scholarly journals Revisiting Hemispheric Asymmetry in Mood Regulation: Implications for rTMS for Major Depressive Disorder

2022 ◽  
Vol 12 (1) ◽  
pp. 112
Author(s):  
Benjamin C. Gibson ◽  
Andrei Vakhtin ◽  
Vincent P. Clark ◽  
Christopher C. Abbott ◽  
Davin K. Quinn

Hemispheric differences in emotional processing have been observed for over half a century, leading to multiple theories classifying differing roles for the right and left hemisphere in emotional processing. Conventional acceptance of these theories has had lasting clinical implications for the treatment of mood disorders. The theory that the left hemisphere is broadly associated with positively valenced emotions, while the right hemisphere is broadly associated with negatively valenced emotions, drove the initial application of repetitive transcranial magnetic stimulation (rTMS) for the treatment of major depressive disorder (MDD). Subsequent rTMS research has led to improved response rates while adhering to the same initial paradigm of administering excitatory rTMS to the left prefrontal cortex (PFC) and inhibitory rTMS to the right PFC. However, accumulating evidence points to greater similarities in emotional regulation between the hemispheres than previously theorized, with potential implications for how rTMS for MDD may be delivered and optimized in the near future. This review will catalog the range of measurement modalities that have been used to explore and describe hemispheric differences, and highlight evidence that updates and advances knowledge of TMS targeting and parameter selection. Future directions for research are proposed that may advance precision medicine and improve efficacy of TMS for MDD.

2010 ◽  
Vol 22 (6) ◽  
pp. 269-279 ◽  
Author(s):  
Alexander Heinzel ◽  
Georg Northoff ◽  
Heinz Boeker ◽  
Peter Boesiger ◽  
Simone Grimm

Heinzel A, Northoff G, Boeker H, Boesiger P, Grimm S. Emotional processing and executive functions in major depressive disorder: dorsal prefrontal activity correlates with performance in the intra–extra dimensional set shift.Objective:Major depressive disorder (MDD) is characterised by predominately negatively valenced emotional symptoms that are often accompanied by cognitive impairments. We posited that cognitive impairments in MDD are related to altered emotional processing in prefrontal cortex.Methods:We compared 20 medication-free patients with MDD and 29 matched healthy controls. Both groups performed an emotional task during functional magnetic resonance imaging (fMRI). Furthermore, they completed the intra–extra dimensional set shift (IED) test probing for cognitive impairments. Then we correlated the results of the IED with the changes in fMRI BOLD signal in MDD patients and healthy subjects.Results:The subcategory of the IED applying extradimensional shift (EDS) showed a divergent performance of the MDD group committing significantly more errors than the control group. Correlating the EDS errors with fMRI signal changes, the healthy subjects showed a positive correlation with the right ventrolateral prefrontal cortex and the right orbitofrontal cortex. MDD subjects, in contrast, showed a positive correlation in right dorsolateral prefrontal cortex (DLPFC) and a negative correlation in the left dorsomedial prefrontal cortex (DMPFC).Conclusion:We hypothesise that the differential correlation in healthy controls and MDD patients may reflect the use of different strategies in their performance. The impaired executive functions, as reflected by altered processing in right DLPFC and left DMPFC, may implicitly influence emotional processing in patients suffering from MDD.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeffrey D. Voigt ◽  
Andrew F. Leuchter ◽  
Linda L. Carpenter

AbstractPatients with major depressive disorder (MDD) may be refractory to or have contraindications that preclude treatment with antidepressant pharmacotherapies. Alternative therapies such as repetitive transcranial magnetic stimulation (rTMS) continue to evolve, and include theta burst stimulation (TBS), which has advantages over conventional rTMS. The aim of this study was to identify and meta-analyze efficacy data from all randomized controlled trials (RCTs) investigating TBS as a treatment for MDD. Published reports of RCTs (January 1, 2010 to October 23, 2020) were identified via systematic searches in computerized databases, followed by review of individual reports for inclusion. Inclusion criteria included primary diagnosis of MDD ≥ 1 week duration of therapy with ≥10 sessions, and treatment with any form of TBS. The Cochrane GRADE methodology and PRISMA criteria were used for evaluation of individual trials. Data from ten RCTs were included, representing 667 patients. Of these, 8 RCTs compared TBS to sham treatment and one compared TBS to standard rTMS (i.e., high frequency stimulation over left dorsolateral prefrontal cortex [HFL]). Quality of evidence assessment yielded high confidence in the finding of TBS being superior to sham on response measured by the Hamilton Depression Rating Scale (HRSD) (RR = 2.4; 95% CI: 1.27 to 4.55; P = 0.007; I2 = 40%). Comparison of HRSD response rates for TBS versus rTMS produced no statistically significant difference (RR = 1.02; 95% CI: 0.85 to 1.23; P = 0.80; I2 = 0%). The incidence of adverse events between TBS and rTMS was not statistically different. The findings of a positive effect of TBS vs. sham, and noninferiority of TBS vs. standard HFL rTMS support the continued development of TBS to treat depression.


2021 ◽  
Vol 11 (6) ◽  
pp. 765
Author(s):  
Jie Tong ◽  
Jie Zhang ◽  
Ying Jin ◽  
Weiqing Liu ◽  
Hao Wang ◽  
...  

Background: Studies have implicated hypofrontality in the pathogenesis of impaired theory of mind (ToM) and executive function (EF) in major depressive disorder (MDD). These symptoms are usually resistant to treatment. Repetitive transcranial magnetic stimulation (rTMS) has been shown to reverse hypofrontality. Moreover, BDNF is an effective biomarker of antidepressant effects, but there have been very few studies on the correlation between BDNF and rTMS. We aimed to evaluate the efficacy of 20 sessions of a 10 Hz unilateral rTMS intervention over the left dorsolateral prefrontal cortex (DLPFC) in improving ToM and EF in patients with MDD and its correlation with BDNF. Methods: A total of 120 MDD patients were enrolled in this randomized, sham-controlled, double-blind trial. Each participant received 20 sessions of rTMS at 10 Hz frequency through the active or the sham coil over 4 weeks. ToM was assessed with the facial emotion identification test (FEIT) and hinting task (HT). EF was assessed with the Wisconsin card sorting test (WCST). BDNF assessments were carried out at baseline and 2-, 4-, 12-, and 24-week follow-ups. Results: The improvement in the ToM (FEIT, HT) in the active rTMS group was significantly different from that in the sham rTMS group (F = 18.09, p < 0.001; F = 5.02, p = 0.026). There were significant differences in the WCST (categories completed, response errors, response perseverative errors, non-response perseverative errors) after logarithmic transformation at different time points in the active rTMS group (F = 14.71, p < 0.001; F = 5.99, p = 0.046; F = 8.90, p = 0.031; F = 2.31, p = 0.048). However, there was no significant difference in log transformed BDNF concentration between the two groups (t = 0.07 to t = 1.29, p > 0.05). BDNF was negatively correlated with WCST categories completed at the 24th week (r = −0.258, p = 0.046). Conclusions: The results show that rTMS may improve the ToM and EF of patients with MDD and there was no significant correlation with serum BDNF concentration. RTMS can not only be used for treatment of patients with MDD but also has a positive effect on ToM and EF.


2011 ◽  
Vol 26 (S2) ◽  
pp. 1144-1144
Author(s):  
Y. Jin ◽  
J. Phillips ◽  
Yueqin Huang ◽  
Steven Heurta

IntroductionEfficacy of conventional repetitive transcranial magnetic stimulation (rTMS) in major depressive disorder (MDD) is limited. The authors report here on an alternative treatment using low energy synchronized TMS (sTMS) at the intrinsic frequency of subjects’ alpha electroencephalogram (EEG).ObjectivesEstablish efficacy and safety profile of sTMS in MDD.Aim(1)Examine the clinical effectiveness of sTMS.(2)Identify adverse effects associated with sTMS.MethodsFifty-two MDD subjects with 17-item Hamilton Depression Rating Scale (HAMD17) scores >17 were enrolled into a randomized, sham controlled, double-blind trial. Current medication remained unchanged during the trial. Depressive symptoms were evaluated by HAMD17 administered weekly.EEGs were recorded at baseline to determine the stimulus frequency and at week 4 to evaluate the physiological effect. sTMS was delivered through three 6000-G cylindrical neodymium magnets synchronously rotating at a rate equal to the subject's intrinsic alpha frequency.ResultsForty-five subjects completed at least 1 week of treatment and were evaluable. Those who received active treatment had superior clinical response to sham (t = 2.54, P = 0.01), where 55.2% in the active treatment group were clinical responders versus 12.5% in sham (X2 = 7.82, P = 0.005). No significant side effects were reported. The clinical improvement was correlated with the degree of EEG improvement (r = .46, P = 0.009).ConclusionsA therapeutic effect in MDD subjects can be achieved through administration of sTMS at the subject's alpha EEG frequency. Because of minimal side effects, this appears to be a safe and effective treatment option.


Author(s):  
Christian Plewnia ◽  
Bettina Brendel ◽  
Tobias Schwippel ◽  
Vanessa Nieratschker ◽  
Thomas Ethofer ◽  
...  

AbstractRepetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (dlPFC) is currently evolving as an effective and safe therapeutic tool in the treatment of major depressive disorder (MDD). However, already established rTMS treatment paradigms are rather time-consuming. With theta burst stimulation (TBS), a patterned form of rTMS, treatment time can be substantially reduced. Pilot studies and a randomized controlled trial (RCT) demonstrate non-inferiority of TBS to 10 Hz rTMS and support a wider use in MDD. Still, data from placebo-controlled multicenter RCTs are lacking. In this placebo-controlled multicenter study, 236 patients with MDD will be randomized to either intermittent TBS (iTBS) to the left and continuous TBS (cTBS) to the right dlPFC or bilateral sham stimulation (1:1 ratio). The treatment will be performed with 80% resting motor threshold intensity over six consecutive weeks (30 sessions). The primary outcome is the treatment response rate (Montgomery-Asberg Depression Rating Scale reduction ≥ 50%). The aim of the study is to confirm the superiority of active bilateral TBS compared to placebo treatment. In two satellite studies, we intend to identify possible MRI-based and (epi-)genetic predictors of responsiveness to TBS therapy. Positive results will support the clinical use of bilateral TBS as an advantageous, efficient, and well-tolerated treatment and pave the way for further individualization of MDD therapy.Trial registration: ClinicalTrials.gov (NCT04392947).


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