Transcranial magnetic stimulation and BDNF plasma levels in amyotrophic lateral sclerosis

Low-intensity pulsed ultrasound modulates disease progression in the SOD1G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the brain and spinal cord, and there are no effective drug treatments. Low-intensity pulsed ultrasound (LIPUS) has garnered attention as a promising noninvasive neuromodulation method. In this study, we investigate its effects on the motor cortex and underlying mechanisms using the SOD1G93A mouse model of ALS. Our results show that LIPUS treatment delays disease onset and prolongs lifespan in ALS mice. LIPUS significantly increases cerebral blood flow in the motor cortex by preserving vascular endothelial cell integrity and increasing microvascular density, which may be mediated via the ion channel TRPV4. RNA sequencing analysis reveals that LIPUS substantially reduces the expression of genes associated with neuroinflammation. These findings suggest that LIPUS applied to the motor cortex may represent a potentially effective therapeutic tool for the treatment of ALS.

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.

Brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling in spinal muscular atrophy and amyotrophic lateral sclerosis

Tropomyosin receptor kinase B (TrkB) and its primary ligand brain-derived neurotrophic factor (BDNF) are expressed in the neuromuscular system, where they affect neuronal survival, differentiation, and functions. Changes in BDNF levels and full-length TrkB (TrkB-FL) signaling have been revealed in spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), two common forms of motor neuron diseases that are characterized by defective neuromuscular junctions in early disease stages and subsequently progressive muscle weakness. This review summarizes the current understanding of BDNF/TrkB-FL-related research in SMA and ALS, with an emphasis on their alterations in the neuromuscular system and possible BDNF/TrkB-FL-targeting therapeutic strategies. The limitations of current studies and future directions are also discussed, giving the hope of discovering novel and effective treatments.

Neuronal Hyperexcitability and Free Radical Toxicity in Amyotrophic Lateral Sclerosis: Established and Future Targets

Amyotrophic lateral sclerosis (ALS) is a devastating disease with evidence of degeneration involving upper and lower motor neuron compartments of the nervous system. Presently, two drugs, riluzole and edaravone, have been established as being useful in slowing disease progression in ALS. Riluzole possesses anti-glutamatergic properties, while edaravone eliminates free radicals (FRs). Glutamate is the excitatory neurotransmitter in the brain and spinal cord and binds to several inotropic receptors. Excessive activation of these receptors generates FRs, inducing neurodegeneration via damage to intracellular organelles and upregulation of proinflammatory mediators. FRs bind to intracellular structures, leading to cellular impairment that contributes to neurodegeneration. As such, excitotoxicity and FR toxicities have been considered as key pathophysiological mechanisms that contribute to the cascade of degeneration that envelopes neurons in ALS. Recent advanced technologies, including neurophysiological, imaging, pathological and biochemical techniques, have concurrently identified evidence of increased excitability in ALS. This review focuses on the relationship between FRs and excitotoxicity in motor neuronal degeneration in ALS and introduces concepts linked to increased excitability across both compartments of the human nervous system. Within this cellular framework, future strategies to promote therapeutic development in ALS, from the perspective of neuronal excitability and function, will be critically appraised.

Therapeutic application of rTMS in neurodegenerative and movement disorders: A review

Transcranial magnetic stimulation (TMS) is a non-invasive form of brain stimulation that makes use of the magnetic field generated when an electric current passes through a magnetic coil placed over the scalp. It can be applied as a single stimulus at a time, in pairs of stimuli, or repetitively in trains of stimuli (repetitive TMS, rTMS). RTMS can induce changes in brain activity, whose after-effects reflect the processes of long-term potentiation and long-term depression, as certain protocols, namely those using low frequencies (≤1 Hz) seem to suppress cortical excitability, while those using high frequencies (>1 Hz) seem to enhance it. It is a technique with very few and mostly mild side-effects, whose effects can persist for long time periods, and as such, it has been studied as a potential treatment option in a multitude of neurodegenerative diseases, including those affecting movement. Although rTMS has received approval as a treatment strategy of only a few aspects in movement disorders in the latest guidelines, its further use seems to also be promising in their context. In this review, we gathered the available literature on the therapeutic application of rTMS in movement disorders, namely Parkinson's disease, Amyotrophic Lateral Sclerosis, Huntington's disease, Dystonia, Tic disorders and Essential Tremor.

Therapeutic Use of Cerebellar Intermittent Theta Burst Stimulation (iTBS) in a Sardinian Family Affected by Spinocerebellar Ataxia 38 (SCA 38)

Spinocerebellar ataxia 38 (SCA 38) is an autosomal dominant disorder caused by conventional mutations in the ELOVL5 gene which encodes an enzyme involved in the synthesis of very long fatty acids, with a specific expression in cerebellar Purkinje cells. Three Italian families carrying the mutation, one of which is of Sardinian descent, have been identified and characterized. One session of cerebellar intermittent theta burst stimulation (iTBS) was applied to 6 affected members of the Sardinian family to probe motor cortex excitability measured by motor-evoked potentials (MEPs). Afterwards, patients were exposed to ten sessions of cerebellar real and sham iTBS in a cross-over study and clinical symptoms were evaluated before and after treatment by Modified International Cooperative Ataxia Rating Scale (MICARS). Moreover, serum BDNF levels were evaluated before and after real and sham cerebellar iTBS and the role of BDNF Val66Met polymorphism in influencing iTBS effect was explored. Present data show that one session of cerebellar iTBS was able to increase MEPs in all tested patients, suggesting an enhancement of the cerebello-thalamo-cortical pathway in SCA 38. MICARS scores were reduced after ten sessions of real cerebellar iTBS showing an improvement in clinical symptoms. Finally, although serum BDNF levels were not affected by cerebellar iTBS when considering all samples, segregating for genotype a difference was found between Val66Val and Val66Met carriers. These preliminary data suggest a potential therapeutic use of cerebellar iTBS in improving motor symptoms of SCA38.

Frontotemporal Transcranial Direct Current Stimulation Decreases Serum Mature Brain-Derived Neurotrophic Factor in Schizophrenia

Although transcranial direct current stimulation (tDCS) shows promise as a treatment for auditory verbal hallucinations in patients with schizophrenia, mechanisms through which tDCS may induce beneficial effects remain unclear. Evidence points to the involvement of neuronal plasticity mechanisms that are underpinned, amongst others, by brain-derived neurotrophic factor (BDNF) in its two main forms: pro and mature peptides. Here, we aimed to investigate whether tDCS modulates neural plasticity by measuring the acute effects of tDCS on peripheral mature BDNF levels in patients with schizophrenia. Blood samples were collected in 24 patients with schizophrenia before and after they received a single session of either active (20 min, 2 mA, n = 13) or sham (n = 11) frontotemporal tDCS with the anode over the left prefrontal cortex and the cathode over the left temporoparietal junction. We compared the tDCS-induced changes in serum mature BDNF (mBDNF) levels adjusted for baseline values between the two groups. The results showed that active tDCS was associated with a significantly larger decrease in mBDNF levels (mean −20% ± standard deviation 14) than sham tDCS (−8% ± 21) (F = 5.387; p = 0.030; η² = 0.205). Thus, mature BDNF may be involved in the beneficial effects of frontotemporal tDCS observed in patients with schizophrenia.

Repetitive Transcranial Magnetic Stimulation With H-Coil in Alzheimer's Disease: A Double-Blind, Placebo-Controlled Pilot Study

Focal repetitive transcranial magnetic stimulation (rTMS) has been applied to improve cognition in Alzheimer's disease (AD) with conflicting results. We applied rTMS in AD in a pilot placebo-controlled study using the H2-coil. H-coils are suitable for targeting wider neuronal structures compared with standard focal coils, in particular the H2-coil stimulates simultaneously the frontal-parietal-temporal lobes bilaterally. Thirty patients (mean age 70.9 year, SD 8.1; mean MMSE score 16.9, SD 5.5) were randomized to sham or real 10 Hz rTMS stimulation with the H2-coil. Each patient underwent 3 sessions/week for 4 weeks, followed by 4 weeks with maintenance treatment (1 session/week). Primary outcome was improvement of ADAS-cog at 4 and 8 weeks compared with baseline. A trend toward an improved ADAS-cog score over time was observed for patients undergoing real rTMS, with actively treated patients experiencing a mean decrease of −1.01 points at the ADAS-Cog scale score per time point (95% CIs −0.02 to −3.13, p < 0.04). This trend was no longer evident 2 months after the end of treatment. Real rTMS showed no significant effect on MMSE and BDI changes over time. These preliminary findings suggest that rTMS with H-coil is feasible and safe in patients with probable AD and might provide beneficial, even though transient, effects on cognition. This study prompts larger studies in the early stages of AD, combining rTMS and cognitive rehabilitation.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT04562506.

Brain Stimulation as a Therapeutic Tool in Amyotrophic Lateral Sclerosis: Current Status and Interaction With Mechanisms of Altered Cortical Excitability

In the last 20 years, several modalities of neuromodulation, mainly based on non-invasive brain stimulation (NIBS) techniques, have been tested as a non-pharmacological therapeutic approach to slow disease progression in amyotrophic lateral sclerosis (ALS). In both sporadic and familial ALS cases, neurophysiological studies point to motor cortical hyperexcitability as a possible priming factor in neurodegeneration, likely related to dysfunction of both excitatory and inhibitory mechanisms. A trans-synaptic anterograde mechanism of excitotoxicity is thus postulated, causing upper and lower motor neuron degeneration. Specifically, motor neuron hyperexcitability and hyperactivity are attributed to intrinsic cell abnormalities related to altered ion homeostasis and to impaired glutamate and gamma aminobutyric acid gamma-aminobutyric acid (GABA) signaling. Several neuropathological mechanisms support excitatory and synaptic dysfunction in ALS; additionally, hyperexcitability seems to drive DNA-binding protein 43-kDA (TDP-43) pathology, through the upregulation of unusual isoforms directly contributing to ASL pathophysiology. Corticospinal excitability can be suppressed or enhanced using NIBS techniques, namely, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), as well as invasive brain and spinal stimulation. Experimental evidence supports the hypothesis that the after-effects of NIBS are mediated by long-term potentiation (LTP)-/long-term depression (LTD)-like mechanisms of modulation of synaptic activity, with different biological and physiological mechanisms underlying the effects of tDCS and rTMS and, possibly, of different rTMS protocols. This potential has led to several small trials testing different stimulation interventions to antagonize excitotoxicity in ALS. Overall, these studies suggest a possible efficacy of neuromodulation in determining a slight reduction of disease progression, related to the type, duration, and frequency of treatment, but current evidence remains preliminary. Main limitations are the small number and heterogeneity of recruited patients, the limited "dosage" of brain stimulation that can be delivered in the hospital setting, the lack of a sufficient knowledge on the excitatory and inhibitory mechanisms targeted by specific stimulation interventions, and the persistent uncertainty on the key pathophysiological processes leading to motor neuron loss. The present review article provides an update on the state of the art of neuromodulation in ALS and a critical appraisal of the rationale for the application/optimization of brain stimulation interventions, in the light of their interaction with ALS pathophysiological mechanisms.

Remotely supervised transcranial direct current stimulation: A feasibility study for amyotrophic lateral sclerosis

BACKGROUND

Transcranial direct current stimulation (tDCS) has been investigated as a therapeutic neuromodulation tool in several neurological disorders. However, evidence supporting its efficacy in disorders such as amyotrophic lateral sclerosis (ALS) is limited possibly due to limited patient accessibility for research, particularly for individuals with advanced disease progression. Telerehabilitation using home-based protocols allows for remote supervision of tDCS over longer durations, thereby increasing participation, compliance and adherence. In this study, we explored the safety, feasibility and preliminary effects of a remotely supervised tDCS (RS-tDCS) protocol in ALS.

MATERIAL AND METHODS

In this pre-post case series study, two individuals with ALS completed 24 remotely supervised anodal tDCS sessions (20 minutes, 2 mA). Outcomes included adherence, compliance, disease progression, walking speed, risk of fall, endurance, fatigue and depression.

RESULTS

Both participants successfully completed the study without any major adverse effects. Minor side effects included mild sensations of itching and throbbing under the electrodes during stimulation. Clinical outcomes showed minimal to no change for any of the measures.

CONCLUSIONS

Preliminary findings suggest that the RS-tDCS protocol is safe and feasible in individuals with ALS. Our protocol serves as a model for future long-term studies to evaluate the clinical and neurophysiological effects of tDCS using a telerehabilitation protocol in ALS.

Combination of Human Mesenchymal Stem Cells and Repetitive Transcranial Magnetic Stimulation Enhances Neurological Recovery of 6-Hydroxydopamine Model of Parkinsonian's Disease

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been in use for the treatment of various neurological diseases, including depression, anxiety, stroke and Parkinson's disease (PD), while its underlying mechanism is stills unclear. This study was undertaken to evaluate the potential synergism of rTMS treatment to the beneficial effect of human mesenchymal stem cells (hMSCs) administration for PD and to clarify the mechanism of action of this therapeutic approach.

METHODS

The neuroprotective effect in nigral dopamine neurons, neurotrophic/growth factors and anti-/pro-inflammatory cytokine regulation, and functional recovery were assessed in the rat 6-hydroxydopamine (6-OHDA) model of PD upon administration of hMSCs and rTMS.

RESULTS

Transplanted hMSCs were identified in the substantia nigra, and striatum. Enhancement of the survival of SN dopamine neurons and the expression of the tyrosine hydroxylase protein were observed in the hMSCs + rTMS compared to that of controls. Combination therapy significantly elevated the expression of several key neurotrophic factors, of which the highest expression was recorded in the rTMS + hMSC group. In addition, the combination therapy significantly upregulated IL-10 expression while decreased IFN-γ and TNF-α production in a synergistic manner. The treadmill locomotion test (TLT) revealed that motor function was improved in the rTMS + hMSC treatment with synergy.

CONCLUSION

Our findings demonstrate that rTMS treatment and hMSC transplantation could synergistically create a favorable microenvironment for cell survival within the PD rat brain, through alteration of soluble factors such as neurotrophic/growth factors and anti-/pro-inflammatory cytokines related to neuronal protection or repair, with preservation of DA neurons and improvement of motor functions.

Therapeutic non-invasive brain stimulation in amyotrophic lateral sclerosis: rationale, methods and experience

The neurodegenerative syndrome amyotrophic lateral sclerosis (ALS) is characterised by increased cortical excitability, thought to reflect pathological changes in the balance of local excitatory and inhibitory neuronal influences. Non-invasive brain stimulation (NIBS) has been shown to modulate cortical activity, with some protocols showing effects that outlast the stimulation by months. NIBS has been suggested as a potential therapeutic approach for disorders associated with changes in cortical neurophysiology, including ALS. This article reviews NIBS methodology, rationale for its application to ALS and progress to date.

Rhythmic low-field magnetic stimulation may improve depression by increasing brain-derived neurotrophic factor

BACKGROUND

Low-field magnetic stimulation (LFMS) has mood-elevating effect, and the increase of brain-derived neurotrophic factor (BDNF) is associated with antidepressant treatment. We evaluated the effects and association with BDNF of rhythmic LFMS in the treatment of major depressive disorder (MDD).

METHODS

A total of 22 MDD patients were randomized to rhythmic alpha stimulation (RAS) or rhythmic delta stimulation (RDS), with 5 sessions per week, lasting for 6 weeks. Outcomes assessments included the 17-item Hamilton Depression Rating Scale (HAMD-17), the Hamilton Anxiety Rating Scale (HAMA), and the Clinical Global Impressions-Severity scale (CGI-S) at baseline and at weeks 1, 2, 3, 4, and 6. Serum BDNF level was measured at baseline and at weeks 2, 4, and 6.

RESULTS

HAMD-17, HAMA, and CGI-S scores were significantly reduced with both RAS and RDS. RAS patients had numerically greater reductions in HAMD-17 scores than RDS patients (8.9 ± 7.4 vs. 6.2 ± 6.2, effect size [ES]=0.40), while RDS patients had greater improvement in HAMA scores (8.2 ± 8.0 vs. 5.3 ± 5.8, ES=0.42). RAS was associated with clinically relevant advantages in response (54.5% vs. 18.2%, number-needed-to-treat [NNT]=3) and remission (36.4% vs. 9.1%, NNT=4). BDNF increased significantly during the 6-week study period (p&lt;0.05), with greater increases in RAS at weeks 4 and 6 (ES=0.66-0.76) and statistical superiority at week 2 (p=0.034, ES=1.23). Baseline BDNF in the 8 responders (24.8±9.0 ng/ml) was lower than in the 14 nonresponders (31.1±7.3 ng/ml, p=0.083, ES=-0.79), and BDNF increased more in responders (8.9±7.8 ng/ml) than in nonresponders (1.8±3.5 ng/ml, p=0.044). The change in BDNF at week 2 was the most strongly predicted response (p=0.016).

CONCLUSIONS

Rhythmic LFMS was effective for MDD. BDNF may moderate/mediate the efficacy of LFMS.

50-Hz magnetic field impairs the expression of iron-related genes in the in vitro SOD1G93A model of amyotrophic lateral sclerosis

PURPOSE

We characterized the response to the extremely low frequency magnetic field (ELF-MF) in an in vitro model of familial Amyotrophic Lateral Sclerosis (fALS), carrying two mutant variants of the superoxide dismutase 1 (SOD1) gene.

MATERIALS AND METHODS

SH-SY5Y human neuroblastoma cells, stably over-expressing the wild type, the G93A or the H46R mutant SOD1 cDNA, were exposed to either the ELF-MF (50 Hz, 1 mT) or the sham control field, up to 72 h. Analysis of (i) viability, proliferation and apoptosis, (ii) reactive oxygen species generation, and (iii) assessment of the iron metabolism, were carried out in all clones in response to the MF exposure.

RESULTS

We report that 50-Hz MF exposure induces: (i) no change in proliferation and viability; (ii) no modulation of the intracellular superoxide and H₂O₂ levels; (iii) a significant deregulation in the expression of iron-related genes IRP1, MFRN1 and TfR1, this evidence being exclusive for the SOD1^G93A clone and associated with a slight (p = .0512) difference in the total iron content.

CONCLUSIONS

50-Hz MF affects iron homeostasis in the in vitro SOD1^G93A ALS model.

High-Frequency Repetitive Magnetic Stimulation Enhances the Expression of Brain-Derived Neurotrophic Factor Through Activation of Ca2+-Calmodulin-Dependent Protein Kinase II-cAMP-Response Element-Binding Protein Pathway

Repetitive transcranial magnetic stimulation (rTMS) can be used in various neurological disorders. However, neurobiological mechanism of rTMS is not well known. Therefore, in this study, we examined the global gene expression patterns depending on different frequencies of repetitive magnetic stimulation (rMS) in both undifferentiated and differentiated Neuro-2a cells to generate a comprehensive view of the biological mechanisms. The Neuro-2a cells were randomly divided into three groups—the sham (no active stimulation) group, the low-frequency (0.5 Hz stimulation) group, and high-frequency (10 Hz stimulation) group—and were stimulated 10 min for 3 days. The low- and high-frequency groups of rMS on Neuro-2a cells were characterized by transcriptome array. Differentially expressed genes were analyzed using the Database of Annotation Visualization and Integrated Discovery program, which yielded a Kyoto Encyclopedia of Genes and Genomes pathway. Amphetamine addiction pathway, circadian entrainment pathway, long-term potentiation (LTP) pathway, neurotrophin signaling pathway, prolactin signaling pathway, and cholinergic synapse pathway were significantly enriched in high-frequency group compared with low-frequency group. Among these pathways, LTP pathway is relevant to rMS, thus the genes that were involved in LTP pathway were validated by quantitative real-time polymerase chain reaction and western blotting. The expression of glutamate ionotropic receptor N-methyl d-aspartate 1, calmodulin-dependent protein kinase II (CaMKII) δ, and CaMKIIα was increased, and the expression of CaMKIIγ was decreased in high-frequency group. These genes can activate the calcium (Ca²⁺)–CaMKII–cAMP-response element-binding protein (CREB) pathway. Furthermore, high-frequency rMS induced phosphorylation of CREB, brain-derived neurotrophic factor (BDNF) transcription via activation of Ca²⁺–CaMKII–CREB pathway. In conclusion, high-frequency rMS enhances the expression of BDNF by activating Ca²⁺–CaMKII–CREB pathway in the Neuro-2a cells. These findings may help clarify further therapeutic mechanisms of rTMS.

Safety and feasibility of transcranial direct current stimulation in amyotrophic lateral sclerosis - a pilot study with a single subject experimental design

INTRODUCTION

Transcranial direct current stimulation (tDCS) has been explored as a neuromodulatory tool to prime motor function in several neurological disorders. Studies using tDCS in amyotrophic lateral sclerosis (ALS) are limited. We investigated the safety, feasibility and effects of long-term tDCS in an individual with ALS.

METHODS

A 36-year-old male diagnosed with clinically definite ALS received 12 sessions each of anodal, sham, and cathodal tDCS. Outcome measures included disease progression (revised ALS functional rating scale (ALSFRS-R)), clinical measures of endurance and mobility, and corticomotor excitability.

RESULTS

No adverse events or change in disease progression were noticed during the study. Small improvement in gait speed (15% increase) was noticed with anodal tDCS only.

CONCLUSIONS

This case study demonstrates the safety and feasibility of long-term facilitatory and inhibitory tDCS on a single participant with ALS. This study serves as a guideline for implementing tDCS in future ALS trials.

Symptomatic treatments for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Motor neuron disease (MND), which is also known as amyotrophic lateral sclerosis (ALS), causes a wide range of symptoms but the evidence base for the effectiveness of the symptomatic treatment therapies is limited.

OBJECTIVES

To summarise the evidence from Cochrane Systematic Reviews of all symptomatic treatments for MND.

METHODS

We searched the Cochrane Database of Systematic Reviews (CDSR) on 15 November 2016 for systematic reviews of symptomatic treatments for MND. We assessed the methodological quality of the included reviews using the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the GRADE approach. We followed standard Cochrane study (review) selection and data extraction procedures. We reported findings narratively and in tables.

MAIN RESULTS

We included nine Cochrane Systematic Reviews of interventions to treat symptoms in people with MND. Three were empty reviews with no included randomised controlled trials (RCTs); however, all three reported on non-RCT evidence and the remaining six included mostly one or two studies. We deemed all of the included reviews of high methodological quality. Drug therapy for painThere is no RCT evidence in a Cochrane Systematic Review exploring the efficacy of drug therapy for pain in MND. Treatment for crampsThere is evidence (13 RCTs, N = 4012) that for the treatment of cramps in MND, compared to placebo:- memantine and tetrahydrocannabinol (THC) are probably ineffective (moderate-quality evidence);- vitamin E may have little or no effect (low-quality evidence); and- the effects of L-threonine, gabapentin, xaliproden, riluzole, and baclofen are uncertain as the evidence is either very low quality or the trial specified the outcome but did not report numerical data.The review reported adverse effects of riluzole, but it is not clear whether other interventions had adverse effects. Treatment for spasticityIt is uncertain whether an endurance-based exercise programme improved spasticity or quality of life, measured at three months after the programme, as the quality of evidence is very low (1 RCT, comparison "usual activities", N = 25). The review did not evaluate other approaches, such as use of baclofen as no RCTs were available. Mechanical ventilation for supporting respiratory functionNon-invasive ventilation (NIV) probably improves median survival and quality of life in people with respiratory insufficiency and normal to moderately impaired bulbar function compared to standard care, and improves quality of life but not survival for people with poor bulbar function (1 RCT, N = 41, moderate-quality evidence; a second RCT did not provide data). The review did not evaluate other approaches such as tracheostomy-assisted ('invasive') ventilation, or assess timing of NIV initiation. Treatment for sialorrhoeaA single session of botulinum toxin type B injections to parotid and submandibular glands probably improves sialorrhoea and quality of life at up to 4 weeks compared to placebo injections, but not at 8 or 12 weeks after the injections (moderate-quality evidence from 1 placebo-controlled RCT, N = 20). The review authors found no trials of other approaches. Enteral tube feeding for supporting nutritionThere is no RCT evidence in a Cochrane Systematic Review to support benefit or harms of enteral tube feeding in supporting nutrition in MND. Repetitive transcranial magnetic stimulationIt is uncertain whether repetitive transcranial magnetic stimulation (rTMS) improves disability or limitation in activity in MND in comparison with sham rTMS (3 RCTs, very low quality evidence, N = 50). Therapeutic exerciseThere is evidence that exercise may improve disability in MND at three months after the exercise programme, but not quality of life, in comparison with "usual activities" or "usual care" including stretching (2 RCTs, low-quality evidence, N = 43). Multidisciplinary careThere is no RCT evidence in a Cochrane Systematic Review to demonstrate any benefit or harm for multidisciplinary care in MND.None of the reviews, other than the review of treatment for cramps, reported that adverse events occurred. However, the trials were too small for reliable adverse event reporting.

AUTHORS' CONCLUSIONS

This overview has highlighted the lack of robust evidence in Cochrane Systematic Reviews on interventions to manage symptoms resulting from MND. It is important to recognise that clinical trials may fail to demonstrate efficacy of an intervention for reasons other than a true lack of efficacy, for example because of insufficient statistical power, the wrong choice of dose, insensitive outcome measures or inappropriate participant eligibility. The trials were mostly too small to reliably assess adverse effects of the treatments. The nature of MND makes it difficult to research clinically accepted or recommended practice, regardless of the level of evidence supporting the practice. It would not be ethical, for example, to design a placebo-controlled trial for treatment of pain in MND or to withhold multidisciplinary care where such care is available. It is therefore highly unlikely that there will ever be classically designed placebo-controlled RCTs in these areas.We need more research with appropriate study designs, robust methodology, and of sufficient duration to address the changing needs-of people with MND and their caregivers-associated with MND disease progression and mortality. There is a significant gap in studies assessing the effectiveness of interventions for symptoms relating to MND, such as pseudobulbar emotional lability and cognitive and behavioural difficulties. Future studies should use appropriate outcome measures that are reliable, have internal and external validity, and are sensitive to change in what is being measured (such as quality of life).

Effect of Deep Intramuscular Stimulation and Transcranial Magnetic Stimulation on Neurophysiological Biomarkers in Chronic Myofascial Pain Syndrome

OBJECTIVE

The aim was to assess the neuromodulation techniques effects (repetitive transcranial magnetic stimulation [rTMS] and deep intramuscular stimulation therapy [DIMST]) on pain intensity, peripheral, and neurophysiological biomarkers chronic myofascial pain syndrome (MPS) patients.

DESIGN

Randomized, double blind, factorial design, and controlled placebo-sham clinical trial.

SETTING

Clinical trial in the Laboratory of Pain and Neuromodulation at Hospital de Clínicas de Porto Alegre (NCT02381171).

SUBJECTS

We recruited women aged between 19- and 75-year old, with MPS diagnosis.

METHODS

Patients were randomized into four groups: rTMS + DIMST, rTMS + sham-DIMST, sham-rTMS + DIMST, sham-rTMS + sham-DIMST; and received 10 sessions for 20 minutes each one (rTMS and DIMST). Pain was assessed by visual analogue scale (VAS); neurophysiological parameters were assessed by transcranial magnetic stimulation; biochemical parameters were: BDNF, S100β, lactate dehydrogenase, inflammatory (TNF-α, IL6, and IL10), and oxidative stress parameters.

RESULTS

We observed the pain relief assessed by VAS immediately assessed before and after the intervention (P < 0.05, F(1,3)= 3.494 and F(1,3)= 4.656, respectively); in the sham-rTMS + DIMST group and both three active groups in relation to sham-rTMS + sham-DIMST group, respectively. There was an increase in the MEP after rTMS + sham-DIMST (P < 0.05). However, there was no change in all-peripheral parameters analyzed across the treatment (P > 0.05).

CONCLUSION

Our findings add additional evidence about rTMS and DIMST in relieving pain in MPS patients without synergistic effect. No peripheral biomarkers reflected the analgesic effect of both techniques; including those related to cellular damage. Additionally, one neurophysiological parameter (increased MEP amplitude) needs to be investigated.

Induction of Neurorestoration From Endogenous Stem Cells

Neural stem cells (NSCs) persist in the subventricular zone lining the ventricles of the adult brain. The resident stem/progenitor cells can be stimulated in vivo by neurotrophic factors, hematopoietic growth factors, magnetic stimulation, and/or physical exercise. In both animals and humans, the differentiation and survival of neurons arising from the subventricular zone may also be regulated by the trophic factors. Since stem/progenitor cells present in the adult brain and the production of new neurons occurs at specific sites, there is a possibility for the treatment of incurable neurological diseases. It might be feasible to induce neurogenesis, which would be particularly efficacious in the treatment of striatal neurodegenerative conditions such as Huntington's disease, as well as cerebrovascular diseases such as ischemic stroke and cerebral palsy, conditions that are widely seen in the clinics. Understanding of the molecular control of endogenous NSC activation and progenitor cell mobilization will likely provide many new opportunities as therapeutic strategies. In this review, we focus on endogenous stem/progenitor cell activation that occurs in response to exogenous factors including neurotrophic factors, hematopoietic growth factors, magnetic stimulation, and an enriched environment. Taken together, these findings suggest the possibility that functional brain repair through induced neurorestoration from endogenous stem cells may soon be a clinical reality.

Possible Mechanisms Underlying the Therapeutic Effects of Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) is an effective method used to diagnose and treat many neurological disorders. Although repetitive TMS (rTMS) has been used to treat a variety of serious pathological conditions including stroke, depression, Parkinson’s disease, epilepsy, pain, and migraines, the pathophysiological mechanisms underlying the effects of long-term TMS remain unclear. In the present review, the effects of rTMS on neurotransmitters and synaptic plasticity are described, including the classic interpretations of TMS effects on synaptic plasticity via long-term potentiation and long-term depression. We also discuss the effects of rTMS on the genetic apparatus of neurons, glial cells, and the prevention of neuronal death. The neurotrophic effects of rTMS on dendritic growth and sprouting and neurotrophic factors are described, including change in brain-derived neurotrophic factor concentration under the influence of rTMS. Also, non-classical effects of TMS related to biophysical effects of magnetic fields are described, including the quantum effects, the magnetic spin effects, genetic magnetoreception, the macromolecular effects of TMS, and the electromagnetic theory of consciousness. Finally, we discuss possible interpretations of TMS effects according to dynamical systems theory. Evidence suggests that a rTMS-induced magnetic field should be considered a separate physical factor that can be impactful at the subatomic level and that rTMS is capable of significantly altering the reactivity of molecules (radicals). It is thought that these factors underlie the therapeutic benefits of therapy with TMS. Future research on these mechanisms will be instrumental to the development of more powerful and reliable TMS treatment protocols.

Possible Mechanisms Underlying the Therapeutic Effects of Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) is an effective method used to diagnose and treat many neurological disorders. Although repetitive TMS (rTMS) has been used to treat a variety of serious pathological conditions including stroke, depression, Parkinson's disease, epilepsy, pain, and migraines, the pathophysiological mechanisms underlying the effects of long-term TMS remain unclear. In the present review, the effects of rTMS on neurotransmitters and synaptic plasticity are described, including the classic interpretations of TMS effects on synaptic plasticity via long-term potentiation and long-term depression. We also discuss the effects of rTMS on the genetic apparatus of neurons, glial cells, and the prevention of neuronal death. The neurotrophic effects of rTMS on dendritic growth and sprouting and neurotrophic factors are described, including change in brain-derived neurotrophic factor concentration under the influence of rTMS. Also, non-classical effects of TMS related to biophysical effects of magnetic fields are described, including the quantum effects, the magnetic spin effects, genetic magnetoreception, the macromolecular effects of TMS, and the electromagnetic theory of consciousness. Finally, we discuss possible interpretations of TMS effects according to dynamical systems theory. Evidence suggests that a rTMS-induced magnetic field should be considered a separate physical factor that can be impactful at the subatomic level and that rTMS is capable of significantly altering the reactivity of molecules (radicals). It is thought that these factors underlie the therapeutic benefits of therapy with TMS. Future research on these mechanisms will be instrumental to the development of more powerful and reliable TMS treatment protocols.

Impact of repetitive transcranial magnetic stimulation on post-stroke dysmnesia and the role of BDNF Val66Met SNP

Background

Little is known about the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on dysmnesia and the impact of brain nucleotide neurotrophic factor (BDNF) Val66Met single-nucleotide polymorphism (SNP). This study investigated the impact of low-frequency rTMS on post-stroke dysmnesia and the impact of BDNF Val66Met SNP.

Material/Methods

Forty patients with post-stroke dysmnesia were prospectively randomized into the rTMS and sham groups. BDNF Val66Met SNP was determined using restriction fragment length polymorphism. Montreal Cognitive Assessment (MoCA), Loewenstein Occupational Therapy of Cognitive Assessment (LOTCA), and Rivermead Behavior Memory Test (RBMT) scores, as well as plasma BDNF concentrations, were measured at baseline and at 3 days and 2 months post-treatment.

Results

MoCA, LOTCA, and RBMT scores were higher after rTMS. Three days after treatment, BDNF decreased in the rTMS group but it increased in the sham group (P<0.05). Two months after treatment, RMBT scores in the rTMS group were higher than in the sham group, but not MoCA and LOTCA scores.

Conclusions

Low-frequency rTMS may improve after-stoke memory through various pathways, which may involve polymorphisms and several neural genes, but not through an increase in BDNF levels.

Effects of deep repetitive transcranial magnetic stimulation on brain-derived neurotrophic factor serum concentration in healthy volunteers

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive, safe and efficacious technique for treating various neuropsychiatric disorders, but its underlying mechanisms are poorly understood. A newly developed H-coil allows the stimulation of deeper brain regions. This study is the first to investigate the effects of deep high-frequency rTMS on brain-derived neurotrophic factor (BDNF) serum concentrations in healthy volunteers. We aimed to evaluate the short-term effect of deep rTMS on BDNF serum concentrations.

METHODS

This was a double-blind, randomized deep high-frequency rTMS study using an H-coil on a cohort of 13 healthy volunteers (NCT01106365). The following stimulation protocols were applied: 18-Hz stimulation of the left dorsolateral prefrontal cortex (PFC), 5-Hz stimulation of the primary motor cortex (MC) and sham stimulation in random order. Blood samples were obtained before, 30 min after and 60 min after each treatment.

RESULTS

The BDNF serum concentration decreased significantly after MC and PFC stimulation, but not after sham stimulation. Furthermore, BDNF serum level changes were associated with changes in individual alertness.

CONCLUSION

Although BDNF serum concentrations do not necessarily correlate with BDNF levels in the cerebrospinal fluid or the brain, these results indicate an acute biological effect of deep rTMS on BDNF release, and demonstrate that this change correlates with alertness.

Use of transcranial magnetic stimulation in the treatment of selected movement disorders

Transcranial magnetic stimulation (TMS) is a valuable technique for assessing the underlying neurophysiology associated with various neuropathologies, and is a unique tool for establishing potential neural mechanisms responsible for disease progression. Recently, repetitive TMS (rTMS) has been advanced as a potential therapeutic technique to treat selected neurologic disorders. In healthy individuals, rTMS can induce changes in cortical excitability. Therefore, targeting specific cortical areas affected by movement disorders theoretically may alter symptomology. This review discusses the evidence for the efficacy of rTMS in Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and multiple sclerosis. It is hoped that gaining a more thorough understanding of the timing and parameters of rTMS in individuals with neurodegenerative disorders may advance both clinical care and research into the most effective uses of this technology.

An animal study to examine the effects of the bilateral, epidural cortical stimulation on the progression of amyotrophic lateral sclerosis

Background

We examined the effects of the unilateral cortical stimulation on the survival of neurons showing degenerative changes and compared those in delaying the progression of amyotrophic lateral sclerosis (ALS) between the unilateral cortical stimulation and the bilateral one in an animal experimental model using mice.

Methods

We used 19 G93A transgenic mice and randomly divided into three groups: the control group (n = 6) (the implantation of electrodes in the bilateral motor cortex without electrical stimulation), the unilateral stimulation group (n = 7) (the implantation of electrodes in the unilateral motor cortex with a 24-hour cortical stimulation) and the bilateral stimulation group (n = 6) (the implantation of electrodes in the bilateral motor cortex with a 24-hour cortical stimulation).

Results

The mean survival period was significantly longer in the bilateral stimulation group as compared with the control group (124.33 ± 11.00 days vs. 109.50 ± 10.41 days) (P < 0.05). In addition, on postoperative weeks 11, 12, 13, 14 and 15, the mean Rota-rod score was significantly higher in the unilateral stimulation group as compared with the control group (P < 0.05). Furthermore, despite a lack of statistical significance, it was the lowest in the bilateral stimulation group on postoperative weeks 13, 14, 15 and 17. On postoperative weeks 11, 12, 13, 14 and 16, the mean score of paw-grip endurance was significantly higher in the unilateral stimulation group as compared with the control group (P < 0.05). Furthermore, despite a lack of statistical significance, it was the lowest in the bilateral stimulation group on postoperative weeks 13, 14, 15 and 17.

Conclusions

In conclusion, our results indicate that the bilateral epidural cortical stimulation might have a treatment effect in a murine model of ALS. But it is the limitation that we examined a small number of experimental animals. Further studies are therefore warranted to establish our results and to identify the optimal parameters of the epidural cortical stimulation in a larger number of experimental animals.

Electronic supplementary material

The online version of this article (doi:10.1186/1743-0003-11-139) contains supplementary material, which is available to authorized users.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS)

A group of European experts was commissioned to establish guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS) from evidence published up until March 2014, regarding pain, movement disorders, stroke, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, consciousness disorders, tinnitus, depression, anxiety disorders, obsessive-compulsive disorder, schizophrenia, craving/addiction, and conversion. Despite unavoidable inhomogeneities, there is a sufficient body of evidence to accept with level A (definite efficacy) the analgesic effect of high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the pain and the antidepressant effect of HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC). A Level B recommendation (probable efficacy) is proposed for the antidepressant effect of low-frequency (LF) rTMS of the right DLPFC, HF-rTMS of the left DLPFC for the negative symptoms of schizophrenia, and LF-rTMS of contralesional M1 in chronic motor stroke. The effects of rTMS in a number of indications reach level C (possible efficacy), including LF-rTMS of the left temporoparietal cortex in tinnitus and auditory hallucinations. It remains to determine how to optimize rTMS protocols and techniques to give them relevance in routine clinical practice. In addition, professionals carrying out rTMS protocols should undergo rigorous training to ensure the quality of the technical realization, guarantee the proper care of patients, and maximize the chances of success. Under these conditions, the therapeutic use of rTMS should be able to develop in the coming years.

Serial repetitive transcranial magnetic stimulation (rTMS) decreases BDNF serum levels in healthy male volunteers

Although repetitive transcranial magnetic stimulation (rTMS) is established in the treatment of depression, there is little knowledge about the underlying molecular mechanisms. In the last decade, the neurotrophic hypothesis of depression entailed a plethora of studies on the role of neurogenesis-associated factors in affective disorders and rTMS treatment. In the present study, we hypothesised a sham-controlled increase of peripheral brain-derived neurotrophic factor (BDNF) levels following serial rTMS stimulations in healthy individuals. We investigated the influence of a cycle of nine daily high-frequency (HF)-rTMS (25 Hz) stimulations over the left dorsolateral prefrontal cortex (DLPFC) on serum levels of BDNF in 44 young healthy male volunteers. BDNF serum concentrations were measured at baseline, on day 5 and on day 10. Overall, the statistical analyses showed that the active and sham group differed significantly regarding their responses of BDNF serum levels. Contrary to our expectations, there was a significant decrease of BDNF only during active treatment. Following the treatment period, significantly lower BDNF serum levels were quantified in the active group on day 10, when compared to the sham group. The participants' smoking status affected this effect. Our results suggest that serial HF-rTMS stimulations over the left DLPFC decrease serum BDNF levels in healthy male volunteers. This provides further evidence for an involvement of BDNF in clinical rTMS effects.

Therapeutic effects of repetitive transcranial magnetic stimulation in an animal model of Parkinson's disease

Repetitive transcranial magnetic stimulation (rTMS) is used to treat neurological diseases such as stroke and Parkinson's disease (PD). Although rTMS has been used clinically, its underlying therapeutic mechanism remains unclear. The objective of the present study was to clarify the neuroprotective effect and therapeutic mechanism of rTMS in an animal model of PD. Adult Sprague-Dawley rats were unilaterally injected with 6-hydroxydopamine (6-OHDA) into the right striatum. Rats with PD were then treated with rTMS (circular coil, 10 Hz, 20 min/day) daily for 4 weeks. Behavioral assessments such as amphetamine-induced rotational test and treadmill locomotion test were performed, and the dopaminergic (DA) neurons of substantia nigra pas compacta (SNc) and striatum were histologically examined. Expression of neurotrophic/growth factors was also investigated by multiplex ELISA, western blotting analysis and immunohistochemistry 4 weeks after rTMS application. Among the results, the number of amphetamine-induced rotations was significantly lower in the rTMS group than in the control group at 4 weeks post-treatment. Treadmill locomotion was also significantly improved in the rTMS-treated rats. Tyrosine hydroxylase-positive DA neurons and DA fibers in rTMS group rats were greater than those in untreated group in both ipsilateral SNc and striatum, respectively. The expression levels of brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, platelet-derived growth factor, and vascular endothelial growth factor were elevated in both the 6-OHDA-injected hemisphere and the SNc of the rTMS-treated rats. In conclusion, rTMS treatment improved motor functions and survival of DA neurons, suggesting that the neuroprotective effect of rTMS treatment might be induced by upregulation of neurotrophic/growth factors in the PD animal model.

Serum brain-derived neurotrophic factor levels in different neurological diseases

Consistent evidence indicates the involvement of the brain-derived neurotrophic factor (BDNF) in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). In the present study, we compared serum BDNF in 624 subjects: 266 patients affected by AD, 28 by frontotemporal dementia (FTD), 40 by Lewy body dementia (LBD), 91 by vascular dementia (VAD), 30 by PD, and 169 controls. Our results evidenced lower BDNF serum levels in AD, FTD, LBD, and VAD patients (P < 0.001) and a higher BDNF concentration in patients affected by PD (P = 0.045). Analyses of effects of pharmacological treatments suggested significantly higher BDNF serum levels in patients taking mood stabilizers/antiepileptics (P = 0.009) and L-DOPA (P < 0.001) and significant reductions in patients taking benzodiazepines (P = 0.020). In conclusion, our results support the role of BDNF alterations in neurodegenerative mechanisms common to different forms of neurological disorders and underline the importance of including drug treatment in the analyses to avoid confounding effects.

Repetitive transcranial magnetic stimulation for the treatment of amyotrophic lateral sclerosis or motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurodegenerative disease without effective therapies. Several studies have suggested that repetitive transcranial magnetic stimulation (rTMS) may have positive benefit in ALS. However, the efficacy and safety of this therapy remain uncertain. This is the first update of a review published in 2011.

OBJECTIVES

To determine the clinical efficacy and safety of rTMS for treating ALS.

SEARCH METHODS

On 30 July 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, issue 7 in The Cochrane Library), MEDLINE (1966 to July 2012), EMBASE (1980 to July 2012), CINAHL (1937 to July 2012), Science Citation Index Expanded (January 1945 to July 2012), AMED (January 1985 to July 2012). We searched the Chinese Biomedical Database (1979 to August 2012). We also searched for ongoing studies on clinicaltrials.gov (August 2012).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials assessing the therapeutic efficacy and safety of rTMS for patients with a clinical diagnosis of ALS.Comparisons eligible for inclusion were:1. rTMS versus no intervention;2. rTMS versus sham rTMS;3. rTMS versus physiotherapy;4. rTMS versus medications;5. rTMS + other therapies or drugs versus sham rTMS + the same therapies or drugs;6. different methods of application of rTMS such as high-frequency (> 1Hz) compared to low-frequency (≤ 1Hz) rTMS.

DATA COLLECTION AND ANALYSIS

Two authors independently selected papers, assessed risk of bias and extracted data. We resolved disagreements through discussion. We contacted study authors for additional information.

MAIN RESULTS

Three randomised, placebo-controlled trials with a total of 50 participants were included in the review. All three trials compared rTMS with sham TMS. All the trials were of poor methodological quality and were insufficiently homogeneous to allow the pooling of results. Moreover, the high rate of attrition further increased the risk of bias. None of the trials provided detailed data on the ALS Functional Rating Scale-Revised (ALSFRS-R) scores at six months follow-up which was pre-assigned as our primary outcome. One trial contained data in a suitable form for quantitative analysis of our secondary outcomes. No difference was seen between rTMS and sham rTMS using the ALSFRS-R scores and manual muscle testing (MMT) scores at 12 months follow-up in this trial. Additionally, none of the trials reported any adverse events associated with the use of rTMS. However, in view of the small sample size, the methodological limitations and incomplete outcome data, treatment with rTMS cannot be judged as completely safe.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to draw conclusions about the efficacy and safety of rTMS in the treatment of ALS. Further studies may be helpful if their potential benefit is weighed against the impact of participation in a randomised controlled trial on people with ALS.

In vitro effect of antipsychotics on brain energy metabolism parameters in the brain of rats

OBJECTIVE

Typical and atypical antipsychotic drugs have been shown to have different clinical, biochemical and behavioural profiles. It is well described that impairment of metabolism, especially in the mitochondria, leads to oxidative stress and neuronal death and has been implicated in the pathogenesis of a number of diseases in the brain. In this context, we investigated the in vitro effect of antipsychotic drugs on energy metabolism parameters in the brain of rats.

METHODS

Clozapine (0.1, 0.5 and 1.0 mg/ml), olanzapine (0.1, 0.5 and 1.0 mg/ml) and aripiprazole (0.05, 0.15 and 0.3 mg/ml) were suspended in buffer and added to the reaction medium containing rat tissue homogenates and the respiratory chain complexes, succinate dehydrogenase and creatine kinase (CK) activities were evaluated.

RESULTS

Our results showed that olanzapine and aripriprazole increased the activities of respiratory chain complexes. On the other hand, complex IV activity was inhibited by clozapine, olanzapine and aripriprazole. CK activity was increased by clozapine at 0.5 and 1.0 mg/ml in prefrontal cortex, cerebellum, striatum, hippocampus and posterior cortex of rats. Moreover, olanzapine and aripiprazole did not affect CK activity.

CONCLUSION

In this context, if the hypothesis that metabolism impairment is involved in the pathophysiology of neuropsychiatric disorders is correct and these results also occur in vivo, we suggest that olanzapine may reverse a possible diminution of metabolism.

Repetitive transcranial magnetic stimulation for the treatment of amyotrophic lateral sclerosis or motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurodegenerative disease without effective therapies. Several studies have suggested that repetitive transcranial magnetic stimulation (rTMS) may have positive benefit in ALS. However, the efficacy and safety of this therapy remain uncertain.

OBJECTIVES

We aimed to determine the clinical efficacy and safety of rTMS for treating ALS.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (July 2010), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2010), MEDLINE (1966 to July 2010), EMBASE (1980 to July 2010), CINAHL (1937 to July 2010), Science Citation Index Expanded (January 1945 to June 2010), AMED (January 1985 to July 2010) and the Chinese Biomedical Database (1979 to September 2010). We also searched for ongoing studies on clinicaltrials.gov (September 2010).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials assessing the therapeutic efficacy and safety of rTMS for patients with a clinical diagnosis of ALS.Comparisons eligible for inclusion were:1. rTMS versus no intervention;2. rTMS versus sham rTMS;3. rTMS versus physiotherapy;4. rTMS versus medications;5. rTMS + other therapies or drugs versus sham rTMS + the same therapies or drugs;6. different methods of application of rTMS such as high-frequency (> 1Hz) compared to low-frequency (≤ 1Hz) rTMS.

DATA COLLECTION AND ANALYSIS

Two authors independently selected papers, assessed risk of bias and extracted data. We resolved disagreements through discussion. We contacted study authors for additional information.

MAIN RESULTS

Three randomised, placebo-controlled trials with a total of 50 participants were included in the review. All the trials were of poor methodological quality and were insufficiently homogeneous to allow the pooling of results. Moreover, the high rate of attrition further increased the risk of bias. None of the trials provided detailed data on the ALS Functional Rating Scale-Revised (ALSFRS-R) scores at six months follow-up which was pre-assigned as our primary outcome. One trial contained data in a suitable form for quantitative analysis of our secondary outcomes. No difference was seen between rTMS and sham rTMS using the ALSFRS-R scores and manual muscle testing (MMT) scores at 12 months follow-up in this trial. Additionally, none of the trials reported any adverse events associated with the use of rTMS. However, in view of the small sample size, the methodological limitations and incomplete outcome data, treatment with rTMS cannot be judged as completely safe.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to draw conclusions about the efficacy and safety of rTMS in the treatment of ALS. Further studies may be helpful if their potential benefit is weighed against the impact of participation in a randomised controlled trial on people with ALS.

Long-term effects of repetitive transcranial magnetic stimulation on markers for neuroplasticity: differential outcomes in anesthetized and awake animals

Long-term effects of repetitive transcranial magnetic stimulation (rTMS) have been associated with neuroplasticity, but most physiological studies have evaluated only the immediate effects of the stimulation on neurochemical markers. Furthermore, although it is known that baseline excitability state plays a major role in rTMS outcomes, the role of spontaneous neural activity in metaplasticity has not been investigated. The first aim of this study was to evaluate and compare the long-term effects of high- and low-frequency rTMS on the markers of neuroplasticity such as BDNF and GluR1 subunit of AMPA receptor. The second aim was to assess whether these effects depend on spontaneous neural activity, by comparing the neurochemical alterations induced by rTMS in anesthetized and awake rats. Ten daily sessions of high- or low-frequency rTMS were applied over the rat brain, and 3 d later, levels of BDNF, GluR1, and phosphorylated GluR1 were assessed in the hippocampus, prelimbic cortex, and striatum. We found that high-frequency stimulation induced a profound effect on neuroplasticity markers; increasing them in awake animals while decreasing them in anesthetized animals. In contrast, low-frequency stimulation did not induce significant long-term effects on these markers in either state. This study highlights the importance of spontaneous neural activity during rTMS and demonstrates that high-frequency rTMS can induce long-lasting effects on BDNF and GluR1 which may underlie the clinical benefits of this treatment in neuroplasticity-related disorders.

Carbonic anhydrase I, II, and VI, blood plasma, erythrocyte and saliva zinc and copper increase after repetitive transcranial magnetic stimulation

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) has been used to treat symptoms from many disorders; biochemical changes occurred with this treatment. Preliminary studies with rTMS in patients with taste and smell dysfunction improved sensory function and increased salivary carbonic anhydrase (CA) VI and erythrocyte CA I, II. To obtain more information about these changes after rTMS, we measured changes in several CA enzymes, proteins, and trace metals in their blood plasma, erythrocytes, and saliva.

METHODS

Ninety-three patients with taste and smell dysfunction were studied before and after rTMS in an open clinical trial. Before and after rTMS, we measured erythrocyte CA I, II and salivary CA VI, zinc and copper in parotid saliva, blood plasma, and erythrocytes, and appearance of novel salivary proteins by using mass spectrometry.

RESULTS

After rTMS, CA I, II and CA VI activity and zinc and copper in saliva, plasma, and erythrocytes increased with significant sensory benefit. Novel salivary proteins were induced at an m/z value of 21.5K with a repetitive pattern at intervals of 5K m/z.

CONCLUSIONS

rTMS induced biochemical changes in specific enzymatic activities, trace metal concentrations, and induction of novel salivary proteins, with sensory improvement in patients with taste and smell dysfunction. Because patients with several neurologic disorders exhibit taste and smell dysfunction, including Parkinson disease, Alzheimer disease, and multiple sclerosis, and because rTMS improved their clinical symptoms, the biochemical changes we observed may be relevant not only in our patients with taste and smell dysfunction but also in patients with neurologic disorders with these sensory abnormalities.

Mechanisms and applications of theta-burst rTMS on the human motor cortex

Theta-burst Stimulation (TBS) is a novel form of repetitive transcranial magnetic stimulation (rTMS). Applied over the primary motor cortex it has been successfully used to induce changes in cortical excitability. The advantage of this stimulation paradigm is that it is able to induce strong and long lasting effects using a lower stimulation intensity and a shorter time of stimulation compared to conventional rTMS protocols. Since its first description, TBS has been used in both basic and clinical research in the last years and more recently it has been expanded to other domains than the motor system. Its capacity to induce synaptic plasticity could lead to therapeutic implications for neuropsychiatric disorders. The neurobiological mechanisms of TBS are not fully understood at present; they may involve long-term potentiation (LTP)- and depression (LTD)-like processes, as well as inhibitory mechanisms modulated by GABAergic activity. This article highlights current hypotheses regarding the mechanisms of action of TBS and some central factors which may influence cortical responses to TBS. Furthermore, previous and ongoing research performed in the field of TBS on the motor cortex is summarized.

Acute prefrontal cortex transcranial magnetic stimulation in healthy volunteers: no effects on brain-derived neurotrophic factor (BDNF) concentrations in serum

BACKGROUND

Transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex is a brain stimulation technique widely used to treat depression. BDNF serum concentrations have been shown to be decreased in patients with major depressive disorder and can be upregulated by several antidepressive treatment strategies including repetitive TMS.

METHODS

In this study we were interested whether acute TMS evolves effects on serum BDNF concentrations in 42 healthy volunteers.

RESULTS

Mean BDNF serum concentration in 19 male and 23 female volunteers was 10.70+/-3.6 ng/ml (n=42) at baseline, and 10.76+/-3.9 ng/ml (n=42) after TMS treatment. BDNF serum levels did not change after acute TMS (n=42, Z=-0.44, p=0.965). BDNF serum concentrations at baseline did not differ between male (n=19, 10.05+/-2.6 ng/ml) and female (n=23, 11.25+/-4.27 ng/ml) participants of the study (n=42, Z=-0.91, p=0.363).

CONCLUSIONS

Our result suggests that TMS does not change BDNF serum concentrations immediately in healthy human volunteers.

Effect of antipsychotics on succinate dehydrogenase and cytochrome oxidase activities in rat brain

Typical and atypical antipsychotic drugs have been shown to have different clinical, biochemical, and behavioral profiles. It is well described that impairment of metabolism, especially in the mitochondria, leads to oxidative stress and neuronal death and has been implicated in the pathogenesis of a number of diseases in the brain. Considering that some effects of chronic use of antipsychotic drugs are still not well known and that succinate dehydrogenase (SDH) and cytochrome oxidase (COX) are crucial enzymes of mitochondria, in this work, we evaluated the activities of these enzymes in rat brain after haloperidol, clozapine, olanzapine, or aripiprazole chronic administration. Adult male Wistar rats received daily injections of haloperidol (1.5 mg/kg), clozapine (25 mg/kg), olanzapine (2.5, 5, or 10 mg/kg), or aripiprazole (2, 10 or 20 mg/kg) for 28 days. We verified that COX was not altered by any drug tested. Moreover, our results demonstrated that the atypical antipsychotic olanzapine inhibited SDH in the cerebellum and aripiprazole increased the enzyme in the prefrontal cortex. We also observed that haloperidol inhibited SDH in the striatum and hippocampus, whereas clozapine inhibited the enzyme only in the striatum. These results showed that antipsychotic drugs altered SDH activity but not COX. In this context, haloperidol, olanzapine, and clozapine may impair energy metabolism in some brain areas.

Dopamine levels after repetitive transcranial magnetic stimulation of motor cortex in patients with Parkinson's disease: Preliminary results

BACKGROUND

Repeated session of repetitive transcranial magnetic stimulation (rTMS) over motor cortex have been reported to produce significant improvement of motor performance in patients with parkinson's disease (PD). In addition, it is known that a single session of rTMS over motor cortex transiently increases DA in striatum. Here, we test whether repeated sessions of rTMS increase serum dopamine in PD patients and whether this correlates with changes in clinical rating scales.

MATERIAL AND METHODS

Twenty untreated PD patients with moderate to severe symptoms (Hoehn & Yahr state III-V 1967) were assessed on the Unified Parkinson's Disease Rating Scale (UPDRS), and with an enzyme immunoassay for quantitative determination of plasma dopamine before and after six daily sessions of 25 Hz rTMS with 3,000 stimuli over the right and left hand and leg motor cortex.

RESULTS

There was significant improvement in UPDRS compared with the baseline. Serum dopamine level also was significantly elevated over the same interval. There was a significant correlation between UPDRS and serum dopamine level before and after treatment.

CONCLUSION

Improved motor performance in PD after repeated session of rTMS may be related to an elevation of serum dopamine concentration.

Increased central brain-derived neurotrophic factor activity could be a risk factor for substance abuse: Implications for treatment

Drug addiction is a common psychiatric disorder with complex genetic, psychological and social contributing factors. While the midbrain dopaminergic system is crucial for acute reward and the initiation of addiction, evidence suggests that there are permanent neuronal changes at the cellular and molecular levels that underlie the addictive process. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family and the most abundant neurotrophins in the brain, plays a key role in the survival and differentiation of midbrain dopaminergic (DA) neurons. Evidence from animal and clinical studies suggests that increased central BDNF activity may be implicated in the pathogenesis of drug addiction. For example, BDNF infusion into rat midbrain enhances the rewarding effects of cocaine as measured by the condition place preference paradigm. In contrast, cocaine-conditioned place preference was reduced in heterozygous BDNF knockout mice. In humans, the 66Val allele of the BDNF-gene Val66Met polymorphism is associated with higher BDNF secretion in response to neuronal stimulation compared with the 66Met allele. We found higher BDNF 66Val homozygote frequency in people with drug addiction compared with normal controls. Furthermore, plasma BDNF concentrations of methamphetamine users were significantly higher than controls. The increased central BDNF activity hypothesis of drug addiction may provide new insights for improved therapeutic strategies for the prevention and treatment of drug addiction. Several strategies to decrease central BDNF activity that have potential use in the treatment of drug addiction are proposed.

Repetitive transcranial magnetic stimulation for ALS

Repetitive transcranial magnetic stimulation (rTMS) of brain can modulate cortical neurotransmission, a novel paradigm of repetitive stimulation termed continuous theta-burst stimulation (cTBS) produces a pronounced and prolonged suppression of motor cortex excitability. The aim of this preliminary study was to investigate whether cTBS of motor cortex could have any beneficial effect in patients with amyotrophic lateral sclerosis (ALS). We performed a double-blind, placebo-controlled trial. Twenty patients with definite ALS were randomly allocated to blinded active or placebo stimulation. Repetitive stimulation of the motor cortex was performed for five consecutive days every month for six consecutive months. The primary outcome was the rate of decline as evaluated with the ALS functional rating scale. The treatment was well tolerated by the patients. Fifteen patients (seven active and eight sham) completed the study and were included in the 6-months analysis. Both active and sham patients deteriorated during treatment, however, active patients showed a modest but significant slowing of the deterioration rate. Though we cannot be sure whether the effects observed can be attributed to cTBS, because of the restricted number of patients studied, further investigation on a larger group of ALS patients is warranted. The results of the pilot study might open up a new therapeutic perspective in ALS based on neuromodulation.

Low brain-derived neurotrophic factor (BDNF) levels in serum of depressed patients probably results from lowered platelet BDNF release unrelated to platelet reactivity

BACKGROUND

Recent reports have suggested a role for brain-derived neurotrophic factor (BDNF) in psychiatric disorders. Decreased serum BDNF levels have been reported in major depression, but the cause of this decrease has not yet been investigated. The goal of this study was to assess blood BDNF and a platelet activation index, PF4.

METHODS

Forty-three drug-free patients (27 female, 16 male) diagnosed with major depression and 35 healthy control subjects (18 female, 17 male) were assessed for plasma, serum, and blood BDNF content. Brain-derived neurotrophic factor and PF4 were assayed with enzyme-linked immunosorbent assay methods, and severity of depression was evaluated with the Montgomery-Asberg Depression Rating Scale.

RESULTS

Serum and plasma BDNF levels were decreased in depressed patients compared with control subjects. In whole blood, BDNF levels were unaltered in the depressed subjects compared with control subjects. The serum/blood BDNF ratio was lower in patients with major depression. Increased plasma but not serum PF4 levels were observed in depressed subjects compared with control subjects.

CONCLUSIONS

Our results suggest that an alteration of serum or plasma BDNF is not due to the change in blood BDNF but rather is probably related to mechanisms of BDNF release. Secretion of BDNF seems to be independent of platelet reactivity; other mechanisms are therefore probably involved and need to be elucidated.