Effects of continuous theta burst stimulation in mild-to-moderate obsessive compulsive disorder
Presented During:
Monday, June 24, 2024: 5:45 PM - 7:00 PM
COEX
Room:
Grand Ballroom 104-105
Poster No:
521
Submission Type:
Abstract Submission
Authors:
Junjie Bu1, Yueling Liu1, Rui Ni2, Jiafang Liu1, Chunyan Zhu1
Institutions:
1Anhui Medical University, Hefei, Anhui, 2Imperial College London, London, London
First Author:
Co-Author(s):
Introduction:
Obsessive-compulsive disorder (OCD) is a clinically heterogeneous psychiatric disorder characterized by pathologically activated brain activity. Currently, first-line treatments for OCD fail to bring response in up to 60% of patients, indicating the refractory nature of OCD. Meanwhile, over 70% of the patients have only mild-to-moderate severity, their symptoms will develop into severe OCD without timely treatment, resulting in a greater burden on clinical treatment. Continuous theta burst stimulation (cTBS) can non-invasively induce inhibitory effects on the underlying cortex; hence, it is considered a potential treatment for inhibiting aberrantly hyperactivated brain regions in patients with obsessive-compulsive disorder (OCD). This is the first study to investigate the effectiveness of cTBS in the treatment of mild-to-moderate OCD in a preliminary study with an external validation design across two centers.
Methods:
In the first preliminary experiment conducted at the Hangzhou Seventh People's Hospital Center (Hangzhou, China), 50 inpatients with DSM-5 (Diagnostic and Statistical Manual, 5th edition) diagnosis of OCD, having a total Yale-Brown Obsessive-Compulsive Scale (YBOCS) score of >16 or obsession/compulsion subscale of >10, were enrolled to receive cTBS (10 sessions/day for five continuous days) or sham over the personalized right pre-supplementary motor area (preSMA) based on the functional connectivity map of the PreSMA and the subthalamic nucleus according to prior research by our group [1]. Each session contained 1800 pulses in a continuous train of 600 theta bursts, while each burst contained three pulses at 50 Hz, repeated at 5 Hz. Patients in the sham group received stimulation through a placebo coil, which led to similar skin sensations and significantly reduced biological activity compared with active stimulation.
In the external validation experiment conducted at the Anhui Mental Health Center (Hefei, China), 32 outpatients with lesser OCD severity received a cTBS session per day for 15 consecutive days to generalize the treatment effects. Each session contained 1800 cTBS pulses. According to previous study, responders are defined as patients who showed a ≥35% decrease in YBOCS and remission as patients who showed a post-treatment YBOCS score of ≤14. OCD can be classified as mild, moderate, or severe: mild, 6–15 points (O-YBOCS or C-YBOCS 6–9 points); moderate, 16–25 points (O-YBOCS or C-YBOCS 10–14 points); severe, ≥25 points (O-YBOCS, YBOCS, or C-YBOCS >15 points).
In the external validation experiment conducted at the Anhui Mental Health Center (Hefei, China), 32 outpatients with lesser OCD severity received a cTBS session per day for 15 consecutive days to generalize the treatment effects. Each session contained 1800 cTBS pulses. According to previous study, responders are defined as patients who showed a ≥35% decrease in YBOCS and remission as patients who showed a post-treatment YBOCS score of ≤14. OCD can be classified as mild, moderate, or severe: mild, 6–15 points (O-YBOCS or C-YBOCS 6–9 points); moderate, 16–25 points (O-YBOCS or C-YBOCS 10–14 points); severe, ≥25 points (O-YBOCS, YBOCS, or C-YBOCS >15 points).
Results:
In the preliminary experiment, there was a marginally significant difference in the YBOCS improvement between the groups. The response and remission rates in the cTBS group were 56·52% and 57·14%, respectively, significantly higher than those in the sham group (χ2=3·94, p=0·047; χ2=5·41, p=0·02, respectively). Further analysis revealed significant YBOCS improvement in patients with moderate OCD (F=9·45, p=0·005, η2=0·27) than those with severe OCD (F=0·16, p=0·69, η2=0·01).
In the extension experiment, YBOCS scores significantly decreased after treatment (t=5·56, p<0·001, Cohen's d=0·98). The extension group had a response rate of 50% and a remission rate of 56·52%. Additionally, a significant difference in YBOCS scores before and after cTBS intervention was found in patients with mild-to-moderate OCD, but not in those with severe OCD (mild: t=2·57, p=0·03, Cohen's d=0·86; moderate: t=4·70, p<0·001, Cohen's d=1·08; severe: t=2·02, p=0·14, Cohen's d=1·01). No severe adverse reactions were observed.
In the extension experiment, YBOCS scores significantly decreased after treatment (t=5·56, p<0·001, Cohen's d=0·98). The extension group had a response rate of 50% and a remission rate of 56·52%. Additionally, a significant difference in YBOCS scores before and after cTBS intervention was found in patients with mild-to-moderate OCD, but not in those with severe OCD (mild: t=2·57, p=0·03, Cohen's d=0·86; moderate: t=4·70, p<0·001, Cohen's d=1·08; severe: t=2·02, p=0·14, Cohen's d=1·01). No severe adverse reactions were observed.
Conclusions:
This is the first preliminary study with an external validation design across two centers to determine the treatment effects of cTBS over the right preSMA in patients with OCD, especially mild-to-moderate OCD. The treatment effect of cTBS was comparable to that of the first-line method for OCD. Therefore, cTBS can be applied as an effective alternative for OCD within a certain range of symptom severity.
Brain Stimulation:
Non-invasive Magnetic/TMS 2
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia) 1
Keywords:
Obessive Compulsive Disorder
Transcranial Magnetic Stimulation (TMS)
Treatment
Other - Continuous theta burst stimulation
1|2Indicates the priority used for review