Pre-supplementary motor network connectivity and clinical outcome of magnetic stimulation in obsessive-compulsive disorder

A Controlled Clinical Study of Accelerated High-Dose Theta Burst Stimulation in Patients with Obsessive-Compulsive Disorder

Background

Obsessive-compulsive disorder (OCD) is frequently treated using a combination of counseling, drugs, and, more recently various transcranial stimulation protocols, but all require several weeks to months for clinically significant improvement, so there is a need for treatments with faster onset. This study investigated whether an accelerated high-dose theta burst stimulation (ahTBS) protocol significantly improves the efficacy of OCD compared to traditional 1-Hz repetitive transcranial magnetic stimulation (rTMS) in the routine clinical setting.

Method

Forty-five patients with OCD were randomized into two groups and treated with ahTBS or 1-Hz rTMS for 5 days. Patients were assessed at baseline at the end of treatment using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).

Results

After 5 days of treatment, there was a significant decrease in Y-BOCS scores in both groups (p < 0.001), and the difference between the two groups was not statistically significant (group × time interaction, F = 1.90, p=0.18). There was also no statistically significant difference in other secondary outcome indicators, including depression, anxiety symptoms, and response rate. However, the ahTBS group had a greater trend in response rate. Neuropsychological testing showed no negative cognitive side effects of either treatment.

Conclusion

Accelerated high-dose TBS is as safe and has comparable short-term efficacy to traditional 1-Hz rTMS for the clinical treatment of OCD. Further research is needed to explore optimal ahTBS parameters, validate the utility of this treatment modality, and identify factors predictive of rapid clinical response to guide clinical decision-making. This trial is registered with NCT05221632.

TMS-induced plasticity improving cognitive control in OCD I: Clinical and neuroimaging outcomes from a randomised trial of rTMS for OCD

Background

Repetitive transcranial magnetic stimulation (rTMS) is an emerging treatment option for obsessive-compulsive disorder (OCD). The neurobiological mechanisms of rTMS in OCD have, however, been incompletely characterized. We compared clinical outcomes and changes in task-based brain activation following three different rTMS stimulation protocols, all combined with exposure and response prevention (ERP).

Methods

In this three-arm proof-of-concept randomized controlled clinical trial, 61 treatment-refractory adult OCD patients received 16 sessions of rTMS immediately prior to ERP over 8 weeks, with task-based functional MRI (tb-fMRI) scans and clinical assessments pre- and post-treatment. Patients received either: high frequency (HF) rTMS to the left dorsolateral prefrontal cortex (DLPFC) (n=19 (6M/13F)); HF rTMS to the left pre-supplementary motor area (preSMA) (n=23 (10M/13F)); or control rTMS to the vertex (n=19 (6M/13F)). Changes in tb-fMRI activation pre-post treatment were compared using both a Bayesian region-of-interest and a general linear model whole-brain approach.

Results

Mean OCD symptom severity decreased significantly in all treatment groups (delta=- 10.836, p<0.001, 95% CI [-12.504, -9.168]), with no differences between groups. Response rate in the entire sample was 57.4%. Groups receiving DLPFC or preSMA rTMS showed, respectively, a decrease in planning and error processing task-related activation after treatment that was associated with symptom improvement, while individuals in the vertex rTMS group with greater symptom improvement showed an increase in inhibition-related activation.

Conclusions

PreSMA and DLPFC rTMS combined with ERP led to significant symptom improvement related to activation decreases in targeted task networks, although we observed no differences in symptom reduction between groups. This trial was registered at clinicaltrials.gov ( NCT03667807 ).

A Meta-analysis of Transcranial Magnetic Stimulation in Obsessive-Compulsive Disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a debilitating illness with substantial morbidity. Although pharmacological and behavioral evidence-based treatments have shown efficacy, many patients remain unresponsive to this first-line care. Repetitive transcranial magnetic stimulation (rTMS) has shown significant promise for patients with treatment-refractory affective disorders. Therefore, we conducted a meta-analysis of randomized controlled trials to examine the therapeutic benefit of rTMS in patients with OCD and explore moderators of its treatment effects.

METHODS

PubMed (1997-Dec 31, 2022) and PsycINFO were searched for randomized sham-controlled trials of rTMS to treat OCD using the following terms: "obsessive-compulsive disorder," "transcranial magnetic stimulation," and "randomized controlled trial." Clinical characteristics and effect sizes were extracted from 25 randomized controlled trials (860 participants). A random effects model calculated the effect sizes for treatment efficacy and treatment response using the clinician-rated Yale-Brown Obsessive Compulsive Scale.

RESULTS

Across randomized controlled trials, rTMS exhibited a moderate therapeutic effect (g = 0.65) on OCD symptom severity and a 3-fold increased likelihood of treatment response (relative risk = 3.15) compared with sham conditions. Greater improvement in comorbid depression severity corresponded with greater treatment effects of rTMS on OCD symptom severity. In addition, longer rTMS sessions and fewer overall sessions predicted greater clinical improvement.

CONCLUSIONS

rTMS is moderately effective for reducing OCD symptom severity. It holds potential to serve as a therapeutic intervention, particularly for patients with OCD who have failed standard treatments and those with comorbid depression. Further research is needed to optimize rTMS protocols and evaluate the long-term efficacy of rTMS for OCD.

Effects of repetitive transcranial magnetic stimulation and their underlying neural mechanisms evaluated with magnetic resonance imaging-based brain connectivity network analyses

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain modulation and rehabilitation technique used in patients with neuropsychiatric diseases. rTMS can structurally remodel or functionally induce activities of specific cortical regions and has developed to an important therapeutic method in such patients. Magnetic resonance imaging (MRI) provides brain data that can be used as an explanation tool for the neural mechanisms underlying rTMS effects; brain alterations related to different functions or structures may be reflected in changes in the interaction and influence of brain connections within intrinsic specific networks. In this review, we discuss the technical details of rTMS and the biological interpretation of brain networks identified with MRI analyses, comprehensively summarize the neurobiological effects in rTMS-modulated individuals, and elaborate on changes in the brain network in patients with various neuropsychiatric diseases receiving rehabilitation treatment with rTMS. We conclude that brain connectivity network analysis based on MRI can reflect alterations in functional and structural connectivity networks comprising adjacent and separated brain regions related to stimulation sites, thus reflecting the occurrence of intrinsic functional integration and neuroplasticity. Therefore, MRI is a valuable tool for understanding the neural mechanisms of rTMS and practically tailoring treatment plans for patients with neuropsychiatric diseases.

Linking Personalized Brain Atrophy to Schizophrenia Network and Treatment Response

BACKGROUND AND HYPOTHESIS

Schizophrenia manifests with marked heterogeneity in both clinical presentation and underlying biology. Modeling individual differences within clinical cohorts is critical to translate knowledge reliably into clinical practice. We hypothesized that individualized brain atrophy in patients with schizophrenia may explain the heterogeneous outcomes of repetitive transcranial magnetic stimulation (rTMS).

STUDY DESIGN

The magnetic resonance imaging (MRI) data of 797 healthy subjects and 91 schizophrenia patients (between January 1, 2015, and December 31, 2020) were retrospectively selected from our hospital database. The healthy subjects were used to establish normative reference ranges for cortical thickness as a function of age and sex. Then, a schizophrenia patient's personalized atrophy map was computed as vertex-wise deviations from the normative model. Each patient's atrophy network was mapped using resting-state functional connectivity MRI from a subgroup of healthy subjects (n = 652). In total 52 of the 91 schizophrenia patients received rTMS in a randomized clinical trial (RCT). Their longitudinal symptom changes were adopted to test the clinical utility of the personalized atrophy map.

RESULTS

The personalized atrophy maps were highly heterogeneous across patients, but functionally converged to a putative schizophrenia network that comprised regions implicated by previous group-level findings. More importantly, retrospective analysis of rTMS-RCT data indicated that functional connectivity of the personalized atrophy maps with rTMS targets was significantly associated with the symptom outcomes of schizophrenia patients.

CONCLUSIONS

Normative modeling can aid in mapping the personalized atrophy network associated with treatment outcomes of patients with schizophrenia.

Assessing the Effectiveness of Repetitive Transcranial Magnetic Stimulation in the Treatment of Obsessive- Compulsive Disorder

Objective. Obsessive-compulsive disorder (OCD) is a frequent and disabling neuropsychiatric disorder with a lifetime prevalence of 3%. About 40% to 60% of patients show no or just partial symptom improvement to treatment with a first-line drug and cognitive behavior therapy. Ten percent of patients remain treatment refractory despite several treatments. For these patients, repetitive Transcranial Magnetic Stimulation (rTMS) has been suggested as a treatment option. Method. We investigated the efficacy of rTMS on the Supplementary Motor Area (SMA) in 16 right handed pharmaco-resistant OCD patients in an outpatient setting. The patients have been diagnosed with OCD by two psychiatrists and referred for rTMS intervention. Patients received 16 sessions of low frequency (0.5 HZ) rTMS on SMA,100% motor threshold, 1200 stimuli/day for 40 minutes every other day. OCD, depression, and anxiety symptoms were measured at baseline, 2, 6, and 12 weeks by Yale-Brown Obsessive Compulsive Scale(Y-BOCS) and Hamilton Depressive and Anxiety rating scales (HAM-D and HAM-A). We assessed the side effects of rTMS by a self-administrative questionnaire. Results. Patients' scores in Y-BOCS, HAM-D, and HAM-A were significantly decreased following rTMS treatment. The baseline and 12 weeks scores of Y-BOCS were 28.94 and 18.31 (P-value < 0.01), HAM-D were 14.69 and 7.94 (P-value <0.01) and HAM-A were 16.38 and 6.94 (P- value < 0.01), respectively. The patients reported no serious side effects of rTMS except two case that reported light headach. Conclusion. This study showed that low-frequency rTMS on SMA improved OCD, anxiety, and depression symptoms after 16 sessions.

Pre-supplementary motor network connectivity and clinical outcome of magnetic stimulation in obsessive-compulsive disorder

A large proportion of patients with obsessive–compulsive disorder (OCD) respond unsatisfactorily to pharmacological and psychological treatments. An alternative novel treatment for these patients is repetitive transcranial magnetic stimulation (rTMS). This study aimed to investigate the underlying neural mechanism of rTMS treatment in OCD patients. A total of 37 patients with OCD were randomized to receive real or sham 1‐Hz rTMS (14 days, 30 min/day) over the right pre‐supplementary motor area (preSMA). Resting‐state functional magnetic resonance imaging data were collected before and after rTMS treatment. The individualized target was defined by a personalized functional connectivity map of the subthalamic nucleus. After treatment, patients in the real group showed a better improvement in the Yale–Brown Obsessive Compulsive Scale than the sham group (F_1,35 = 6.0, p = .019). To show the neural mechanism involved, we identified an “ideal target connectivity” before treatment. Leave‐one‐out cross‐validation indicated that this connectivity pattern can significantly predict patients' symptom improvements (r = .60, p = .009). After real treatment, the average connectivity strength of the target network significantly decreased in the real but not in the sham group. This network‐level change was cross‐validated in three independent datasets. Altogether, these findings suggest that personalized magnetic stimulation on preSMA may alleviate obsessive–compulsive symptoms by decreasing the connectivity strength of the target network.