Accelerated Repetitive Transcranial Magnetic Stimulation to Treat Major Depression: The Past, Present, and Future

Repetitive Transcranial Magnetic Stimulation for the Treatment of Depression in a Real-World Setting: Findings from a Cohort Study

BACKGROUND/OBJECTIVES

In the past two decades, significant advancements in neuromodulation techniques have occurred, such as transcranial magnetic stimulation (TMS) for treatment-resistant depression (TRD). According to the assumption that repeated stimulation within a condensed timeframe can yield sustained efficacy, an accelerated protocol may be more effective in reducing time to response. With those premises, this study aimed to evaluate a sample of TRD patients treated with standard repetitive TMS (rTMS) and accelerated rTMS (arTMS).

METHODS

Nine subjects were treated with standard rTMS and 19 with arTMS. Psychometric assessment was made at the baseline and one week, one month, and three months after the treatment. A linear mixed-effect regression was performed along with other appropriate statistical analyses.

RESULTS

A significant improvement over time was observed for both depressive and cognitive symptoms. Moreover, considering the reduction in the Montgomery-Asberg Depression Rating Scale scores, a better treatment response was observed in subjects treated with arTMS (p < 0.05).

CONCLUSIONS

Our findings showed a significant difference between the two protocols in terms of clinical response. Although further studies are needed to confirm the superiority of arTMS, the better cost-effectiveness of this technique should be considered.

Differential analgesic effects of high-frequency or accelerated intermittent theta burst stimulation of M1 on experimental tonic pain: Correlations with cortical activity changes assessed by TMS-EEG

Accelerated intermittent theta burst stimulation (AiTBS) has attracted much attention in the past few years as a new form of brain stimulation paradigm. However, it is unclear the relative efficacy of AiTBS on cortical excitability compared to conventional high-frequency rTMS. Using concurrent TMS and electroencephalogram (TMS-EEG), this study systematically compared the efficacy on cortical excitability and a typical clinical application (i.e. pain), between AiTBS with different intersession interval (ISIs) and 10-Hz rTMS. Participants received 10-Hz rTMS, AiTBS-15 (3 iTBS sessions with a 15-min ISI), AiTBS-50 (3 iTBS sessions with a 50-min ISI), or Sham stimulation over the primary motor cortex on four separate days. All four protocols included a total of 1800 pulses but with different session durations (10-Hz rTMS ​= ​18, AiTBS-15 ​= ​40, and AiTBS-50 ​= ​110 ​min). AiTBS-50 and 10-Hz rTMS were more effective in pain reduction compared to AiTBS-15. Using single-pulse TMS-induced oscillation, our data revealed low gamma oscillation as a shared cortical excitability change across all three active rTMS protocols but demonstrated completely opposite directions. Changes in low gamma oscillation were further associated with changes in pain perception across the three active conditions. In contrast, a distinct pattern of TMS-evoked potentials (TEPs) was revealed, with 10-Hz rTMS decreasing inhibitory N100 amplitude and AiTBS-15 reducing excitatory P60 amplitude. These changes in TEPs were also covarying with low gamma power changes. Sham stimulation indicated no significant effect on either cortical excitability or pain perception. These results are relevant only for provoked experimental pain, without being predictive for chronic pain, and revealed a change in low gamma oscillation, particularly around the very particular frequency of 40 ​Hz, shared between AiTBS and high-frequency rTMS. Conversely, cortical excitability (balance between excitation and inhibition) assessed by TEP recording was modulated differently by AiTBS and high-frequency rTMS paradigms.

Chronometric TMS-fMRI of personalized left dorsolateral prefrontal target reveals state-dependency of subgenual anterior cingulate cortex effects

Transcranial magnetic stimulation (TMS) applied to a left dorsolateral prefrontal cortex (DLPFC) area with a specific connectivity profile to the subgenual anterior cingulate cortex (sgACC) has emerged as a highly effective non-invasive treatment option for depression. However, antidepressant outcomes demonstrate significant variability among therapy plans and individuals. One overlooked contributing factor is the individual brain state at the time of treatment. In this study we used interleaved TMS-fMRI to investigate the influence of brain state on acute TMS effects, both locally and remotely. TMS was performed during rest and during different phases of cognitive task processing. Twenty healthy participants were included in this study. In the first session, imaging data for TMS targeting were acquired, allowing for identification of individualized targets in the left DLPFC based on highest anti-correlation with the sgACC. The second session involved chronometric interleaved TMS-fMRI measurements, with 10 Hz triplets of TMS administered during rest and at distinct timings during an N-back task. Consistent with prior findings, interleaved TMS-fMRI revealed significant BOLD activation changes in the targeted network. The precise timing of TMS relative to the cognitive states during the task demonstrated distinct BOLD response in clinically relevant brain regions, including the sgACC. Employing a standardized timing approach for TMS using a task revealed more consistent modulation of the sgACC at the group level compared to stimulation during rest. In conclusion, our findings strongly suggest that acute local and remote effects of TMS are influenced by brain state during stimulation. This study establishes a basis for considering brain state as a significant factor in designing treatment protocols, possibly improving TMS treatment outcomes.

Status and trends of TMS research in depressive disorder: a bibliometric and visual analysis

Background

Depression is a chronic psychiatric condition that places significant burdens on individuals, families, and societies. The rapid evolution of non-invasive brain stimulation techniques has facilitated the extensive clinical use of Transcranial Magnetic Stimulation (TMS) for depression treatment. In light of the substantial recent increase in related research, this study aims to employ bibliometric methods to systematically review the global research status and trends of TMS in depression, providing a reference and guiding future studies in this field.

Methods

We retrieved literature on TMS and depression published between 1999 and 2023 from the Science Citation Index Expanded (SCIE) and Social Science Citation Index (SSCI) databases within the Web of Science Core Collection (WoSCC). Bibliometric analysis was performed using VOSviewer and CiteSpace software to analyze data on countries, institutions, authors, journals, keywords, citations, and to generate visual maps.

Results

A total of 5,046 publications were extracted covering the period from 1999 to 2023 in the field of TMS and depression. The publication output exhibited an overall exponential growth trend. These articles were published across 804 different journals, BRAIN STIMULATION is the platform that receives the most articles in this area. The literature involved contributions from over 16,000 authors affiliated with 4,573 institutions across 77 countries. The United States contributed the largest number of publications, with the University of Toronto and Daskalakis ZJ leading as the most prolific institution and author, respectively. Keywords such as "Default Mode Network," "Functional Connectivity," and "Theta Burst" have recently garnered significant attention. Research in this field primarily focuses on TMS stimulation patterns, their therapeutic efficacy and safety, brain region and network mechanisms under combined brain imaging technologies, and the modulation effects of TMS on brain-derived neurotrophic factor (BDNF) and neurotransmitter levels.

Conclusion

In recent years, TMS therapy has demonstrated extensive potential applications and significant implications for the treatment of depression. Research in the field of TMS for depression has achieved notable progress. Particularly, the development of novel TMS stimulation patterns and the integration of TMS therapy with multimodal techniques and machine learning algorithms for precision treatment and investigation of brain network mechanisms have emerged as current research hotspots.

A New Angle on Transcranial Magnetic Stimulation Coil Orientation: A Targeted Narrative Review

Transcranial magnetic stimulation (TMS) is used to treat several neuropsychiatric disorders including depression, where it is effective in approximately one half of patients for whom pharmacological approaches have failed. Treatment response is related to stimulation parameters such as the stimulation frequency, pattern, intensity, location, total number of pulses and sessions applied, and target brain network engagement. One critical but underexplored component of the stimulation procedure is the orientation or yaw angle of the commonly used figure-of-eight TMS coil, which is known to impact neuronal response to TMS. However, coil orientation has remained largely unchanged since TMS was first used to treat depression and continues to be based on motor cortex anatomy, which may not be optimal for the dorsolateral prefrontal cortex treatment site. In this targeted narrative review, we evaluate experimental, clinical, and computational evidence indicating that optimizing coil orientation may improve TMS treatment outcomes. The properties of the electric field induced by TMS, the changes to this field caused by the differing conductivities of head tissues, and the interaction between coil orientation and the underlying cortical anatomy are summarized. We describe evidence that the magnitude and site of cortical activation, surrogate markers of TMS dosing and brain network targeting considered central in clinical response to TMS, are influenced by coil orientation. We suggest that coil orientation should be considered when applying therapeutic TMS and propose several approaches to optimizing this potentially important treatment parameter.

Effectiveness of rTMS and tDCS treatment for chronic TBI symptoms: A systematic review and meta-analysis

INTRODUCTION

Traumatic brain injury (TBI) is a major cause of long-term disability with conventional treatments frequently falling short to restore a good quality-of-life. Non-invasive brain stimulation (NIBS) techniques have shown potential as therapeutic options for neuropsychiatric conditions, including TBI sequelae. This study aims at providing a systematic review and meta-analysis on the effectiveness of repetitive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) on post-TBI symptoms.

METHODS

Fifteen randomized controlled trials (RCTs) on adult TBI patients that examined the effects of multiple treatment sessions of NIBS techniques were selected from five databases. Symptoms were clustered into four categories: depression, anxiety, headache and cognitive dysfunctions. Meta-analysis was performed using correlated and hierarchical effects models.

RESULTS

There were only few and heterogeneous studies with generally small sample sizes. Most studies targeted the dorsolateral prefrontal cortex (dlPFC). Overall, the effects of NIBS were small. However, there was a significant effect for overall symptoms (0.404, p = 0.031). Moreover, subgroup analyses revealed significant overall effects for anxiety (0.195, p = 0.020) and headache (0.354, p = 0.040).

CONCLUSIONS

To date, there is limited evidence supporting the effectiveness of NIBS concerning treatment for TBI sequelae. The observed effect sizes were modest, suggesting subtle improvements rather than drastic changes. While NIBS techniques remain promising for treating neuropsychiatric conditions, larger RCT studies with longer follow-ups, optimized stimulation parameters and standardized methodology are required to establish their efficacy in addressing TBI sequelae.

Real world efficacy and safety of various accelerated deep TMS protocols for major depression

There is growing interest in accelerated rTMS dosing regimens, wherein multiple sessions of rTMS are applied per day. This Phase IV study evaluated the safety, efficacy, and durability of various accelerated Deep TMS protocols used in clinical practice. Data were aggregated from 111 patients with major depressive disorder (MDD) at 4 sites. Patients received one of several accelerated Deep TMS protocols (2x/day, 3x/day, 5x/day, 10x/day). Self-assessment questionnaires (PHQ-9, BDI-II) and clinician-based rating scales (HDRS-21, MADRS) were collected. On average, accelerated TMS led to an 80.2% response and 50.5% remission rate in the first month based on the most rated scale for each patient. There was no significant difference between protocols (Response: 2x/day:89.6%; 3x/day:75%; 5x/day:81%; 10x/day:67.6%). Response occurred after 10 (3x/day), 20 (5x/day), and 31 sessions (10x/day) on average- all of which occur on day 3-4 of treatment. Of patients with longer term follow up, durability was found in 86.7% (n = 30; 60 days) and 92.9% (n = 14; 180 days). The protocols were well-tolerated with no reported serious adverse events. Accelerated Deep TMS protocols are found to be safe, effective therapeutic options for MDD. They offer treatment resistant patients a treatment option with a rapid onset of action and with long durability.

Repetitive transcranial magnetic stimulation in the treatment of middle-aged and elderly major depressive disorder: A randomized controlled trial

BACKGROUND

Studies have reported the use of repetitive transcranial magnetic stimulation (rTMS) in patients with major depressive disorder (MDD). However, most studies focus on antidepressant effect of rTMS, but few on cognitive aspects. The present study aimed to explore the effect of rTMS on BDNF levels and cognitive function in the treatment of middle-aged and elderly MDD.

METHODS

This was a randomized controlled trial. A total of 120 elderly patients with MDD treated in The Second Affiliated Hospital of Xi'an Medical University from January 2021 to January 2023 were selected as research subjects. The patients were randomly divided into control group (n = 60, patients received simple oral treatment with escitalopram and sham rTMS) and study group (n = 60, patients received oral treatment with escitalopram combined with rTMS) according to the random number table method. We compared the clinical efficacy, serum BDNF levels, and cognitive function between the 2 groups.

RESULTS

After treatment, the HAMD-17 score in the study group was lower than that in the control group [13.00 (12.00-16.00) vs 17.00 (15.00-19.00), P < .05], and the RBANS score was higher than that in the control group [166.00 (161.25-171.75) vs 133.00 (130.00-136.75), P < .05]. The total effective rate of the research group was 95.0%, which was higher than the 82.0% of the control group (P < .05). The serum BDNF levels [36.00 (33.00-38.00) vs 30.00 (28.00-32.00), P < .05] and MoCA scores [24.00 (22.00-26.75) vs 23.00 (21.00-25.00), P < .05] of the study group were higher than those of the control group. There were no significant adverse reactions during the treatment of both groups.

CONCLUSIONS

Compared with oral escitalopram alone, repeated transcranial magnetic stimulation in the treatment of middle-aged and elderly patients with major depressive disorder can further improve the efficacy, and can more effectively improve the BDNF level and cognitive function, with ideal safety.