be randomised to one of four arms: (1) PFMT, (2) PFMT with biofeedback, (3) PFMT and rTMS and (4) PFMT with biofeedback and rTMS. There will be 44 participants in each arm and all the subjects will undergo 20 treatment sessions, five times a week for 4 weeks. The outcomes will be evaluated at 4 weeks, 3 months and 6 months after randomisation. The primary outcome is the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, and the secondary outcomes include bladder diary, pelvic floor muscle function and the International Spinal Cord Injury Quality of Life Basic Data Set.

ETHICS AND DISSEMINATION

The Clinical Research and Biomedical Ethics Committee of the West China Hospital, Sichuan University has approved this trial and the approval number is 2019-885. All participants will be provided written informed consent after verification of the eligibility criteria. The results of this study will be accessible in peer-reviewed publications and be presented at academic conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR1900026126).

Transcranial magnetic stimulation and bladder function: A systematic review

OBJECTIVE

We aimed at assessing the usefulness of motor evoked potentials (MEPs) for exploring the integrity of striated sphincters and pelvic floor motor innervation in normal subjects and of repetitive transcranial magnetic stimulation TMS (rTMS) in patients with neurogenic bladder dysfunction.

METHODS

A systematic literature search was conducted using PubMed and Embase.

RESULTS

We identified, reviewed and discussed 11 articles matching the inclusion criteria.

CONCLUSIONS

The assessment of MEPs could represent a useful tool in the investigation of patients with urologic disorders. High frequency rTMS can improve detrusor contraction and/or urethral sphincter relaxation in patients with multiple sclerosis and bladder dysfunction. Low frequency (LF) rTMS seems to be an effective treatment of neurogenic lower urinary tract dysfunctions in subjects with Parkinson's disease and possibly other neurodegenerative disorders. Furthermore, rTMS might have the potential to restore bladder and bowel sphincter function after incomplete spinal cord injury. LF rTMS could also relieve some symptoms of bladder pain syndrome and chronic pelvic pain.

SIGNIFICANCE

The clinical applicability of MEPs appears to be questionable, since a poor reproducibility was detected for all pelvic floor muscles. The use of rTMS in this field is emerging and the results of a few preliminary studies should be replicated in controlled, randomized studies with larger sample sizes.

Repetitive Transcranial Magnetic Stimulation Enhances Recovery in Central Cord Syndrome Patients

Objective

To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on neurological and functional recovery in patients with central cord syndrome (CCS) involving the upper extremities between the treated and non-treated sides of the treated group and whether the outcomes are comparable to that of the untreated control group.

Methods

Nineteen CCS patients were treated with high-frequency (20 Hz) rTMS over the motor cortex for 5 days. The stimulation side was randomly selected, and all the subjects received conventional occupational therapy during the rTMS-treatment period. Twenty CCS patients who did not receive rTMS were considered as controls. Clinical assessments, including those by the International Standard for Neurological Classification of Spinal Cord Injury, the Jebsen-Taylor Hand Function Test, and the O'Connor Finger Dexterity Test were performed initially and followed up for 1 month after rTMS treatment or 5 weeks after initial assessments.

Results

The motor scores for upper extremities were increased and the number of improved cases was greater for the treated side in rTMS-treated patients than for the non-treated side in rTMS-treated patients or controls. The improved cases for writing time and score measured on the Jebsen-Taylor Hand Function Test were also significantly greater in number on the rTMS-treated side compared with the non-treated side and controls. There were no adverse effects during rTMS therapy or the follow-up period.

Conclusion

The results of the application of high-frequency rTMS treatment to CCS patients suggest that rTMS can enhance the motor recovery and functional fine motor task performance of the upper extremities in such individuals.

Effects of high-frequency transcranial magnetic stimulation on functional performance in individuals with incomplete spinal cord injury: study protocol for a randomized controlled trial

Background

Repetitive transcranial magnetic stimulation (rTMS) has been investigated as a new tool in neurological rehabilitation of individuals with spinal cord injury (SCI). However, due to the inconsistent results regarding the effects of rTMS in people with SCI, a randomized controlled double-blind crossover trial is needed to clarify the clinical utility and to assess the effect size of rTMS intervention in this population. Therefore, this paper describes a study protocol designed to investigate whether the use of rTMS can improve the motor and sensory function, as well as reduce spasticity in patients with incomplete SCI.

Methods

A double-blind randomized sham-controlled crossover trial will be performed by enrolling 20 individuals with incomplete SCI. Patients who are at least six months post incomplete SCI (aged 18–60 years) will be recruited through referral by medical practitioners or therapists. Individuals will be randomly assigned to either group 1 or group 2 in a 1:1 ratio, with ten individuals in each group. The rTMS protocol will include ten sessions of high-frequency rTMS (5 Hz) over the bilateral lower-limb motor area positioned at the vertex (Cz). Clinical evaluations will be performed at baseline and after rTMS active and sham.

Discussion

rTMS has produced positive results in treating individuals with physical impairments; thus, it might be promising in the SCI population. The results of this study may provide new insights to motor rehabilitation thereby contributing towards the better usage of rTMS in the SCI population.

Trial registration

ClinicalTrials.gov, NCT02899637. Registered on 25 August 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2280-1) contains supplementary material, which is available to authorized users.

Brain White Matter Impairment in Patients with Spinal Cord Injury

It remains unknown whether spinal cord injury (SCI) could indirectly impair or reshape the white matter (WM) of human brain and whether these changes are correlated with injury severity, duration, or clinical performance. We choose tract-based spatial statistics (TBSS) to investigate the possible changes in whole-brain white matter integrity and their associations with clinical variables in fifteen patients with SCI. Compared with the healthy controls, the patients exhibited significant decreases in WM fractional anisotropy (FA) in the left angular gyrus (AG), right cerebellum (CB), left precentral gyrus (PreCG), left lateral occipital region (LOC), left superior longitudinal fasciculus (SLF), left supramarginal gyrus (SMG), and left postcentral gyrus (PostCG) (p < 0.01, TFCE corrected). No significant differences were found in all diffusion indices between the complete and incomplete SCI. However, significantly negative correlation was shown between the increased radial diffusivity (RD) of left AG and total motor scores (uncorrected p < 0.05). Our findings provide evidence that SCI can cause not only direct degeneration but also transneuronal degeneration of brain WM, and these changes may be irrespective of the injury severity. The affection of left AG on rehabilitation therapies need to be further researched in the future.

Paired Stimulation to Promote Lasting Augmentation of Corticospinal Circuits

After injury, electrical stimulation of the nervous system can augment plasticity of spared or latent circuits through focal modulation. Pairing stimulation of two parts of a spared circuit can target modulation more specifically to the intended circuit. We discuss 3 kinds of paired stimulation in the context of the corticospinal system, because of its importance in clinical neurorehabilitation. The first uses principles of Hebbian plasticity: by altering the stimulation timing of presynaptic neurons and their postsynaptic targets, synapse function can be modulated up or down. The second form uses synchronized presynaptic inputs onto a common synaptic target. We dub this a “convergent” mechanism, because stimuli have to converge on a common target with coordinated timing. The third form induces focal modulation by tonic excitation of one region (e.g., the spinal cord) during phasic stimulation of another (e.g., motor cortex). Additionally, endogenous neural activity may be paired with exogenous electrical stimulation. This review addresses what is known about paired stimulation of the corticospinal system of both humans and animal models, emphasizes how it qualitatively differs from single-site stimulation, and discusses the gaps in knowledge that must be addressed to maximize its use and efficacy in neurorehabilitation.

Long-term paired associative stimulation can restore voluntary control over paralyzed muscles in incomplete chronic spinal cord injury patients

Emerging therapeutic strategies for spinal cord injury aim at sparing or restoring at least part of the corticospinal tract at the acute stage. Hence, approaches that strengthen the weak connections that are spared or restored are crucial. Transient plastic changes in the human corticospinal tract can be induced through paired associative stimulation, a noninvasive technique in which transcranial magnetic brain stimulation is synchronized with electrical peripheral nerve stimulation. A single paired associative stimulation session can induce transient plasticity in spinal cord injury patients. It is not known whether paired associative stimulation can strengthen neuronal connections persistently and have therapeutic effects that are clinically relevant. We recruited two patients with motor-incomplete chronic (one para- and one tetraplegic) spinal cord injuries. The patients received paired associative stimulation for 20-24 weeks. The paraplegic patient, previously paralyzed below the knee level, regained plantarflexion and dorsiflexion of the ankles of both legs. The tetraplegic patient regained grasping ability. The newly acquired voluntary movements could be performed by the patients in the absence of stimulation and for at least 1 month after the last stimulation session. In this unblinded proof-of-principle demonstration in two subjects, long-term paired associative stimulation induced persistent and clinically relevant strengthening of neural connections and restored voluntary movement in previously paralyzed muscles. Further study is needed to confirm whether long-term paired associative stimulation can be used in rehabilitation after spinal cord injury by itself and, possibly, in combination with other therapeutic strategies.

BDNF Overexpression Exhibited Bilateral Effect on Neural Behavior in SCT Mice Associated with AKT Signal Pathway

Spinal cord injury (SCI), a severe health problem in worldwide, was commonly associated with functional disability and reduced quality of life. As the expression of brain-derived neurotrophic factor (BDNF) was substantial event in injured spinal cord, we hypothesized whether BDNF-overexpression could be in favor of the recovery of both sensory function and hindlimb function after SCI. By using BDNF-overexpression transgene mice [CMV-BDNF 26 (CB26) mice] we assessed the role of BDNF on the recovery of neurological behavior in spinal cord transection (SCT) model. BMS score and tail-flick test was performed to evaluate locomotor function and sensory function, respectively. Immunohistochemistry was employed to detect the location and the expression of BDNF, NeuN, 5-HT, GAP-43, GFAP as well as CGRP, and the level of p-AKT and AKT were examined through western blot analysis. BDNF overexpressing resulted in significant locomotor functional recovery from 21 to 28 days after SCT, compared with wild type (WT)+SCT group. Meanwhile, the NeuN, 5-HT and GAP-43 positive cells were markedly increased in ventral horn in BDNF overexpression animals, compared with WT mice with SCT. Moreover, the crucial molecular signal, p-AKT/AKT has been largely up-regulated, which is consistent with the improvement of locomotor function. However, in this study, thermal hyperpathia encountered in sham (CB26) group and WT+SCT mice and further aggravated in CB26 mice after SCT. Also, following SCT, the significant augment of positive-GFAP astrocytes and CGRP fibers were found in WT+SCT mice, and further increase was seen in BDNF over-expression transgene mice. BDNF-overexpression may not only facilitate the recovery of locomotor function via AKT pathway, but also contributed simultaneously to thermal hyperalgesia after SCT.

Electrical management of neurogenic lower urinary tract disorders

Management of lower urinary tract dysfunction (LUTD) in neurological diseases remains a priority because it leads to many complications such as incontinence, renal failure and decreased quality of life. A pharmacological approach remains the first-line treatment for patients with neurogenic LUTD, but electrical stimulation is a well-validated and recommended second-line treatment. However, clinicians must be aware of the indications, advantages and side effects of the therapy. This report provides an update on the 2 main electrical stimulation therapies for neurogenic LUTD - inducing direct bladder contraction with the Brindley procedure and modulating LUT physiology (sacral neuromodulation, tibial posterior nerve stimulation or pudendal nerve stimulation). We also describe the indications of these therapies for neurogenic LUTD, following international guidelines, as illustrated by their efficacy in patients with neurologic disorders. Electrical stimulation could be proposed for neurogenic LUTD as second-line treatment after failure of oral pharmacologic approaches. Nevertheless, further investigations are needed for a better understanding of the mechanisms of action of these techniques and to confirm their efficacy. Other electrical investigations, such as deep-brain stimulation and repetitive transcranial magnetic stimulation, or improved sacral anterior root stimulation, which could be associated with non-invasive and highly specific deafferentation of posterior roots, may open new fields in the management of neurogenic LUTD.

Descending motor pathways and cortical physiology after spinal cord injury assessed by transcranial magnetic stimulation: a systematic review

We performed here a systematic review of the studies using transcranial magnetic stimulation (TMS) as a research and clinical tool in patients with spinal cord injury (SCI). Motor evoked potentials (MEPs) elicited by TMS represent a highly accurate diagnostic test that can supplement clinical examination and neuroimaging findings in the assessment of SCI functional level. MEPs allows to monitor the changes in motor function and evaluate the effects of the different therapeutic approaches. Moreover, TMS represents a useful non-invasive approach for studying cortical physiology, and may be helpful in elucidating the pathophysiological mechanisms of brain reorganization after SCI. Measures of motor cortex reactivity, e.g., the short interval intracortical inhibition and the cortical silent period, seem to point to an increased cortical excitability. However, the results of TMS studies are sometimes contradictory or divergent, and should be replicated in a larger sample of subjects. Understanding the functional changes at brain level and defining their effects on clinical outcome is of crucial importance for development of evidence-based rehabilitation therapy. TMS techniques may help in identifying neurophysiological biomarkers that can reliably assess the extent of neural damage, elucidate the mechanisms of neural repair, predict clinical outcome, and identify therapeutic targets. Some researchers have begun to therapeutically use repetitive TMS (rTMS) in patients with SCI. Initial studies revealed that rTMS can induce acute and short duration beneficial effects especially on spasticity and neuropathic pain, but the evidence is to date still very preliminary and well-designed clinical trials are warranted. This article is part of a Special Issue entitled SI: Spinal cord injury.