Efficacy and acceptability of non-invasive brain stimulation for the treatment of adult unipolar and bipolar depression: A systematic review and meta-analysis of randomised sham-controlled trials

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.

Cognitive effects of non-surgical brain stimulation for major depressive disorder: protocol for a systematic review and meta-analysis

INTRODUCTION

Non-surgical brain stimulation techniques may be considered as alternative or add-on treatments for patients with major depressive disorder who failed to respond to pharmacological interventions. Electroconvulsive therapy has been shown to be highly effective in reducing depressive symptoms but stakeholders remain concerned about adverse cognitive effects. Repetitive transcranial magnetic stimulation and transcranial direct current stimulation may be associated with more benign adverse effect profiles and may indeed improve certain cognitive functions such as memory and attention. To guide clinical decision-making, we will carry out a systematic review and meta-analysis of the cognitive effects of eight non-surgical brain stimulation techniques.

METHODS AND ANALYSIS

A systematic literature search of the Embase, PubMed/MEDLINE and PsycINFO databases, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and OpenGrey will be performed. We will include both randomised clinical trials which report on at least one cognitive measure post treatment as well as non-randomised trials and pre-post intervention studies. There are no restrictions to the type of cognitive outcome measures, except that the tests are standardised and psychometrically validated. The Revised Cochrane tool for assessing risk of bias in randomised trials (RoB 2.0) will be used to evaluate included trials. Pre-post studies will be evaluated using the quality assessment tool developed by the US National Heart, Lung and Blood Institute. Meta-analysis, meta-regression, subgroup and sensitivity analyses will be conducted where sufficient data are available.

ETHICS AND DISSEMINATION

No ethical approval is needed to conduct this work. The findings will be submitted for publication in peer-reviewed journals and presented at scientific meetings.

PROSPERO REGISTRATION NUMBER

CRD42018118850.

Do bipolar disorder soft signs impact outcomes following Transcranial Magnetic Stimulation (TMS) therapy for depression?

BACKGROUND

Transcranial Magnetic Stimulation (TMS) is not currently FDA approved for depressed patients with bipolar disorder (BD), but many unipolar depressed patients presenting for TMS have soft signs of bipolarity. It is not known whether or not these soft signs portend differential outcomes.

OBJECTIVE

To investigate the relationship between BD soft signs and TMS treatment outcomes in a naturalistic treatment setting.

METHODS

We conducted a retrospective chart review of MDD patients (n = 105) treated with TMS. BD diathesis was defined by responses to a modified version of the Mood Disorder Questionnaire and family history.

RESULTS

TMS response rates for the group with BD diathesis and the group without were equivalent using two self-report depression severity scales. Remission rate was significantly lower for the bipolar soft signs group (13.5% versus 30.2%; p = 0.04) on one scale. This result does not hold when corrected for multiple comparisons. We did not observe switch to mania.

LIMITATIONS

These data are limited to patients diagnosed with unipolar depression with "soft" bipolar features defined by subthreshold symptoms. The results cannot be extrapolated to patients with a full bipolar diagnosis.

CONCLUSION

Bipolar diathesis in MDD is not a safety concern but may lead to somewhat lower remission rates when considering TMS treatment.

Brain Modulation by Electric Currents in Fibromyalgia: A Structured Review on Non-invasive Approach With Transcranial Electrical Stimulation

Fibromyalgia syndrome (FMS) is a complex disorder where widespread musculoskeletal pain is associated with many heterogenous symptoms ranging from affective disturbances to cognitive dysfunction and central fatigue. FMS is currently underdiagnosed and often very poorly responsive to pharmacological treatment. Pathophysiology of the disease remains still obscure even if in the last years fine structural and functional cerebral abnormalities have been identified, principally by neurophysiological and imaging studies delineating disfunctions in pain perception, processing and control systems. On such basis, recently, neurostimulation of brain areas involved in mechanism of pain processing and control (primary motor cortex: M1 and dorsolateral prefrontal cortex: DLPFC) has been explored by means of different approaches and particularly through non-invasive brain stimulation techniques (transcranial magnetic and electric stimulation: TMS and tES). Here we summarize studies on tES application in FMS. The great majority of reports, based on direct currents (transcranial direct currents stimulation: tDCS) and targeting M1, showed efficacy on pain measures and less on cognitive and affective symptoms, even if several aspects as maintenance of therapeutical effects and optimal stimulation parameters remain to be established. Differently, stimulation of DLPFC, explored in a few studies, was ineffective on pain and showed limited effects on cognitive and affective symptoms. Very recently new tES techniques as high-density tDCS (HD-tDCS), transcranial random noise stimulation (tRNS) and tDCS devices for home-based treatment have been explored in FMS with interesting even if very preliminary results opening interesting perspectives for more effective, well tolerated, cheap and easy therapeutic approaches.

Transcranial Direct-Current Stimulation (tDCS) Versus Venlafaxine ER In The Treatment Of Depression: A Randomized, Double-Blind, Single-Center Study With Open-Label, Follow-Up

OBJECTIVE

Transcranial direct-current stimulation (tDCS), a relatively new neuromodulation approach, provides some evidence of an antidepressant effect. This randomized, 4-week, double-blind study with 8-week, open-label, follow-up compared the efficacy and tolerability of left anodal tDCS with venlafaxine ER (VNF) in the treatment of depression and prevention of early relapse.

METHODS

Subjects (n = 57) received tDCS (2 mA, 20 sessions, 30 mins) plus placebo (n = 29) or VNF plus sham tDCS (n = 28). Responders to both interventions entered the open-label follow-up. The primary outcome was score change in the Montgomery-Åsberg Depression Rating Scale (MADRS) at week 4 of the study. Secondary outcomes were response, remission, dropout rates and relapse rates within the follow-up.

The mean change in the MADRS score from baseline to week for patients treated with tDCS was 7.69 (95% CI, 5.09-10.29) points and 9.64 (95% CI, 6.20-13.09) points for patients from the VNF group, a nonsignificant difference (1.95, 95% CI -2.25-6.16; t (55) = 0.93, p= 0.36, Cohen´s d = 0.24). There were no significant between-group differences in the MADRS scores from baseline to endpoint (intention-to-treat analysis). The response/remission rate for tDCS (24%/17%) and VNF (43%/32%) as well as the dropout rate (tDCS/VNF; 6/6) did not differ significantly between groups. In the follow-up, relapse (tDCS/VNF; 1/2) and dropout (tDCS/VNF; 2/3) rates were low and comparable.

LIMITATIONS

A relatively small sample size and short duration of the antidepressant treatment; no placebo arm.

CONCLUSION

Overall, this study found a similar efficacy of tDCS and VNF in the acute treatment of depression and prevention of early relapse. The real clinical usefulness of tDCS and its optimal parameters in the treatment of depression should be further validated.

A systematic review on the therapeutic effectiveness of non-invasive brain stimulation for the treatment of anxiety disorders

The interest in the use of non-invasive brain stimulation for enhancing neural functions and reducing symptoms in anxiety disorders is growing. Based on the DSM-V classification for anxiety disorders, we examined all available research using repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) for the treatment of specific phobias, social anxiety disorder, panic disorder, agoraphobia, and generalized anxiety disorder. A systematic literature search conducted in PubMed and Google Scholar databases provided 26 results: 12 sham-controlled studies and 15 not sham-controlled studies. With regard to the latter sub-group of studies, 9 were case reports, and 6 open label studies. Overall, our work provides preliminary evidence that both, excitatory stimulation of the left prefrontal cortex and inhibitory stimulation of the right prefrontal cortex can reduce symptom severity in anxiety disorders. The current results are discussed in the light of a model for the treatment for anxiety disorders via non-invasive brain stimulation, which is based on up-/downregulation mechanisms and might serve as guide for future systematic investigations in the field.

Response and Remission Rates Following High-Frequency vs. Low-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS) Over Right DLPFC for Treating Major Depressive Disorder (MDD): A Meta-Analysis of Randomized, Double-Blind Trials

Background: High-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (L-DLPFC) is the most widely applied treatment protocol for major depressive disorder (MDD), while low-frequency (LF) rTMS over the right DLPFC (R-DLPFC) also exhibits similar, if not better, efficacy for MDD. Therefore, a meta-analysis is warranted to compare the efficacy of the two protocols for MDD. Method: We searched the literature from 1990 through to August 1, 2017 using MEDLINE, and the literature from 1995 through to August 1, 2017 using EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), SCOPUS, and ProQuest Dissertations and Theses (PQDT). We included randomized controlled trials (RCT) comparing the efficacy of HF rTMS over the L-DLPFC and LF rTMS over the R-DLPFC for MDD, which used response and/or remission rates as the primary endpoints, with and without sham-controlled. Results: (1) The meta-analysis of the response rates was based on 12 studies, including 361 patients with MDD (175 for HF (> 5 Hz) over the L-DLPFC, and 186 for LF (<5 Hz) over the R-DLPFC; odds ratio = 1.08; 95%, confidence interval = 0.88-1.34). (2) The meta-analysis of the remission rate was based on 5 studies, including 131 MDD patients (64 for HF over the L-DLPFC and 67 for LF over the R-DLPFC; odds ratio = 1.29; 95% confidence interval = 0.54-3.10). Conclusion: Both HF rTMS over the L-DLPFC and LF over the R-DLPFC demonstrated similar therapeutic efficacy for the treatment of patients with MDD. The results suggested that further investigation on treatment efficacy indicators before/during treatment is necessary and helpful for optimizing a personalized protocol for patients.