Effects of intermittent theta burst stimulation on spasticity in patients with multiple sclerosis

Intermittent theta-burst stimulation alleviates hypoxia-ischemia-caused myelin damage and neurologic disability

Neonatal hypoxia-ischemia (HI) results in behavioral deficits, characterized by neuronal injury and retarded myelin formation. To date, limited treatment methods are available to prevent or alleviate neurologic sequelae of HI. Intermittent theta-burst stimulation (iTBS), a non-invasive therapeutic procedure, is considered a promising therapeutic tool for treating some neurocognitive disorders and neuropsychiatric diseases. Hence, this study aims to investigate whether iTBS can prevent the negative behavioral manifestations of HI and explore the mechanisms for associations. We exposed postnatal day 10 Sprague-Dawley male and female rats to 2 h of hypoxia (6% O2) following right common carotid artery ligation, resulting in oligodendrocyte (OL) dysfunction, including reduced proliferation and differentiation of oligodendrocyte precursor cells (OPCs), decreased OL survival, and compromised myelin in the corpus callosum (CC) and hippocampal dentate gyrus (DG). These alterations were concomitant with cognitive dysfunction and depression-like behaviors. Crucially, early iTBS treatment (15 G, 190 s, seven days, initiated one day post-HI) significantly alleviated HI-caused myelin damage and mitigated the neurologic sequelae both in male and female rats. However, the late iTBS treatment (initiated 18 days after HI insult) could not significantly impact these behavioral deficits. In summary, our findings support that early iTBS treatment may be a promising strategy to improve HI-induced neurologic disability. The underlying mechanisms of iTBS treatment are associated with promoting the differentiation of OPCs and alleviating myelin damage.

Brain stimulation for patients with multiple sclerosis: an umbrella review of therapeutic efficacy

Multiple sclerosis patients often experience various symptoms that can greatly impact their quality of life. There are various brain stimulation techniques that have been evaluated for their ability to reduce the symptoms of multiple sclerosis. However, there is inconsistency in the specific stimulation methods used and the symptoms targeted in the existing research. This umbrella review conducted in order to evaluate the effectiveness of brain stimulation and identify limitations and gaps for further research. In this umbrella review, we conducted a searched on Web of Knowledge, PubMed, and Scopus database. We specifically looked for reviews, with or without meta-analyses, that have investigated the effects of brain stimulation methods on symptoms of multiple sclerosis. All articles were examined by AMSTAR 2 (A Measure Tool to Assess Systematic Review 2). We identified 155 articles, of which 14 were eligible for inclusion. Of those, five were qualitative studies and nine were meta-analyses. Among the included studies, four examined the use of deep brain stimulation, while ten investigated the therapeutic potential of noninvasive brain stimulation. Considering the heterogeneity of studies, the current evidence suggests that repetitive transcranial magnetic stimulation may be effective in treating pain and improving motor function, while transcranial direct current stimulation may be useful in alleviating fatigue and enhancing certain aspects of cognitive performance. Deep brain stimulation, on the other hand, appears to be effective in reducing tremors. However, further research is warranted to validate these findings and address the existing limitations in the field.

Synergistic efficacy of repetitive peripheral magnetic stimulation on central intermittent theta burst stimulation for upper limb function in patients with stroke: a double-blinded, randomized controlled trial

BACKGROUND

Non-invasive techniques such as central intermittent theta burst stimulation (iTBS) and repetitive peripheral magnetic stimulation (rPMS) have shown promise in improving motor function for patients with stroke. However, the combined efficacy of rPMS and central iTBS has not been extensively studied. This randomized controlled trial aimed to investigate the synergistic effects of rPMS and central iTBS in patients with stroke.

METHOD

In this study, 28 stroke patients were randomly allocated to receive either 1200 pulses of real or sham rPMS on the radial nerve of the affected limb, followed by 1200 pulses of central iTBS on the ipsilesional hemisphere. The patients received the intervention for 10 sessions over two weeks. The primary outcome measures were the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) and the Action Research Arm Test (ARAT). Secondary outcomes for activities and participation included the Functional Independence Measure-Selfcare (FIM-Selfcare) and the Stroke Impact Scale (SIS). The outcome measures were assessed before and after the intervention.

RESULTS

Both groups showed significant improvement in FMA-UE and FIM-Selfcare after the intervention (p < 0.05). Only the rPMS + iTBS group had significant improvement in ARAT-Grasp and SIS-Strength and activity of daily living (p < 0.05). However, the change scores in all outcome measures did not differ between two groups.

CONCLUSIONS

Overall, the study's findings suggest that rPMS may have a synergistic effect on central iTBS to improve grasp function and participation. In conclusion, these findings highlight the potential of rPMS as an adjuvant therapy for central iTBS in stroke rehabilitation. Further large-scale studies are needed to fully explore the synergistic effects of rPMS on central iTBS.

TRIAL REGISTRATION

This trial was registered under ClinicalTrials.gov ID No.NCT04265365, retrospectively registered, on February 11, 2020.

Low-intensity repetitive transcranial magnetic stimulation is safe and well tolerated by people living with MS - outcomes of the phase I randomised controlled trial (TAURUS)

Background

Low-intensity repetitive transcranial magnetic stimulation (rTMS), delivered as a daily intermittent theta burst stimulation (iTBS) for four consecutive weeks, increased the number of new oligodendrocytes in the adult mouse brain. Therefore, rTMS holds potential as a remyelinating intervention for people with multiple sclerosis (MS).

Objective

Primarily to determine the safety and tolerability of our rTMS protocol in people with MS. Secondary objectives include feasibility, blinding and an exploration of changes in magnetic resonance imaging (MRI) metrics, patient-reported outcome measures (PROMs) and cognitive or motor performance.

Methods

A randomised (2:1), placebo controlled, single blind, parallel group, phase 1 trial of 20 rTMS sessions (600 iTBS pulses per hemisphere; 25% maximum stimulator output), delivered over 4-5 weeks. Twenty participants were randomly assigned to 'sham' (n = 7) or active rTMS (n = 13), with the coil positioned at 90° or 0°, respectively.

Results

Five adverse events (AEs) including one serious AE reported. None were related to treatment. Protocol compliance was high (85%) and blinding successful. Within participant MRI metrics, PROMs and cognitive or motor performance were unchanged over time.

Conclusion

Twenty sessions of rTMS is safe and well tolerated in a small group of people with MS. The study protocol and procedures are feasible. Improvement of sham is warranted before further investigating safety and efficacy.

Noninvasive brain stimulation for spasticity rehabilitation in multiple sclerosis: A systematic review of randomized controlled trials

OBJECTIVE

To investigate the effects of noninvasive brain stimulation (NIBS) on spasticity in people with multiple sclerosis (PwMS).

LITERATURE SURVEY

We searched PubMed, SCOPUS, MEDLINE, REHABDATA, PEDro, CINAHL, AMED, and Web of Science until December 2022.

METHODOLOGY

Studies were selected if they included PwMS, used transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) as a main intervention, and were randomized controlled trials (RCTs) including at least one outcome measure evaluating spasticity. Two researchers individually screened the selected studies. The study's quality was assessed using the Cochrane Collaborations tool. The researchers decided that the meta-analysis was not possible because the treatment interventions varied among the selected studies.

SYNTHESIS

In total, 147 studies were reviewed. Of them, nine studies met the eligibility criteria and included 193 PwMS (mean age = 43.2 years), 54.4% of whom were female. Eight studies were considered "high" quality and one was considered "moderate" quality. Seven studies that used rTMS demonstrated a significant decrease in spasticity in PwMS after the intervention. The remaining studies that provided tDCS did not show meaningful effects.

CONCLUSIONS

The evidence for the influences of rTMS on spasticity in PwMS is promising. The evidence for the impact of tDCS on spasticity in PwMS was limited. Further RCTs with long-term follow-ups are encouraged.

Theta-burst stimulation as a therapeutic tool in neurological pathology: a systematic review

TBS (theta-burst stimulation) is a novel therapeutic approach in a wide range of neurological diseases. The present systematic review aims to identify the various protocols used in the last years, to assess study quality and to offer a general overview of the current state of the literature. The systematic review was conducted according to the Preferred Reporting Item for Systematic Review and Meta-Analyses (PRISMA) guidelines. We applied the following inclusion criteria: (1) population over 18 years old with diagnosed neurological disorders, (2) patients treated with sessions of theta-burst stimulation, (3) randomized-controlled clinical trials, (4) articles in the English language, and (5) studies that report response and score reduction on a validated scale of the investigated disorder or remission rates. We included in the final analysis 56 randomized controlled trials focusing on different neurological pathologies (stroke, Parkinson`s disease, multiple sclerosis, tinnitus, dystonia, chronic pain, essential tremor and tic disorder), and we extracted data regarding study design, groups and comparators, sample sizes, type of coil, stimulation parameters (frequency, number of pulses, intensity, stimulation site etc.), number of sessions, follow-up, assessment through functional connectivity and neurological scales used. We observed a great interstudy heterogenicity that leads to a difficulty in drawing plain conclusions. TBS protocols have shown promising results in improving various symptoms in patients with neurological disorders, but larger and more coherent studies, using similar stimulation protocols and evaluation scales, are needed to establish guideline recommendations.

Novel approaches to motoneuron disease/ALS treatment using non-invasive brain and spinal stimulation: IFCN handbook chapter

Non-invasive brain stimulation techniques have been exploited in motor neuron disease (MND) with multifold objectives: to support the diagnosis, to get insights in the pathophysiology of these disorders and, more recently, to slow down disease progression. In this review, we consider how neuromodulation can now be employed to treat MND, with specific attention to amyotrophic lateral sclerosis (ALS), the most common form with upper motoneuron (UMN) involvement, taking into account electrophysiological abnormalities revealed by human and animal studies that can be targeted by neuromodulation techniques. This review article encompasses repetitive transcranial magnetic stimulation methods (including low-frequency, high-frequency, and pattern stimulation paradigms), transcranial direct current stimulation as well as experimental findings with the newer approach of trans-spinal direct current stimulation. We also survey and discuss the trials that have been performed, and future perspectives.

The effectiveness of intermittent theta burst stimulation for upper limb motor recovery after stroke: a systematic review and meta-analysis of randomized controlled trials

Background

Intermittent theta burst stimulation (iTBS) is a promising noninvasive therapy to restore the excitability of the cortex, and subsequently improve the function of the upper extremities. Several studies have demonstrated the effectiveness of iTBS in restoring upper limb function and modulating cortical excitability. We aimed to evaluate the effects of iTBS on upper limb motor recovery after stroke.

Objective

The purpose of this article is to evaluate the influence of intermittent theta-burst stimulation on upper limb motor recovery and improve the quality of life.

Method

A literature search was conducted using PubMed, EMBASE, MEDLINE, The Cochrane Library, Web of Science, and CBM, including only English studies, to identify studies that investigated the effects of iTBS on upper limb recovery, compared with sham iTBS used in control groups. Effect size was reported as standardized mean difference (SMD) or weighted mean difference (WMD).

Results

Ten studies were included in the meta-analysis. The results of the meta-analysis indicated that when compared to the control group, the iTBS group had a significant difference in the Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT) (WMD: 3.20, 95% CI: 1.42 to 4.97; WMD: 3.72, 95% CI: 2.13 to 5.30, respectively). In addition, there was also a significant improvement in the modified Ashworth scale (MAS) compared to the sham group (WMD: -0.56; 95% CI: -0.85 to -0.28). More evidence is still needed to confirm the effect of Barthel Index (BI) scores after interventions. However, no significant effect was found for the assessment of Motor Evoked Potential (MEP) amplitude and MEP latency (SMD: 0.35; 95% CI: -0.21 to 0.90; SMD: 0.35, 95% CI: -0.18 to 0.87; SMD: 0.03, 95% CI: -0.49 to 0.55; respectively).

Conclusion

Our results showed that iTBS significantly improved motor impairment, functional activities, and reduced muscle tone of upper limbs, thereby increasing the ability to perform Activities of Daily Living (ADL) in stroke patients, while there were no significant differences in MEPs. In conclusion, iTBS is a promising non-invasive brain stimulation as an adjunct to therapy and enhances the therapeutic effect of conventional physical therapy. In the future, more randomized controlled trials with large sample sizes, high quality, and follow-up are necessary to explore the neurophysiological effects.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023392739.

Non-invasive brain stimulation on clinical symptoms in multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

Non-invasive brain stimulation (NIBS) has demonstrated mixed effects on the clinical symptoms of multiple sclerosis. This systematic review and meta-analysis aimed to evaluate the effects of NIBS techniques on the most common symptoms of MS.

METHODS

A literature search was performed until October 2022 which included randomized controlled trials and quasi-experimental studies that used sham-controlled NIBS in patients with MS. We calculated the Hedge's effect sizes of each domain of interest and their 95% confidence intervals (95% CIs) and performed random effects meta-analyses.

RESULTS

A total of 49 studies were included in the systematic review (944 participants). Forty-four eligible studies were included for quantitative analysis, of which 33 applied transcranial direct current stimulation (tDCS), 9 transcranial magnetic stimulation (TMS), and 2 transcranial random noise stimulation (tRNS). We found a significant decrease in fatigue (ES:  - 0.86, 95% CI:  - 1.22 to - 0.51, p < 0.0001), pain (ES: - 1.91, 95% CI, - 3.64 to - 0.19, p=  0.03) and psychiatric symptoms (ES: - 1.44, 95% CI - 2.56 to - 0.32, p = 0.01) in favor of tDCS compared with the sham. On the other hand, there was no strong evidence showing tDCS effectiveness on motor performance and cognition (ES: - 0.03, 95% CI - 0.35 to 0.28, p = 0.83 and ES: 0.71, 95% CI, - 0.09 to 1.52, p = 0.08, respectively). Regarding TMS, we found a significant decrease in fatigue (ES: - 0.45, 95% CI: - 0.84 to -0.07, p = 0.02) and spasticity levels (ES: - 1.11, 95% CI: - 1.48 to - 0.75, p < 0.00001) compared to the sham. However, there was no strong evidence of the effectiveness of TMS on motor performance (ES: - 0.39, 95% CI - 0.95 to 0.16, p = 0.16). Finally, there was no significant evidence showing the effectiveness of tRNS on fatigue levels (ES: - 0.28, 95% CI: - 1.02 to 0.47, p = 0.46) and cognitive improvement (ES: - 0.04, 95% CI: - 0.6, 0.52, p = 0.88) compared with the sham.

CONCLUSIONS

Overall, most studies have investigated the effects of tDCS on MS symptoms, particularly fatigue. The symptom that most benefited from NIBS was fatigue, while the least to benefit was motor performance. In addition, we found that disability score was associated with fatigue improvement. Thus, these findings support the idea that NIBS could have some promising effects on specific MS symptoms. It is also important to underscore that studies are very heterogeneous regarding the parameters of stimulation, and this may also have influenced the effects on some specific behavioral domains.

Research progress on the application of transcranial magnetic stimulation in spinal cord injury rehabilitation: a narrative review

Traumatic or non-traumatic spinal cord injury (SCI) can lead to severe disability and complications. The incidence of SCI is high, and the rehabilitation cycle is long, which increases the economic burden on patients and the health care system. However, there is no practical method of SCI treatment. Recently, transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique, has been shown to induce changes in plasticity in specific areas of the brain by regulating the activity of neurons in the stimulation site and its functionally connected networks. TMS is a new potential method for the rehabilitation of SCI and its complications. In addition, TMS can detect the activity of neural circuits in the central nervous system and supplement the physiological evaluation of SCI severity. This review describes the pathophysiology of SCI as well as the basic principles and classification of TMS. We mainly focused on the latest research progress of TMS in the physiological evaluation of SCI as well as the treatment of motor dysfunction, neuropathic pain, spasticity, neurogenic bladder, respiratory dysfunction, and other complications. This review provides new ideas and future directions for SCI assessment and treatment.

Repetitive transcranial magnetic stimulation for treatment of limb spasticity following multiple sclerosis: a systematic review and meta-analysis

Pilot trials have suggested that repetitive transcranial magnetic stimulation (rTMS) may reduce limb spasticity in multiple sclerosis (MS). We carried out the current meta-analysis to synthesize currently available evidence regarding such correlation. Up to November 2022, five international electronic databases (Cochrane CENTRAL, PubMed, Embase, Web of Science, and CINAHL) and four Chinese electronic databases (CBM, CNKI, WanFang Data, and VIP) were systematically searched to identify randomized trials comparing active rTMS and sham stimulation in patients with MS-related spasticity. Two reviewers independently selected studies and extracted data on study design, quality, clinical outcomes, and time points measured. The primary outcome was clinical spasticity relief after intervention. Secondary outcomes included spasticity at the follow-up visit 2 weeks later and post-treatment fatigue. Of 831 titles found, we included 8 studies (181 participants) in the quantitative analysis. Pooled analyses showed that rTMS therapy was associated with significant spasticity relief in the early post-intervention period [standardized mean differences (SMD): -0.67; 95%CI: -1.12 to -0.21], but there was insufficient evidence for rTMS in reducing spasticity at the follow-up visit 2 weeks later (SMD: -0.17; 95%CI: -0.52 to 0.17) and fatigue (SMD: -0.26; 95%CI: -0.84 to 0.31). This evidence supports the recommendations to treat MS-related spasticity with rTMS, but underlines the need for further large randomized trials.

A Randomized Controlled Trial of the Effect of Repetitive Transcranial Magnetic Stimulation of the Motor Cortex on Lower Extremity Spasticity in Hereditary Spastic Paraplegia

INTRODUCTION

Hereditary spastic paraplegia refers to a group of conditions characterized by a slow progression of spasticity in lower limbs resulting in gait abnormalities. Current treatment options have proven to be insufficient in terms of symptom alleviation. In this study, we tested the effectiveness of repetitive transcranial magnetic stimulation (rTMS) on lower limb spasticity in patients with hereditary spastic paraplegia.

METHODS

Eight patients were randomly assigned to receive either five sessions of active 5 Hz-rTMS ( n = 4) or sham rTMS ( n = 4). The primary outcome was a change in spasticity assessed by the modified Ashworth scale. Secondary outcomes were change in 10 m walking test, Fugl-Meyer assessment of lower extremity motor function, and quality-of-life short-form survey scores. Assessment of the outcomes was done before, upon completion, and 1 month after the intervention. We analyzed the data using repeated-measure analysis of variance.

RESULTS

Mean age of the participants was 38.5 (SD = 5.4) years, and 50% were women. Compared with sham rTMS, real rTMS was effective in decreasing modified Ashworth scale (rTMS × time: F [df = 2] = 7.44; P = 0.008). Real rTMS group had lower modified Ashworth scale scores at the end of rTMS sessions (estimate = -0.938; SE = 0.295; P = 0.019) and at the end of follow-up (estimate = -0.688; SE = 0.277; P = 0.048) compared with the sham rTMS group. Real and sham rTMS groups were not different in the secondary outcomes.

CONCLUSIONS

Repetitive transcranial magnetic stimulation is an effective method in reducing lower limb spasticity of patients with hereditary spastic paraplegia.

Non-invasive brain stimulation therapy on neurological symptoms in patients with multiple sclerosis: A network meta analysis

OBJECTIVE

The aim of the study was to evaluate non-invasive brain stimulation (NIBS) [including transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES)] on neurological symptoms in patients with multiple sclerosis (PwMS).

METHOD

We searched PubMed, Embase, Cochrane Library, Web of Science and Ovid MEDLINE until February 2022. And we evaluated the included studies for methodological quality by the Cochrane bias risk assessment tool and assessed the studies' certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. We performed network meta analysis (NMA) by using Stata 15 and ranked the results of the NMA by using the surface under the cumulative ranking curve (SUCRA) ranking chart.

RESULT

Twenty seven clinical trials were finally included (N = 596, 66.4% women). For the immediate effects, rTMS over M1 yielded the most optimal scheme for fatigue reduction among all the interventions compared to the sham stimulation groups [MD = -0.85, 95% CI (-1.57, -0.14)] (SUCRA = 82.6%). iTBS over M1 yielded the most signifcant reduced pain level than the sham groups did [MD = -1.26, 95% CI (-2.40, -0.11)] (SUCRA = 98.4%). tDCS over F3 was the best protocol of NIBS to improve quality of life (QOL) [MD = 1.41, 95% CI = (0.45,2.36)] (SUCRA = 76.7%), and iTBS over M1 may significantly reduce spasticity compared to sham stimulation [MD = -1.20, 95% CI = (-1.99, -0.41)] (SUCRA = 90.3%). Furthermore, rTMS, tRNS, and tDCS on certain areas may improve PwMS accuracy, response time, manual dexterity, pain relief and QOL, but does not show statistically significant differences. The evidence assessed using GRADE is very low.

CONCLUSION

Based on the NMA and SUCRA ranking, we can conclude that symptoms including fatigue, pain, spasticity, and QOL can be improved by following NIBS protocol after treatment. Nonetheless, most of the included studies lack a good methodology, and more high-quality randomized clinical trials are needed.

Clinical application of transcranial magnetic stimulation in multiple sclerosis

Multiple sclerosis (MS) is a common chronic, autoimmune-mediated inflammatory and neurodegenerative disease of the central nervous system. The treatment of MS has enormous progress with disease-modifying drugs, but the complexity of the disease course and the clinical symptoms of MS requires personalized treatment and disease management, including non-pharmacological treatment. Transcranial magnetic stimulation (TMS) is a painless and non-invasive brain stimulation technique, which has been widely used in neurological diseases. In this review, we mainly focus on the progress of physiological assessment and treatment of TMS in MS.

Transcranial Magnetic Stimulation in the Treatment of Neurological Diseases

Transcranial Magnetic Stimulation (TMS) has widespread use in research and clinical application. For psychiatric applications, such as depression or OCD, repetitive TMS protocols (rTMS) are an established and globally applied treatment option. While promising, rTMS is not yet as common in treating neurological diseases, except for neurorehabilitation after (motor) stroke and neuropathic pain treatment. This may soon change. New clinical studies testing the potential of rTMS in various other neurological conditions appear at a rapid pace. This can prove challenging for both practitioners and clinical researchers. Although most of these neurological applications have not yet received the same level of scientific/empirical scrutiny as motor stroke and neuropathic pain, the results are encouraging, opening new doors for TMS in neurology. We here review the latest clinical evidence for rTMS in pioneering neurological applications including movement disorders, Alzheimer's disease/mild cognitive impairment, epilepsy, multiple sclerosis, and disorders of consciousness.

Current evidence on the potential therapeutic applications of transcranial magnetic stimulation in multiple sclerosis: a systematic review of the literature

INTRODUCTION

A growing number of studies have evaluated the effects of transcranial magnetic stimulation (TMS) for the symptomatic treatment of multiple sclerosis (MS).

METHODS

We performed a PubMed search for articles, recent books, and recommendations from the most relevant clinical practice guidelines and scientific societies regarding the use of TMS as symptomatic treatment in MS.

CONCLUSIONS

Excitatory electromagnetic pulses applied to the affected cerebral hemisphere allow us to optimise functional brain activity, including the transmission of nerve impulses through the demyelinated corticospinal pathway. Various studies into TMS have safely shown statistically significant improvements in spasticity, fatigue, lower urinary tract dysfunction, manual dexterity, gait, and cognitive deficits related to working memory in patients with MS; however, the exact level of evidence has not been defined as the results have not been replicated in a sufficient number of controlled studies. Further well-designed, randomised, controlled clinical trials involving a greater number of patients are warranted to attain a higher level of evidence in order to recommend the appropriate use of TMS in MS patients across the board. TMS acts as an adjuvant with other symptomatic and immunomodulatory treatments. Additional studies should specifically investigate the effect of conventional repetitive TMS on fatigue in these patients, something that has yet to see the light of day.

Current evidence on the potential therapeutic applications of transcranial magnetic stimulation in multiple sclerosis: A systematic review of the literature

INTRODUCTION

A growing number of studies have evaluated the effects of transcranial magnetic stimulation (TMS) for the symptomatic treatment of multiple sclerosis (MS).

METHODS

We performed a PubMed search for articles, recent books, and recommendations from the most relevant clinical practice guidelines and scientific societies regarding the use of TMS as symptomatic treatment in MS.

CONCLUSIONS

Excitatory electromagnetic pulses applied to the affected cerebral hemisphere allow us to optimise functional brain activity, including the transmission of nerve impulses through the demyelinated corticospinal pathway. Various studies into TMS have safely shown statistically significant improvements in spasticity, fatigue, lower urinary tract dysfunction, manual dexterity, gait, and cognitive deficits related to working memory in patients with MS; however, the exact level of evidence has not been defined as the results have not been replicated in a sufficient number of controlled studies. Further well-designed, randomised, controlled clinical trials involving a greater number of patients are warranted to attain a higher level of evidence in order to recommend the appropriate use of TMS in MS patients across the board. TMS acts as an adjuvant with other symptomatic and immunomodulatory treatments. Additional studies should specifically investigate the effect of conventional repetitive TMS on fatigue in these patients, something that has yet to see the light of day.

Efficacy of repetitive transcranial magnetic stimulation for improving lower limb function in individuals with neurological disorders: A systematic review and meta-analysis of randomized sham-controlled trials

OBJECTIVE

To determine the efficacy of repetitive transcranial magnetic stimulation vs sham stimulation on improving lower-limb functional outcomes in individuals with neurological disorders.

DATA SOURCES

PubMed, CINAHL, Embase and Scopus databases were searched from inception to 31 March 2020 to identify papers (n = 1,198). Two researchers independently reviewed studies for eligibility. Randomized clinical trials with parallel-group design, involving individuals with neurological disorders, including lower-limb functional outcome measures and published in scientific peer-reviewed journals were included.

DATA EXTRACTION

Two researchers independently screened eligible papers (n = 27) for study design, clinical population characteristics, stimulation protocol and relevant outcome measures, and assessed study quality.

DATA SYNTHESIS

Studies presented a moderate risk of selection, attrition and reporting bias. An overall effect of repetitive transcranial magnetic stimulation was found for outcomes: gait (effect size [95% confidence interval; 95% CI]: 0.51 [0.29; 0.74], p = 0.003) and muscle strength (0.99 [0.40; 1.58], p = 0.001) and disorders: stroke (0.20 [0.00; 0.39], p = 0.05), Parkinson's disease (1.01 [0.65; 1.37], p = 0.02) and spinal cord injury (0.50 [0.14; 0.85], p = 0.006), compared with sham. No effect was found for outcomes: mobility and balance.

CONCLUSION

Supplementary repetitive transcranial magnetic stimulation may promote rehabilitation focused on ambulation and muscle strength and overall lower-limb functional recovery in individuals with stroke, Parkinson's disease and spinal cord injury. Further evidence is needed to extrapolate these findings.

Multiple sclerosis: Inflammation, autoimmunity and plasticity

In recent years, experimental studies have clarified that immune system influences the functioning of the central nervous system (CNS) in both physiologic and pathologic conditions. The neuro-immune crosstalk plays a crucial role in neuronal development and may be critically involved in mediating CNS response to neuronal damage. Multiple sclerosis (MS) represents a good model to investigate how the immune system regulates neuronal activity. Accordingly, a growing body of evidence has demonstrated that increased levels of pro-inflammatory mediators may significantly impact synaptic mechanisms, influencing overall neuronal excitability and synaptic plasticity expression. In this chapter, we provide an overview of preclinical data and clinical studies exploring synaptic functioning noninvasively with transcranial magnetic stimulation (TMS) in patients with MS. Moreover, we examine how inflammation-driven synaptic dysfunction could affect synaptic plasticity expression, negatively influencing the MS course. Contrasting CSF inflammation together with pharmacologic enhancement of synaptic plasticity and application of noninvasive brain stimulation, alone or in combination with rehabilitative treatments, could improve the clinical compensation and prevent the accumulating deterioration in MS.

Clinical Applications of Myelin Plasticity for Remyelinating Therapies in Multiple Sclerosis

Central nervous system demyelination in multiple sclerosis (MS) and subsequent axonal degeneration represent a major cause of clinical morbidity. Learning, salient experiences, and stimulation of neuronal activity induce new myelin formation in rodents, and in animal models of demyelination, remyelination can be enhanced via experience- and activity-dependent mechanisms. Furthermore, preliminary studies in MS patients support the use of neuromodulation and rehabilitation exercises for symptomatic improvement, suggesting that these interventions may represent nonpharmacological strategies for promoting remyelination. Here, we review the literature on myelin plasticity processes and assess the potential to leverage these mechanisms to develop remyelinating therapies. ANN NEUROL 2021;90:558-567.

Augmented efficacy of intermittent theta burst stimulation on the virtual reality-based cycling training for upper limb function in patients with stroke: a double-blinded, randomized controlled trial

Background

Virtual reality and arm cycling have been reported as effective treatments for improving upper limb motor recovery in patients with stroke. Intermittent theta burst stimulation (iTBS) can increase ipsilesional cortical excitability, and has been increasingly used in patients with stroke. However, few studies examined the augmented effect of iTBS on neurorehabilitation program. In this study, we investigated the augmented effect of iTBS on virtual reality-based cycling training (VCT) for upper limb function in patients with stroke.

Methods

In this randomized controlled trial, 23 patients with stroke were recruited. Each patient received either 15 sessions of iTBS or sham stimulation in addition to VCT on the same day. Outcome measures were assessed before and after the intervention. Primary outcome measures for the improvement of upper limb motor function and spasticity were Fugl-Meyer Assessment-Upper Extremity (FMA-UE) and Modified Ashworth Scale Upper-Extremity (MAS-UE). Secondary outcome measures for activity and participation were Action Research Arm Test (ARAT), Nine Hole Peg Test (NHPT), Box and Block Test (BBT) and Motor Activity Log (MAL), and Stroke Impact Scale (SIS). Wilcoxon signed-rank tests were performed to evaluate the effectiveness after the intervention and Mann–Whitney U tests were conducted to compare the therapeutic effects between two groups.

Results

At post-treatment, both groups showed significant improvement in FMA-UE and ARAT, while only the iTBS + VCT group demonstrated significant improvement in MAS-UE, BBT, NHPT, MAL and SIS. The Mann–Whitney U tests revealed that the iTBS + VCT group has presented greater improvement than the sham group significantly in MAS-UE, MAL-AOU and SIS. However, there were no significant differences in the changes of the FMA-UE, ARAT, BBT, NHPT and MAL-QOM between groups.

Conclusions

Intermittent TBS showed augmented efficacy on VCT for reducing spasticity, increasing actual use of the affected upper limb, and improving participation in daily life in stroke patients. This study provided an integrated innovative intervention, which may be a promising therapy to improve upper limb function recovery in stroke rehabilitation. However, this study has a small sample size, and thus a further larger-scale study is warranted to confirm the treatment efficacy.

Trial registration This trial was registered under ClinicalTrials.gov ID No. NCT03350087, retrospectively registered, on November 22, 2017

Non-invasive brain stimulation to assess neurophysiologic underpinnings of lower limb motor impairment in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a neuroinflammatory disease resulting in axonal demyelination and an amalgamation of symptoms which commonly result in decreased quality of life due to mobility dysfunction and limited participation in meaningful activities.

NEW METHOD

The use of non-invasive brain stimulation (NIBS) techniques, specifically transcranial magnetic and transcranial direct current stimulation, have been essential in understanding the pathophysiological decrements related to disease progression, particularly with regard to motor impairments. Although the research in this area has primarily focused on the upper extremities, new interest has arisen in understanding the neurophysiological underpinnings of lower limb impairment. Therefore, the purpose of this review is to: first, provide an overview of common NIBS techniques used to explore sensorimotor neurophysiology; second, summarize lower limb neuromuscular and mobility impairments typically observed in PwMS; third, review the current knowledge regarding interactions between TMS-assessed neurophysiology and lower limb impairments in PwMS; and fourth, provide recommendations for future NIBS studies based on current gaps in the literature.

RESULTS

PwMS exhibit reduced excitability and increased inhibitory neurophysiologic function which has been related to disease severity and lower limb motor impairments. Comparison with existing methods: Moreover, promising results indicate that the use of repetitive stimulation and transcranial direct current stimulation may prime neural adaptability and prove useful as a therapeutic tool in ameliorating lower limb impairments.

CONCLUSIONS

While these studies are both informative and promising, additional studies are necessary to be conclusive. As such, studies assessing objective measures of lower limb impairments associated with neurophysiological adaptations need further evaluation.

Transcranial magnetic stimulation (TMS) and repetitive TMS in multiple sclerosis

Multiple sclerosis (MS) is the most well-known autoimmune disorder of the central nervous system, and constitutes a major cause of disability, especially in young individuals. A wide array of pharmacological treatments is available, but they have often been proven to be ineffective in ameliorating disease symptomatology or slowing disease progress. As such, non-invasive and non-pharmacological techniques have been gaining more ground. Transcranial magnetic stimulation (TMS) utilizes the electric field generated by a magnetic coil to stimulate neurons and has been applied, usually paired with electroencephalography, to study the underlying pathophysiology of MS, and in repetitive trains, in the form of repetitive transcranial magnetic stimulation (rTMS), to induce long-lasting changes in neuronal circuits. In this review, we present the available literature on the application of TMS and rTMS in the context of MS, with an emphasis on its therapeutic potential on various clinical aspects, while also naming the ongoing trials, whose results are anticipated in the future.

Ozanimod to Treat Relapsing Forms of Multiple Sclerosis: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators.

Clinical and Neurochemical Effects of Transcranial Magnetic Stimulation (TMS) in Multiple Sclerosis: A Study Protocol for a Randomized Clinical Trial

Background: Transcranial Magnetic Stimulation (TMS) is a technique based on the principles of electromagnetic induction. It applies pulses of magnetic radiation that penetrate the brain tissue, and it is a non-invasive, painless, and practically innocuous procedure. Previous studies advocate the therapeutic capacity of TMS in several neurodegenerative and psychiatric processes, both in animal models and in human studies. Its uses in Parkinson's disease, Alzheimer's disease and in Huntington's chorea have shown improvement in the symptomatology and in the molecular profile, and even in the cellular density of the brain. Consequently, the extrapolation of these TMS results in the aforementioned neurodegenerative disease to other entities with etiopathogenic and clinical analogy would raise the relevance and feasibility of its use in multiple sclerosis (MS). The overall objective will be to demonstrate the effectiveness of the TMS in terms of safety and clinical improvement, as well as to observe the molecular changes in relation to the treatment.

Methods and Design: Phase II clinical trial, unicentric, controlled, randomized, single blind. A total of 90 patients diagnosed with relapsing-remitting multiple sclerosis (RRMS) who meet all the inclusion criteria and do not present any of the exclusion criteria that are established and from which clinically evaluable results can be obtained. The patients included will be assigned under the 1:1:1 randomization formula, constituting three groups for the present study: 30 patients treated with natalizumab + white (placebo) + 30 patients treated with natalizumab + TMS (1 Hz) + 30 patients treated with natalizumab + TMS (5 Hz).

Discussion: Results of this study will inform on the efficiency of the TMS for the treatment of MS. The expected results are that TMS is a useful therapeutic resource to improve clinical status (main parameters) and neurochemical profile (surrogate parameters); both types of parameters will be checked.

Ethics and Dissemination: The study is approved by the Local Ethics Committee and registered in https://clinicaltrials.gov (NCT04062331). Dissemination will include submission to a peer-reviewed journal, patients, associations of sick people and family members, healthcare magazines and congress presentations.

Trial Registration:ClinicalTrials.gov ID: NCT04062331 (registration date: 19^th/ August/2019).

Version Identifier: EMTr-EMRR, ver-3, 21/11/2017.

Can Operant Conditioning of EMG-Evoked Responses Help to Target Corticospinal Plasticity for Improving Motor Function in People With Multiple Sclerosis?

Corticospinal pathway and its function are essential in motor control and motor rehabilitation. Multiple sclerosis (MS) causes damage to the brain and descending connections, and often diminishes corticospinal function. In people with MS, neural plasticity is available, although it does not necessarily remain stable over the course of disease progress. Thus, inducing plasticity to the corticospinal pathway so as to improve its function may lead to motor control improvements, which impact one's mobility, health, and wellness. In order to harness plasticity in people with MS, over the past two decades, non-invasive brain stimulation techniques have been examined for addressing common symptoms, such as cognitive deficits, fatigue, and spasticity. While these methods appear promising, when it comes to motor rehabilitation, just inducing plasticity or having a capacity for it does not guarantee generation of better motor functions. Targeting plasticity to a key pathway, such as the corticospinal pathway, could change what limits one's motor control and improve function. One of such neural training methods is operant conditioning of the motor-evoked potential that aims to train the behavior of the corticospinal-motoneuron pathway. Through up-conditioning training, the person learns to produce the rewarded neuronal behavior/state of increased corticospinal excitability, and through iterative training, the rewarded behavior/state becomes one's habitual, daily motor behavior. This minireview introduces operant conditioning approach for people with MS. Guiding beneficial CNS plasticity on top of continuous disease progress may help to prolong the duration of maintained motor function and quality of life in people living with MS.

Safety Considerations for Cerebellar Theta Burst Stimulation

PURPOSE

The cerebellum is an intricate neural structure that orchestrates various cognitive and behavioral functions. In recent years, there has been an increasing interest in neuromodulation of the cerebellum with transcranial magnetic stimulation (TMS) for therapeutic and basic science applications. Theta burst stimulation (TBS) is an efficient and powerful TMS protocol that is able to induce longer-lasting effects with shorter stimulation times compared with traditional TMS. Parameters for cerebellar TBS are traditionally framed in the bounds of TBS to the cerebral cortex, even when the 2 have distinct histologic, anatomical, and functional characteristics. Tolerability limits have not been systematically explored in the literature for this specific application. Therefore, we aimed to determine the stimulation parameters that have been used for cerebellar. TBS to date and evaluate adverse events and adverse effects related to stimulation parameters.

METHODS

We used PubMed to perform a critical review of the literature based on a systematic review of original research studies published between September 2008 and November 2019 that reported on cerebellar TBS. We recovered information from these publications and communication with authors about the stimulation parameters used and the occurrence of adverse events.

FINDINGS

We identified 61 research articles on interventions of TBS to the cerebellum. These articles described 3176 active sessions of cerebellar TBS in 1203 individuals, including healthy participants and patients with various neurologic conditions, including brain injuries. Some studies used substantial doses (eg, pulse intensity and number of pulses) in short periods. No serious adverse events were reported. The specific number of patients who experienced adverse events was established for 48 studies. The risk of an adverse event in this population (n = 885) was 4.1%. Adverse events consisted mostly of discomfort attributable to involuntary muscle contractions. Authors used a variety of methods for calculating stimulation dosages, ranging from the long-established reference of electromyography of a hand muscle to techniques that atone for some of the differences between cerebrum and cerebellum.

IMPLICATIONS

No serious adverse events have been reported for cerebellar TBS. There is no substantial evidence of a tolerable maximal-efficacy stimulation dose in humans. There is no assurance of equivalence in the translation of cortical excitability and stimulation intensities from the cerebral cortex to cerebellar regions. Further research for the stimulation dose in cerebellar TBS is warranted, along with consistent report of adverse events. © 2020 Elsevier HS Journals, Inc.

The Potential Role of Neurophysiology in the Management of Multiple Sclerosis-Related Fatigue

Fatigue is a very common symptom among people with multiple sclerosis (MS), but its management in clinical practice is limited by the lack of clear evidence about the pathogenic mechanisms, objective tools for diagnosis, and effective pharmacological treatments. In this scenario, neurophysiology could play a decisive role, thanks to its ability to provide objective measures and to explore the peripheral and the central structures of the nervous system. We hereby review and discuss current evidence about the potential role of neurophysiology in the management of MS-related fatigue. In the first part, we describe the use of neurophysiological techniques for exploring the pathogenic mechanisms of fatigue. In the second part, we review the potential application of neurophysiology for monitoring the response to pharmacological therapies. Finally, we show data about the therapeutic implications of neurophysiological techniques based on non-invasive brain stimulation.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

Theta burst stimulation for upper limb motor dysfunction in patients with stroke: A protocol of systematic review and meta-analysis

BACKGROUND

Upper limb dysfunction is one of common sequelae of stroke which limits daily activities and decreases quality of life of patients, as well as increasing caregiving burden on families. Theta burst stimulation (TBS) is considered to be a beneficial therapy for post-stroke patients with upper limb motor dysfunction, but there is a lack of a high quality evidence. We aim to investigate the effectiveness and safety of TBS for upper limb motor dysfunction in patients with stroke.

METHODS

The following databases will be searched: PubMed, EMBASE, The Cochrane Library, Web of Science, China Biology Medicine (CBM), China National Knowledge infrastructure (CNKI), Technology Periodical Database (VIP) and WanFang Data from the inception to October 2019. All relevant randomized controlled trials (RCTs) using TBS to treat poststroke patients with upper limb motor dysfunction will be included. The primary outcome is Upper Limb Fugl-Meyer Assessment (UL-FMA). Secondary outcomes will include Action Research Arm Test (ARAT), Box and Block Test (BBT), Wolf Motor Function Test (WMFT), Motor Assessment Scale (MAS), Nine Hole Peg Test (NHPT), Grip strength and other scales evaluating the upper limb motor function. Adverse effects will also be evaluated. Two reviewers will screen studies, extract data and assess the risk of bias of included studies independently. Data analysis will be conducted using Review Manager software (RevMan, version 5.3.5) and R software (version 3.6.1).

RESULTS

Our SR will be conducted according to AMSTAR 2.0 and reported in compliance with PRISMA. The findings of this SR will be disseminated through peer-reviewed publications or conference presentations.

CONCLUSION

Our study will provide evidence for the effectiveness and safety of theta burst stimulation for upper limb motor dysfunction in patients with stroke.

ETHICS AND DISSEMINATION

This systematic review (SR) does not require formal ethical approval since no privacy health information will be included. The findings of this SR will be disseminated through peer-reviewed publications or conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42019142462.

Beyond rehabilitation in MS: Insights from non-invasive brain stimulation

Although the number of disease-modifying treatments for people with multiple sclerosis (pwMS) has meaningfully increased in the past years, targeting repair or compensation for central nervous system damage associated with the disease process remains an important clinical goal. With this aim, neurorehabilitation is a powerful approach targeting central nervous system plasticity. Another driver of brain plasticity is non-invasive brain stimulation (NIBS), receiving recent attention in neurology, particularly for its potential synergy with neurorehabilitation and as add-on treatment for several neurological conditions, from pain to fatigue to sensorimotor and cognitive deficits. In this review, we will resume the evidence exploring the neurobiological basis of NIBS and its applications to MS-related conditions.

Non-invasive brain stimulation for fatigue in multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

To investigate the efficacy and safety of non-invasive brain stimulation for fatigue in multiple sclerosis patients.

METHODS

We searched MEDLINE, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and Wanfang databases up to October 25, 2018 (PROSPERO registration number: CRD42018112823). Randomized or pseudo-randomized, sham-controlled clinical trials evaluating the effect of non-invasive brain stimulation (NIBS) such as transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), transcranial random noise stimulation (tRNS), transcranial alternating current stimulation (tACS), cranial electrotherapy stimulation, and reduced impedance non-invasive cortical electrostimulation were included. Two authors independently performed data extraction and risk of bias assessment according to Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1. The primary outcome was fatigue scores before and after stimulation and the secondary outcome was adverse events.

RESULTS

Data from cross-over and parallel group studies were pooled using a generic inverse-variance approach. A total of 14 studies (11 for tDCS, 2 for TMS, and 1 for tRNS) recruiting 207 patients were included in the systematic review and meta-analysis. No eligible tACS, cranial electrotherapy stimulation or reduced impedance non-invasive cortical electrostimulation studies were found. Short-term and long-term treatment effects were significant for tDCS, whereas TMS and tRNS were not superior to sham stimulation. The available evidence supported the effectiveness of the 1.5 mA subgroup and bilateral S1 subgroup of tDCS. Adverse events were minor and transient but comparable between real and sham stimulation.

CONCLUSIONS

tDCS is a safe and effective treatment for fatigue in MS patients. However, further studies are required to confirm our results in a large-scale population and to investigate the effectiveness of other NIBS subtypes.

Low-intensity transcranial magnetic stimulation promotes the survival and maturation of newborn oligodendrocytes in the adult mouse brain

Neuronal activity is a potent extrinsic regulator of oligodendrocyte generation and central nervous system myelination. Clinically, repetitive transcranial magnetic stimulation (rTMS) is delivered to noninvasively modulate neuronal activity; however, the ability of rTMS to facilitate adaptive myelination has not been explored. By performing cre‐lox lineage tracing, to follow the fate of oligodendrocyte progenitor cells in the adult mouse brain, we determined that low intensity rTMS (LI‐rTMS), administered as an intermittent theta burst stimulation, but not as a continuous theta burst or 10 Hz stimulation, increased the number of newborn oligodendrocytes in the adult mouse cortex. LI‐rTMS did not alter oligodendrogenesis per se, but instead increased cell survival and enhanced myelination. These data suggest that LI‐rTMS can be used to noninvasively promote myelin addition to the brain, which has potential implications for the treatment of demyelinating diseases such as multiple sclerosis.

Neurophysiological markers of network dysfunction in neurodegenerative diseases

There is strong clinical, imaging and pathological evidence that neurodegeneration is associated with altered brain connectivity. While functional imaging (fMRI) can detect resting and activated states of metabolic activity, its use is limited by poor temporal resolution, cost and confounding vascular parameters. By contrast, electrophysiological (e.g. EEG/MEG) recordings provide direct measures of neural activity with excellent temporal resolution, and source localization methodologies can address problems of spatial resolution, permitting measurement of functional activity of brain networks with a spatial resolution similar to that of fMRI. This opens an exciting therapeutic approach focussed on pharmacological and physiological modulation of brain network activity. This review describes current neurophysiological approaches towards evaluating cortical network dysfunction in common neurodegenerative disorders. It explores how modern neurophysiologic tools can provide markers for diagnosis, prognosis, subcategorization and clinical trial outcome measures, and how modulation of brain networks can contribute to new therapeutic approaches.

Neuromodulation in multiple sclerosis

Neuromodulation, or the utilization of advanced technology for targeted electrical or chemical neuronal stimulation or inhibition, has been expanding in several neurological subspecialties. In the past decades, immune-modulating therapy has been the main focus of multiple sclerosis (MS) research with little attention to neuromodulation. However, with the recent advances in disease-modifying therapies, it is time to shift the focus of MS research to neuromodulation and restoration of function as with other neurological subspecialties. Preliminary research supports the value of intrathecal baclofen pump and functional electrical stimulation in improving spasticity and motor function in MS patients. Deep brain stimulation can improve MS-related tremor and trigeminal neuralgia. Spinal cord stimulation has been shown to be effective against MS-related pain and bladder dysfunction. Bladder overactivity also responds to sacral neuromodulation and posterior tibial nerve stimulation. Despite limited data in MS, transcranial magnetic stimulation and brain-computer interface are promising neuromodulatory techniques for symptom mitigation and neurorehabilitation of MS patients. In this review, we provide an overview of the available neuromodulatory techniques and the evidence for their use in MS.

The therapeutic use of non-invasive brain stimulation in multiple sclerosis - a review

BACKGROUND

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system and a leading cause of disability in young adults. Many disabling symptoms in MS, such as spasticity, pain, depression and cognitive deficits are not fully controlled by drug treatment. Non-invasive brain stimulation (NIBS) techniques can be used as tools for modulating altered cortical excitability and plasticity MS patients, providing an improvement in disabling symptoms affecting such patients.

OBJECTIVE

This review reported and summarized some of the most interesting and promising recent achievements regarding the therapeutic use of NIBS in MS patients.

METHODS

We reviewed the clinical application of transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), emphasizing their effect on clinical symptoms and signs that are commonly involved in MS patients. In addition, we shortly described new NIBS protocols, such as transcranial alternating current stimulation and transcranial focused ultrasound stimulation as potential and innovative therapeutic options to be applied in future studies in MS patients.

RESULTS

We reviewed twenty-one studies covering six main clinical domains. Most of such studies focused on fatigues (33.3%), motor performance (19%) and spasticity (19%), sparse results were about pain (9.5%), cognitive abilities (9.5%), sensory deficit (4.8%) and bladder function (4.8%). The most promising results have been published for the improvement of motor (i.e. hand dexterity) and cognitive performances (i.e. attention and working memory) by applying rTMS or tDCS alone or in association with motor/cognitive training, for pain's treatment by using tDCS.

CONCLUSION

There are still no official recommendations for the therapeutic use of tDCS or rTMS in MS. The huge inter-individual variability of NIBS efficacy is still a big challenge which needs to be solved. However, well-designed studies, deeper knowledge about pathomechanisms underlying MS, and the combination of such techniques with motor and cognitive rehabilitation might results in higher effectiveness of NIBS.

Effects of intermittent theta burst stimulation on spasticity after spinal cord injury

PURPOSE

Spasticity is a common disorder in patients with spinal cord injury (SCI). The aim of this study was to investigate whether intermittent theta burst stimulation (iTBS), a safe, non-invasive and well-tolerated protocol of excitatory repetitive transcranial magnetic stimulation (rTMS), is effective in modulating spasticity in SCI patients.

METHODS

In this randomized, double-blind, crossover, sham-controlled study, ten subjects with incomplete cervical or thoracic SCI received 10 days of daily sessions of real or sham iTBS. The H/M amplitude ratio of the Soleus H reflex, the amplitude of the motor evoked potentials (MEPs) at rest and during background contraction, as well as Modified Ashworth Scale (MAS) and the Spinal Cord Injury Assessment Tool for Spasticity (SCAT) were compared before and after the stimulation protocols.

RESULTS

Patients receiving real iTBS showed significant increased resting and active MEPs amplitude and a significant reduction of the H/M amplitude ratio. In these patients also the MAS and SCAT scores were significantly reduced after treatment. These changes persisted up to 1 week after the end of the iTBS treatment, and were not observed under the sham-TBS condition.

CONCLUSION

These findings suggest that iTBS may be a promising therapeutic tool for the spasticity in SCI patients.

Depression in Multiple Sclerosis: Epidemiology, Aetiology, Diagnosis and Treatment

Depressive disorders are common in patients with multiple sclerosis, influencing their quality of life and adherence to treatments, as well as becoming more frequent with the progression of the disease and in the secondary progressive form of multiple sclerosis. Patients with multiple sclerosis often experience a typical cluster of symptoms in association with depression, such as fatigue, pain and cognitive impairment. However, the pathogenesis of multiple sclerosis-related depression remains partially unclear, even though genetic, immune-inflammatory and psychosocial factors might be seen to play a role, in addition to the brain structural alterations documented by magnetic resonance imaging studies. The high incidence and burden of depression in people affected with multiple sclerosis are matters of crucial importance. Despite such importance, the efficacy of pharmacologic treatments has been poorly studied and, for the most part, the access to non-pharmacological treatments is partially dependent on the local health system availability. It has been determined that interferon-beta and glatiramer acetate do not cause depressive symptoms; however, no definitive data in this regard are avaible for the newer disease-modifyng medications. In this review, we discuss the diagnosis, prevalence, pathogenesis, clinical aspects, magnetic resonance imaging findings and treatments available in patients experiencing multiple sclerosis-related depression.

Repetitive Transcranial Magnetic Stimulation, Cognition, and Multiple Sclerosis: An Overview

Multiple sclerosis (MS) affects cognition in the majority of patients. A major aspect of the disease is brain volume loss (BVL), present in all phases and types (relapsing and progressive) of the disease and linked to both motor and cognitive disabilities. Due to the lack of effective pharmacological treatments for cognition, cognitive rehabilitation and other nonpharmacological interventions such as repetitive transcranial magnetic stimulation (rTMS) have recently emerged and their potential role in functional connectivity is studied. With recently developed advanced neuroimaging and neurophysiological techniques, changes related to alterations of the brain's functional connectivity can be detected. In this overview, we focus on the brain's functional reorganization in MS, theoretical and practical aspects of rTMS utilization in humans, and its potential therapeutic role in treating cognitively impaired MS patients.

Remodeling Functional Connectivity in Multiple Sclerosis: A Challenging Therapeutic Approach

Neurons in the central nervous system are organized in functional units interconnected to form complex networks. Acute and chronic brain damage disrupts brain connectivity producing neurological signs and/or symptoms. In several neurological diseases, particularly in Multiple Sclerosis (MS), structural imaging studies cannot always demonstrate a clear association between lesion site and clinical disability, originating the "clinico-radiological paradox." The discrepancy between structural damage and disability can be explained by a complex network perspective. Both brain networks architecture and synaptic plasticity may play important roles in modulating brain networks efficiency after brain damage. In particular, long-term potentiation (LTP) may occur in surviving neurons to compensate network disconnection. In MS, inflammatory cytokines dramatically interfere with synaptic transmission and plasticity. Importantly, in addition to acute and chronic structural damage, inflammation could contribute to reduce brain networks efficiency in MS leading to worse clinical recovery after a relapse and worse disease progression. These evidence suggest that removing inflammation should represent the main therapeutic target in MS; moreover, as synaptic plasticity is particularly altered by inflammation, specific strategies aimed at promoting LTP mechanisms could be effective for enhancing clinical recovery. Modulation of plasticity with different non-invasive brain stimulation (NIBS) techniques has been used to promote recovery of MS symptoms. Better knowledge of features inducing brain disconnection in MS is crucial to design specific strategies to promote recovery and use NIBS with an increasingly tailored approach.

Effects of repetitive transcranial magnetic stimulation on lower extremity spasticity and motor function in stroke patients

PURPOSE

To investigate the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) on lower extremity (LE) spasticity, motor function and motor neurone excitability in chronic stroke patients.

METHOD

This study was a randomised sham-controlled cross-over trial with 1-week follow-up. A total of 20 post-stroke patients were randomised to receive active (n = 10) or sham (n = 10) rTMS. Fourteen of them (7 in each group) crossed over to the sham or active rTMS after a washout period of 1 month. Interventions consist of five consecutive daily sessions of active or sham rTMS to the unaffected lower extremity motor area (1000 pulses; 1 Hz; 90% of the tibialis anterior motor threshold). Outcome measures were modified modified ashworth scale (MMAS), the H-reflex, lower extremity section of Fugl-Mayer assessment (LE-FMA) and timed UP and GO (TUG) test. All outcomes were measured at three levels in each intervention period: pre- and post-intervention and 1-week follow-up.

RESULTS

Friedman's test revealed significant improvement in MMAS score only after active rTMS. This improvement lasted for one week after the active rTMS. Repeated measure analysis of variance (ANOVA) showed significant time*intervention interaction for LE-FMA. There are no differences between groups for the MMAS and LE-FMA. No significant change in Hmax/Mmax ratio and TUG test was noted.

CONCLUSION

Low-frequency rTMS over the LE motor area can improve clinical measures of muscle spasticity and motor function. More studies are needed to clarify the changes underlying this improvement in spasticity. Implications for Rehabilitation Spasticity is a common disorder and one of the causes of long-term disability after stroke. Physical therapy modalities, oral medications, focal intervention and surgical procedures have been used for spasticity reduction. Beneficial effect of the repetitive transcranial magnetic stimulation (rTMS) for post-stroke upper extremity spasticity reduction and motor function improvement was demonstrated in previous studies. This study shows amelioration of lower extremity spasticity and motor function improvement after five daily sessions of inhibitory rTMS to the unaffected brain hemisphere which lasted for at least 1 week following the intervention.