The expanding evidence base for rTMS treatment of depression

Mapping cognitive brain functions at scale

A fundamental set of cognitive abilities enable humans to efficiently process goal-relevant information, suppress irrelevant distractions, maintain information in working memory, and act flexibly in different behavioral contexts. Yet, studies of human cognition and their underlying neural mechanisms usually evaluate these cognitive constructs in silos, instead of comprehensively in-tandem within the same individual. Here, we developed a scalable, mobile platform, "BrainE" (short for Brain Engagement), to rapidly assay several essential aspects of cognition simultaneous with wireless electroencephalography (EEG) recordings. Using BrainE, we rapidly assessed five aspects of cognition including (1) selective attention, (2) response inhibition, (3) working memory, (4) flanker interference and (5) emotion interference processing, in 102 healthy young adults. We evaluated stimulus encoding in all tasks using the EEG neural recordings, and isolated the cortical sources of the spectrotemporal EEG dynamics. Additionally, we used BrainE in a two-visit study in 24 young adults to investigate the reliability of the neuro-cognitive data as well as its plasticity to transcranial magnetic stimulation (TMS). We found that stimulus encoding on multiple cognitive tasks could be rapidly assessed, identifying common as well as distinct task processes in both sensory and cognitive control brain regions. Event related synchronization (ERS) in the theta (3-7 Hz) and alpha (8-12 Hz) frequencies as well as event related desynchronization (ERD) in the beta frequencies (13-30 Hz) were distinctly observed in each task. The observed ERS/ERD effects were overall anticorrelated. The two-visit study confirmed high test-retest reliability for both cognitive and neural data, and neural responses showed specific TMS protocol driven modulation. We also show that the global cognitive neural responses are sensitive to mental health symptom self-reports. This first study with the BrainE platform showcases its utility in studying neuro-cognitive dynamics in a rapid and scalable fashion.

Exploratory study on neurochemical effects of low-intensity pulsed ultrasound in brains of mice

There is now a relatively large body of evidence suggesting a relationship between dysfunction of myelin and oligodendrocytes and the etiology of several neuropsychiatric disorders, including depression and schizophrenia, and also suggesting that ultrasound methods may alleviate some of the symptoms of depression. We have applied low-intensity pulsed ultrasound (LIPUS) to the brains of mice treated with the demyelinating drug cuprizone, a drug that has been used as the basis for a rodent model relevant to a number of psychiatric and neurologic disorders including depression, schizophrenia, and multiple sclerosis. Prior to conducting the studies in mice, preliminary studies were carried out on the effects of LIPUS in vitro in neuron-like SH-SY5Y cells and primary glial cells. In subsequent studies in mice, female C57BL/6 mice were restrained in plastic tubes for 20 min daily with the ultrasound transducer near the end of the tube directly above the mouse's head. LIPUS was used at an intensity of 25 mW/cm² once daily for 22 days in control mice and in mice undergoing daily repetitive restraint stress (RRS). Behavioral or neurochemical studies were done on the mice or the brain tissue obtained from them. The studies in vitro indicated that LIPUS stimulation at an intensity of 15 mW/cm² delivered for 5 min daily for 3 days in an enclosed sterile cell culture plate in an incubator increased the viability of SH-SY5Y and primary glial cells. In the studies in mice, LIPUS elevated levels of doublecortin, a marker for neurogenesis, in the cortex compared to levels in the RRS mice and caused a trend in elevation of brain levels of brain-derived neurotrophic factor in the hippocampus relative to control levels. LIPUS also increased sucrose preference (a measure of the attenuation of anhedonia, a common symptom of several psychiatric disorders) in the RRS model in mice. The ability of LIPUS administered daily to rescue damaged myelin and oligodendrocytes was studied in mice treated chronically with cuprizone for 35 days. LIPUS increased cortex and corpus callosum levels of myelin basic protein, a protein marker for mature oligodendrocytes, and neural/glial antigen 2, a protein marker for oligodendrocyte precursor cells, relative to levels in the cuprizone + sham animals. These results of this exploratory study suggest that future comprehensive time-related studies with LIPUS on brain chemistry and behavior related to neuropsychiatric disorders are warranted. Exploratory Study on Neurochemical Effects of Low Intensity Pulsed Ultrasound in Brains of Mice. Upper part of figure: LIPUS device and in-vitro cell experimental set-up. The center image is the LIPUS generating box; the image in the upper left shows the cell experiment set-up; the image in the upper right shows a zoomed-in sketch for the cell experiment; the image in the lower left shows the set-up of repetitive restraint stress (RRS) with a mouse; the image in the lower middle shows the set-up of LIPUS treatment of a mouse; the image in the lower right shows a zoomed-in sketch for the LIPUS treatment of a mouse.

Targeting location relates to treatment response in active but not sham rTMS stimulation

Background:

Precise targeting of brain functional networks is believed critical for treatment efficacy of rTMS (repetitive pulse transcranial magnetic stimulation) in treatment resistant major depression.

Objective:

To use imaging data from a “failed” clinical trial of rTMS in Veterans to test whether treatment response was associated with rTMS coil location in active but not sham stimulation, and compare fMRI functional connectivity between those stimulation locations.

Methods:

An imaging substudy of 49 Veterans (mean age, 56 years; range, 27e78 years; 39 male) from a randomized, sham-controlled, double-blinded clinical trial of rTMS treatment, grouping participants by clinical response, followed by group comparisons of treatment locations identified by individualized fiducial markers on structural MRI and resting state fMRI derived networks.

Results:

The average stimulation location for responders versus nonresponders differed in the active but not in the sham condition (P = .02). The average responder location derived from the active condition showed significant negative functional connectivity with the subgenual cingulate (P < .001) while the nonresponder location did not (P = .17), a finding replicated in independent cohorts of 84 depressed and 35 neurotypical participants. The responder and nonresponder stimulation locations evoked different seed based networks (FDR corrected clusters, all P < .03), revealing additional brain regions related to rTMS treatment outcome.

Conclusion:

These results provide evidence from a randomized controlled trial that clinical response to rTMS is related to accuracy in targeting the region within DLPFC that is negatively correlated with subgenual cingulate. These results support the validity of a neuro-functionally informed rTMS therapy target in Veterans.

Application of transcranial magnetic stimulation for major depression: Coil design and neuroanatomical variability considerations

High-frequency repeated transcranial magnetic stimulation (rTMS) as a treatment for major depressive disorder (MDD) has received FDA clearance for both the figure-of-8 coil (figure-8 coil) and the H1 coil. The FDA-cleared MDD protocols for both coils include high frequency (10-18 Hz) stimulation targeting the dorsolateral prefrontal cortex (dlPFC) at an intensity that is 120% of the right-hand resting motor threshold. Despite these similar parameters, the two coils generate distinct electrical fields (e-fields) which result in differences in the cortical stimulation they produce. Due to the differences in coil designs, the H1 coil induces a stimulation e-field that is broader and deeper than the one induced by the figure-8 coil. In this paper we review theoretical and clinical implications of these differences between the two coils and compare evidence of their safety and efficacy in treating MDD. We present the design principles of the coils, the challenges of identifying, finding, and stimulating the optimal brain target of each individual (both from functional and connectivity perspectives), and the possible implication of stimulating outside that target. There is only one study that performed a direct comparison between clinical effectiveness of the two coils, using the standard FDA-approved protocols in MDD patients. This study indicated clinical superiority of the H1 coil but did not measure long-term effects. Post-marketing data suggest that both coils have a similar safety profile in clinical practice, whereas effect size comparisons of the two respective FDA pivotal trials suggests that the H1 coil may have an advantage in efficacy. We conclude that further head-to-head experiments are needed, especially ones that will compare long-term effects and usage of similar temporal stimulation parameters and similar number of pulses.

Oxolipidomics profile in major depressive disorder: Comparing remitters and non-remitters to repetitive transcranial magnetic stimulation treatment

BACKGROUND

Repetitive Transcranial Magnetic Stimulation [rTMS] is increasingly being used to treat Major Depressive Disorder [MDD]. Given that not all patients respond to rTMS, it would be clinically useful to have reliable biomarkers that predict treatment response. Oxidized phosphatidylcholine [OxPC] and some oxylipins are important plasma biomarkers of oxidative stress and inflammation. Not only is depression associated with oxidative stress, but rTMS has been shown to have anti-oxidative effects.

OBJECTIVES

To investigate whether plasma oxolipidomics profiles could predict treatment response in patients with treatment resistant MDD.

METHODS

Fourty-eight patients undergoing rTMS treatment for MDD were recruited along with nine healthy control subjects. Plasma OxPCs and oxylipins were extracted and analyzed through high performance liquid chromatography coupled with mass spectrometry. Patients with a Hamilton Depression Rating Scale score [Ham-D] ≤7 post-treatment were defined as having entered remission.

RESULTS

Fifty-seven OxPC and 32 oxylipin species were identified in our subjects. MDD patients who entered remission following rTMS had significantly higher pre-rTMS levels of total and fragmented OxPCs compared to non-remitters and controls [one-way ANOVA, p<0.05]. However, no significant changes in OxPC levels were found as a result of rTMS, regardless of treatment response [p>0.05]. No differences in plasma oxylipins were found between remitters and non-remitters at baseline.

CONCLUSION

Certain categories of OxPCs may be useful predictive biomarkers for response to rTMS treatment in MDD. Given that elevated oxidized lipids may indicate higher levels of oxidative stress and inflammation in the brain, patients with this phenotype of depression may be more receptive to rTMS treatment.

Repetitive transcranial magnetic stimulation treatment for peripartum depression: systematic review & meta-analysis

Background

Peripartum depression is a common disorder with very high potential hazards for both the patients and their babies. The typical treatment options include antidepressants and electroconvulsive therapy. However, these treatments do not ensure the safety of the fetus. Recently, repetitive transcranial magnetic stimulation has emerged as a promising treatment for neuropathies as well as depression. Nevertheless, many studies excluded pregnant women. This systematic review was conducted to confirm whether repetitive transcranial magnetic stimulation was a suitable treatment option for peripartum depression.

Methods

We performed a systematic review that followed the PRISMA guidelines. We searched for studies in the MEDLINE, PsycINFO, EMBASE, and Cochrane library databases published until the end of September 2020. Eleven studies were selected for the systematic review, and five studies were selected for quantitative synthesis. Data analysis was conducted using Comprehensive Meta-Analysis 3 software. The effect size was analyzed using the standardized mean difference, and the 95% confidence interval (CI) was determined by the generic inverse variance estimation method.

Results

The therapeutic effect size of repetitive transcranial magnetic stimulation for peripartum depression was 1.394 (95% CI: 0.944–1.843), and the sensitivity analysis effect size was 1.074 (95% CI: 0.689–1.459), indicating a significant effect. The side effect size of repetitive transcranial magnetic stimulation for peripartum depression was 0.346 (95% CI: 0.214–0.506), a meaningful result. There were no severe side effects to the mothers or fetuses.

Conclusions

From various perspectives, repetitive transcranial magnetic stimulation can be considered an alternative treatment to treat peripartum depression to avoid exposure of fetuses to drugs and the severe side effects of electroconvulsive therapy. Further research is required to increase confidence in the results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03600-3.

A Retrospective Naturalistic Study Comparing the Efficacy of Ketamine and Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression

Depression is a common mental disorder that affects many people worldwide, while a significant proportion of patients remain non-responsive to antidepressant medications. Alternative treatment options such as ketamine therapy and repetitive transcranial magnetic stimulation (rTMS) therapy are offered nowadays. This study aims to describe and compare the acute antidepressive efficacy of both, intramuscular ketamine and rTMS in depression patients seeking help in a naturalistic clinical mental health setting. The clinical records of 24 patients with treatment resistant depression were collected from the clinical base of a real life clinic. Twelve patients were treated with intramuscular ketamine, twice weekly for 8 sessions, and twelve patients were treated with 30 sessions of left dorsolateral prefrontal cortex - intermittent theta-burst stimulation (DLPFC-iTBS). Using three clinical assessments (HDRS, HAM-A, BDI-II), our data reveal that both therapies led to significant improvement in symptoms from pre- to post- treatment, as well as that the two experimental groups did not differ significantly with respect to pre- to post- depressive and anxiety symptoms, indicating that the effect of both experimental groups in our sample was equally effective. Furthermore, our results showed high remission and response rates in both groups, with no statistical differences between the patients of ketamine group and rTMS group in remission and response rates. We show a significant pre- to post- treatment reduction in depressive and anxiety symptoms, with no significant differences between the two experimental groups, indicating that the effect of both therapies was equally effective in our limited sample.

A qualitative study of key stakeholders' perceived risks and benefits of psychiatric electroceutical interventions

Amid a renewed interest in alternatives to psychotherapy and medication to treat depression, there is limited data as to how different stakeholders perceive of the risks and benefits of psychiatric electroceutical interventions (PEIs), including electroconvulsive therapy (ECT) and deep brain stimulation (DBS). To address this gap, we conducted 48 semi-structured interviews, including 16 psychiatrists, 16 persons diagnosed with depression, and 16 members of the general public. To provide a basis of comparison, we asked participants to also compare each modality to front-line therapies for depression and to neurosurgical procedures used for non-psychiatric conditions. Across all stakeholder groups, perceived memory loss was the most frequently mentioned potential risk with ECT. The most discussed benefits across all stakeholder groups were efficacy and quick response. Psychiatrists most often referenced effectiveness when discussing ECT, while patients and the public did so when discussing DBS. Taken as a whole, these data highlight stakeholders' contrasting perspectives on the risks and benefits of electroceuticals.

Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression in Active-Duty Service Members Improves Depressive Symptoms

OBJECTIVES

Current research on the efficacy of repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex as a noninvasive therapy for treatment-resistant depression is largely settled science. However, little is known about its efficacy with active-duty service members (ADSMs) with major depressive disorder. In a retrospective chart review, we examined depressive symptom ratings in ADSMs seeking treatment at the US Army Outpatient Behavioral Health Service Clinic at Eisenhower Army Medical Center, Fort Gordon, Ga.

METHODS

We reviewed 121 consecutive outpatient charts, which yielded 61 ADSMs who completed a minimum of 20 rTMS sessions for refractory depression, and for whom both pretreatment and posttreatment depressive symptom ratings were available. Pre- and post-Patient Health Questionnaire 9 (PHQ-9) scores were subjected to a paired t test, and Reliable Change Indices were calculated to determine both reliable and clinical significance.

RESULTS

Average (SD) pretreatment and posttreatment PHQ-9 scores were 15.8 (6.2) and 12.6 (7.6), respectively. Statistically significant reduction in post-PHQ-9 was demonstrated (P < 0.001), with 69% of patients lowering their ratings and 31% demonstrating reliable change (improvement >5.64). Additionally, 20% demonstrated a reliable change that placed them in the nondysfunctional range (post-PHQ-9 <9.6), demonstrating clinical significance.

CONCLUSIONS

These data confirm a course of standard rTMS to ADSMs with major depression is promising in reducing depressive symptoms. Given that success and completion rates from this clinic are similar to those reported in civilian populations (80%), rTMS may be an adequate additional treatment or augmentation strategy for refractory depression in ADSMs.

Diminished corticomotor excitability in Gulf War Illness related chronic pain symptoms; evidence from TMS study

Chronic diffuse body pain is unequivocally highly prevalent in Veterans who served in the 1990-91 Persian Gulf War and diagnosed with Gulf War Illness (GWI). Diminished motor cortical excitability, as a measurement of increased resting motor threshold (RMT) with transcranial magnetic stimulation (TMS), is known to be associated with chronic pain conditions. This study compared RMT in Veterans with GWI related diffuse body pain including headache, muscle and joint pain with their military counterparts without GWI related diffuse body pain. Single pulse TMS was administered over the left motor cortex, using anatomical scans of each subject to guide the TMS coil, starting at 25% of maximum stimulator output (MSO) and increasing in steps of 2% until a motor response with a 50 µV peak to peak amplitude, defined as the RMT, was evoked at the contralateral flexor pollicis brevis muscle. RMT was then analyzed using Repeated Measures Analysis of Variance (RM-ANOVA). Veterans with GWI related chronic headaches and body pain (N = 20, all males) had a significantly (P < 0.001) higher average RMT (% ± SD) of 77.2% ± 16.7% compared to age and gender matched military controls (N = 20, all males), whose average was 55.6% ± 8.8%. Veterans with GWI related diffuse body pain demonstrated a state of diminished corticomotor excitability, suggesting a maladaptive supraspinal pain modulatory state. The impact of this observed supraspinal functional impairment on other GWI related symptoms and the potential use of TMS in rectifying this abnormality and providing relief for pain and co-morbid symptoms requires further investigation.Trial registration: This study was registered on January 25, 2017, on ClinicalTrials.gov with the identifier: NCT03030794. Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03030794 .

Maintenance treatment of transcranial magnetic stimulation (TMS) for treatment-resistant depression patients responding to acute TMS treatment

A growing body of studies has demonstrated that acute transcranial magnetic stimulation (TMS) therapy for treatment-resistant major depressive disorder (MDD) has achieved significant antidepressant effects and can alleviate other related symptoms. However, MDD has a high relapse rate, and patients with depressive symptoms can relapse weeks or months after acute TMS treatment. The lack of necessary TMS maintenance protocols after completing acute TMS treatment with full remission might be one of the reasons for the high relapse rates in MDD patients. Thus, investigating post-TMS treatment maintenance guidelines is important for decreasing relapse in treatment-resistant depression patients who had initially responded to acute TMS therapy. Therefore, we recommend a scientific approach to decrease relapse in treatment-resistant depression patients who had initially responded to acute TMS treatment.

Transcranial Magnetic Stimulation: A Clinical Primer for Nonexperts

Transcranial magnetic stimulation (TMS) is a safe and effective therapeutic modality for a rapidly expanding range of neuropsychiatric indications. Among psychiatric conditions, it is presently approved by the US Food and Drug Administration for treatment-resistant unipolar major depressive disorder and obsessive-compulsive disorder, 2 highly prevalent conditions with a considerable public health impact. There is also mounting evidence for its clinical utility in numerous other neuropsychiatric conditions. Nonetheless, many mental health providers, as well as primary care and other providers, remain unfamiliar with its clinical use. In this primer, we seek to describe in nontechnical terms how the magnetic field is applied to the brain, the unmet needs that may be remediated with TMS, the present state of evidence for clinical effectiveness, particularly in major depressive disorder, the safety profile of TMS, what patients experience during TMS, and some recent developments that serve to advance the use of this still novel intervention. TMS is poised to assume an important place in the armamentarium of interventions to better serve our patients, especially those with serious, chronic conditions with high rates of resistance to more conventional treatments. Consequently, it is essential that mental health providers gain as adequate a working knowledge of device-based interventions such as TMS as they currently have of psychopharmacological and psychosocial interventions. Among other potential benefits, this information should aid the process of obtaining informed consent from patients who are candidates for these treatments.

Deep Brain Stimulation for Treatment-Resistant Depression: Towards a More Personalized Treatment Approach

Major depressive disorder (MDD) affects approximately 4.4% of the world’s population. One third of MDD patients do not respond to routine psychotherapeutic and pharmacotherapeutic treatment and are said to suffer from treatment-resistant depression (TRD). Deep brain stimulation (DBS) is increasingly being investigated as a treatment modality for TRD. Although early case studies showed promising results of DBS, open-label trials and placebo-controlled studies have reported inconsistent outcomes. This has raised discussion about the correct interpretation of trial results as well as the criteria for patient selection, the choice of stimulation target, and the optimal stimulation parameters. In this narrative review, we summarize recent studies of the effectiveness of DBS in TRD and address the relation between the targeted brain structures and clinical outcomes. Elaborating upon that, we hypothesize that the effectiveness of DBS in TRD can be increased by a more personalized and symptom-based approach. This may be achieved by using resting-state connectivity mapping for neurophysiological subtyping of TRD, by using individualized tractography to help decisions about stimulation target and electrode placement, and by using a more detailed registration of symptomatic improvements during DBS, for instance by using ‘experience sampling’ methods.

Stanford Accelerated Intelligent Neuromodulation Therapy for Treatment-Resistant Depression

OBJECTIVE

New antidepressant treatments are needed that are effective, rapid acting, safe, and tolerable. Intermittent theta-burst stimulation (iTBS) is a noninvasive brain stimulation treatment that has been approved by the U.S. Food and Drug Administration for treatment-resistant depression. Recent methodological advances suggest that the current iTBS protocol might be improved through 1) treating patients with multiple sessions per day at optimally spaced intervals, 2) applying a higher overall pulse dose of stimulation, and 3) precision targeting of the left dorsolateral prefrontal cortex (DLPFC) to subgenual anterior cingulate cortex (sgACC) circuit. The authors examined the feasibility, tolerability, and preliminary efficacy of Stanford Accelerated Intelligent Neuromodulation Therapy (SAINT), an accelerated, high-dose resting-state functional connectivity MRI (fcMRI)-guided iTBS protocol for treatment-resistant depression.

METHODS

Twenty-two participants with treatment-resistant depression received open-label SAINT. fcMRI was used to individually target the region of the left DLPFC most anticorrelated with sgACC in each participant. Fifty iTBS sessions (1,800 pulses per session, 50-minute intersession interval) were delivered as 10 daily sessions over 5 consecutive days at 90% resting motor threshold (adjusted for cortical depth). Neuropsychological testing was conducted before and after SAINT.

RESULTS

One participant withdrew, leaving a sample size of 21. Nineteen of 21 participants (90.5%) met remission criteria (defined as a score <11 on the Montgomery-Åsberg Depression Rating Scale). In the intent-to-treat analysis, 19 of 22 participants (86.4%) met remission criteria. Neuropsychological testing demonstrated no negative cognitive side effects.

CONCLUSIONS

SAINT, an accelerated, high-dose, iTBS protocol with fcMRI-guided targeting, was well tolerated and safe. Double-blinded sham-controlled trials are needed to confirm the remission rate observed in this initial study.

Indirect frontocingulate structural connectivity predicts clinical response to accelerated rTMS in major depressive disorder

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is an established treatment for major depressive disorder (MDD), but its clinical efficacy remains rather modest. One reason for this could be that the propagation of rTMS effects via structural connections from the stimulated area to deeper brain structures (such as the cingulate cortices) is suboptimal.

METHODS

We investigated whether structural connectivity — derived from diffusion MRI data — could serve as a biomarker to predict treatment response. We hypothesized that stronger structural connections between the patient-specific stimulation position in the left dorsolateral prefrontal cortex (dlPFC) and the cingulate cortices would predict better clinical outcomes. We applied accelerated intermittent theta burst stimulation (aiTBS) to the left dlPFC in 40 patients with MDD. We correlated baseline structural connectivity, quantified using various metrics (fractional anisotropy, mean diffusivity, tract density, tract volume and number of tracts), with changes in depression severity scores after aiTBS.

RESULTS

Exploratory results (p < 0.05) showed that structural connectivity between the patient-specific stimulation site and the caudal and posterior parts of the cingulate cortex had predictive potential for clinical response to aiTBS.

LIMITATIONS

We used the diffusion tensor to perform tractography. A main limitation was that multiple fibre directions within voxels could not be resolved, which might have led to missing connections in some patients.

CONCLUSION

Stronger structural frontocingular connections may be of essence to optimally benefit from left dlPFC rTMS treatment in MDD. Even though the results are promising, further investigation with larger numbers of patients, more advanced tractography algorithms and classic daily rTMS treatment paradigms is warranted.

CLINICAL TRIAL REGISTRATION

http://clinicaltrials.gov/show/NCT01832805

A Clinical Program to Implement Repetitive Transcranial Magnetic Stimulation for Depression in the Department of Veterans Affairs

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) uses a device to create magnetic fields that cause electrical current to flow into targeted neurons in the brain. The most common clinical use of rTMS is for the treatment of major depressive disorder (MDD). The annual suicide rate of veterans has been higher than the national average; treating depression with rTMS would likely decrease suicide risk. MDD in many patients can be chronic and reoccurring with medication and psychotherapy providing inadequate relief.

METHODS

A pilot program was created to supply rTMS devices to 35 different sites in the VA nationwide in order to treat treatment-resistant depression.

CONCLUSIONS

At time of analysis more than 950 veterans have started the program and 412 have finished. Nationwide, we have seen the depression scores decline, indicating an improvement in well-being. In addition, there is high patient satisfaction. Collecting data on a national level is a powerful way to examine rTMS efficacy and predictors of response which might be lost on a smaller subset of cases.

New Developments in Non-invasive Brain Stimulation in Chronic Pain

Purpose of Review

The goal of this review is to present a summary of the recent literature of a non-invasive brain stimulation (NIBS) to alleviate pain in people with chronic pain syndromes. This article reviews the current evidence for the use of transcranial direct current (tDCS) and repetitive transcranial magnetic stimulation (rTMS) to improve outcomes in chronic pain. Finally, we introduce the reader to novel stimulation methods that may improve therapeutic outcomes in chronic pain.

Recent Findings

While tDCS is approved for treatment of fibromyalgia in Canada and the European Union, no NIBS method is currently approved for chronic pain in the United States. Increasing sample sizes in randomized clinical trials (RCTs) seems the most efficient way to increase confidence in initial promising results. Trends at funding agencies reveal increased interest and support for NIBS such as recent Requests for Application from the National Institutes of Health. NIBS in conjunction with cognitive behavioral therapy and physical therapy may enhance outcomes in chronic pain. Novel stimulation methods, such as transcranial ultrasound stimulation, await rigorous study in chronic pain.

Distinct Symptom-Specific Treatment Targets for Circuit-Based Neuromodulation

OBJECTIVE

Treatment of different depression symptoms may require different brain stimulation targets with different underlying brain circuits. The authors sought to identify such targets, which could improve the efficacy of therapeutic brain stimulation and facilitate personalized therapy.

METHODS

The authors retrospectively analyzed two independent cohorts of patients who received left prefrontal transcranial magnetic stimulation (TMS) for treatment of depression (discovery sample, N=30; active replication sample, N=81; sham replication sample, N=87). Each patient's TMS site was mapped to underlying brain circuits using functional connectivity MRI from a large connectome database (N=1,000). Circuits associated with improvement in each depression symptom were identified and then clustered based on similarity. The authors tested for reproducibility across data sets and whether symptom-specific targets derived from one data set could predict symptom improvement in the other independent cohort.

RESULTS

The authors identified two distinct circuit targets effective for two discrete clusters of depressive symptoms. Dysphoric symptoms, such as sadness and anhedonia, responded best to stimulation of one circuit, while anxiety and somatic symptoms responded best to stimulation of a different circuit. These circuit maps were reproducible, predicted symptom improvement in independent patient cohorts, and were specific to active compared with sham stimulation. The maps predicted symptom improvement in an exploratory analysis of stimulation sites from 14 clinical TMS trials.

CONCLUSIONS

Distinct clusters of depressive symptoms responded better to different TMS targets across independent retrospective data sets. These symptom-specific targets can be prospectively tested in a randomized clinical trial. This data-driven approach for identifying symptom-specific targets may prove useful for other disorders and facilitate personalized neuromodulation therapy.

Dosing parameters for the effects of high-frequency transcranial magnetic stimulation on smoking cessation: study protocol for a randomized factorial sham-controlled clinical trial

BACKGROUND

Despite the considerable success of comprehensive tobacco control efforts, tobacco use remains one of the greatest preventable causes of death and disease today. Over half of all smokers in the US make quit attempts every year, but over 90% relapse within 12 months, choosing the immediate reinforcement of smoking over the long-term benefits of quitting. Conceptual and empirical evidence supports continued investigation of high frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex in reducing relapse and decreasing cigarette consumption. While this evidence is compelling, an optimal dosing strategy must be determined before a long-term efficacy trial can be conducted. The goal of this study is to determine a dosing strategy for 20 Hz rTMS that will produce the best long-term abstinence outcomes with the fewest undesirable effects.

METHODS

This is a fully crossed, double-blinded, sham-controlled, 3x2x2 randomized factorial study. The three factors are duration (stimulation days: 8, 12, and 16); intensity (900 or 1800 pulses per day); and sham control. Participants (n = 258) will consist of adults (18-65) who are motivated to quit smoking cigarettes and who will be followed for 6 months post-quit. Outcomes include latency to relapse, point prevalence abstinence rates, delay discounting rates, cognitive-behavioral skills acquisition, and multiple measures of potential undesirable effects that impact participant compliance.

DISCUSSION

This study integrates existing theoretical concepts and methodologies from neuropsychology, behavioral economics, brain stimulation, clinical psychology, and the evidence-based treatment of tobacco dependence in the development of a promising and innovative approach to treat tobacco dependence. This study will establish an optimal dosing regimen for efficacy testing. Findings are expected to have a significant influence on advancing this approach as well as informing future research on clinical approaches that combine rTMS with other evidence-based treatments for tobacco dependence and perhaps other addictions.

TRIAL REGISTRATION

Clinical Trials NCT03865472 (retrospectively registered). The first participant was fully enrolled on November 26, 2018. Registration was posted on March 7, 2019.

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 Randomized Study Comparing the Short-Term Neurocognitive Outcome of Electroconvulsive Therapy Versus Repetitive Transcranial Magnetic Stimulation in the Treatment of Patients With Depression

BACKGROUND

Studies have compared electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS) with regard to their clinical efficacy in the treatment of depression, but only a few studies have addressed their differential impact on cognition. The purpose of this study was to compare the neurocognitive side effects of both treatment modalities.

METHODS

In this comparative study, 40 patients with major depressive disorder referred for ECT were randomly assigned either to a course of 25 sessions of rTMS to the left dorsolateral prefrontal cortex or to a course of ECT ranging from 4 to 8 sessions. The primary outcome measures were the results of a cognitive battery that assessed different aspects of cognitive functioning. The cognitive battery comprised the Digit Span Subtest from the Wechsler Adult Intelligence Scale, the Stroop Color-Word Test-Victoria version, the Color Trails Test Trials 1 and 2, and the Rey-Osterrieth Complex Figure Test.

RESULTS

At the end of treatment, scores on the Digit Span Subtest, the Stroop Color-Word Test-Victoria version, and the Color Trails Test showed statistically significant better results in the rTMS group compared with the ECT group.

CONCLUSIONS

rTMS was well tolerated with less negative impact on cognitive functioning than ECT.

White matter integrity and functional predictors of response to repetitive transcranial magnetic stimulation for posttraumatic stress disorder and major depression

BACKGROUND

Recent evidence suggests that therapeutic repetitive transcranial magnetic stimulation (TMS) is an effective treatment for pharmacoresistant posttraumatic stress disorder (PTSD) and comorbid major depressive disorder (MDD). We recently demonstrated that response to 5 Hz TMS administered to the dorsolateral prefrontal cortex was predicted by functional connectivity of the medial prefrontal (MPFC) and subgenual anterior cingulate cortex (sgACC). This functionally-defined circuit is a novel target for treatment optimization research, however, our limited knowledge of the structural pathways that underlie this functional predisposition is a barrier to target engagement research.

METHODS

To investigate underlying structural elements of our previous functional connectivity findings, we submitted pre-TMS diffusion-weighted imaging data from 20 patients with PTSD and MDD to anatomically constrained tract-based probabilistic tractography (FreeSurfer's TRActs Constrained by UnderLying Anatomy). Averaged pathway fractional anisotropy (FA) was extracted from four frontal white matter tracts: the forceps minor, cingulum, anterior thalamic radiations (ATRs), and uncinate fasciculi. Tract FA statistics were treated as explanatory variables in backward regressions testing the relationship between tract integrity and functional connectivity coefficients from MPFC and sgACC predictors of symptom improvement after TMS.

RESULTS

FA in the ATRs was consistently associated with symptom improvement in PTSD and MDD (Bonferroni-corrected p < .05).

CONCLUSION

We found that structural characteristics of the ATR account for significant variance in individual-level functional predictors of post-TMS improvement. TMS optimization studies should target this circuit either in stand-alone or successive TMS stimulation protocols.

Implementation of intermittent theta burst stimulation compared to conventional repetitive transcranial magnetic stimulation in patients with treatment resistant depression: A cost analysis

Background

Repetitive transcranial magnetic stimulation (rTMS) is an evidence-based treatment for depression that is increasingly implemented in healthcare systems across the world. A new form of rTMS called intermittent theta burst stimulation (iTBS) can be delivered in 3 min and has demonstrated comparable effectiveness to the conventional 37.5 min 10Hz rTMS protocol in patients with depression.

Objectives

To compare the direct treatment costs per course and per remission for iTBS compared to 10Hz rTMS treatment in depression.

Methods

We conducted a cost analysis from a healthcare system perspective using patient-level data from a large randomized non-inferiority trial (THREE-D). Depressed adults 18 to 65 received either 10Hz rTMS or iTBS treatment. Treatment costs were calculated using direct healthcare costs associated with equipment, coils, physician assessments and technician time over the course of treatment. Cost per remission was estimated using the proportion of patients achieving remission following treatment. Deterministic sensitivity analyses and non-parametric bootstrapping was used to estimate uncertainty.

Results

From a healthcare system perspective, the average cost per patient was USD$1,108 (SD 166) for a course of iTBS and $1,844 (SD 304) for 10Hz rTMS, with an incremental net savings of $735 (95% CI 688 to 783). The average cost per remission was $3,695 (SD 552) for iTBS and $6,146 (SD 1,015) for 10Hz rTMS, with an average incremental net savings of $2,451 (95% CI 2,293 to 2,610).

Conclusions

The shorter session durations and treatment capacity increase associated with 3 min iTBS translate into significant cost-savings per patient and per remission when compared to 10Hz rTMS.

Effectiveness of high-frequency left prefrontal repetitive transcranial magnetic stimulation in patients with treatment-resistant depression: A randomized clinical trial of 37.5-minute vs 18.75-minute protocol

Aim

Clinical trials and meta‐analyses have demonstrated the efficacy of high‐frequency repetitive transcranial magnetic stimulation (rTMS) over the left prefrontal cortex in treatment‐resistant depression. The aim of this study was to prospectively evaluate the effectiveness of the conventional 37.5‐minute vs 18.75‐minute rTMS protocol over the left prefrontal cortex in patients with treatment‐resistant depressive episode.

Methods

Thirty patients with treatment‐resistant depression or bipolar disorder depressive episode were randomized 1:1 to either 37.5‐minute or 18.75‐minute rTMS protocol groups. rTMS treatment was applied at 120% resting motor threshold with 10 Hz over the left prefrontal cortex. Treatment sessions were delivered for a total of 3000 pulses/d, 5 days a week, for 4‐6 weeks. Patients received a 75 trains with “4 sec on and 26 sec off” for 37.5 minutes or a 75 trains with “4 sec on and 11 sec off” for 18.75 minutes. Severity of depression was rated with the Quick Inventory of Depressive Symptomatology (QIDS) and Patient Health Questionnaire (PHQ‐9). Remission was defined as a total score of 5 or less on the QIDS. The primary outcome measure was to compare the remission rate between the both groups.

Results

Thirteen of 30 patients (43.3%) showed remission at week 6. There were no significant differences in the remission rate between the conventional 37.5‐ and 18.75‐minute protocol groups (46.7% and 40.0%, respectively). No seizures or treatment‐emergent mania/hypomania were occurred.

Conclusion

These findings suggest that, compared with the conventional one, rTMS with 18.75‐minute protocol might be equally effective and clinically beneficial in saving the treatment session length. Further well‐designed studies are needed.

Effectiveness of rTMS in treatment‐resistant depression: a randomized clinical trial of 37.5‐minute vs 18.75‐minute protocol

Use of Transcranial Magnetic Stimulation for Depression

Transcranial magnetic stimulation (TMS), a research tool with various effects on brain cells, can depolarize cerebral neurons noninvasively. This method offers temporal and spatial resolution and can be combined with other neurocognitive and neuro-experimental techniques. Prefrontal TMS therapy repeated daily for four to six weeks is a neuromodulation technique approved by the US Food and Drug Administration for the treatment of major depressive disorder (MDD) in patients resistant to medications. This technique utilizes electromagnetic induction to excite neuronal cells. Several recent studies have enhanced our understanding of this novel treatment intervention. This report reviews recent studies on the mechanism of action, patient eligibility, effectiveness, and safety of TMS in treating depression.

Electrical stimulation affects neural stem cell fate and function in vitro

Electrical stimulation (ES) has been applied in cell culture system to enhance neural stem cell (NSC) proliferation, neuronal differentiation, migration, and integration. According to the mechanism of its function, ES can be classified into induced electrical (EFs) and electromagnetic fields (EMFs). EFs guide axonal growth and induce directional cell migration, whereas EMFs promote neurogenesis and facilitates NSCs to differentiate into functional neurons. Conductive nanomaterials have been used as functional scaffolds to provide mechanical support and biophysical cues in guiding neural cell growth and differentiation and building complex neural tissue patterns. Nanomaterials may have a combined effect of topographical and electrical cues on NSC migration and differentiation. Electrical cues may promote NSC neurogenesis via specific ion channel activation, such as SCN1α and CACNA1C. To accelerate the future application of ES in preclinical research, we summarized the specific setting, such as current frequency, intensity, and stimulation duration used in various ES devices, as well as the nanomaterials involved, in this review with the possible mechanisms elucidated. This review can be used as a checklist for ES work in stem cell research to enhance the translational process of NSCs in clinical application.

Concomitant medication use and clinical outcome of repetitive Transcranial Magnetic Stimulation (rTMS) treatment of Major Depressive Disorder

BACKGROUND

Repetitive Transcranial Magnetic Stimulation (rTMS) is commonly administered to Major Depressive Disorder (MDD) patients taking psychotropic medications, yet the effects on treatment outcomes remain unknown. We explored how concomitant medication use relates to clinical response to a standard course of rTMS.

METHODS

Medications were tabulated for 181 MDD patients who underwent a six-week rTMS treatment course. All patients received 10 Hz rTMS administered to left dorsolateral prefrontal cortex (DLPFC), with 1 Hz administered to right DLPFC in patients with inadequate response to and/or intolerance of left-sided stimulation. Primary outcomes were change in Inventory of Depressive Symptomatology Self Report (IDS-SR30) total score after 2, 4, and 6 weeks.

RESULTS

Use of benzodiazepines was associated with less improvement at week 2, whereas use of psychostimulants was associated with greater improvement at week 2 and across 6 weeks. These effects were significant controlling for baseline variables including age, overall symptom severity, and severity of anxiety symptoms. Response rates at week 6 were lower in benzodiazepine users versus non-users (16.4% vs. 35.5%, p = 0.008), and higher in psychostimulant users versus non-users (39.2% vs. 22.0%, p = 0.02).

CONCLUSIONS

Concomitant medication use may impact rTMS treatment outcome. While the differences reported here could be considered clinically significant, results were not corrected for multiple comparisons and findings should be replicated before clinicians incorporate the evidence into clinical practice. Prospective, hypothesis-based treatment studies will aid in determining causal relationships between medication treatments and outcome.

Repetitive Transcranial Magnetic Stimulation with Resting-State Network Targeting for Treatment-Resistant Depression in Traumatic Brain Injury: A Randomized, Controlled, Double-Blinded Pilot Study

Repetitive transcranial magnetic stimulation (rTMS) has demonstrated antidepressant efficacy but has limited evidence in depression associated with traumatic brain injury (TBI). Here, we investigate the use of rTMS targeted with individualized resting-state network mapping (RSNM) of dorsal attention network (DAN) and default mode network (DMN) in subjects with treatment-resistant depression associated with concussive or moderate TBI. The planned sample size was 50 with first interim analysis planned at 20, but only 15 were enrolled before the study was terminated for logistical reasons. Subjects were randomized to 20 sessions of bilateral rTMS (4000 left-sided excitatory pulses, 1000 right-sided inhibitory pulses) or sham. Treatment was targeted to the dorsolateral prefrontal cluster with maximal difference between DAN and DMN correlations based on resting-state functional magnetic resonance imaging with individualized RSNM. Mean improvement in the primary outcome, Montgomery-Asberg Depression Rating Scale (MADRS), was 56% ± 14% (n = 9) with active treatment and 27% ± 25% (n = 5) with sham (Cohen's d = 1.43). One subject randomized to sham withdrew before starting treatment. There were no seizures or other significant adverse events. MADRS improvement was inversely correlated with functional connectivity between the right-sided stimulation site and the subgenual anterior cingulate cortex (sgACC; r = -0.68, 95% confidence interval 0.03-0.925). Active treatment led to increased sgACC-DMN connectivity (d = 1.55) and increased sgACC anti-correlation with the left- and right-sided stimulation sites (d = -1.26 and -0.69, respectively). This pilot study provides evidence that RSNM-targeted rTMS is feasible in TBI patients with depression. Given the dearth of existing evidence-based treatments for depression in this patient population, these preliminarily encouraging results indicate that larger controlled trials are warranted.

Time to remission analysis for major depressive disorder after repetitive transcranial magnetic stimulation (rTMS)

We previously examined the efficacy of rTMS for major depressive disorder in an applied clinical practice. Clinical response was related to severity of depression as well as the rTMS instrument utilized suggesting a relationship to instrument or magnetic field parameters and individual factors. The effectiveness of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder was further evaluated using Log-Rank statistics for time to remission outcomes. A follow-up retrospective medical records study was carried out on patients with major depressive disorder undergoing rTMS therapy at AwakeningsKC Clinical Neuroscience Institute (CNI), a suburban tertiary psychiatric clinic. Cox Proportional Hazard with Log-Rank statistics were applied and the time course to clinical remission was evaluated over a 6-week period with respect to age, gender, and depression severity. Clinical response was observed referencing two different rTMS instruments (MagVenture; NeuroStar). Time to remission studies of 247 case reports (N=98 males; N=149 females) showed consistently greater clinically defined remission rates after 6 weeks of rTMS treatment for patients using the MagVenture vs NeuroStar instrument. Patients previously admitted for inpatient psychiatric hospitalization exhibited higher response rates when treated with the MagVenture rTMS unit. Stepwise Cox Proportional Hazards Regression final model of time to remission included rTMS unit, inpatient psychiatric hospitalization and obese body habitus. Response to rTMS in applied clinical practice is related to severity of psychiatric illness and may require consideration of magnetic field parameters of the rTMS unit with respect to individual factors such as sex or body composition.

Repetitive transcranial magnetic stimulation (rTMS) using different TMS instruments for major depressive disorder at a suburban tertiary clinic

Repetitive transcranial magnetic stimulation (rTMS) is a neurostimulatory technique used to modulate orbital frontal corticostriatal (OFC) activity and clinical symptomatology for psychiatric disorders involving OFC dysfunction. We examined the effectiveness of rTMS in the treatment of major depressive disorder in an applied clinical setting (Awakening KC CNI) to assess efficacy and optimize rTMS parameters within clinical practice. A retrospective review of medical records was carried out on patients with major depressive disorder undergoing rTMS therapy at Awakenings KC Clinical Neuroscience Institute (CNI), a suburban tertiary psychiatric clinic. A detailed de-identified data set of clinical outcomes was compiled. Patient Health Questionnaire 9 (PHQ-9) total score, clinical remission rate and week achieved were evaluated over 6 weeks of treatment to assess clinical response referencing two different rTMS instruments (MagVenture; NeuroStar). Our survey included 247 participants from males (N=98) and females (N=149) with average baseline PHQ-9 scores of 21.7±4, classified as severe depression. Clinically rated remission rates of 72% were achieved in 3.1±1.0 weeks and associated with prior history of psychiatric hospitalization, suicide attempts and substance use disorder. Average baseline PHQ- 9 scores decreased significantly over time with proportionately greater remission rates achieved for patients treated using the MagVenture over NeuroStar instrument. rTMS in applied clinical practice is efficacious over a wide range of settings and patients. Clinical response was related to severity of depression symptoms (e.g., prior hospitalization; suicide attempts) validating efficacy in critically ill groups. Clinical response may be impacted by rTMS instrument, magnetic field parameters or individual factors.

Relationship between body mass and clinical response to repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder

Repetitive transcranial magnetic stimulation (rTMS) has been proven to be efficacious in the treatment of Major Depressive Disorder (MDD). We previously examined the effectiveness of rTMS for MDD in an applied clinical setting, AwakeningsKC Clinical Neuroscience Institute (CNI) and found high remission rates for patients diagnosed with MDD following rTMS treatment. An unexpected relationship with body composition and rTMS unit was discovered. This sub-study extends the previous investigation through a focused analysis of the effects of body composition on response to rTMS in the treatment of MDD. We utilized data collected from a retrospective review of medical records for patients diagnosed with MDD undergoing rTMS therapy at AwakeningsKC CNI. Patient Health Questionnaire 9 (PHQ-9) scores, time to remission status and body mass index (BMI) at baseline were considered while referencing two different rTMS instruments (MagVenture; NeuroStar). We found 23 (9%) of 247 participants met criteria for obese status (BMI≥30) with an average baseline PHQ-9 score of 22±4, classified as “severe depression”. Obesity status was differentially impacted by the rTMS instrument used for treatment. Patients with obesity showed a shorter time to remission (mean 2.7±0.27 vs. mean 3.4±0.3 weeks) and proportionately greater remission rate (100% vs. 71%) when treated using the MagVenture relative to the NeuroStar instrument. Clinical response to rTMS therapy for MDD appears to be guided by individual factors including body composition and rTMS parameters such as the unit used for treatment. Further study of these influences could aid in the optimization of clinical response to rTMS.

A Systematic Review of Integrated Functional Near-Infrared Spectroscopy (fNIRS) and Transcranial Magnetic Stimulation (TMS) Studies

Background: The capacity for TMS to elicit neural activity and manipulate cortical excitability has created significant expectation regarding its use in both cognitive and clinical neuroscience. However, the absence of an ability to quantify stimulation effects, particularly outside of the motor cortex, has led clinicians and researchers to pair noninvasive brain stimulation with noninvasive neuroimaging techniques. fNIRS, as an optical and wearable neuroimaging technique, is an ideal candidate for integrated use with TMS. Together, TMS+fNIRS may offer a hybrid alternative to "blind" stimulation to assess NIBS in therapy and research. Objective: In this systematic review, the current body of research into the transient and prolonged effects of TMS on fNIRS-based cortical hemodynamic measures while at rest and during tasks are discussed. Additionally, studies investigating the relation of fNIRS to measures of cortical excitability as produced by TMS-evoked Motor-Evoked-Potential (MEP) are evaluated. The aim of this review is to outline the integrated use of TMS+fNIRS and consolidate findings related to use of fNIRS to monitor changes attributed to TMS and the relationship of fNIRS to cortical excitability itself. Methods: Key terms were searched in PubMed and Web-of-Science to identify studies investigating the use of both fNIRS and TMS. Works from Google-Scholar and referenced works in identified papers were also assessed for relevance. All published experimental studies using both fNIRS and TMS techniques in the study methodology were included. Results: A combined literature search of neuroimaging and neurostimulation studies identified 53 papers detailing the joint use of fNIRS and TMS. 22/53 investigated the immediate effects of TMS at rest in the DLPFC and M1 as measured by fNIRS. 21/22 studies reported a significant effect in [HbO] for 40/54 stimulation conditions with 14 resulting an increase and 26 in a decrease. While 15/22 studies also reported [HbR], only 5/37 conditions were significant. Task effects of fNIRS+TMS were detailed in 16 studies, including 10 with clinical populations. Most studies only reported significant changes in [HbO] related measures. Studies comparing fNIRS to changes in MEP-measured cortical excitability suggest that fNIRS measures may be spatially more diffuse but share similar traits. Conclusion: This review summarizes the progress in the development of this emerging hybrid neuroimaging & neurostimulation methodology and its applications. Despite encouraging progress and novel applications, a lack of replicated works, along with highly disparate methodological approaches, highlight the need for further controlled studies. Interpretation of current research directions, technical challenges of TMS+fNIRS, and recommendations regarding future works are discussed.

Change in drawing placement: A measure of change in mood state reflective of hemispheric lateralization of emotion

The Valence Hypothesis of cerebral lateralization of emotion suggests greater right hemisphere activation during negative mood and greater left hemisphere activation during positive mood. This can manifest as visual field attentional bias. Here, study participants completed an assessment of current mood state (PANAS) and made a drawing (Drawing 1). To induce positive or negative mood, participants played a game; then, the winner read a script depicting a positive interpersonal interaction and the loser read a script depicting a negative interpersonal interaction. Participants then drew a second picture (Drawing 2) and completed the PANAS. We hypothesized that the game outcome would change current mood state and hemispheric activation, which would be reflected in drawing placement. The placement of Drawing 2 moved right for winners and left for losers. Winners experienced a greater increase in positive affect from Time 1 to Time 2 than losers and had decreased negative affect from Time 1. Losers had decreased positive affect from Time 1 and had a greater increase in negative affect from Time 1 to Time 2 than winners. Our results suggest that change in current mood state may be objectively observed by evaluating hemispatial bias reflective of brain hemispheric activation with drawings.

Neurophysiological markers of network dysfunction in neurodegenerative diseases

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

Update on treatments for nonmotor symptoms of Parkinson's disease-an evidence-based medicine review

OBJECTIVE

To update evidence-based medicine recommendations for treating nonmotor symptoms in Parkinson's disease (PD).

BACKGROUND

The International Parkinson and Movement Disorder Society Evidence-Based Medicine Committee's recommendations for treatments of PD were first published in 2002, updated in 2011, and now updated again through December 31, 2016.

METHODS

Level I studies testing pharmacological, surgical, or nonpharmacological interventions for the treatment of nonmotor symptoms in PD were reviewed. Criteria for inclusion and quality scoring were as previously reported. The disorders covered were a range of neuropsychiatric symptoms, autonomic dysfunction, disorders of sleep and wakefulness, pain, fatigue, impaired olfaction, and ophthalmologic dysfunction. Clinical efficacy, implications for clinical practice, and safety conclusions are reported.

RESULTS

A total of 37 new studies qualified for review. There were no randomized controlled trials that met inclusion criteria for the treatment of anxiety disorders, rapid eye movement sleep behavior disorder, excessive sweating, impaired olfaction, or ophthalmologic dysfunction. We identified clinically useful or possibly useful interventions for the treatment of depression, apathy, impulse control and related disorders, dementia, psychosis, insomnia, daytime sleepiness, drooling, orthostatic hypotension, gastrointestinal dysfunction, urinary dysfunction, erectile dysfunction, fatigue, and pain. There were no clinically useful interventions identified to treat non-dementia-level cognitive impairment.

CONCLUSIONS

The evidence base for treating a range of nonmotor symptoms in PD has grown substantially in recent years. However, treatment options overall remain limited given the high prevalence and adverse impact of these disorders, so the development and testing of new treatments for nonmotor symptoms in PD remains a top priority. © 2019 International Parkinson and Movement Disorder Society.

Anti-Suicidal Efficacy of Repetitive Transcranial Magnetic Stimulation in Depressive Patients: A Retrospective Analysis of a Large Sample

Background: Suicide is a major public health problem. About 90% of suicide victims have one or more major psychiatric disorder, with a reported 20-fold increased risk for suicide in patients with affective disorders in comparison with healthy subjects. Repetitive transcranial magnetic stimulation (rTMS) has been established as an effective alternative or adjunctive treatment option for patients with depressive disorders, but little is known about its effects on suicide risk. Objective: For the assessment of the effectiveness of rTMS on suicidal ideation and behaviors, we performed a retrospective analysis of a large sample of patients with depressive disorders, who were treated with rTMS. Methods: We analyzed the records of 711 TMS in- and out-patients with depressive affective disorders in a tertiary referral hospital between 2002 and 2017. Out of these patients we were able to collect Hamilton depression rating scale (HAMD) data of 332 patients (180 females, 152 males; age range 20 to 79 years; mean age 47.3 ± 12.3) for which we analyzed the change of suicidal ideation by using item 3 (suicidality) of HAMD. Results: Out of all 711 patients treated with rTMS for their depression, one patient (0.1%) committed suicide during the TMS treatment. In the statistical analysis of the subsample with 332 patients there was an overall amelioration of depressive symptoms accompanied by a significant decrease in the suicidality item with a medium effect size. Decrease in suicidality was not inferior to changes in other items as indicated by effect sizes. Forty-seven percent of patients showed an amelioration in suicidality, 41.3% of patients did not show a change in their suicidality's scores, and 11.7% of patients showed an increase in suicidality's scores from baseline to final rating. Correlation of item 3 (suicidality) and item 7 (drive) demonstrated a significant positive association, revealing improved drive with a parallel decreased suicidality. Conclusion: Based on the proposed data, there is no evidence that rTMS increases the risk for suicide during the course of the treatment. Conversely, rTMS tends to reduce suicidal ideation. Our findings call for further rTMS controlled studies using large sample sizes and specific suicidality assessment measures to obtain more conclusive results.

A Critical Review and Synthesis of Clinical and Neurocognitive Effects of Noninvasive Neuromodulation Antidepressant Therapies

There is a plethora of current and emerging antidepressant therapies in the psychiatric armamentarium for the treatment of major depressive disorder. Noninvasive neuromodulation therapies are one such therapeutic category; they typically involve the transcranial application of electrical or magnetic stimulation to modulate cortical and subcortical brain activity. Although electroconvulsive therapy (ECT) has been used since the 1930s, with the prevalence of major depressive disorder and treatment-resistant depression (TRD), the past three decades have seen a proliferation of noninvasive neuromodulation antidepressant therapeutic development. The purpose of this critical review was to synthesize information regarding the clinical effects, neurocognitive effects, and possible mechanisms of action of noninvasive neuromodulation therapies, including ECT, transcranial magnetic stimulation, magnetic seizure therapy, and transcranial direct current stimulation. Considerable research has provided substantial information regarding their antidepressant and neurocognitive effects, but their mechanisms of action remain unknown. Although the four therapies vary in how they modulate neurocircuitry and their resultant antidepressant and neurocognitive effects, they are nonetheless useful for patients with acute and chronic major depressive disorder and TRD. Continued research is warranted to inform dosimetry, algorithm for administration, and integration among the noninvasive neuromodulation therapies and with other antidepressant strategies to continue to maximize their safety and antidepressant benefit.

Deep brain stimulation targets for treating depression

Deep brain stimulation (DBS) is a new therapeutic approach for treatment-resistant depression (TRD). There is a preliminary evidence of the efficacy and safety of DBS for TRD in the subgenual anterior cingulate cortex, the ventral capsule/ventral striatum, the nucleus accumbens, the lateral habenula, the inferior thalamic peduncle, the medial forebrain bundle, and the bed nucleus of the stria terminalis. Optimal stimulation targets, however, have not yet been determined. Here we provide updated knowledge substantiating the suitability of each of the current and potential future DBS targets for treating depression. In this review, we discuss the future outlook for DBS treatment of depression in light of the fact that antidepressant effects of DBS can be achieved using different targets.

Rapid acquisition of dynamic control over DLPFC using real-time fMRI feedback

It has been postulated that gaining control over activity in the dorsolateral prefrontal cortex (DLPFC), a key region of the working memory brain network, may be beneficial for cognitive performance and treatment of certain psychiatric disorders. Several studies have reported that, with neurofeedback training, subjects can learn to increase DLPFC activity. However, improvement of dynamic control in terms of switching between low and high activity in DLPFC brain states may potentially constitute more effective self-regulation. Here, we report on feasibility of obtaining dynamic control over DLPFC, meaning the ability to both in- and decrease activity at will, within a single functional MRI scan session. Two groups of healthy volunteers (N = 24) were asked to increase and decrease activity in the left DLPFC as often as possible during fMRI scans (at 7 Tesla), while receiving real-time visual feedback. The experimental group practiced with real-time feedback, whereas the control group received sham feedback. The experimental group significantly increased the speed of intentionally alternating DLPFC activity, while performance of the control group did not change. Analysis of the characteristics of the BOLD signal during successful trials revealed that training with neurofeedback predominantly reduced the time for the DLPFC to return to baseline after activation. These results provide a preliminary indication that people may be able to learn to dynamically down-regulate the level of physiological activity in the DLPFC, and may have implications for psychiatric disorders where DLPFC plays a role.

Focal application of accelerated iTBS results in global changes in graph measures

Graph analysis was used to study the effects of accelerated intermittent theta burst stimulation (aiTBS) on the brain's network topology in medication‐resistant depressed patients. Anatomical and resting‐state functional MRI (rs‐fMRI) was recorded at baseline and after sham and verum stimulation. Depression severity was assessed using the Hamilton Depression Rating Scale (HDRS). Using various graph measures, the different effects of sham and verum aiTBS were calculated. It was also investigated whether changes in graph measures were correlated to clinical responses. Furthermore, by correlating baseline graph measures with the changes in HDRS in terms of percentage, the potential of graph measures as biomarker was studied. Although no differences were observed between the effects of verum and sham stimulation on whole‐brain graph measures and changes in graph measures did not correlate with clinical response, the baseline values of clustering coefficient and global efficiency showed to be predictive of the clinical response to verum aiTBS. Nodal effects were found throughout the whole brain. The distribution of these effects could not be linked to the strength of the functional connectivity between the stimulation site and the node. This study showed that the effects of aiTBS on graph measures distribute beyond the actual stimulation site. However, additional research into the complex interactions between different areas in the brain is necessary to understand the effects of aiTBS in more detail.

Effect of Repetitive Transcranial Magnetic Stimulation on Treatment-Resistant Major Depression in US Veterans: A Randomized Clinical Trial

IMPORTANCE

Treatment-resistant major depression (TRMD) in veterans is a major clinical challenge given the high risk for suicidality in these patients. Repetitive transcranial magnetic stimulation (rTMS) offers the potential for a novel treatment modality for these veterans.

OBJECTIVE

To determine the efficacy of rTMS in the treatment of TRMD in veterans.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, sham-controlled randomized clinical trial was conducted from September 1, 2012, to December 31, 2016, in 9 Veterans Affairs medical centers. A total of 164 veterans with TRD participated.

INTERVENTIONS

Participants were randomized to either left prefrontal rTMS treatment (10 Hz, 120% motor threshold, 4000 pulses/session) or to sham (control) rTMS treatment for up to 30 treatment sessions.

MAIN OUTCOMES AND MEASURES

The primary dependent measure of the intention-to-treat analysis was remission rate (Hamilton Rating Scale for Depression score ≤10, indicating that depression is in remission and not a clinically significant burden), and secondary analyses were conducted on other indices of posttraumatic stress disorder, depression, hopelessness, suicidality, and quality of life.

RESULTS

The 164 participants had a mean (SD) age of 55.2 (12.4) years, 132 (80.5%) were men, and 126 (76.8%) were of white race. Of these, 81 were randomized to receive active rTMS and 83 to receive sham. For the primary analysis of remission, there was no significant effect of treatment (odds ratio, 1.16; 95% CI, 0.59-2.26; P = .67). At the end of the acute treatment phase, 33 of 81 (40.7%) of those in the active treatment group achieved remission of depressive symptoms compared with 31 of 83 (37.4%) of those in the sham treatment group. Overall, 64 of 164 (39.0%) of the participants achieved remission.

CONCLUSIONS AND RELEVANCE

A total of 39.0% of the veterans who participated in this trial experienced clinically significant improvement resulting in remission of depressive symptoms; however, there was no evidence of difference in remission rates between the active and sham treatments. These findings may reflect the importance of close clinical surveillance, rigorous monitoring of concomitant medication, and regular interaction with clinic staff in bringing about significant improvement in this treatment-resistant population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01191333.