Efficacy of Deep TMS with the H1 Coil for Anxious Depression

Intermittent theta-burst stimulation to the right dorsolateral prefrontal cortex may increase potentiated startle in healthy individuals

Repetitive transcranial magnetic stimulation (rTMS) treatment protocols targeting the right dlPFC have been effective in reducing anxiety symptoms comorbid with depression. However, the mechanism behind these effects is unclear. Further, it is unclear whether these results generalize to non-depressed individuals. We conducted a series of studies aimed at understanding the link between anxiety potentiated startle and the right dlPFC, following a previous study suggesting that continuous theta burst stimulation (cTBS) to the right dlPFC can make people more anxious. Based on these results we hypothesized that intermittent TBS (iTBS), which is thought to have opposing effects on plasticity, may reduce anxiety when targeted at the same right dlPFC region. In this double-blinded, cross-over design, 28 healthy subjects underwent 12 study visits over a 4-week period. During each of their 2 stimulation weeks, they received four 600 pulse iTBS sessions (2/day), with a post-stimulation testing session occurring 24 h following the final iTBS session. One week they received active stimulation, one week they received sham. Stimulation weeks were separated by a 1-week washout period and the order of active/sham delivery was counterbalanced across subjects. During the testing session, we induced anxiety using the threat of unpredictable shock and measured anxiety potentiated startle. Contrary to our initial hypothesis, subjects showed increased startle reactivity following active compared to sham stimulation. These results replicate work from our two previous trials suggesting that TMS to the right dlPFC increases anxiety potentiated startle, independent of both the pattern of stimulation and the timing of the post stimulation measure. Although these results confirm a mechanistic link between right dlPFC excitability and startle, capitalizing upon this link for the benefit of patients will require future exploration.

Causal network localization of brain stimulation targets for trait anxiety

Transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) can treat some neuropsychiatric disorders, but there is no consensus approach for identifying new targets. We localized causal circuit-based targets for anxiety that converged across multiple natural experiments. Lesions (n=451) and TMS sites (n=111) that modify anxiety mapped to a common normative brain circuit (r=0.68, p=0.01). In an independent dataset (n=300), individualized TMS site connectivity to this circuit predicted anxiety change (p=0.02). Subthalamic DBS sites overlapping the circuit caused more anxiety (n=74, p=0.006), thus demonstrating a network-level effect, as the circuit was derived without any subthalamic sites. The circuit was specific to trait versus state anxiety in datasets that measured both (p=0.003). Broadly, this illustrates a pathway for discovering novel circuit-based targets across neuropsychiatric disorders.

Targeting Symptom-Specific Networks With Transcranial Magnetic Stimulation

Increasing evidence suggests that the clinical effects of transcranial magnetic stimulation are target dependent. Within any given symptom, precise targeting of specific brain circuits may improve clinical outcomes. This principle can also be extended across symptoms-stimulation of different circuits may lead to different symptom-level outcomes. This may include targeting different symptoms within the same disorder (such as dysphoria vs. anxiety in patients with major depression) or targeting the same symptom across different disorders (such as primary major depression and depression secondary to stroke, traumatic brain injury, epilepsy, multiple sclerosis, or Parkinson's disease). Some of these symptom-specific changes may be desirable, while others may be undesirable. This review focuses on the conceptual framework through which symptom-specific target circuits may be identified, tested, and implemented.

Bilateral deep transcranial magnetic stimulation of motor and prefrontal cortices in Parkinson's disease: a comprehensive review

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by both motor and non-motor symptoms, many of which are resistant to currently available treatments. Since the discovery that non-invasive transcranial magnetic stimulation (TMS) can cause dopamine release in PD patients, there has been growing interest in the use of TMS to fill existing gaps in the treatment continuum for PD. This review evaluates the safety and efficacy of a unique multifocal, bilateral Deep TMS protocol, which has been evaluated as a tool to address motor and non-motor symptoms of PD. Six published clinical trials have delivered a two-stage TMS protocol with an H-Coil targeting both the prefrontal cortex (PFC) and motor cortex (M1) bilaterally (220 PD patients in total; 108 from two randomized, sham-controlled studies; 112 from open label or registry studies). In all studies TMS was delivered to M1 bilaterally (Stage 1) and then to the PFC bilaterally (Stage 2) with approximately 900 pulses per stage. For Stage 1 (M1), two studies delivered 10 Hz at 90% motor threshold (MT) while four studies delivered 1 Hz at 110% MT. For Stage 2 (PFC), all studies delivered 10 Hz at 100% MT. The results suggest that this two-stage Deep TMS protocol is a safe, moderately effective treatment for motor symptoms of PD, and that severely impaired patients have the highest benefits. Deep TMS also improves mood symptoms and cognitive function in these patients. Further research is needed to establish optimal dosing and the long-term durability of treatment effects.

Comparing different non-invasive brain stimulation interventions for bipolar depression treatment: A network meta-analysis of randomized controlled trials

Non-invasive brain stimulation (NIBS) is a promising treatment for bipolar depression. We systematically searched for randomized controlled trials on NIBS for treating bipolar depression (INPLASY No: 202340019). Eighteen articles (N = 617) were eligible for network meta-analysis. Effect sizes were reported as standardized mean differences (SMDs) or odds ratios (ORs) with 95% confidence intervals (CIs). Anodal transcranial direct current stimulation over F3 plus cathodal transcranial direct current stimulation over F4 (a-tDCS-F3 +c-tDCS-F4; SMD = -1.18, 95%CIs = -1.66 to -0.69, N = 77), high-definition tDCS over F3 (HD-tDCS-F3; -1.17, -2.00 to -0.35, 25), high frequency deep transcranial magnetic stimulation (HF-dTMS; -0.81, -1.62 to -0.001, 25), and high frequency repetitive TMS over F3 plus low frequency repetitive TMS over F4 (HF-rTMS-F3 +LF-rTMS-F4; -0.77, -1.43 to -0.11, 38) significantly improved depressive symptoms compared to sham controls. Only a-tDCS-F3 +c-tDCS-F4 (OR = 4.53, 95%CIs = 1.51-13.65) and HF-rTMS-F3 +LF-rTMS-F4 (4.69, 1.02-21.56) showed higher response rates. No active NIBS interventions exhibited significant differences in dropout or side effect rates, compared with sham controls.

Next-generation cognitive assessment: Combining functional brain imaging, system perturbations and novel equipment interfaces

Conventional cognitive assessment is widely used in clinical and research settings, in educational institutions, and in the corporate world for personnel selection. Such approaches involve having a client, a patient, or a research participant complete a series of standardized cognitive tasks in order to challenge specific and global cognitive abilities, and then quantify performance for the desired end purpose. The latter may include a diagnostic confirmation of a disease, description of a state or ability, or matching cognitive characteristics to a particular occupational role requirement. Metrics derived from cognitive assessments are putatively informative about important features of the brain and its function. For this reason, the research sector also makes use of cognitive assessments, most frequently as a stimulus for cognitive activity from which to extract functional neuroimaging data. Such "task-related activations" form the core of the most widely used neuroimaging technologies, such as fMRI. Much of what we know about the brain has been drawn from the interleaving of cognitive assessments of various types with functional brain imaging technologies. Despite innovation in neuroimaging (i.e., quantifying the neural response), relatively little innovation has occurred on task presentation and volitional response measurement; yet these together comprise the core of cognitive performance. Moreover, even when cognitive assessment is interleaved with functional neuroimaging, this is most often undertaken in the research domain, rather than the primary applications of cognitive assessment in diagnosis and monitoring, education and personnel selection. There are new ways in which brain imaging-and even more importantly, brain modulation-technologies can be combined with automation and artificial intelligence to deliver next-generation cognitive assessment methods. In this review paper, we describe some prototypes for how this can be done and identify important areas for progress (technological and otherwise) to enable it to happen. We will argue that the future of cognitive assessment will include semi- and fully-automated assessments involving neuroimaging, standardized perturbations via neuromodulation technologies, and artificial intelligence. Furthermore, the fact that cognitive assessments take place in a social/interpersonal context-normally between the patient and clinician-makes the human-machine interface consequential, and this will also be discussed.

Hindbrain Stimulation Modulates Object Recognition Discrimination Efficiency and Hippocampal Synaptic Connections

(1) Background: The cerebellum is well known to have functionalities beyond the control of motor function. However, brain stimulation studies have not explored the potential of this region to impact downstream processes which are imperative to multiple neurological conditions. Our study aimed to look at preliminary evidence that hindbrain-targeted repetitive transcranial magnetic stimulation (rTMS) in mice could alter motor, cognitive and anxiety measures; (2) Methods: Male B6129SF2/J mice (n = 16) were given rTMS (n = 9) over lambda at 10 Hz for 10 min or Sham (n = 7) for 14 consecutive days. Mice then underwent a battery of behavioral measures. (3) Results: In the object recognition test, only rTMS-treated mice distinguished between the novel object at 5 min, whereas those that received Sham treatment continued to improve discrimination from 5 to 10 min. Additionally, over the 10 min test phase, rTMS-stimulated mice explored the objects less than the Sham mice. This was accompanied by increased colocalization of presynaptic and postsynaptic markers in the hippocampus in the rTMS mice (4) Conclusions: Hindbrain rTMS stimulation elicits improved processing speed in the object recognition test via structural plasticity mechanisms in the hippocampus and could provide additional ways of targeting these important substructures of the brain.

Deep TMS H1 Coil treatment for depression: Results from a large post marketing data analysis

Phase IV study evaluated Deep TMS for major depression in community settings. Data were aggregated from 1753 patients at 21 sites, who received Deep TMS (high frequency or iTBS) using the H1 coil. Outcome measures varied across subjects and included clinician-based scales (HDRS-21) and self-assessment questionnaires (PHQ-9, BDI-II). 1351 patients were included in the analysis, 202 received iTBS. For participants with data from at least 1 scale, 30 sessions of Deep TMS led to 81.6% response and 65.3% remission rate. 20 sessions led to 73.6% response and 58.1% remission rate. iTBS led to 72.4% response and 69.2% remission. Remission rates were highest when assessed with HDRS (72%). In 84% of responders and 80% of remitters, response and remission was sustained in the subsequent assessment. Median number of sessions (days) for onset of sustained response was 16 (21 days) and for sustained remission 17 (23 days). Higher stimulation intensity was associated with superior clinical outcomes. This study shows that beyond its proven efficacy in RCTs, Deep TMS with the H1 coil is effective for treating depression under naturalistic conditions, and the onset of improvement is usually within 20 sessions. However, initial non-responders and non-remitters benefit from extended treatment.

Pursuing personalized medicine for depression by targeting the lateral or medial prefrontal cortex with Deep TMS

BACKGROUNDMajor depressive disorder (MDD) can benefit from novel interventions and personalization. Deep transcranial magnetic stimulation (Deep TMS) targeting the lateral prefrontal cortex (LPFC) using the H1 coil was FDA cleared for treatment of MDD. However, recent preliminary data indicate that targeting the medial prefrontal cortex (MPFC) using the H7 coil might induce outcomes that are as good or even better. Here, we explored whether Deep TMS targeting the MPFC is noninferior to targeting the LPFC and whether electrophysiological or clinical markers for patient selection can be identified.METHODSThe present prospective, multicenter, randomized study enrolled 169 patients with MDD for whom antidepressants failed in the current episode. Patients were randomized to receive 24 Deep TMS sessions over 6 weeks, using either the H1 coil or the H7 coil. The primary efficacy endpoint was the change from baseline to week 6 in Hamilton Depression Rating Scale scores.RESULTSClinical efficacy and safety profiles were similar and not significantly different between groups, with response rates of 60.9% for the H1 coil and 64.2% for the H7 coil. Moreover, brain activity measured by EEG during the first treatment session correlated with clinical outcomes in a coil-specific manner, and a cluster of baseline clinical symptoms was found to potentially distinguish between patients who can benefit from each Deep TMS target.CONCLUSIONThis study provides a treatment option for MDD, using the H7 coil, and initial guidance to differentiate between patients likely to respond to LPFC versus MPFC stimulation targets, which require further validation studies.TRIAL REGISTRATIONClinicalTrials.gov NCT03012724.FUNDINGBrainsWay Ltd.

Real-world data of non-invasive stimulation of the human insula-prefrontal cortices using deep TMS to treat anxiety for occupational stress and generalized anxiety disorder

Activation of the insula is found in all anxiety-related disorders and increased insular-prefrontal cortex (PFC) functional connectivity is associated with reduced anxiety. In this study, the combined stimulation of the insula and PFC using the dTMS H4 (insula+LPFC) and H2 (PFC) coils were used to reduce anxiety in 13 subjects experiencing occupational stress, and 55 participants suffering from generalized anxiety disorder (GAD). The combined HF stimulation of the insula and PFC significantly decreased anxiety scores according to the HARS, CAS, and STAI anxiety scales, leading to a reduction in anxiety according to HARS of 88.7% and 70.7% in participants with occupational stress and the clinical sample of participants diagnosed with GAD, respectively. The findings suggest that the prefrontal-insular axis is critical for the regulation of anxiety and its stimulation can be used for the treatment of anxiety in people suffering from occupational stress and GAD.

Transcranial Magnetic Stimulation and its Imaging Features in Patients With Depression, Post-traumatic Stress Disorder, and Traumatic Brain Injury

Transcranial magnetic stimulation (TMS) is a type of noninvasive neurostimulation used increasingly often in clinical medicine. While most studies to date have focused on TMS's ability to treat major depressive disorder, it has shown promise in several other conditions including post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI). As different treatment protocols are often used across studies, the ability to predict patient outcomes and evaluate immediate and long-term changes using imaging becomes increasingly important. Several imaging features, such as thickness, connectedness, and baseline activity of a variety of cortical and subcortical areas, have been found to be correlated with a greater response to TMS therapy. Intrastimulation imaging can reveal in real time how TMS applied to superficial areas activates or inhibits activity in deeper brain regions. Functional imaging performed weeks to months after treatment can offer an understanding of how long-term effects on brain activity relate to clinical improvement. Further work should be done to expand our knowledge of imaging features relevant to TMS therapy and how they vary across patients with different neurological and psychiatric conditions.

Changing Cerebral Blood Flow, Glucose Metabolism, and Dopamine Binding Through Transcranial Magnetic Stimulation: A Systematic Review of Transcranial Magnetic Stimulation-Positron Emission Tomography Literature

Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation tool currently used as a treatment in multiple psychiatric and neurologic disorders. Despite its widespread use, we have an incomplete understanding of the way in which acute and chronic sessions of TMS affect various neural and vascular systems. This systematic review summarizes the state of our knowledge regarding the effects TMS may be having on cerebral blood flow, glucose metabolism, and neurotransmitter release. Forty-five studies were identified. Several key themes emerged: 1) TMS transiently increases cerebral blood flow in the area under the coil; 2) TMS to the prefrontal cortex increases glucose metabolism in the anterior cingulate cortex of patients with depression; and 3) TMS to the motor cortex and prefrontal cortex decreases dopamine receptor availability in the ipsilateral putamen and caudate respectively. There is, however, a paucity of literature regarding the effects TMS may have on other neurotransmitter and neuropeptide systems of interest, all of which may shed vital light on existing biologic mechanisms and future therapeutic development. SIGNIFICANCE STATEMENT: Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation tool currently used as a treatment in multiple psychiatric and neurologic disorders. This systematic review summarizes the state of our knowledge regarding the effects TMS on cerebral blood flow, glucose metabolism, and neurotransmitter release.