Repetitive transcranial magnetic stimulation in psychiatry

Clinical efficacy of deep transcranial magnetic stimulation (dTMS) in psychiatric and cognitive disorders: A systematic review

Deep transcranial magnetic stimulation (dTMS) has gained attention as an enhanced form of traditional TMS, targeting broader and deeper regions of the brain. However, a fulsome synthesis of dTMS efficacy across psychiatric and cognitive disorders using sham-controlled trials is lacking. We systematically reviewed 28 clinical trials comparing active dTMS to a sham/controlled condition to characterize dTMS efficacy across diverse psychiatric and cognitive disorders. A comprehensive search of APA PsycINFO, Cochrane, Embase, Medline, and PubMed databases was conducted. Predominant evidence supports dTMS efficacy in patients with obsessive-compulsive disorder (OCD; n = 2), substance use disorders (SUDs; n = 8), and in those experiencing depressive episodes with major depressive disorder (MDD) or bipolar disorder (BD; n = 6). However, the clinical efficacy of dTMS in psychiatric disorders characterized by hyperactivity or hyperarousal (i.e., attention-deficit/hyperactivity disorder, posttraumatic stress disorder, and schizophrenia) was heterogeneous. Common side effects included headaches and pain/discomfort, with rare but serious adverse events such as seizures and suicidal ideation/attempts. Risk of bias ratings indicated a collectively low risk according to the Grading of Recommendations, Assessment, Development, and Evaluations checklist (Meader et al., 2014). Literature suggests promise for dTMS as a beneficial alternative or add-on treatment for patients who do not respond well to traditional treatment, particularly for depressive episodes, OCD, and SUDs. Mixed evidence and limited clinical trials for other psychiatric and cognitive disorders suggest more extensive research is warranted. Future research should examine the durability of dTMS interventions and identify moderators of clinical efficacy.

Multimodal workflows optimally predict response to repetitive transcranial magnetic stimulation in patients with schizophrenia: a multisite machine learning analysis

The response variability to repetitive transcranial magnetic stimulation (rTMS) challenges the effective use of this treatment option in patients with schizophrenia. This variability may be deciphered by leveraging predictive information in structural MRI, clinical, sociodemographic, and genetic data using artificial intelligence. We developed and cross-validated rTMS response prediction models in patients with schizophrenia drawn from the multisite RESIS trial. The models incorporated pre-treatment sMRI, clinical, sociodemographic, and polygenic risk score (PRS) data. Patients were randomly assigned to receive active (N = 45) or sham (N = 47) rTMS treatment. The prediction target was individual response, defined as ≥20% reduction in pre-treatment negative symptom sum scores of the Positive and Negative Syndrome Scale. Our multimodal sequential prediction workflow achieved a balanced accuracy (BAC) of 94% (non-responders: 92%, responders: 95%) in the active-treated group and 50% in the sham-treated group. The clinical, clinical + PRS, and sMRI-based classifiers yielded BACs of 65%, 76%, and 80%, respectively. Apparent sadness, inability to feel, educational attainment PRS, and unemployment were most predictive of non-response in the clinical + PRS model, while grey matter density reductions in the default mode, limbic networks, and the cerebellum were most predictive in the sMRI model. Our sequential modelling approach provided superior predictive performance while minimising the diagnostic burden in the clinical setting. Predictive patterns suggest that rTMS responders may have higher levels of brain grey matter in the default mode and salience networks which increases their likelihood of profiting from plasticity-inducing brain stimulation methods, such as rTMS. The future clinical implementation of our models requires findings to be replicated at the international scale using stratified clinical trial designs.

Repetitive transcranial magnetic stimulation improves cardiovascular autonomic nervous system control: A meta-analysis

BACKGROUND

Cardiovascular autonomic system (ANS) may be affected by altered neural activations in the brain. This systematic review and meta-analysis investigated potential effects of repetitive transcranial magnetic stimulation (rTMS) protocols on cardiovascular ANS control.

METHODS

Through 19 qualified studies, we acquired 70 comparisons for data synthesis. Individual effect sizes were estimated by comparing changes in following cardiovascular ANS control variables between active and sham stimulation conditions: (a) blood pressure (BP), (b) heart rate (HR), and (c) heart rate variability (HRV). Moreover, two moderator variable analyses determined whether changes in cardiovascular ANS control were different based on (a) rTMS protocols (excitatory rTMS versus inhibitory rTMS) and (b) specific targeted cortical regions, respectively.

RESULTS

The random-effects model meta-analysis revealed significant improvements in cardiovascular ANS control after the rTMS protocols. Specifically, applying excitatory and inhibitory rTMS protocols significantly decreased values of BP and HR variables. For HRV variables, excitatory rTMS protocols showed significant positive effects. These improvements in cardiovascular ANS control were observed while applying either excitatory rTMS protocols to the left dorsolateral prefrontal cortex or inhibitory rTMS protocols to the right dorsolateral prefrontal cortex.

LIMITATIONS

Relatively small number of studies for inhibitory rTMS on the right dorsolateral prefrontal cortex were included in this meta-analysis.

CONCLUSION

These findings suggest that applying excitatory and inhibitory rTMS protocols on prefrontal cortical regions may be effective to improve cardiovascular ANS control.

Excitatory Dorsal Lateral Prefrontal Cortex Transcranial Magnetic Stimulation Increases Social Anxiety

Social exclusion refers to the experience of rejection by one or more people during a social event and can induce pain-related sensations. Cyberball, a computer program, is one of the most common tools for analyzing social exclusion. Regions of the brain that underlie social pain include networks linked to the dorsal lateral prefrontal cortex (DLPFC). Specifically, self-directed negative socially induced exclusion is associated with changes in DLPFC activity. Direct manipulation of this area may provide a better understanding of how the DLPFC can influence the perception of social exclusion and determine a causal role of the DLPFC. Transcranial magnetic stimulation (TMS) was applied to both the left and right DLPFC to gauge different reactions to the Cyberball experience. It was found that there were elevated exclusion indices following right DLPFC rTMS; participants consistently felt more excluded when the right DLPFC was excited. This may relate to greater feelings of social pain when the right DLPFC is manipulated. These data demonstrate that direct manipulation of the DLPFC results in changes in responses to social exclusion.

High-frequency rTMS improves quality of life and depressive symptoms in Parkinson's disease: A case report

Introduction

Parkinson's disease (PD) is a common neurodegenerative disorder, characterised by both motor and nonmotor symptoms. There is currently no cure for PD, although there are several treatment options for relieving PD symptoms. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation therapy that shows promising results for the treatment of PD.

Methods

Here, we present a patient with PD. We investigated whether an accelerate form of high-frequency (HF) rTMS on the contralateral side to the patient's main difficulties is clinically effective in treating health-related quality of life (QoL) symptomatology and depressive symptoms in PD as well as the long-term effects of rTMS in PD during the maintenance phase.

Results

Results showed that HF-rTMS administered over the right primary motor cortex (M1) is a safe and well-tolerated treatment that improved the patient's health related QoL and depressive symptoms. These positive effects lasted at least five months post treatment.

Conclusion

Therefore, HF-rTMS over the right M1 can be a possible treatment option for patients with PD, although further investigations are necessary to validate the findings of the present case report.

Neuromodulation and Hippocampal Neurogenesis in Depression: A Scoping Review

The 'neurogenesis hypothesis of depression' emphasizes the importance of upregulated hippocampal neurogenesis for the efficacy of antidepressant treatment. Neuromodulation is a promising therapeutic method that stimulates neural circuitries to treat neuropsychiatric illnesses. We conducted a scoping review on the neurogenic and antidepressant outcomes of neuromodulation in animal models of depression. PubMed, Web of Science, and PsycInfo were comprehensively searched for full-text English articles from inception to October 5, 2021. Data screening and extraction were conducted independently by two researchers. Seventeen eligible studies were included in this review. The majority of studies used non-invasive neuromodulation (n = 14) and assessed neurogenesis using neural proliferation (n = 16) and differentiation markers (n = 9). Limited reports (n = 2) used neurogenic inhibitors to evaluate the role of neurogenesis on the depressive-like behavioral outcomes. Overall, neuromodulation substantially effectuated both hippocampal cell proliferation and antidepressant-like behavior in animal models of depression, with some providing evidence for enhanced neuronal differentiation and maturation. The proposed neurogenic-related mechanisms mediating the neuromodulation efficacies included neurotrophic processes, anti-apoptotic pathways, and normalization of HPA axis functions. Further research is warranted to explore the role of neuromodulation-induced neurogenic effects on treatment efficacies and to elucidate the underlying molecular mechanisms.

Working Memory and Transcranial-Alternating Current Stimulation-State of the Art: Findings, Missing, and Challenges

Working memory (WM) is a cognitive process that involves maintaining and manipulating information for a short period of time. WM is central to many cognitive processes and declines rapidly with age. Deficits in WM are seen in older adults and in patients with dementia, schizophrenia, major depression, mild cognitive impairment, Alzheimer's disease, etc. The frontal, parietal, and occipital cortices are significantly involved in WM processing and all brain oscillations are implicated in tackling WM tasks, particularly theta and gamma bands. The theta/gamma neural code hypothesis assumes that retained memory items are recorded via theta-nested gamma cycles. Neuronal oscillations can be manipulated by sensory, invasive- and non-invasive brain stimulations. Transcranial alternating-current stimulation (tACS) and repetitive transcranial magnetic stimulation (rTMS) are frequency-tuned non-invasive brain stimulation (NIBS) techniques that have been used to entrain endogenous oscillations in a frequency-specific manner. Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for improving cognitive performance. Although cognitive research with tACS is still in its infancy compared to rTMS, a number of studies have shown a promising WM enhancement effect, especially in the elderly and patients with cognitive deficits. This review focuses on the various methods and outcomes of tACS on WM in healthy and unhealthy human adults and highlights the established findings, unknowns, challenges, and perspectives important for translating laboratory tACS into realistic clinical settings. This will allow researchers to identify gaps in the literature and develop frequency-tuned tACS protocols with promising safety and efficacy outcomes. Therefore, research efforts in this direction should help to consider frequency-tuned tACS as a non-pharmacological tool of cognitive rehabilitation in physiological aging and patients with cognitive deficits.

Understanding complex functional wiring patterns in major depressive disorder through brain functional connectome

Brain function relies on efficient communications between distinct brain systems. The pathology of major depressive disorder (MDD) damages functional brain networks, resulting in cognitive impairment. Here, we reviewed the associations between brain functional connectome changes and MDD pathogenesis. We also highlighted the utility of brain functional connectome for differentiating MDD from other similar psychiatric disorders, predicting recurrence and suicide attempts in MDD, and evaluating treatment responses. Converging evidence has now linked aberrant brain functional network organization in MDD to the dysregulation of neurotransmitter signaling and neuroplasticity, providing insights into the neurobiological mechanisms of the disease and antidepressant efficacy. Widespread connectome dysfunctions in MDD patients include multiple, large-scale brain networks as well as local disturbances in brain circuits associated with negative and positive valence systems and cognitive functions. Although the clinical utility of the brain functional connectome remains to be realized, recent findings provide further promise that research in this area may lead to improved diagnosis, treatments, and clinical outcomes of MDD.

Electromagnetic Field as a Treatment for Cerebral Ischemic Stroke

Cerebral stroke is a leading cause of death and adult-acquired disability worldwide. To this date, treatment options are limited; hence, the search for new therapeutic approaches continues. Electromagnetic fields (EMFs) affect a wide variety of biological processes and accumulating evidence shows their potential as a treatment for ischemic stroke. Based on their characteristics, they can be divided into stationary, pulsed, and sinusoidal EMF. The aim of this review is to provide an extensive literature overview ranging from in vitro to even clinical studies within the field of ischemic stroke of all EMF types. A thorough comparison between EMF types and their effects is provided, as well as an overview of the signal pathways activated in cell types relevant for ischemic stroke such as neurons, microglia, astrocytes, and endothelial cells. We also discuss which steps have to be taken to improve their therapeutic efficacy in the frame of the clinical translation of this promising therapy.

Technological Improvement Rates and Evolution of Energy-Based Therapeutics

This paper examines the field of energy-based medical therapies based on the analysis of patents. We define the field as the use of external stimuli to achieve biomedical modifications to treat disease and to increase health. Based upon distinct sets of patents, the field is subdivided into sub-domains for each energy category used to achieve the stimulation: electrical, magnetic, microwave, ultrasound, and optical. Previously developed techniques are used to retrieve the relevant patents for each of the stimulation modes and to determine main paths along the trajectory followed by each sub-domain. The patent sets are analyzed to determine key assignees, number of patents, and dates of emergence of the sub-domains. The sub-domains are found to be largely independent as to patent assignees. Electrical and magnetic stimulation patents emerged earliest in the 1970s and microwave most recently around 1990. The annual rate of improvement of all sub-domains (12-85%) is found to be significantly higher than one we find for an aggregate pharmaceutical domain (5%). Overall, the results suggest an increasingly important role for energy-based therapies in the future of medicine.

Memory changes following adjuvant temporo-parietal repetitive transcranial magnetic stimulation in schizophrenia

OBJECTIVE

The use of repetitive transcranial magnetic stimulation (rTMS) in schizophrenia has shown improvement as well as deficits in memory. Though most studies had focused on dorsolateral prefrontal cortex only, but impact of rTMS on cognitive functions remain inconclusive. The need of the study is to assess the impact of rTMS on memory in schizophrenia.

MATERIALS AND METHODS

Forty right-handed male patients with schizophrenia were included by purposive sampling and rated on Positive and Negative Syndrome Scale (PANSS) before starting the rTMS treatment with the experimental group. Low frequency 1 Hz rTMS including 1200 stimulations were given over temporo-parietal cortex for 20 min as add on to medications. At the end of 10 session treatment (5 days a week for 2 weeks), the patients were re-evaluated.

RESULTS

A total of 39 patients (20 for experimental group and 19 for control group) with mean age of 29.70 ± 9.05 and 31.26 ± 7.78 years, respectively, shows significant difference to pre- and post-treatment mean PANSS score in positive, negative and general psychopathology domains. The pre- and post-treatment mean Postgraduate Institute Memory Scale Scores with multivariate repeated measures analysis of variance revealed significant improvements in all memory domains (P < 0.01) except remote memory in both experimental and control groups.

CONCLUSION

RTMS in combination with antipsychotics has shown improvement in psychopathology in patients of schizophrenia without any deterioration of memory.

Post-stroke depression: Chaos to exposition

Cerebral ischemia contributes to significant disabilities worldwide, impairing cognitive function and motor coordination in affected individuals. Stroke has severe neuropsychological outcomes, the major one being a stroke. Stroke survivors begin to show symptoms of depression within a few months of the incidence that overtime progresses to become a long-term ailment. As the pathophysiology for the progression of the disease is multifactorial and complex, it limits the understanding of the disease mechanism completely. Meta-analyses and randomized clinical trials have shown that intervening early with tricyclic antidepressants and selective serotonin receptor inhibitors can be effective. However, these pharmacotherapies possess several limitations that have given rise to newer approaches such as brain stimulation, psychotherapy and rehabilitation therapy, which in today's time are gaining attention for their beneficial results in post-stroke depression (PSD). The present review highlights numerous factors like lesion location, inflammatory mediators and genetic abnormalities that play a crucial role in the development of depression in stroke patients. Further, we have also discussed various mechanisms involved in post-stroke depression (PSD) and strategies for early detection and diagnosis using biomarkers that may revolutionize treatment for the affected population. Towards the end, along with the preclinical scenario, we have also discussed the various treatment approaches like pharmacotherapy, traditional medicines, psychotherapy, electrical stimulation and microRNAs being utilized for effectively managing PSD.

Repetitive Transcranial Magnetic Stimulation in the Treatment of Bipolar Disorder

Bipolar disorder (BD) is a debilitating mood disorder marked by manic, hypomanic and/or mixed or depressive episodes. It affects approximately 1-2% of the population and is linked to high rates of suicide, functional impairment and poorer quality of life. Presently, treatment options for BD are limited. There is a strong evidence base for pharmacological (e.g., lithium) and psychological (e.g., psychoeducation) treatments; however, both of these pose challenges for treatment outcomes (e.g., non-response, side-effects, limited access). Repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, is a recommended treatment for unipolar depression, but it is unclear whether rTMS is an effective, safe and well tolerated treatment in people with BD. This article reviews the extant literature on the use of rTMS to treat BD across different mood states. We found 34 studies in total (N = 611 patients), with most assessing bipolar depression (n = 26), versus bipolar mania (n = 5), mixed state bipolar (n = 2) or those not in a current affective episode (n = 1). Across all studies, there appears to be a detectable signal of efficacy for rTMS treatment, as most studies report that rTMS treatment reduced bipolar symptoms. Importantly, within the randomised controlled trial (RCT) study designs, most reported that rTMS was not superior to sham in the treatment of bipolar depression. However, these RCTs are based on small samples (NBD ⩽ 52). Reported side effects of rTMS in BD include headache, dizziness and sleep problems. Ten studies (N = 14 patients) reported cases of affective switching; however, no clear pattern of potential risk factors for affective switching emerged. Future adequately powered, sham-controlled trials are needed to establish the ideal rTMS treatment parameters to help better determine the efficacy of rTMS for the treatment of BD.

Efficacy of Repetitive Transcranial Magnetic Stimulation (rTMS)in Inducing Weight Loss among Obese Filipino Patients:A Randomized Controlled Trial

OBJECTIVE

To determine the efficacy of rTMS in decreasing body mass index (BMI) versus sham stimulation among obese Filipino patients.

Methodology

This was a single-center, randomized, sham-controlled, single-blind, parallel group trial. Participants were 15-65 years old with BMI ≥30 kg/m² and weight stable for 6 weeks. Participants were randomized to receive real rTMS or sham stimulation. Each underwent 4 sessions of stimulation over 2 weeks. Anthropometrics, total caloric intake (TCI), and VAS score for appetite were taken at baseline, 2, 4, 6, and 12 weeks.

RESULTS

A total of 31 patients were randomized with 15 to the treatment and 14 to sham stimulation completing treatment, with 2 lost to follow-up. A significant decrease in BMI was noted after 4 weeks from the start of rTMS in the treatment group, (0.6±0.6, p-value=0.001), with weight change of -1.3±1.3 kg (p-value=0.009), but was no longer observed at 6 weeks onwards. No severe adverse effects were noted.

Conclusion

rTMS to the DLPFC effectively decreased BMI (0.6±0.6) and weight (-1.3±1.3 kg) from baseline to 4 weeks. At 6-12 weeks after rTMS however, there was no longer a significant difference, indicating that 4 sessions of rTMS may not be enough to produce a prolonged effect on weight loss.

Obsessive-Compulsive Disorder in Older Adults: A Comprehensive Literature Review

We reviewed English-language articles concerning obsessive-compulsive disorder (OCD) in older adults. PubMed was searched using key words that included obsessive-compulsive disorder, geriatric, elderly, aging, and older. Of the 644 articles identified, we included 78 that were relevant to the topic. Articles that were excluded as irrelevant included studies that were not focused on OCD in older adults, animal studies, and older case reports if we identified similar more recent case reports. The literature contains very little information about the epidemiology, diagnosis, psychopathology, and treatment of OCD in older adults. Even though the diagnostic criteria for OCD are the same for older and younger adults, different manifestations and progression in older patients have been reported. While the domains and severity of symptoms of OCD do not change with age, pathologic doubt may worsen. The Yale-Brown Obsessive Compulsive Scale is used for diagnosing and evaluating illness severity, and the Obsessive-Compulsive Inventory-Revised is another valuable tool for use in older adults. Psychotherapy, specifically exposure and response prevention, is the first-line treatment for OCD because of minimal adverse effects and reported benefit. Although the US Food and Drug Administration has not approved any medications specifically for OCD in older adults, pharmacotherapy is a consideration if psychotherapy is not successful. Selective serotonin reuptake inhibitors have the fewest side effects, while the cardiovascular and anticholinergic side effects of tricyclic antidepressants are especially worrisome in older adults. OCD in older adults has received little attention, and further studies are needed.

Repetitive Transcranial Magnetic Stimulation Combined with Antidepressants for the First Episode of Major Depressive Disorder

OBJECTIVES

The aims of this study were to systematically review the efficacy, acceptability, and tolerability of repetitive transcranial magnetic stimulation (rTMS) combined with antidepressants in the treatment of the first major depressive disorder (MDD) episode.

MATERIALS AND METHODS

The primary efficacious outcome was the pooled mean-endpoint scores of the Hamilton Depression Rating Scale (HAMD). Rates of response, remission rate, overall discontinuation and discontinuation due to adverse events were also evaluated. Search in the Scopus, PubMed, CINAHL, and Cochrane Controlled Trials Register databases for interesting outcomes was carried out in March 2018.

RESULTS

A total of 108 randomized patients of two randomized controlled trials were included in this study. The pooled mean- endpoint scores of the HAMD in one, two, and four weeks for rTMS plus antidepressants (citalopram or paroxetine) were greater than that of sham plus the antidepressants. The pooled rates of overall discontinuation and discontinuation rates due to adverse events were not different between the two groups.

CONCLUSION

According to a piece of limited evidence, the high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) could accelerate the antidepressant effect of SSRIs in young patients with a first-episode major depressive disorder. However, the acceptability and tolerability of HF-rTMS in the treatment of such patients are no better than an antidepressant alone. However, further well-defined and large sample-size studies of HF-rTMS combined with an antidepressant in MDD should be carried out to warrant these results.

Clinical applications of transcranial magnetic stimulation in bipolar disorder

BACKGROUND

Many patients with bipolar disorder (BD) fail to experience benefit following traditional pharmacotherapy, necessitating alternative treatment options that will enable such patients to achieve remission. Transcranial magnetic stimulation (TMS) is a relatively new, noninvasive neuromodulation technique that involves the application of magnetic pulses on hyperactive or hypoactive cortical brain areas. We evaluated the existing literature on TMS as a treatment for BD across varied mood states.

METHODS

We searched PubMed up to October 2018 for original data articles published in English that evaluated outcomes in a bipolar sample across depressive, manic, mixed, and maintenance phases of BD.

RESULTS

Clinical trials of TMS for BD particularly suggest the potential of repetitive TMS for reducing depressive symptoms. Studies of TMS for mania have yielded more mixed findings. Few studies have evaluated TMS in other phases of the bipolar illness. TMS is generally associated with mild side effects though, in a few studies, it has been shown to contribute to a manic switch in previously depressed bipolar patients.

CONCLUSIONS

Transcranial magnetic stimulation is a promising approach for treating patients with BD who have failed to respond to pharmacological or psychosocial treatment. Future research should more clearly elucidate which TMS protocols may be most effective for a given bipolar patient.

The effects of high-frequency repetitive transcranial magnetic stimulation on resting-state functional connectivity in obese adults

AIMS

We conducted a 4-week randomized, sham-controlled, single-blind, parallel-group trial to examine the effect of repetitive transcranial magnetic stimulation (rTMS) delivered to the left dorsolateral prefrontal cortex (DLPFC) on functional brain connectivity and body weight in adults with obesity.

MATERIALS AND METHODS

Of the 45 volunteers with obesity, aged between 18 and 70 years (body mass index [BMI] ≥25 kg/m² according to the obesity criterion for an Asian population), 36 participants (54.1 ± 11.0 years, BMI 30.2 ± 3.5 kg/m² , 77.8% female) completed the 4 weeks of follow-up, undergoing two resting state fMRI scans (20 in the real stimulation group and 16 in the sham stimulation group). A total of eight sessions of high-frequency rTMS targeting the left DLPFC were provided over a period of 4 weeks (5-second trains with 25-second inter-train intervals, 10 Hz, 110% motor threshold; 2000 pulses over 20 minutes).

RESULTS

Participants in the real stimulation group showed significantly greater weight loss from baseline following the eight session of rTMS (-2.53 ± 2.41 kg vs 0.38 ± 1.13 kg, P < 0.01). For intrinsic brain connectivity comparisons, the between-ness centrality values within the right frontoparietal network tended to increase with rTMS, and a significant interaction effect was identified for time (pre vs post) × rTMS (real vs sham) in the right frontoparietal network (P = 0.031, FDR corrected).

CONCLUSIONS

We observed that rTMS selectively increased resting state functional connectivity within the right frontoparietal network. Our findings suggest that high-frequency rTMS to the left DLPFC might strengthen the frontoparietal network that orchestrates top-down inhibitory control to reduce food intake.

Predictors of Response to Repetitive Transcranial Magnetic Stimulation in Depression: A Review of Recent Updates

Transcranial magnetic stimulation (TMS) has been increasingly used in the treatment of various neuropsychiatric disorders including depression over the past two decades. The responses to treatment with TMS are variable as found in the recent studies. Evidences suggest that various factors influence the outcome of depression treated with TMS. Understanding the predictors of response to TMS treatment in depression will guide the clinician in appropriate selection of patients for TMS treatment as well as needful modification in the TMS technique and protocol to have a better clinical outcome. This article comprehensively reviews the factors that predict the outcome of TMS treatment in depression.

Tachyphylaxis in major depressive disorder: A review of the current state of research

BACKGROUND

Patients with major depressive disorder (MDD) often experience a re-emergence or worsening of symptoms despite ongoing treatment with previously effective antidepressant pharmacotherapy. This lost or reduced antidepressant response during maintenance, referred to as tachyphylaxis, negatively impacts treatment outcomes and quality of life for patients with MDD. This review assesses the prevalence of antidepressant tachyphylaxis as well as the evidence for interventions to manage it.

METHODS

We searched PubMed/Medline for the relevant clinical trials and meta-analyses on antidepressant tachyphylaxis up to January 2017. Search terms included "depression" paired with "treatment" (n = 186,674), "tachyphylaxis" paired with "depression" (n = 112), "tachyphylaxis" paired with "major depressive disorder" (n = 21), and "antidepressant" paired with "tachyphylaxis" (n = 68). Studies were included if they reported on a clinical trial or meta-analysis exploring tachyphylaxis in MDD and were excluded if the sample population did not have a primary DSM diagnosis of MDD.

RESULTS

Rates of tachyphylaxis varied from 9% to 57% depending on the patient population and duration of follow-up. Limited evidence suggests potentially beneficial strategies for managing tachyphylaxis, including change in antidepressant dosing, switch of class of antidepressant medication, augmentation or combination pharmacotherapy, and psychotherapy.

LIMITATIONS

Studies of antidepressant tachyphylaxis are largely heterogeneous in nature and employ strict inclusion/exclusion criteria; thus, these findings may not be generalizable to all depressed populations.

CONCLUSION

Few established treatment strategies exist to manage antidepressant tachyphylaxis. Further interventional research is needed to provide symptomatic relief for patients with tachyphylaxis in MDD.

rTMS Reduces Psychopathological Burden and Cocaine Consumption in Treatment-Seeking Subjects With Cocaine Use Disorder: An Open Label, Feasibility Study

Introduction: Cocaine use disorder (CUD) currently represents a notable public health concern, linked with significant disability, high chances of chronicity, and lack of effective pharmacological or psychological treatments. Repetitive transcranial magnetic stimulation (rTMS) is supposed to be a potential therapeutic option for addictive disorders. Aim of this study was to evaluate the feasibility of rTMS on (1) cocaine craving and consumption and (2) other comorbid psychiatric symptoms. Methods: Twenty treatment seeking CUD subjects underwent 2 weeks of intensive rTMS treatment (15Hz; 5 days/week, twice a day for a total of 20 stimulation sessions) of the left dorsolateral prefrontal cortex, followed by 2 weeks of maintenance treatment (15Hz, 1 day/week, twice a day). Sixteen patients completed the study. Patients were evaluated at baseline (T0), after 2 weeks of treatment (T1), and at the end of the study (T2; 4 weeks), with the following scales: Cocaine Selective Severity Assessment (CSSA), Zung Self-Rating Anxiety Scale, Beck Depression Inventory (BDI), Symptom Checklist-90 (SCL-90), and the Insomnia Severity Index. Results: After four weeks of rTMS treatment, 9 out of 16 subjects (56.25%) had a negative urinalysis test, with a significant conversion rate with respect to baseline (Z = -3.00; p = 0.003). Craving scores significantly improved only at T2 (p = 0.020). The overall psychopathological burden, as measured by the SCL-90 Global Severity Index (GSI), significantly decreased during the study period (Z = -2.689; p = 0.007), with a relevant improvement with regards to depressive symptoms, anhedonia, and anxiety. Subjects exhibiting lower baseline scores on the SCL-90 were more likely to be in the positive outcome group at the end of the study (Z = -3.334; p = 0.001). Discussion: Findings from this study are consistent with previous contributions on rTMS use in subjects with cocaine use disorder. We evidenced a specific action on some psychopathological areas and a consequent indirect effect in terms of relapse prevention and craving reduction. A double-blind, sham-controlled, neuro-navigated rTMS study design is needed, in order to confirm the potential benefits of this technique, opening new scenarios in substance use disorders treatment.

Invasive and Non-invasive Stimulation of the Obese Human Brain

Accumulating evidence suggests that non-invasive and invasive brain stimulation may reduce food craving and calorie consumption rendering these techniques potential treatment options for obesity. Non-invasive transcranial direct current stimulation (tDCS) or repetitive transcranial magnet stimulation (rTMS) are used to modulate activity in superficially located executive control regions, such as the dorsolateral prefrontal cortex (DLPFC). Modulation of the DLPFC’s activity may alter executive functioning and food reward processing in interconnected dopamine-rich regions such as the striatum or orbitofrontal cortex. Modulation of reward processing can also be achieved by invasive deep brain stimulation (DBS) targeting the nucleus accumbens. Another target for DBS is the lateral hypothalamic area potentially leading to improved energy expenditure. To date, available evidence is, however, restricted to few exceptional cases of morbid obesity. The vagal nerve plays a crucial role in signaling the homeostatic demand to the brain. Invasive or non-invasive vagal nerve stimulation (VNS) is thus assumed to reduce appetite, rendering VNS another possible treatment option for obesity. Based on currently available evidence, the U.S. Food and Drug Administration recently approved VNS for the treatment of obesity. This review summarizes scientific evidence regarding these techniques’ efficacy in modulating food craving and calorie intake. It is time for large controlled clinical trials that are necessary to translate currently available research discoveries into patient care.

Transcranial magnetic stimulation: A review of its evolution and current applications

Repetitive transcranial magnetic stimulation (rTMS) is a recently developed noninvasive brain stimulation method for the treatment of psychiatric and neurological disorders. Although, its exact mechanism of action is still not clear, current evidence points toward its role in causing long-term inhibition and excitation of neurons in certain brain areas. As evidence steadily grows in favor of rTMS as a therapeutic tool; there is a need to develop standardized protocols for its administration. There have been no reports of any serious side effects with rTMS, though its use is restricted in those having magnetic implants or recent adverse neurological or cardiac event. Of all the psychiatric indications of rTMS, the evidence is most robust for treatment of refractory unipolar depression. This paper reviews contemporary literature highlighting the evolution of rTMS as a diagnostic and therapeutic tool, especially in the management of treatment-resistant depression.

The Differential Effects of Repetitive Magnetic Stimulation in an In Vitro Neuronal Model of Ischemia/Reperfusion Injury

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive therapy that has been implicated in treatment of serious neurological disorders. However, the neurobiological mechanisms underlying the effects of rTMS remain unclear. Therefore, this study examined the differential effects of repetitive magnetic stimulation (rMS) in an in vitro neuronal model of ischemia/reperfusion (I/R) injury, depending on low and high frequency. Neuro-2a cells were differentiated with retinoic acid and established for in vitro neuronal model of I/R injury under a subsequent 3 h of oxygen and glucose deprivation/reoxygenation (OGD/R) condition. After the I/R injury, the differentiated neuronal cells were stimulated with rMS on day 1 and randomly divided into three groups: OGD/R+sham, OGD/R+low-frequency, and OGD/R+high-frequency groups. High-frequency rMS increases cell proliferation through activation of extracellular signal-regulated kinases and AKT-signaling pathway and inhibits apoptosis in OGD/R-injured cells. Furthermore, high-frequency rMS increases Ca²⁺–calmodulin-dependent protein kinase II (CaMKII)-cAMP-response element binding protein (CREB) signaling pathway, further leading to alternation of brain-derived neurotrophic factor expression and synaptic plasticity in OGD/R injured cells. These results verified the neurobiological mechanisms of frequency-dependent rMS in I/R injury-treated neuronal cells. These mechanisms will help develop more powerful and credible rTMS stimulation treatment protocols.

Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders: A meta-analysis

OBJECTIVE

This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders.

DATA SOURCES

Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Controlled Trials databases from January 1985 to May 2012. Key words were "transcranial magnetic stimulation", "TMS", "repetitive transcranial magnetic stimulation", and "hallucination".

STUDY SELECTION

Selected studies were randomized controlled trials assessing therapeutic efficacy of repetitive transcranial magnetic stimulation for hallucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hallucination in schizophrenia spectrum disorders. Control groups received sham stimulation.

MAIN OUTCOME MEASURES

The primary outcome was total scores of Auditory Hallucinations Rating Scale, Auditory Hallucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hallucination item, and Hallucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function.

RESULTS

Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. All data were completely effective, involving 398 patients. Overall mean weighted effect size for repetitive transcranial magnetic stimulation versus sham stimulation was statistically significant (MD = -0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P = 0.005). No significant differences were found between active repetitive transcranial magnetic stimulation and sham stimulation for positive or negative symptoms. Compared with sham stimulation, active repetitive transcranial magnetic stimulation had equivocal outcome in cognitive function and commonly caused headache and facial muscle twitching.

CONCLUSION

Repetitive transcranial magnetic stimulation is a safe and effective treatment for auditory hallucination in schizophrenia spectrum disorders.

[Fundamentals and Clinical Applications of Transcranial Magnetic Stimulation in Neuropsychiatry]

Transcranial Magnetic Stimulation (TMS) is a non-invasive method for stimulation of brain that is based on the ability of a generated magnetic field to penetrate skull and brain meninges, inducing an electric current in the brain tissues that produces neuronal depolarization. TMS can be applied as single pulse of stimulation, pairs of stimuli separated by variable intervals to the same or different brain areas, or as trains of repetitive stimuli at various frequencies. Its mechanism of action is currently unknown. Repetitive TMS can modify the excitability of the cerebral cortex, and has been postulated as a diagnostic and therapeutic tool in the area of neuropsychiatry. The aim of this article is to review the knowledge of the TMS as regards its basic principles, pathophysiological mechanism, and its usefulness in clinical practice.

Potential role of repetitive transcranial magnetic stimulation in obesity

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique with mild side effects. Some forms of obesity may arise from eating disorders and recent data suggest that rTMS treatment could have beneficial effects in eating disorders.

PURPOSE

The purpose of this comprehensive review is to hypothesize that rTMS may play a role in obesity.

MATERIALS AND METHODS

Articles were selected based on a search on medline using the terms "rTMS", "food craving", "eating disorders", "addiction", and "obesity". They were published between 1995 and 2013.

RESULTS

Repetitive transcranial magnetic stimulation has been evaluated in the treatment of bulimia nervosa. It appears that it exerts its effect via the reduction of the level of craving for food. Obesity is being recognized as one of the endpoints of food addiction and craving. Besides, rTMS and transcranial direct current stimulation are brain stimulation techniques being used in the treatment of psychoactive substance addiction.

CONCLUSIONS

Repetitive transcranial magnetic stimulation, through the reduction of food craving may be a potential treatment for a subset of individuals suffering from obesity. Further studies with a higher number of subjects are still needed to confirm the effects of rTMS on obesity.