Transcranial Magnetic Stimulation: Basic Principles and Clinical Applications in Migraine

Effects of Transcranial Ultrasound Stimulation on Blood Oxygen Metabolism and Brain Rhythms in Nitroglycerin-Induced Migraine Mice

OBJECTIVES

In this study, we aimed to investigate the regulatory mechanism of transcranial ultrasound stimulation (TUS) on nitroglycerin-induced migraine in mice.

MATERIALS AND METHODS

The experiment was divided into four groups, namely, the normal saline control group (n = 9), ultrasound stimulation control group (n = 6), nitroglycerin-induced migraine group (n = 9), and ultrasound stimulation group (n = 9). The behavior, blood oxygen metabolism, and brain rhythm distribution of the four groups were analyzed.

RESULTS

We found that after TUS, the movement time and speed of mice with migraine are modulated to those of the control groups, and the number of head scratching and grooming events is significantly reduced. TUS increased the deoxygenated hemoglobin, and the power of the 4-to-40 Hz frequency band of local field potentials in the cortex of migraine mice. TUS also decreased the expression of plasma calcitonin gene-related peptide and cortical c-Fos protein.

CONCLUSIONS

Ultrasound stimulation can regulate brain rhythm and blood oxygen metabolism and reduce migraine symptoms in mice. The regulatory mechanism may be related to reducing calcitonin gene-related peptide in blood vessels.

Exploring the Therapeutic Potential of Quadripulse rTMS over the Visual Cortex: A Proof-of-Concept Study in Healthy Volunteers and Chronic Migraine Patients with Medication Overuse Headache

In chronic migraine with medication overuse (CM-MOH), sensitization of visual cortices is reflected by (i) increased amplitude of stimulus-evoked responses and (ii) habituation deficit during repetitive stimulation. Both abnormalities might be mitigated by inhibitory transcranial neurostimulation. Here, we tested an inhibitory quadripulse repetitive transcranial magnetic stimulation (rTMS-QPI) protocol to decrease durably visual cortex excitability in healthy subjects (HS) and explored its therapeutic potential in CM-MOH patients. Pattern-reversal visual evoked potentials (VEP) were used as biomarkers of effect and recorded before (T1), immediately after (T2), and 3 h after stimulation (T3). In HS, rTMS-QPI durably decreased the VEP 1st block amplitude (p < 0.05) and its habituation (p < 0.05). These changes were more pronounced for the P1N2 component that was modified already at T2 up to T3, while for N1P1 they were significant only at T3. An excitatory stimulation protocol (rTMS-QPE) tended to have an opposite effect, restricted to P1N2. In 12 CM-MOH patients, during a four-week treatment (2 sessions/week), rTMS-QPI significantly reduced monthly headache days (p < 0.01). In patients reversing from CM-MOH to episodic migraine (n = 6), VEP habituation significantly improved after treatment (p = 0.005). rTMS-QPI durably decreases visual cortex responsivity in healthy subjects. In a proof-of-concept study of CM-MOH patients, rTMS-QPI also has beneficial clinical and electrophysiological effects, but sham-controlled trials are needed.

The complex landscape of TMS devices: A brief overview

The increasing application of TMS in research and therapy has spawned an ever-growing number of commercial and non-commercial TMS devices and technology development. New CE-marked devices appear at a rate of approximately one every two years, with new FDA-approved application of TMS occurring at a similar rate. With the resulting complex landscape of TMS devices and their application, accessible information about the technological characteristics of the TMS devices, such as the type of their circuitry, their pulse characteristics, or permitted protocols would be beneficial. We here present an overview and open access database summarizing key features and applications of available commercial and non-commercial TMS devices (http://www.tmsbase.info). This may guide comparison and decision making about the use of these devices. A bibliometric analysis was performed by identifying commercial and non-commercial TMS devices from which a comprehensive database was created summarizing their publicly available characteristics, both from a technical and clinical point of view. In this document, we introduce both the commercial devices and prototypes found in the literature. The technical specifications that unify these devices are briefly analysed in two separate tables: power electronics, waveform, protocols, and coil types. In the prototype TMS systems, the proposed innovations are focused on improving the treatment regarding the patient: noise cancellation, controllable parameters, and multiple stimulation. This analysis shows that the landscape of TMS is becoming increasingly fragmented, with new devices appearing ever more frequently. The review provided here can support development of benchmarking frameworks and comparison between TMS systems, inform the choice of TMS platforms for specific research and therapeutic applications, and guide future technology development for neuromodulation devices. This standardisation strategy will allow a better end-user choice, with an impact on the TMS manufacturing industry and a homogenisation of patient samples in multi-centre clinical studies. As an open access repository, we envisage the database to grow along with the dynamic development of TMS devices and applications through community-lead curation.

Neuromodulation for the Sphenopalatine Ganglion-a Narrative Review

PURPOSE OF REVIEW

To provide an integrated overview of the current state of knowledge of neuromodulation for the sphenopalatine ganglion (SPG) by reviewing relevant and significant literature.

RECENT FINDINGS

There are several case reports and clinical trials evaluating neuromodulation for the SPG. We identified two blinded, randomized clinical trials for patients with chronic cluster headache. The randomized trials and additional studies demonstrated the long-term safety, efficacy, and cost-effectiveness of neuromodulation for the SPG. Recent studies in Europe and the USA suggest that SPG neuromodulation is a novel modality with clinical importance for treating acute cluster headaches and reducing the frequency of attacks.

Nonpharmacological modulation of cortical spreading depolarization

AIMS

Cortical spreading depolarization (CSD) is a wave of pathologic neuronal dysfunction that spreads through cerebral gray matter, causing neurologic disturbance in migraine and promoting lesion development in acute brain injury. Pharmacologic interventions have been found to be effective in migraine with aura, but their efficacy in acutely injured brains may be limited. This necessitates the assessment of possible adjunctive treatments, such as nonpharmacologic methods. This review aims to summarize currently available nonpharmacological techniques for modulating CSDs, present their mechanisms of action, and provide insight and future directions for CSD treatment.

MAIN METHODS

A systematic literature review was performed, generating 22 articles across 3 decades. Relevant data is broken down according to method of treatment.

KEY FINDINGS

Both pharmacologic and nonpharmacologic interventions can mitigate the pathological impact of CSDs via shared molecular mechanisms, including modulating K⁺/Ca²⁺/Na⁺/Cl^- ion channels and NMDA, GABA_A, serotonin, and CGRP ligand-based receptors and decreasing microglial activation. Preclinical evidence suggests that nonpharmacologic interventions, including neuromodulation, physical exercise, therapeutic hypothermia, and lifestyle changes can also target unique mechanisms, such as increasing adrenergic tone and myelination and modulating membrane fluidity, which may lend broader modulatory effects. Collectively, these mechanisms increase the electrical initiation threshold, increase CSD latency, slow CSD velocity, and decrease CSD amplitude and duration.

SIGNIFICANCE

Given the harmful consequences of CSDs, limitations of current pharmacological interventions to inhibit CSDs in acutely injured brains, and translational potentials of nonpharmacologic interventions to modulate CSDs, further assessment of nonpharmacologic modalities and their mechanisms to mitigate CSD-related neurologic dysfunction is warranted.

Novel Treatments for Chronic Ocular Surface Pain

ABSTRACT

Several etiologies can contribute to ocular surface pain including nociceptive, peripheral neuropathic, and central neuropathic mechanisms. Clinical clues can help identify contributors to ocular surface pain in a patient. In individuals whose pain persists despite targeting nociceptive contributors, neuropathic mechanisms should be considered and addressed using oral, topical, and/or adjuvant agents.

A method for non-destructive microwave focusing for deep brain and tissue stimulation

Non-invasive stimulation of biological tissue is highly desirable for several biomedical applications. Of specific interest are methods for tumor treatment, endometrial ablation, and neuro-modulation. In traditional neuro-modulation, single- and multi-coil transcranial stimulation techniques in low oscillation frequencies are utilized to non-invasively penetrate the skull and elicit action potentials in cortical neurons. Although these methods have been proven effective, tightly focusing these signals to localized regions is difficult. In recent years, microwave (MW) methods have seen an increase usage as a minimally invasive treatment modality for ablation and neuro-stimulation. Unlike low frequency signals, MW signals can be focused to localized sub-centimeter regions. In this work we demonstrate that a three-dimensional array of MW antennas can be used to tightly focus signals to a localized region in space within the human body with MW frequencies. Assuming an array of small MW loop antennas are placed around the body, the optimal amplitude and phase of each array element can be accurately determined to match an arbitrary desired field profile. The major innovation of the presented method is that the fields that penetrate the biological region are determined via computing numerical Green's functions (NGF) that are then used to drive an optimization algorithm. Using simplified models of regions in the human body, it is shown that the MW fields at 1 GHz can be focused to sub-centimeter sized "hot spots" at depths of several centimeters. The algorithm can be easily extended to more realistic models of the human body or for non-biological applications.

Effects of Low-Frequency (0.5 Hz) and High-Frequency (10 Hz) Repetitive Transcranial Magnetic Stimulation on Neurological Function, Motor Function, and Excitability of Cortex in Ischemic Stroke Patients

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulation technique. The purpose of our study is to explore the effects of low-frequency (0.5 Hz) and high-frequency (10 Hz) rTMS on neurological function, motor function, and excitability of cortex in Chinese ischemic stroke patients.

MATERIALS AND METHODS

A total of 240 ischemic stroke patients were collected. The National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), motor-evoked potential (MEP) cortical latency, central motor conduction time (CMCT), Fugel-Meyer assessment (FMA), Berg balance scale (BBS), and modified Barthel index (MBI) scores were recorded.

RESULTS

After treatment, the NIHSS, mRS, MEP cortical latency, CMCT, FMA, BBS, and MBI scores of the high-frequency group and low-frequency group were significantly improved than the sham stimulation group, and the changes in the low-frequency group were more significant (adjusted P <0.05). Compared with the sham stimulation group, high-frequency stimulation reduced the NIHSS score by 9.5%, mRS score by 12.6%, MEP latency by 2.5%, and CMCT by 5.8%, and increased the upper limb FMA scale by 16.4%, lower limb FMA scale by 8.8%, BBS by 26.3%, and MBI by 9.3%, while low-frequency stimulation reduced the NIHSS score by 23.8%, mRS score by 25.3%, MEP Latency by 11.7%, and CMCT by 9.1%, and increased the upper limb FMA scale by 24.1%, lower limb FMA scale by 18.4%, BBS by 27.4%, and MBI by 23.7% in our cohort.

CONCLUSIONS

Low-frequency rTMS is better than high-frequency rTMS stimulation in improving neurological function, motor function, and excitability of cortex in ischemic stroke.

Effectiveness of High-Frequency Repetitive Transcranial Magnetic Stimulation in Migraine: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study was to evaluate the effectiveness of repetitive transcranial magnetic stimulation in migraine measured by decrease in pain severity or attack frequency.

METHODS

A search at the Cochrane Controlled Trials Register (CENTRAL), MEDLINE (via PubMed), Embase, CINAHL, Web of Science, and Scopus. The risk of systematic bias was rated by using the Cochrane domain-based quality assessment tool. A random-effects model was used.

RESULTS

Of 434 identified records, 8 randomized control studies were included in the meta-synthesis. All have used a high-frequency repetitive transcranial magnetic stimulation targeting the left dorsolateral prefrontal cortex. The risk of systematic bias was low. The difference between repetitive transcranial magnetic stimulation and control groups in frequency of migraine days per month was 8.1 (95% confidence interval = 4.8 - 11.4) days in favor of repetitive transcranial magnetic stimulation. Respectively, for intensity of migraine pain (scaled from 0 to 100), this difference was 13.6 (95% confidence interval = 5.3 - 21.8) points in favor of repetitive transcranial magnetic stimulation. The heterogeneity was substantial with I2 = 86%.

CONCLUSIONS

In chronic migraine, repetitive transcranial magnetic stimulation seems to have positive effects on both migraine pain severity and attack frequency compared with sham stimulation. Although the effect on pain intensity was probably clinically insignificant, repetitive transcranial magnetic stimulation reduced pain frequency by 8 days per month on average.

Advances in the Treatment of Dysphagia in Neurological Disorders: A Review of Current Evidence and Future Considerations

Dysphagia, which refers to difficult and/or disordered swallowing, is a common problem associated with various neurological diseases such as stroke, motor neuron diseases and neurodegenerative diseases. Traditionally, dysphagia treatments are either compensatory, which includes modifications of bolus texture or feeding posture, or rehabilitative, which includes behavioral exercises and sensory stimulation. Despite being widely adopted in clinical practice, recent views have challenged the clinical efficacy of these treatments due to the low level of evidence supported by mainly non-controlled studies. As such, with advancements in technology and scientific research methods, recent times have seen a surge in the development of novel dysphagia treatments and an increasing number of robust randomized controlled clinical trials. In this review, we will review the clinical evidence of several newly introduced treatments for dysphagia in the last two decades, including rehabilitative exercises, biofeedback, pharmacological treatments, neuromodulation treatments and soft robotics. Despite the recent improvements in the quality of evidence for the efficacy of dysphagia treatments, several critical issues, including heterogeneity in treatment regimens, long-term treatment effects, underlying mechanisms of some neuromodulation treatments, and the effects of these techniques in non-stroke dysphagia, remain to be addressed in future clinical trials.

Recognition and Processing of Visual Information after Neuronavigated Transcranial Magnetic Stimulation Session

Background: Transcranial magnetic stimulation (TMS) is a method of noninvasive and painless stimulation of the nervous system, which is based on Faraday’s law of electromagnetic induction. Over the past twenty years, the TMS technique has been deployed as a tool for the diagnosis and therapy of neurodegenerative diseases, as well as in the treatment of mental disorders (e.g., depression). Methods: We tested the inhibitory effects of repetitive TMS (rTMS) on reaction times to militarily relevant visual stimuli amidst distractors and on accompanying blood oxygenation level dependent (BOLD) signal functional magnetic resonance imaging (fMRI) in 20 healthy people. rTMS was applied over the visual cortices, V1, on both hemispheres with the inhibitory theta burst paradigm with the intensity of 70% of the active motor threshold fMRI in 20 healthy people. Results: Analysis of the reaction time to visual stimuli after using TMS to the V1 visual cortex revealed an increase in the number of incorrect recognitions, and the reaction time was from 843 to 910 ms. In the subgroup of participants (n = 15), after the stimulation, there were significant reductions of BOLD signal in blood flow within V1 cortices. Conclusions: The studies of reaction times after the rTMS revealed the inhibitory effect of rTMS on the reaction times and recognition performance of significant (military) objects in the visual field.

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 as a Therapeutic Option for Neurologic Diseases and Psychiatric Disorders: A Systematic Review

In the last two decades, transcranial magnetic stimulation (TMS) has attracted considerable interest in the research field and clinical applications because of its capacity to induce adequate electric current non-invasively for depolarizing cortex networks and superficial axons. Notably, the interest in TMS has been due to its ability to be utilized in exploring brain functioning. Indeed, reports have pointed out that TMS may effectively be used as a diagnostic and therapeutic approach for many neuropsychiatric diseases. However, they have not been sufficiently conclusive on the topic, with evidence showing mixed results. Against this backdrop, this systematic review explores TMS as a therapy option for neurologic diseases and psychiatric disorders. It summarizes and illustrates the current therapeutic uses of TMS in adults and children for detecting and treating neuropsychiatric conditions and prospective future applications. Using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines, findings show that TMS is viable and has neuro-modulatory potential that can be employed successfully as a therapy alternative for neuropsychiatric disorders. Conversely, it is essential to more deeply understand the underlying mechanisms, alongside stimulation protocol optimization, of TMS for more practical applications.

fMRI Findings in Cortical Brain Networks Interactions in Migraine Following Repetitive Transcranial Magnetic Stimulation

Background

Repetitive transcranial magnetic stimulation (rTMS) is one of the high-potential non-pharmacological methods for migraine treatment. The purpose of this study is to define the neuroimaging markers associated with rTMS therapy in patients with migraine based on data from functional MRI (fMRI).

Materials and Methods

A total of 19 patients with episodic migraine without aura underwent a 5-day course of rTMS of the fronto-temporo-parietal junction bilaterally, at 10 Hz frequency and 60% of motor threshold response of 900 pulses. Resting-state functional MRI (1.5 T) and a battery of tests were carried out for each patient to clarify their diagnosis, qualitative and quantitative characteristics of pain, and associated affective symptoms. Changes in functional connectivity (FC) in the brain's neural networks before and after the treatment were identified through independent components analysis.

Results

Over the course of therapy, we observed an increase in FC of the default mode network within it, with pain system components and with structures of the visual network. We also noted a decrease in FC of the salience network with sensorimotor and visual networks, as well as an increase in FC of the visual network. Besides, we identified 5 patients who did not have a positive response to one rTMS course after the first week of treatment according to the clinical scales results, presumably because of an increasing trend of depressive symptoms and neuroimaging criteria for depressive disorder.

Conclusions

Our results show that a 5-day course of rTMS significantly alters the connectivity of brain networks associated with pain and antinociceptive brain systems in about 70% of cases, which may shed light on the neural mechanisms underlying migraine treatment with rTMS.

Angle-tuned coils: attractive building blocks for TMS with improved depth-spread performance

Objective.A novel angle-tuned ring coil is proposed for improving the depth-spread performance of transcranial magnetic stimulation (TMS) coils and serve as the building blocks for high-performance composite coils and multisite TMS systems.Approach.Improving depth-spread performance by reducing field divergence through creating a more elliptical emitted field distribution from the coil. To accomplish that, instead of enriching the Fourier components along the planarized (x-y) directions, which requires different arrays to occupy large brain surface areas, we worked along the radial (z) direction by using tilted coil angles and stacking coil numbers to reduce the divergence of the emitted near field without occupying large head surface areas. The emitted electric field distributions were theoretically simulated in spherical and real human head models to analyze the depth-spread performance of proposed coils and compare with existing figure-8 coils. The results were then experimentally validated with field probes andin-vivoanimal tests.Main results.The proposed 'angle-tuning' concept improves the depth-spread performance of individual coils with a significantly smaller footprint than existing and proposed coils. For composite structures, using the proposed coils as basic building blocks simplifies the design and manufacturing process and helps accomplish a leading depth-spread performance. In addition, the footprint of the proposed system is intrinsically small, making them suitable for multisite stimulations of inter and intra-hemispheric brain regions with an improved spread and less electric field divergence.Significance.Few brain functions are operated by isolated single brain regions but rather by coordinated networks involving multiple brain regions. Simultaneous or sequential multisite stimulations may provide tools for mechanistic studies of brain functions and the treatment of neuropsychiatric disorders. The proposed AT coil goes beyond the traditional depth-spread tradeoff rule of TMS coils, which provides the possibility of building new composite structures and new multisite TMS tools.

Transcranial Magnetic Stimulation for the Neurological Patient: Scientific Principles and Applications

Non-invasive brain stimulation has been increasingly recognized for its potential as an investigational, diagnostic and therapeutic tool across the clinical neurosciences. Transcranial magnetic stimulation (TMS) is a non-invasive method of focal neuromodulation. Diagnostically, TMS can be used to probe cortical excitability and plasticity, as well as for functional mapping. Therapeutically, depending on the pattern employed, TMS can either facilitate or inhibit stimulated cortex potentially modulating maladaptive physiology through its effects on neuroplasticity. Despite this potential, applications of TMS in neurology have only been approved for diagnostic clinical neurophysiology, pre-surgical mapping of motor and language cortex, and the treatment of migraines. In this article, we discuss the principles of TMS and its clinical applications in neurology, including experimental applications in stroke rehabilitation, seizures, autism spectrum disorder, neurodegenerative disorders, movement disorders, tinnitus, chronic pain and functional neurological disorder. To promote increased cross-talk across neurology and psychiatry, we also succinctly review the TMS literature for the treatment of major depression and obsessive compulsive disorder. Overall, we argue that larger clinical trials that are better informed by circuit-level biomarkers and pathophysiological models will lead to an expansion of the application of TMS for patients cared for by neurologists.

Devices for Episodic Migraine: Past, Present, and Future

PURPOSE OF REVIEW

Historically, therapies for migraine have generally involved pharmacological treatments using non-selective or selective analgesics and preventive treatments. However, for many patients these treatments are not effective, while others prefer to use non-pharmacological-based therapies. To fill this need, over the last 15 years, neuromodulatory devices have entered the market for migraine treatment. Here, we will review the most recent findings for the use of these devices in the treatment of migraine.

RECENT FINDINGS

Non-invasive vagus nerve stimulation and spring-pulse transcranial magnetic stimulation are both cleared for the treatment of migraine, supported by preclinical studies that validate efficacy and mechanism of action, and complemented with clinical trial data. Other options also authorized for use include transcutaneous supraorbital nerve stimulation and remote electrical neuromodulation. Various options are available to treat migraine using authorized neuromodulatory devices. These data support their efficacy in the treatment of episodic migraine, although further studies are necessary to elucidate their mechanism of action and to provide rigor to clinical trial data.

Transcranial Magnetic Stimulation for Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that causes significant functional impairment and is related to altered stress response and reinforced learned fear behavior. PTSD has been found to impact three functional networks in the brain: default mode, executive control, and salience. The executive control network includes the dorsolateral prefrontal cortex (DLPFC) and lateral PPC. The salience network involves the anterior cingulate cortex, anterior insula, and amygdala. This latter network has been found to have increased functional connectivity in PTSD. Transcranial Magnetic Stimulation (TMS) is a technique used in treating PTSD and involves stimulating specific portions of the brain through electromagnetic induction. Currently, high-frequency TMS applied to the left dorsolateral prefrontal cortex (DLPFC) is approved for use in treating major depressive disorder (MDD) in patients who have failed at least one medication trial. In current studies, high-frequency stimulation has been shown to be more effective in PTSD rating scales posttreatment than low-frequency stimulation. The most common side effect is headache and scalp pain treated by mild analgesics. Seizures are a rare side effect and are usually due to predisposing factors. Studies have been done to assess the overall efficacy of TMS. However, results have been conflicting, and sample sizes were small. More research should be done with larger sample sizes to test the efficacy of TMS in the treatment of PTSD. Overall, TMS is a relatively safe treatment. Currently, the only FDA- approved to treat refractory depression, but with the potential to treat many other conditions.

Repetitive transcranial magnetic stimulation as a prophylactic treatment in migraine

Background

Clinical applications of transcranial magnetic stimulation (TMS) have shown promising results in the treatment of headache disorders, with migraine being one of the most encountered.

Objective

To assess the role of low-frequency repetitive transcranial magnetic stimulation as a preventive treatment of migraine (with and without aura) and correlate the results with the serum level of the inflammatory biomarker (neurokinin A).

Methods

Forty patients, with age ranging from 15 to 55 years, diagnosed with migraine (30 migraine without aura and 10 with aura) and 20 apparently healthy individuals, who were age and sex matched with the patient group, were included in this study.

A low-frequency (1 Hz) rTMS protocol was applied for all patients for five consecutive days interictally. Assessment of pain intensity using visual analogue scale and frequency and duration of attacks as well as number of pills taken by patients as an abortive treatment according to the Basic Diagnostic Headache Diary for 4 weeks before and 4 weeks after TMS sessions was done. In addition, the Migraine Disability Assessment scale (MIDAS) was applied to assess the severity and degree of disability caused by migraine.

Measurement of neurokinin A serum level was done by using ELISA for all patients before and after TMS and for control group once.

Results

There was a significant reduction in pain intensity, frequency and duration of migraine attacks, migraine disability scores, and number of pills taken as abortive treatment for attacks after rTMS (P < 0.001). Also, serum level of neurokinin A in the patients was significantly reduced after rTMS (P < 0.001).

Conclusion

Low-frequency rTMS is an effective prophylactic treatment for migraine with and without aura.

Update of Neuromodulation in Chronic Migraine

Purpose of Review

Neuromodulation devices have become an attractive alternative to traditional pharmacotherapy for migraine, especially for patients intolerant to medication or who prefer non-pharmacological options. In the past decades, many studies demonstrated the efficacy of neuromodulation devices in patients with episodic migraine (EM). However, the benefit of these devices on chronic migraine (CM), which is typically more debilitating and refractory than EM, remains not well studied.

Recent Findings

We reviewed the literature within the last five years on using FDA-cleared and investigational devices for CM. There were eight randomized controlled trials and 15 open-label observational studies on ten neuromodulation devices.

Summary

Neuromodulation is promising for use in CM, although efficacy varies among devices or individuals. Noninvasive devices are usually considered safe with minimal adverse events. However, stimulation protocol and methodology differ between studies. More well-designed studies adhering to the guideline may facilitate FDA clearance and better insurance coverage.

Precise Modulation Strategies for Transcranial Magnetic Stimulation: Advances and Future Directions

Transcranial magnetic stimulation (TMS) is a popular modulatory technique for the noninvasive diagnosis and therapy of neurological and psychiatric diseases. Unfortunately, current modulation strategies are only modestly effective. The literature provides strong evidence that the modulatory effects of TMS vary depending on device components and stimulation protocols. These differential effects are important when designing precise modulatory strategies for clinical or research applications. Developments in TMS have been accompanied by advances in combining TMS with neuroimaging techniques, including electroencephalography, functional near-infrared spectroscopy, functional magnetic resonance imaging, and positron emission tomography. Such studies appear particularly promising as they may not only allow us to probe affected brain areas during TMS but also seem to predict underlying research directions that may enable us to precisely target and remodel impaired cortices or circuits. However, few precise modulation strategies are available, and the long-term safety and efficacy of these strategies need to be confirmed. Here, we review the literature on possible technologies for precise modulation to highlight progress along with limitations with the goal of suggesting future directions for this field.

Comparison of Peripheral Neurectomy vs. Medical Treatment for Migraine: A Randomized Controlled Trial

Background

Migraine is a common form of primary neurologic headache. Many patients are chronic migraineurs and suffer from a significant disability and adverse effects of drugs. There are various surgical options available to treat migraines, including peripheral neurectomies.

Objective

To study the surgical and functional outcomes of migraine surgeries using peripheral neurectomies and compare them with conservatively treated patients.

Materials and Methods

Migraine patients who had a unilateral onset pain were given local bupivacaine block at the suspected trigger site, and those who were relieved were given the option for surgery. In the operative group, the peripheral nerve of the trigger site was lysed under local anesthesia. The conservative group was continued with the standard treatment. Evaluations with a baseline and 6 months visual analog score (VAS), migraine headache index (MHI), migraine disability assessment test (MIDAS), and pain self-efficacy questionnaire (PSEQ) scores were done.

Results

A total of 26 patients got benefitted with the local bupivacaine block, out of which 13 underwent surgery. At baseline, the VAS, MHI, MIDAS, and PSEQ scores were similar in both the groups. The operative group had significant (P < 0.001) improvement in all these parameters 6 months after the surgery. All patients of the operative group got free from prophylactic migraine treatment; however, 11 out of 13 patients still needed occasional  use of analgesics. There was one complication of transient temporal numbness.

Conclusion

Migraine surgery using peripheral neurectomies was more effective than chronic drug treatment in appropriately selected patients.

Self-Referential Processing Effects of Non-invasive Brain Stimulation: A Systematic Review

Systematic reviews of neuroimaging studies confirm stimulus-induced activity in response to verbal and non-verbal self-referential processing (SRP) in cortical midline structures, temporoparietal cortex and insula. Whether SRP can be causally modulated by way of non-invasive brain stimulation (NIBS) has also been investigated in several studies. Here we summarize the NIBS literature including 27 studies of task-based SRP comparing response between verbal and non-verbal SRP tasks. The studies differed in design, experimental tasks and stimulation parameters. Results support the role of left inferior parietal lobule (left IPL) in verbal SRP and for the medial prefrontal cortex when valenced stimuli were used. Further, results support roles for the bilateral parietal lobe (IPL, posterior cingulate cortex), the sensorimotor areas (the primary sensory and motor cortex, the premotor cortex, and the extrastriate body area) and the insula in non-verbal SRP (bodily self-consciousness). We conclude that NIBS may differentially modulate verbal and non-verbal SRP by targeting the corresponding brain areas.

Magnetic fields as a potential therapy for diabetic wounds based on animal experiments and clinical trials

Diabetes mellitus (DM) is a chronic metabolic disorder with various complications that poses a huge worldwide healthcare burden. Wounds in diabetes, especially diabetic foot ulcers (DFUs), are difficult to manage, often leading to prolonged wound repair and even amputation. Wound management in people with diabetes is an extremely clinical and social concern. Nowadays, physical interventions gain much attention and have been widely developed in the fields of tissue regeneration and wound healing. Magnetic fields (MFs)-based devices are translated into clinical practice for the treatment of bone diseases and neurodegenerative disorder. This review attempts to give insight into the mechanisms and applications of MFs in wound care, especially in improving the healing outcomes of diabetic wounds. First, we discuss the pathological conditions associated with chronic diabetic wounds. Next, the mechanisms involved in MFs' effects on wounds are explored. At last, studies and reports regarding the effects of MFs on diabetic wounds from both animal experiments and clinical trials are reviewed. MFs exhibit great potential in promoting wound healing and have been practised in the management of diabetic wounds. Further studies on the exact mechanism of MFs on diabetic wounds and the development of suitable MF-based devices could lead to their increased applications into clinical practice.

Theta burst stimulation over the prefrontal cortex: Effects on cerebral oximetry and cardiovascular measures in healthy humans

Theta Burst Stimulation (TBS) is a non-invasive neurophysiological technique, able to induce changes in synaptic activity. Research suggests that TBS may induce changes in cerebral oxygenation, cerebral blood flow, blood pressure and heart rate but there are conflicting results across studies. Thus, the objective of our sham-controlled study is to evaluate if TBS applied to the dorsolateral prefrontal cortex (DLPFC) of healthy volunteers produces changes in cerebral oximetry, heart rate and blood pressure. Forty-nine volunteers of both sexes were randomly allocated to one of five stimulation groups. Before and after real TBS or sham stimulation, blood pressure, heart rate, and cerebral oxygenation of the volunteers were measured. Cerebral oxygenation values were obtained with a near infra-red spectroscopy system. We found a significant reduction in left cortex oximetry after continuous TBS (cTBS) over the left DLPFC (p = 0.039) and a non-significant reduction in right cortex oximetry (p = 0.052). Right hemisphere inhibition (using cTBS) seemed to originate a significant reduction of 8 mmHg in systolic arterial pressure. No other changes were seen in oximetry, cardiac frequency and diastolic arterial pressure. In our group of normal subjects, cTBS applied to the left DLPFC was able to reduce oxygenation in the left cortex. Right hemisphere inhibition was associated with a significant reduction in systolic pressure.

Non-Pharmacological Approaches to Headaches: Non-Invasive Neuromodulation, Nutraceuticals, and Behavioral Approaches

Significant side effects or drug interactions can make pharmacological management of headache disorders very difficult. Non-conventional and non-pharmacological treatments are becoming increasingly used to overcome these issues. In particular, non-invasive neuromodulation, nutraceuticals, and behavioral approaches are well tolerated and indicated for specific patient categories such as adolescents and pregnant women. This paper aims to present the main approaches reported in the literature in the management of headache disorders. We therefore reviewed the available literature published between 2010 and 2020 and performed a narrative presentation for each of the three categories (non-invasive neuromodulation, nutraceuticals, and behavioral therapies). Regarding non-invasive neuromodulation, we selected transcranial magnetic stimulation, supraorbital nerve stimulation, transcranial direct current stimulation, non-invasive vagal nerve stimulation, and caloric vestibular stimulation. For nutraceuticals, we selected Feverfew, Butterbur, Riboflavin, Magnesium, and Coenzyme Q10. Finally, for behavioral approaches, we selected biofeedback, cognitive behavioral therapy, relaxation techniques, mindfulness-based therapy, and acceptance and commitment therapy. These approaches are increasingly seen as a valid treatment option in headache management, especially for patients with medication overuse or contraindications to drug treatment. However, further investigations are needed to consider the effectiveness of these approaches also with respect to the long-term effects.

Transcranial alternating current stimulation (tACS): from basic mechanisms towards first applications in psychiatry

Transcranial alternating current stimulation (tACS) is a unique form of non-invasive brain stimulation. Sinusoidal alternating electric currents are delivered to the scalp to affect mostly cortical neurons. tACS is supposed to modulate brain function and, in turn, cognitive processes by entraining brain oscillations and inducing long-term synaptic plasticity. Therefore, tACS has been investigated in cognitive neuroscience, but only recently, it has been also introduced in psychiatric clinical trials. This review describes current concepts and first findings of applying tACS as a potential therapeutic tool in the field of psychiatry. The current understanding of its mechanisms of action is explained, bridging cellular neuronal activity and the brain network mechanism. Revisiting the relevance of altered brain oscillations found in six major psychiatric disorders, putative targets for the management of mental disorders using tACS are discussed. A systematic literature search on PubMed was conducted to report findings of the clinical studies applying tACS in patients with psychiatric conditions. In conclusion, the initial results may support the feasibility of tACS in clinical psychiatric populations without serious adverse events. Moreover, these results showed the ability of tACS to reset disturbed brain oscillations, and thus to improve behavioural outcomes. In addition to its potential therapeutic role, the reactivity of the brain circuits to tACS could serve as a possible tool to determine the diagnosis, classification or prognosis of psychiatric disorders. Future double-blind randomised controlled trials are necessary to answer currently unresolved questions. They may aim to detect response predictors and control for various confounding factors.

Targeting temporal parietal junction for assessing and treating disembodiment phenomena: a systematic review of TMS effect on depersonalization and derealization disorders (DPD) and body illusions

The temporal-parietal junction (TPJ) is a key structure for the embodiment, term referred to as the sense of being localized within one's physical body and is a fundamental aspect of the self. On the contrary, the sense of disembodiment, an alteration of one's sense of self or the sense of being localized out of one's physical body, is a prominent feature in specific dissociative disorders, namely depersonalization/derealization disorders (DPD). The aims of the study were to provide: 1) a qualitative synthesis of the effect of Transcranial Magnetic Stimulation (TMS), taking into account its use for therapeutic and experimental purposes; 2) a better understanding on whether the use of TMS could support the treatment of DPD and other clinical conditions in which depersonalization and derealization are displayed. To identify suitable publications, an online search of the PubMed, Cochrane Library, Web of science and Scopus databases was performed using relevant search terms. In addition, an in-depth search was performed by screening review articles and the references section of each included articles. Our search yielded a total of 108 records through multiple databases searching and one additional record was identified through other sources. After duplicates removal, title and abstract reading, we retained 16 records for the assessment of eligibility. According to our inclusion criteria, we retained 8 studies. The selected studies showed that TMS targeting the TPJ is a promising technique for treating disembodiment phenomena DPD and for inducing reversible disembodiment states in healthy subjects. These data represent the first step towards a greater understanding of possible treatments to be used in disembodiment disorders. The use of TMS over the TPJ appears to be promising for treating disembodiment phenomena.

Peripheral Neuromodulation for the Management of Headache

Context

Neuromodulation is an expanding field of study for headache treatment to reduce pain by targeting structures within the nervous system that are commonly involved in headache pathophysiology, such as the vagus nerve (VNS), occipital nerves, or sphenopalatine ganglion (SPG) for stimulation. Pharmaceutical medical therapies for abortive and prophylactic treatment, such as triptans, NSAIDs, beta-blockers, TCAs, and antiepileptics, are effective for some individuals, but the role that technology plays in investigating other therapeutic modalities is essential. Peripheral neuromodulation has gained popularity and FDA approval for use in treating certain headaches and migraine headache conditions, particularly in those who are refractory to treatment. Early trials found FDA approved neurostimulatory implant devices, including Cephaly and SpringTMS, improved patient-oriented outcomes with reductions in headaches per month (frequency) and severity.

Evidence Acquisition

This was a narrative review. The sources for this review are as follows: Searching on PubMed, Google Scholar, Medline, and ScienceDirect from 1990 - 2019 using keywords: Peripheral Neuromodulation, Headache, vagus nerve, occipital nerves, sphenopalatine ganglion.

Results

The first noninvasive neurostimulator device approved for migraine treatment was the Cefaly device, an external trigeminal nerve stimulation device (e-TNS) that transcutaneously excites the supratrochlear and supraorbital branches of the ophthalmic nerve. The second noninvasive neurostimulation device receiving FDA approval was the single-pulse transcranial magnetic stimulator, SpringTMS, positioned at the occiput to treat migraine with aura. GammaCore is a handheld transcutaneous vagal nerve stimulator applied directly to the neck at home by the patient for treatment of cluster headache (CH) and migraine. Several other devices are in development for the treatment of headaches and target headache evolution at different levels and inputs. The Scion device is a caloric vestibular stimulator (CVS) which interfaces with the user through a set of small cones resting in the ear canal on either side and held in place by modified over-ear headphones. The pulsante SPG Microstimulator is a patient-controlled device implanted in the patient’s upper jaw via an hour-long oral procedure to target the sphenopalatine ganglion. The occipital nerve stimulator (ONS) is an invasive neuromodulation device for headache treatment that consists of an implanted pulse generator on the chest wall connected to a subcutaneous lead with 4 - 8 electrodes that is tunneled the occiput.

Conclusions

The aim of this review is to provide a comprehensive overview of the efficacy, preliminary outcomes, and limitations of neurostimulatory implants available for use in the US and those pending further development.

Central motor conduction time in spinocerebellar ataxia: a meta-analysis

The dominantly inherited spinocerebellar ataxias (SCAs) are a large class of neurodegenerative diseases. Transcranial magnetic stimulation has been used to evaluate the function of the pyramidal tract, and central motor conduction time (CMCT) is one index used to detect pyramidal tract dysfunction. We conducted a comprehensive search of PubMed, Embase and Web of Science. Eight eligible studies were included in the meta-analysis. For upper limb CMCT, the mean difference (95% confidence interval (CI)) between the combined SCA group and the control group was 2.24 [1.76-2.72], while the mean differences (95% CIs) between the subtypes and the control group were as follows: 4.43 [3.58-5.28] for SCA1, 0.25 [-0.15,0.65] for SCA2, 1.04 [-0.37,2.46] for SCA3 and 0.49 [-0.29,1.28] for SCA6. Additionally, SCA1 significantly differed from SCA2 and SCA3 in terms of CMCT (P=0.0006 and P=0.010, respectively). We also compared lower limb CMCT between the SCA2 and control groups. The mean difference (95% CI) was 6.58 [4.49-8.67], which was clearly statistically significant. The differences in CMCT values among different subtypes suggests diverse pathological mechanisms. In general, CMCT is a promising objective index to judge the severity of disease deserving further investigation.

The effects of direct brain stimulation in humans depend on frequency, amplitude, and white-matter proximity

BACKGROUND

Researchers have used direct electrical brain stimulation to treat a range of neurological and psychiatric disorders. However, for brain stimulation to be maximally effective, clinicians and researchers should optimize stimulation parameters according to desired outcomes.

OBJECTIVE

The goal of our large-scale study was to comprehensively evaluate the effects of stimulation at different parameters and locations on neuronal activity across the human brain.

METHODS

To examine how different kinds of stimulation affect human brain activity, we compared the changes in neuronal activity that resulted from stimulation at a range of frequencies, amplitudes, and locations with direct human brain recordings. We recorded human brain activity directly with electrodes that were implanted in widespread regions across 106 neurosurgical epilepsy patients while systematically stimulating across a range of parameters and locations.

RESULTS

Overall, stimulation most often had an inhibitory effect on neuronal activity, consistent with earlier work. When stimulation excited neuronal activity, it most often occurred from high-frequency stimulation. These effects were modulated by the location of the stimulating electrode, with stimulation sites near white matter more likely to cause excitation and sites near gray matter more likely to inhibit neuronal activity.

CONCLUSION

By characterizing how different stimulation parameters produced specific neuronal activity patterns on a large scale, our results provide an electrophysiological framework that clinicians and researchers may consider when designing stimulation protocols to cause precisely targeted changes in human brain activity.

Trends of Repetitive Transcranial Magnetic Stimulation From 2009 to 2018: A Bibliometric Analysis

Repetitive transcranial magnetic stimulation (rTMS) technology, which is amongst the most used non-invasive brain stimulation techniques currently available, has developed rapidly from 2009 to 2018. However, reports on the trends of rTMS using bibliometric analysis are rare. The goal of the present bibliometric analysis is to analyze and visualize the trends of rTMS, including general (publication patterns) and emerging trends (research frontiers), over the last 10 years by using the visual analytic tool CiteSpace V. Publications related to rTMS from 2009 to 2018 were retrieved from the Web of Science (WoS) database, including 2,986 peer-reviewed articles/reviews. Active authors, journals, institutions, and countries were identified by WoS and visualized by CiteSpace V, which could also detect burst changes to identify emerging trends. GraphPad Prism 8 was used to analyze the time trend of annual publication outputs. The USA ranked first in this field. Pascual-Leone A (author A), Fitzgerald PB (author B), George MS (author C), Lefaucheur JP (author D), and Fregni F (author E) made great contributions to this field of study. The most prolific institution to publish rTMS-related publications in the last decade was the University of Toronto. The journal Brain Stimulation published most papers. Lefaucheur et al.'s paper in 2014, and the keyword "sham controlled trial" showed the strongest citation bursts by the end of 2018, which indicates increased attention to the underlying work, thereby indicating the research frontiers. This study reveals the publication patterns and emerging trends of rTMS based on the records published from 2009 to 2018. The insights obtained have reference values for the future research and application of rTMS.

A Multicenter, Prospective, Randomized, Placebo-Controlled, Double-Blind Study of a Novel Pain Management Device, AT-02, in Patients with Fibromyalgia

Objectives

Existing treatments for fibromyalgia have limited efficacy, and only a minority of individuals clinically respond to any single intervention. This study was a prospective, multicenter, randomized, double-blind, controlled clinical trial to evaluate the feasibility of alternating magnetic field therapy in fibromyalgia patients by comparing the Angel Touch device (AT-02) with a sham control (S-01).

Methods

Two sites enrolled 44 subjects with diagnosed fibromyalgia. After informed consent, subjects taking prohibited concomitant drugs underwent a washout period of two or more weeks. All subjects then began a one-week run-in period. Numerical rating scale (NRS) pain scores were collected without device intervention for one day, followed by S-01 application to four or more painful sites for 10 minutes at each site, twice daily for six days. Subjects were then randomized to AT-02 or S-01, applied to four or more painful sites for 10 minutes at each site, twice daily for eight weeks. NRS scores were obtained twice daily during the entire treatment period.

Results

The primary end point (change in NRS ± SD at week 8 vs baseline) was –0.94 ± 1.33 in the AT-02 group and –0.22 ± 1.38 in the S-01 group. A trend toward a between-group difference in eight-week NRS scores favored the AT-02 group (–0.73, 95% confidence interval = –1.56 to 0.11, P = 0.086). An adjusted repeated measure analysis detected a significant difference in NRS scores (P = 0.039).

Conclusions

The reduction in NRS scores for AT-02 relative to sham was comparable to reductions observed in meta-analyses of fibromyalgia drug therapy. The unadjusted results and the persistence of the pain score reductions remain encouraging.

[Peripheral neurostimulation in headache treatment]

According to rough estimates, at least one third of the population in developed countries suffers, to varying degrees, from certain forms of primary headache, the modern pharmacotherapy of which is not always effective and has a number of limitations. The non-pharmacological treatment of headache can be an alternative to the prescription of pharmacological agents and the only possible assistance option for patients developing drug-resistant cephalalgias. This review describes various methods of electrical neuromodulation that are used for the management of primary headaches. The authors provide information on current stages in implementation of implantable and non-invasive equipment into clinical practice, which makes possible electrical stimulations of peripheral nerves and of the sphenopalatine ganglion, as well as allows transcranial magnetic stimulation. Also the appearance and usage of portable electrical devices available on the world market are described, and mechanisms that can underlie anticephalgic action of neuromodulation therapy are discussed. Special attention is paid to the methods that are applied for electrostimulation of the vagus nerve and occipital nerves.

Peripheral neuromodulation for the treatment of migraine and headache: recent advances

Noninvasive neuromodulation is a rapidly developing field that offers an attractive nonpharmacologic treatment option for headache patients. Devices that stimulate peripheral nerves (e.g., vagus nerve, trigeminal sensory nerve, somatic sensory nerve) or brain parenchyma (e.g., occipital cortex) have been developed for this purpose, with promising results in clinical trials. There are currently four US FDA-cleared devices for the treatment of migraine and/or cluster headache: Cefaly®, a trigeminal nerve stimulator; gammaCore™, a vagus nerve stimulator; sTMS mini™, a transcranial magnetic stimulator and Nerivio™, a remote electrical neurostimulator. This narrative review will provide an overview of FDA-cleared neuromodulatory devices, including their proposed mechanisms of action as well as device safety and efficacy as demonstrated in clinical trials.

Effects of Non-invasive Brain Stimulation on Headache Intensity and Frequency of Headache Attacks in Patients With Migraine: A Systematic Review and Meta-Analysis

BACKGROUND

Non-invasive brain stimulation (NIBS) techniques such as repetitive transcranial magnetic stimulation (rTMS), as well as transcranial direct current stimulation (tDCS) electrically stimulate the brain and modify brain activity to suppress pain. This method is emerging as a potential clinical intervention against migraine.

OBJECTIVE

To quantitatively review the efficacy of rTMS and tDCS in randomized controlled trials (RCTs) in modifying headache intensity and frequency of headache attacks in patients suffering from migraine.

METHODS

We searched 5 databases: PubMed, EMBASE, Web of Science, Cochrane Library, and Scopus for articles from January 2000 to September 2018. Any RCT regarding the efficacy on rTMS and tDCS on patients with migraine, was considered to be included. A random effects meta-analysis was performed to pool effect sizes of outcomes related to headache intensity or frequency of headache attacks. The methodological quality of the included RCTs was assessed using the Physiotherapy Evidence Database scale.

RESULTS

Nine RCTs with 276 participants in total (experimental group [EG] = 149; control group [CG] = 127) were included in this review. Five included articles used rTMS (EG = 81; CG = 80), and 4 used tDCS (EG = 68; CG = 47). Meta-analysis of excitatory primary motor cortex (M1) stimulation showed significant effects on reducing headache intensity in patients with migraine (Hedges' g = -0.94; 95% CI, -1.28 to -0.59; P < .001, I²  = 18.39%) with a large effect size. Meta-analysis of excitatory M1 stimulation showed significant effects on reducing frequency of headache attacks in patients with migraine, with a large effect size (Hedges' g = -0.88; 95% CI, -1.38 to -0.38; P = .001, I²  = 57.15%). Excitatory dorsolateral prefrontal cortex stimulation showed a significant effect on the headache intensity in patients with migraine (Hedges' g = -1.14; 95% CI, -2.21 to -0.07; P = .04, I²  = 61.86%) with a large effect size. However, reductions of frequency of headache attacks was not significant.

LIMITATIONS

Potential differential effects of rTMS and tDCS, various sham methods, and potential overlapping headache disorders among included subjects may affect the estimation of effect sizes.

CONCLUSION

Excitatory NIBS of the M1 is likely to reduce headache intensity and the frequency of headache attacks in patients with migraine.

VETA: An Open-Source Matlab-Based Toolbox for the Collection and Analysis of Electromyography Combined With Transcranial Magnetic Stimulation

The combination of electromyography (EMG) and transcranial magnetic stimulation (TMS) offers a powerful non-invasive approach for investigating corticospinal excitability in both humans and animals. Acquiring and analyzing the data produced with this combination of tools requires overcoming multiple technical hurdles. Due in part to these technical hurdles, the field lacks standard routines for EMG data collection and analysis. This poses a problem for study replication and direct comparisons. Although software toolboxes already exist that perform either online EMG data visualization or offline analysis, there currently are no openly available toolboxes that flexibly perform both and also interface directly with peripheral EMG and TMS equipment. Here, we introduce Visualize EMG TMS Analyze (VETA), a MATLAB-based toolbox that supports simultaneous EMG data collection and visualization as well as automated offline processing and is specially tailored for use with motor TMS. The VETA toolbox enables the simultaneous recording of EMG, timed administration of TMS, and presentation of behavioral stimuli from a single computer. These tools also provide a streamlined analysis pipeline with interactive data visualization. Finally, VETA offers a standard EMG data format to facilitate data sharing and open science.

Practice Current: How do you diagnose and treat post-concussive headache?

A common complaint after concussion is the development of new or worsening headaches which can make it difficult or even impossible for patients to work or function in their day-to-day lives. Uncertainties associated with the complaints and a wide variety of approaches exist regarding the appropriate work-up and management of these patients. Areas of ongoing debate include the need for neuroimaging; optimal, acute, and preventative treatment; and proper counseling and expectation management. Given the wide variety of potential approaches and the lack of consensus, we sought expert opinion from around the globe on how to evaluate and manage patients with headache following concussion. Similar questions were posed to the rest of our readership in an online survey (links.lww.com/CPJ/A96), the results of which are also presented.

Micro/nanomachines: what is needed for them to become a real force in cancer therapy?

Conventional drug delivery systems face several issues in medical applications, such as cyto/genotoxicity and off-targeting. These issues are particularly significant for cancer therapeutics because many of the currently used systems are toxic in their free form. Self-propelled autonomous micro/nanomachines offer promising alternative drug delivery systems based on high cargo loading, fast autonomous movement, precise targeting and the on-demand release of therapeutics in vivo. With this unique set of properties, it is not surprising that they are receiving considerable research attention. However, much less is reported about the drawbacks that hinder their systemic in vivo application. In this review, a biomedical perspective is used to assess micro/nanomotor-based anticancer drug delivery systems reported to date. Advantages along with present issues are highlighted and recommendations which need to be considered to develop an effective biocompatible micro/nanomotor-based delivery system for cancer therapy are discussed.

Treatment of migraine attacks and prevention of migraine: Guidelines by the German Migraine and Headache Society and the German Society of Neurology

In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.

Non-pharmacological Approaches for Headaches in Young Age: An Updated Review

Headache disorders are common in children and adolescents. Most of the studies on non-pharmacological treatments have however been carried out on adults. In this review we provide information on recent studies examining non-pharmacological approaches for managing headache in children and adolescents. Our search of SCOPUS for primary studies conducted between January 2010 and July 2018 uncovered 11 controlled studies, mostly addressing behavioral approaches, in which a total of 613 patients with a diagnosis of primary headache, and average age 10.2–15.7 years (30–89% females) were recruited. Non-pharmacological treatments were shown to produce sizeable effects on the classical primary endpoint, i.e., headache frequency, with reductions from baseline ranging between 34 and 78%. Among commonly reported secondary endpoints, particularly disability, quality of life, depression and anxiety, marked improvements were noted as well. Taken as a whole, our findings suggest that non-pharmacological treatments constitute a valid option for the prevention of primary headaches in young age. Future research with higher-quality studies is needed. Particular attention needs to be given to studies that randomize patients to condition, blind researchers in charge of evaluating treatment outcomes, routinely include headache frequency as the primary endpoint, include adequate-length follow-up, address changes in biomarkers of disease and other possible mediators of outcome, and that employ predictive models to enhance the level of evidence for these approaches.

Non-invasive Brain Stimulation: A Paradigm Shift in Understanding Brain Oscillations

Cognitive neuroscience set out to understand the neural mechanisms underlying cognition. One central question is how oscillatory brain activity relates to cognitive processes. Up to now, most of the evidence supporting this relationship was correlative in nature. This situation changed dramatically with the recent development of non-invasive brain stimulation (NIBS) techniques, which open up new vistas for neuroscience by allowing researchers for the first time to validate their correlational theories by manipulating brain functioning directly. In this review, we focus on transcranial alternating current stimulation (tACS), an electrical brain stimulation method that applies sinusoidal currents to the intact scalp of human individuals to directly interfere with ongoing brain oscillations. We outline how tACS can impact human brain oscillations by employing different levels of observation from non-invasive tACS application in healthy volunteers and intracranial recordings in patients to animal studies demonstrating the effectiveness of alternating electric fields on neurons in vitro and in vivo. These findings likely translate to humans as comparable effects can be observed in human and animal studies. Neural entrainment and plasticity are suggested to mediate the behavioral effects of tACS. Furthermore, we focus on mechanistic theories about the relationship between certain cognitive functions and specific parameters of brain oscillaitons such as its amplitude, frequency, phase and phase coherence. For each of these parameters we present the current state of testing its functional relevance by means of tACS. Recent developments in the field of tACS are outlined which include the stimulation with physiologically inspired non-sinusoidal waveforms, stimulation protocols which allow for the observation of online-effects, and closed loop applications of tACS.

A multicenter, prospective, single arm, open label, observational study of sTMS for migraine prevention (ESPOUSE Study)

Objective To evaluate the efficacy and tolerability of single pulse transcranial magnetic stimulation (sTMS) for the preventive treatment of migraine. Background sTMS was originally developed for the acute treatment of migraine with aura. Open label experience has suggested a preventive benefit. The objective of this trial was to evaluate the efficacy and tolerability of sTMS for migraine prevention. Methods The eNeura SpringTMS Post-Market Observational U.S. Study of Migraine (ESPOUSE) Study was a multicenter, prospective, open label, observational study. From December 2014 to March 2016, patients with migraine (n = 263) were consented to complete a 1-month baseline headache diary followed by 3 months of treatment. The treatment protocol consisted of preventive (four pulses twice daily) and acute (three pulses repeated up to three times for each attack) treatment. Patients reported daily headache status, medication use, and device use with a monthly headache diary. The primary endpoint, mean reduction of headache days compared to baseline, was measured over the 28-day period during weeks 9 to 12. The primary endpoint was compared to a statistically-derived placebo estimate (performance goal). Secondary endpoints included: 50% responder rate, acute headache medication consumption, HIT-6, and mean reduction in total headache days from baseline of any intensity. Results Of a total of 263 consented subjects, 229 completed a baseline diary, and 220 were found to be eligible based on the number of headache days. The device was assigned to 217 subjects (Safety Data Set) and 132 were included in the intention to treat Full Analysis Set. For the primary endpoint, there was a -2.75 ± 0.40 mean reduction of headache days from baseline (9.06 days) compared to the performance goal (-0.63 days) ( p < 0.0001). The 50% responder rate of 46% (95% CI 37%, 56%) was also significantly higher ( p < 0.0001) than the performance goal (20%). There was a reduction of -2.93 (5.24) days of acute medication use, headache impact measured by HIT-6, -3.1 (6.4) ( p < 0.0001), and total headache days of any intensity -3.16 days (5.21) compared to the performance goal (-0.63 days) ( p < 0.0001). The most common adverse events were lightheadedness (3.7%), tingling (3.2%), and tinnitus (3.2%). There were no serious adverse events. Conclusions This open label study suggests that sTMS may be an effective, well-tolerated treatment option for migraine prevention. Trial registration number NCT02357381.

A Short Review of the Non-invasive Transcutaneous Pericranial Electrical Stimulation Techniques and their Application in Headache

PURPOSE OF REVIEW

In this short review, the most common non-invasive neuromodulatory techniques will be described, along with their advantages and disadvantages and their application in headache. Available preventive treatments can be unhelpful or may have unpleasant side effects; moreover, the rate of response to preventive drugs does not exceed 50%, lower in chronic migraine; alternative options would be welcome. Though the concept of neuromodulation was originally developed with invasive methods, newer non-invasive techniques are appearing.

RECENT FINDINGS

The novel neuromodulatory techniques have been developed with encouraging results: compared with traditional pharmacotherapy, advantages of non-invasive neuromodulation include reduced incidence of adverse effects, improved adherence, and safety and ease of use. The results are encouraging for acute or preventive treatment of different kinds of headache. A variety of neuromodulatory approaches is expanding fastly and has opened new possibilities for treatment of patients suffering from many forms of headache, especially those who have failed traditional pharmacotherapy. The non-invasive treatments can be seen as supplementing traditional management in refractory patients. Current study results are encouraging but preliminary and larger and more rigorous trials are needed to clarify benefit and mode of action.