Accelerated intermittent theta burst stimulation in major depressive disorder: A systematic review

Individual electric field in cortical white matter is correlated with cognitive improvement in patients with mild cognitive impairment due to Alzheimer's disease after repetitive transcranial magnetic stimulation treatment

BackgroundRepetitive transcranial magnetic stimulation (rTMS) may be effective for Alzheimer's disease (AD) and mild cognitive impairment (MCI); however, the therapeutic efficacy varies significantly, highlighting the need for reliable biomarkers to predict treatment response. While rTMS may activates cortical white matter, the relationship between induced electric field (E-field) in this region and clinical outcomes remains unclear.ObjectiveThis study characterized the E-field in cortical gray matter (EFgm), cortical white matter (EFwm), and region-of-interest (EFROI) in the left dorsolateral prefrontal cortex (DLPFC), and explored their correlations with treatment efficacy in patients with MCI due to AD.MethodsThirty patients with MCI due to AD received 2-week rTMS treatment, with efficacy measured by Auditory Verbal Learning Test (AVLT) and a comprehensive neuropsychological battery. Responders were defined as those with >25% improvement in AVLT-immediate memory. Correlations between regional brain volumes and E-field magnitudes, and the correlations between E-field magnitudes and cognitive improvement, were analyzed. Predictive performance of E-fields for responder classification was evaluated.ResultsPronounced inter-individual variability in magnitudes of EFgm, EFwm and EFROI was observed, partially explained by differences in regional brain volumes of DLPFC targeted area. Treatment responders exhibited significantly higher EFwm magnitude. EFwm positively correlated with AVLT-immediate memory improvement (R2 = 0.37) and predicted responder groups, achieving an area under the curve (AUC) of 0.76.ConclusionsE-field within cortical white matter in the DLPFC correlates with rTMS efficacy and predicts therapeutic response in MCI due to AD. Personalized stimulation protocols incorporating EFwm modeling may optimize treatment parameters.Trial registrationThis study is registered in the Chinese Clinical Trial Registry, number ChiCTR2200062564, date of registration: 2022-08-11.

Lack of early reduction in depression severity predicts treatment non-response with 10 Hz and accelerated theta burst repetitive transcranial magnetic stimulation in treatment-resistant depression

BACKGROUND

Accelerated forms of repetitive transcranial magnetic stimulation (rTMS) are proving to be a safe and effective for treatment-resistant depression (TRD). However, the likelihood of treatment response remains difficult to predict. It is possible to assess inadequate treatment responses early in treatment courses to predict eventual non-response by course end.

METHODS

Post-hoc analysis of prospective clinical trial data was conducted (N = 298). Participants were randomized to one of three treatment arms: daily, unilateral 10 Hz rTMS to the left dorsolateral prefrontal cortex or accelerated bilateral theta-burst stimulation (TBS) at either 80 % or 120 % resting motor threshold stimulation intensity. Clinical response was assessed using the Quick Inventory of Depressive Symptomatology (QIDS). Negative predictive values (NPVs) were generated at week 1 using various QIDS percentage improvement cut-offs to predict eventual non-response.

RESULTS

Participants who showed a ≤ 10 % or ≤ 20 % improvement in QIDS score by week 1 had NPVs ranging from 70.0 % to 97.5 %. Higher NPVs were found for participants randomized to low-intensity accelerated TBS than 10 Hz daily rTMS at week 1.

LIMITATIONS

Accelerated TBS and standard rTMS courses featured relatively short courses of 20 sessions. Analyses predict eventual treatment response using only change in QIDS severity without subscale analysis.

CONCLUSIONS

Early treatment non-response potentially has predictive utility, including in an accelerated TBS protocol. Further studies should determine whether there is clinical benefit in reviewing and/or adapting treatment protocols in view of these findings.

Understanding and treating postpartum depression: a narrative review

Postpartum depression (PPD) is an increasingly prevalent but still poorly characterized disorder. Causal and modulating factors include hormones fluctuations, such as estrogen, progesterone, and allopregnolone, pathways imbalances, such as oxytocin and kynurenine, chronobiological factors, and brain imaging alterations. Treatment may differ from the traditional major depression management, while selective serotonin reuptake inhibitors such as sertraline are commonly used and suggested by guidelines, neurosteroids such as brexanolone and the more convenient zuranolone have been recently approved. Newer neurosteroids such as ganaxolone, valaxanolone, and lysaxanolone are currently under development, but also esketamine and psychedelics are promising potential treatments. Other somatic treatments including brain stimulation techniques and light therapy also showed benefit. PPD is therefore increasingly understood as, at least partially, independent from major depressive disorder. Specific and individualized treatments including pharmacological and non-pharmacological therapies are progressively being introduced in the routine clinical practice.

Intermittent Theta Burst Stimulation Over Cerebellum Facilitates Neurological Recovery in Poststroke Depression via the cAMP/PKA/CREB Pathway

BACKGROUND

Stroke causes somatic dysfunction and psychological disorders, leading to poststroke depression (PSD). This study investigates mood alterations in PSD models via cerebellar intermittent theta burst stimulation (iTBS).

METHODS

PSD animal models were developed using middle cerebral artery occlusion and chronic unpredictable mild stress procedures. PSD models underwent cerebellar iTBS with different pulse numbers. Neurological recovery was evaluated using open-field test, sucrose preference test, forced swimming test, and balance beam test. Golgi and hematoxylin-eosin staining assessed neuronal repair, while quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and Western blotting evaluated effects on BDNF (brain-derived neurotrophic factor), hypothalamic-pituitary-adrenal axis factors, and the cAMP/PKA (protein kinase A)/CREB (cAMP-response element-binding protein) pathway. The study first determined the effects of different intensities of iTBS stimulation on neurological recovery in PSD rats. Second, the effects of iTBS stimulation on the cAMP/PKA/CREB pathway were verified using adenoviral blockade of PKA and CREB at iTBS-1800.

RESULTS

PSD models showed decreased vertical movement, locomotor distance, and sucrose preference and increased immobility time and balance beam test score, which were reversed by iTBS. iTBS increased dendritic length and spine density in Purkinje cells, alleviated neuronal damage in multiple brain regions, and enhanced BDNF synthesis. It also regulated adrenocorticotropic hormone, cortisol, and GR (glucocorticoid receptor) expression, and activated the cAMP/PKA/CREB pathway.

CONCLUSIONS

Cerebellar iTBS improves PSD by activating the cAMP-PKA/CREB pathway, increasing BDNF, and reducing hypothalamic-pituitary-adrenal axis hyperactivity, suggesting potential for human PSD treatment.

Efficacy and safety of accelerated transcranial magnetic stimulation for obsessive-compulsive disorder: A systematic review and meta-analysis

BACKGROUND

Obsessive-Compulsive Disorder (OCD) is a chronic condition with limited treatment options. Standard transcranial magnetic stimulation (TMS) has shown moderate efficacy but requires 6-8 weeks of daily sessions. This review evaluates the efficacy, safety, and feasibility of accelerated TMS (aTMS) protocols for faster treatment response.

METHODS

We systematically searched PubMed, Web of Science, and Embase databases for randomized controlled trials (RCTs) comparing aTMS to placebo or once-daily TMS, conducting a meta-analysis of clinical and tolerability outcomes. The Cochrane Risk of Bias tool and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach were used to evaluate the quality and strength of evidence.

RESULTS

Of 97 screened records, 7 RCTs were included in the review. Six were analyzed quantitatively, showing that aTMS significantly reduced OCD symptoms (SMD 0.63), depressive symptoms (SMD 0.52), and increased response rate (OR 4.28) compared to sham aTMS. Adverse effects were higher in the aTMS group (OR 5.16), though mild, and dropout rates were similar (OR 0.74). At follow-ups, aTMS sustained significant reductions in depressive symptoms (SMD 0.74), but not in OCD or anxiety symptoms. On risk of bias assessment there were "some concerns" for all included studies. GRADE assessment showed moderate certainty for the primary outcome.

CONCLUSION

Accelerated TMS offers promising, faster treatment for OCD and significantly reduces depressive symptoms, though it has no effect on anxiety. Further studies should explore optimal protocols and long-term effects.

Accelerated Theta Burst Transcranial Magnetic Stimulation for Refractory Depression in Autism Spectrum Disorder

PURPOSE

Major depressive disorder (MDD) disproportionately affects those living with autism spectrum disorder (ASD) and is associated with significant impairment and treatment recidivism.

METHODS

We studied the use of accelerated theta burst stimulation (ATBS) for the treatment of refractory MDD in ASD (3 treatments daily x 10 days). This prospective open-label 12-week trial included 10 subjects with a mean age of 21.5 years, randomized to receive unilateral or bilateral stimulation of the dorsolateral prefrontal cortex.

RESULTS

One participant dropped out of the study due to intolerability. In both treatment arms, depressive symptoms, scored on the Hamilton Depression Rating Scale scores, diminished substantially. At 12 weeks post-treatment, full remission was sustained in 5 subjects and partial remission in 3 subjects. Treatment with ATBS, regardless of the site of stimulation, was associated with a significant, substantial, and sustained improvement in depressive symptomatology via the primary outcome measure, the Hamilton Depression Rating Scale. Additional secondary measures, including self-report depression scales, fluid cognition, and sleep quality, also showed significant improvement. No serious adverse events occurred during the study. Mild transient headaches were infrequently reported, which are expected side effects of ATBS.

CONCLUSION

Overall, ATBS treatment was highly effective and well-tolerated in individuals with ASD and co-occurring MDD. The findings support the need for a larger, sham-controlled randomized controlled trial to further evaluate efficacy of ATBS in this population.

Four weeks standard vs. one week accelerated intermittent Theta Burst Stimulation for the treatment of depression - A retrospective analysis

INTRODUCTION

Intermittent Theta Burst Stimulation (iTBS), a specific form of repetitive transcranial magnetic stimulation (rTMS) is increasingly used for treating affective disorders. Accelerated iTBS protocols (aiTBS) with shorter treatment duration may lead to equal but faster response rates compared to standard protocols.

METHODS

Here, we retrospectively analyzed the records of 66 rTMS in- and out-patients with major depressive disorder in a tertiary care hospital between April 2023 and September 2023. All patients received left prefrontal iTBS with 1200 pulses, either one session/workday over 4 weeks (n = 34) or left prefrontal aiTBS on five sessions/workday for one week (n = 32). Depressive symptoms were assessed with the 21-item Hamilton Depression Rating Scale (HAMD-21) and the Major Depression Inventory (MDI) before and at the end of the respective treatment.

RESULTS

With both treatments, iTBS and aiTBS, the severity of depression improved significantly according to HAMD-21 and MDI. Response rates for iTBS were 38 % (HAMD-21) and 35 % (MDI), for aiTBS 19 % (HAMD-21) and 16 % (MDI), respectively. Remission rates showed a similar pattern. Effect sizes for group differences were small to medium. No serious adverse events occurred in any group. Tolerability was lower in aiTBS. Overall satisfaction was low for aiTBS on a qualitative and subjective level.

CONCLUSION

aiTBS with 1200 pulses and five daily sessions lead to amelioration of symptoms within one week. But benefit, satisfaction, tolerability was slightly lower in contrast to four weeks of iTBS. For everyday clinical practice, aiTBS protocols can be considered after weighing up the logistical disadvantages, such as possible longer waiting time for new patients that want to start a therapy with TMS. Future studies should explore the optimal dosage regime (number of sessions per day, number of pulses per session) for fast and effective symptom reduction.

Comparative efficacy of multiple non-invasive brain stimulation to treat major depressive disorder in older patients: A systematic review and network meta-analysis study based on randomized controlled trials

BACKGROUND

Major depressive disorder (MDD) is prevalent among older patients and is frequently associated with cognitive decline and a reduced quality of life. Non-invasive brain stimulation (NIBS) techniques show promise for treating MDD, but their comparative efficacy and safety older populations remain unclear. This study aimed to compare the efficacy and cognitive effects of various NIBS techniques in treating MDD in older patients.

METHODS

We searched the PubMed, EMBASE, Cochrane Library, and Web of Science core databases from inception to March 2024. Seventeen randomized controlled trials (RCTs) were included.

RESULTS

Surfaces under the cumulative ranking curve (SUCRA) values were used to rank the interventions. The SUCRA rankings for the Hamilton Depression Rating Scale (HDRS) outcomes indicated that repetitive transcranial magnetic stimulation (rTMS) (89.0 %) had the highest efficacy, followed by transcranial direct current stimulation (tDCS) (68.7 %). rTMS demonstrated significantly superior efficacy compared with bilateral electroconvulsive therapy (BL ECT) and right unilateral electroconvulsive therapy (RUL ECT). Theta burst stimulation (TBS) had the highest response rate (69.6 %), followed by rTMS (61.8 %). Based on the Mini-Mental State Examination, rTMS (86.4 %) ranked the highest, with RUL ECT showing significantly better outcomes than BL ECT.

CONCLUSION

NIBS, particularly rTMS and TBS, may offer effective treatment options for older patients with MDD. Further research with larger sample sizes and longer follow-up periods is required to validate these findings and inform clinical practice.

Effectiveness of individualized rTMS under sMRI guidance in reducing depressive symptoms and suicidal ideation in adolescents with depressive disorders: an open-label study

Background

Major Depressive Disorder (MDD) is occurring at a progressively younger age, and suicide is now the second leading cause of death among adolescents with MDD. Studies have shown that structural magnetic resonance imaging (sMRI) can improve the positioning accuracy and anti-depressant effects of repetitive transcranial magnetic stimulation (rTMS), thereby reducing suicidal ideation.

Objective

To compare the efficacy of sMRI-guided rTMS combined with pharmacotherapy, surface 5-cm rTMS positioning combined with pharmacotherapy, and pharmacotherapy alone on reducing depressive symptoms and suicidal ideation (SI) in MDD adolescents.

Methods

This was an open-label study of adjustable-dose pharmacotherapy combined with rTMS for the treatment of depressive symptoms and suicidal ideation in MDD adolescents. The three study groups were as follows: sMRI navigation for individualized rTMS coordinates targeting the dorsolateral prefrontal cortex (DLPFC) and in combination with pharmacotherapy for 10 rTMS sessions over two weeks; surface 5-cm positioning for DLPFC in combination with pharmacotherapy for 10 rTMS sessions over two weeks; pharmacotherapy. All patients received only one type of SSRIs anti-depressant. A total of 123 Chinese adolescents aged 13-18 with MDD were enrolled, and psychological parameters were evaluated in the first and second weeks of treatment.

Results

Following treatment, the clinical symptoms improved in all three groups. The sMRI navigation group exhibited significantly more improvement in depressive symptoms and suicidal ideation, without severe adverse reactions.

Conclusion

Ten sessions of rTMS treatment are feasible and effective in improving depressive symptoms and reducing SI in MDD adolescents. The combination of sMRI navigation rTMS and pharmacotherapy was found to yield the best outcomes.

Clinical trial registration

https://www.medicalresearch.org.cn/index, identifier MR-33-24-030536.

Antidepressant response time across intermittent theta burst stimulation regimens and efficacy indicators in adolescents depression: a secondary analysis from a randomized controlled trial

BACKGROUND

Accelerated intermittent theta burst stimulation (aiTBS), which involves the administration of multiple daily sessions of iTBS, represents a novel regimen of repetitive transcranial magnetic stimulation. Studies have suggested that aiTBS may facilitate a fast response among patients with major depressive disorders. However, whether aiTBS can accelerate antidepressant response in adolescents suffering from depression is still unclear. Additionally, the potential indicators associated with antidepressant response in this population are still understudied.

METHODS

Ninety adolescents with depression were recruited and randomly assigned to aiTBS (two 600-pulse sessions of iTBS spaced for 10 min, N = 31), iTBS (one 600-pulse session, N = 29), or sham iTBS (N = 30) for two treatment weeks. Kaplan-Meier analysis was used to estimate the mean time to antidepressant response among the three groups. The analysis of covariance and the multiple logistic regression were applied to identify potential indicators associated with treatment response.

RESULTS

The mean time to antidepressant response was 7.45 weeks (95% CI: 6.19-8.72) in the aiTBS group, 5.62 weeks (95% CI: 4.09-7.16) in the iTBS group, and 5.07 weeks (95% CI: 3.56-6.58) in the sham group, respectively. The log rank test revealed no significant difference in the mean time to antidepressant response among the three groups (χ2 = 4.156, p = 0.125). For the antidepressant response, there were also no significant interactions between iTBS treatment regimens and the baseline characteristics. Notably, participants with higher motor threshold and worse global function at baseline were likely to be associated with early response and final response, respectively, while those who experiencing child-parent separation were associated with both early and final response. In addition, younger participants were more likely to experience recurrence during follow-up.

CONCLUSIONS

aiTBS did not demonstrate an advantage in terms of a fast antidepressant response. However, some pretreatment characteristics might serve as indicators of antidepressant response. This relatively simple application based on pretreatment characteristics seems to be a cost-effective method to identify adolescents who are more likely to develop an early antidepressant response and sustain it.

TRIAL REGISTRATION

This is a secondary analysis of a primary RCT, which was officially registered in the Chinese Clinical Trial Registry at 19/1/2021 with the number of ChiCTR2100042346. https://www.chictr.org.cn/bin/project/edit?pid=66118 .

Theta burst stimulation for depression: a systematic review and network and pairwise meta-analysis

In clinical practice, theta burst stimulation (TBS) presents as a more efficient and potentially more effective therapeutic modality than conventional repetitive transcranial magnetic stimulation (rTMS), as it allows for the delivery of more stimuli in less time and at similar intensities. To date, accelerated treatment plans according to various continuous (cTBS) and intermittent TBS (iTBS) protocols for depression have been proposed. To investigate which of the TBS protocols provided a favorable risk-benefit balance for individuals with depression, this systematic review and random-effects model network meta-analysis was conducted. The study outcomes included response rate (primary), depression symptom improvement, remission rate, all-cause discontinuation rate, incidence of switch to mania, and incidence of headache/discomfort at treatment site. In this meta-analysis, a total of 23 randomized controlled trials (n = 960, mean age = 41.88 years, with 60.78% females) were included. Approximately 69.57% of the trials included individuals with an exclusive diagnosis of major depressive disorder. The following six TBS protocols (target) were evaluated: cTBS (right-dorsolateral prefrontal cortex [R-DLPFC]), cTBS (R-DLPFC) + iTBS (left-DLPFC [L-DLPFC]), iTBS (L-DLPFC), iTBS (L-DLPFC) + iTBS (R-DLPFC), iTBS (left-dorsomedial prefrontal cortex) + iTBS (right-dorsomedial prefrontal cortex), and iTBS (occipital lobe). Compared to sham, cTBS (R-DLPFC) + iTBS (L-DLPFC), iTBS (L-DLPFC), and iTBS (occipital lobe) had a higher response rate (k = 23); cTBS (R-DLPFC) + iTBS (L-DLPFC) and iTBS (L-DLPFC) dominated in the depression symptom improvement (k = 23); and iTBS (L-DLPFC) had a higher remission rate (k = 15). No significant differences were found for all-cause discontinuation rate (k = 17), incidence of switch to mania (k = 7), and incidence of headache/discomfort at treatment site (k = 10) between any TBS protocols and sham. Thus, cTBS (R-DLPFC) + iTBS (L-DLPFC) and iTBS (L-DLPFC) demonstrate favorable risk-benefit balance for the treatment of depression.

Altered resting-state and dynamic functional connectivity of hypothalamic in first-episode depression: A functional magnetic resonance imaging study

The hypothalamus is an important component of the hypothalamic-pituitary-adrenal axis and an important brain region of the limbic system. Twenty-four first depressive episode(FDE) patients and 25 healthy controls were recruited for this study. The hypothalamus was used as a seed to observe the characteristics of resting state and dynamic functional connectivity (FC) changes in FDE patients, and further observed the correlation between the different brain regions and clinical symptoms. The results found that compared with the HC group, the FDE group showed sFC was increased of the left hypothalamus with right superior parietal gyrus and right middle temporal gyrus, and dFC was increased of the left hypothalamus with left inferior occipital gyrus. And sFC was increased of the right hypothalamus with right orbital part of inferior frontal gyrus, right supplementary motor area, and right middle temporal gyrus, and the dFC was also increased of right hypothalamus with right superior parietal gyrus and left middle temporal gyrus. In addition,there was a negative correlation between dFC values of the right hypothalamus with the right superior parietal gyrus and clinical symptoms in the FDE group. This study provides new insights into understanding the altered neuropathological mechanisms of the hypothalamic circuit in FDE.

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.

Association of periodontitis with all-cause and cause-specific mortality among individuals with depression: a population-based study

To detect the association between periodontitis and all-cause as well as cause-specific mortality rates among adults diagnosed with depression. Participants diagnosed with depression were selected from NHANES across three periods (1988-1994; 1999-2004; 2009-2014). Cox proportional hazards and Weibull accelerated failure time (AFT) models were utilized to calculate hazard ratios (HRs), time ratios (TRs), and their 95% confidence intervals (CIs) to evaluate the association between moderate-to-severe periodontitis and all-cause as well as cause-specific mortality among participants with depression. white blood counts and C-reactive protein were used to assess the mediating role of systemic inflammation. Among the 1,189 participants with a median follow-up of 9.25 years, 133 deaths were recorded. After adjusting for multiple variables, moderate-to-severe periodontitis was obvious associated with an increased risk of cancer-related mortality in individuals with depression (Cox: HR 3.22, 95% CI 1.51-6.83, P = 0.002; AFT: TR 0.70, 95% CI 0.52-0.94, P = 0.017). Neither WBC nor CRP significantly mediate the association between periodontitis and cancer-related mortality. The risk of cancer-related mortality rose with the severity of periodontitis (P for trend = 0.021). However, no association was observed between moderate-to-severe periodontitis and other kinds of mortality. Moderate-to-severe periodontitis is linked to an elevated risk of cancer-related mortality among adults diagnosed with depression, with the mortality risk increasing alongside the severity of periodontitis. No significant mediating effect of systemic inflammation was found in this association. These findings highlight the importance of addressing periodontal health in individuals with depression. By uncovering the association between periodontitis and mortality in this population, our study underscores the potential benefits of preventive dental care and periodontal treatment in reducing the risk of cancer-related mortality in individuals with depression.

Dose-Dependent Target Engagement of a Clinical Intermittent Theta Burst Stimulation Protocol: An Interleaved Transcranial Magnetic Stimulation-Functional Magnetic Resonance Imaging Study in Healthy People

BACKGROUND

Intermittent theta burst stimulation (iTBS) of the dorsolateral prefrontal cortex (DLPFC) is widely applied as a therapeutic intervention in mental health; however, the understanding of its mechanisms is still incomplete. Prior magnetic resonance imaging (MRI) studies have mainly used offline iTBS or short sequences in concurrent transcranial magnetic stimulation (TMS)-functional MRI (fMRI). This study investigated a full 600-stimuli iTBS protocol using interleaved TMS-fMRI in comparison with 2 control conditions in healthy subjects.

METHODS

In a crossover design, 18 participants underwent 3 sessions of interleaved iTBS-fMRI: 1) the left DLPFC at 40% resting motor threshold (rMT) intensity, 2) the left DLPFC at 80% rMT intensity, and 3) the left primary motor cortex (M1) at 80% rMT intensity. We compared immediate blood oxygen level-dependent (BOLD) responses during interleaved iTBS-fMRI across these conditions including correlations between individual fMRI BOLD activation and iTBS-induced electric field strength at the target sites.

RESULTS

Whole-brain analysis showed increased activation in several regions following iTBS. Specifically, the left DLPFC, as well as the bilateral M1, anterior cingulate cortex, and insula, showed increased activation during 80% rMT left DLPFC stimulation. Increased BOLD activity in the left DLPFC was observed with neither 40% rMT left DLPFC stimulation nor left M1 80% rMT iTBS, whereas activation in other regions was found to overlap between conditions. Of note, BOLD activation and electric field intensities were only correlated for M1 stimulation and not for the DLPFC conditions.

CONCLUSIONS

This interleaved TMS-fMRI study showed dosage- and target-specific BOLD activation during a 600-stimuli iTBS protocol in healthy individuals. Future studies may use our approach for investigating target engagement in clinical samples.

Resting-state EEG biomarkers of accelerated intermittent theta burst stimulation treatment for depression: a pilot study

Accelerated intermittent theta burst stimulation (aiTBS) is a novel and effective treatment for drug-resistant depression. While past studies have identified encephalography (EEG) features predicting repetitive transcranial magnetic stimulation (rTMS) outcomes, EEG biomarkers specifically for aiTBS in depression patients have not been explored. In this pilot trial on 5 depression patients undergoing aiTBS, we assessed clinical outcome using the Montgomery-Asberg Depression Rating Scale (MADRS) and collected resting-state EEG pre and post-treatment. All patients showed an improvement in MADRS, with 3 having at least 50% improvement. We found significant correlations between MADRS change and pre-treatment frontal beta power, midline frontal Lempel-Ziv Complexity (LZC) and alpha connectivity. We also observed a trend of increased frontal theta power post-treatment. However, no significant correlations emerged between MADRS change and change in EEG feature post-treatment. This preliminary trial highlights the potential for investigating aiTBS-specific EEG biomarkers, paving the way for larger studies to enhance personalized neurostimulation and predict treatment outcomes in drug-resistant depression patients.

Assessment of noninvasive brain stimulation interventions in Parkinson's disease: a systematic review and network meta-analysis

A network meta-analysis of randomized controlled trials was conducted to compare and rank the effectiveness of various noninvasive brain stimulation (NIBS) for Parkinson's disease (PD). We searched PubMed, Web of Science, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), and Chinese Biomedical Literature Service System (SinoMed) databases from the date of database inception to April 30th, 2024. Two researchers independently screened studies of NIBS treatment in patients with PD based on inclusion and exclusion criteria. Two researchers independently performed data extraction of the included studies using an Excel spreadsheet and assessed the quality of the literature according to the Cochrane Risk of Bias Assessment Tool (RoB2). Network meta-analysis was performed in StataMP 17.0. A total of 28 studies involving 1628 PD patients were included. The results showed that HF-rTMS over the SMA (SMD = - 2.01; 95% CI [- 2.87, - 1.15]), HF-rTMS over the M1 and DLPFC (SMD = - 1.80; 95% CI [- 2.90, - 0.70]), HF-rTMS over the M1 (SMD = - 1.10; 95% CI [- 1.55, - 0.65]), a-tDCS over the DLPFC (SMD = - 1.08; 95% CI [- 1.90, - 0.27]), HF-rTMS over the M1 and PFC (SMD = - 0.92; 95% CI [- 1.71, - 0.14]), LF-rTMS over the M1 (SMD = - 0.72; 95% CI [- 1.17, - 0.28]), and HF-rTMS over the DLPFC (SMD = - 0.70; 95% CI [- 1.21, - 0.19]) were significantly improved motor function compared with sham stimulation. The SUCRA three highest ranked were HF-rTMS over the SMA (95.1%), HF-rTMS over the M1 and DLPFC (89.6%), and HF-rTMS over the M1 (73.0%). In terms of enhanced cognitive function, HF-rTMS over the DLPFC (SMD = 0.80; 95% CI [0.03,1.56]) was significantly better than sham stimulation. The SUCRA three most highly ranked were a-tDCS over the M1 (69.8%), c-tDCS over the DLPFC (66.9%), and iTBS over the DLPFC (65.3%). HF-rTMS over the M1 (SMD = - 1.43; 95% CI [- 2.26, - 0.61]) and HF-rTMS over the DLPFC (SMD = - 0.79; 95% CI [- 1.45, - 0.12)]) significantly improved depression. The SUCRA three highest ranked were HF-rTMS over the M1 (94.1%), LF-rTMS over the M1 (71.8%), and HF-rTMS over the DLPFC (69.0%). HF-rTMS over the SMA may be the best option for improving motor symptoms in PD patients. a-tDCS and HF-rTMS over the M1 may be the NIBS with the most significant effects on cognition and depression, separately.Trial registration: International Prospective Register of Systematic Review, PROSPERO (CRD42023456088).

Single session of intermittent theta burst stimulation alters brain activity of patients in vegetative state

BACKGROUND

Non-invasive brain stimulation is considered as a promising technology for treating patients with disorders of consciousness (DOC). Various approaches and protocols have been proposed; however, few of them have shown potential effects on patients with vegetative state (VS). This study aimed to explore the neuro-modulation effects of intermittent theta burst stimulation (iTBS) on the brains of patients with VS and to provide a pilot investigation into its possible role in treating such patients.

METHODS

We conducted a sham-controlled crossover study, a real and a sham session of iTBS were delivered over the left dorsolateral prefrontal cortex of such patients. A measurement of an electroencephalography (EEG) and a behavioral assessment of the Coma Recovery Scale-Revised (CRS-R) were applied to evaluate the modulation effects of iTBS before and after stimulation.

RESULTS

No meaningful changes of CRS-R were found. The iTBS altered the spectrum, complexity and functional connectivity of the patients. The real stimulation induced a trend of decreasing of delta power at T1 and T2 in the frontal region, significant increasing of permutation entropy at the T2 in the left frontal region. In addition, brain functional connectivity, particularly inter-hemispheric connectivity, was strengthened between the electrodes of the frontal region. The sham stimulation, however, did not induce any significant changes of the brain activity.

CONCLUSIONS

One session of iTBS significantly altered the oscillation power, complexity and functional connectivity of brain activity of VS patients. It may be a valuable tool on modulating the brain activities of patients with VS.

Mitochondria of intestinal epithelial cells in depression: Are they at a crossroads of gut-brain communication?

The role of gut dysbiosis in depression is well established. However, recent studies have shown that gut microbiota is regulated by intestinal epithelial cell (IEC) mitochondria, which has yet to receive much attention. This review summarizes the recent developments about the critical role of IEC mitochondria in actively maintaining gut microbiota, intestinal metabolism, and immune homeostasis. We propose that IEC mitochondrial dysfunction alters gut microbiota composition, participates in cell fate, mediates oxidative stress, activates the peripheral immune system, causes peripheral inflammation, and transmits peripheral signals through the vagus and enteric nervous systems. These pathological alterations lead to brain inflammation, disruption of the blood-brain barrier, activation of the hypothalamic-pituitary-adrenal axis, activation of microglia and astrocytes, induction of neuronal loss, and ultimately depression. Furthermore, we highlight the prospect of treating depression through the mitochondria of IECs. These new findings suggest that the mitochondria of IECs may be a newly found important factor in the pathogenesis of depression and represent a potential new strategy for treating depression.