Background

Intermittent theta-burst stimulation priming (iTBS-P) can improve clinical outcome of patients with Major Depressive Disorder (MDD) who do not show early benefit from 10 Hz stimulation of left dorsolateral prefrontal cortex (DLPFC), also known as high-frequency left-sided (HFL) stimulation. The intensity and pulse number for iTBS-P needed to induce clinical benefit have not been systematically examined.

Objective

To study the effect of intensity and pulse number on the clinical efficacy of iTBS-P.

Methods

We conducted a retrospective review of 71 participants who received at least five sessions of HFL with limited clinical benefit and received iTBS-P augmentation for between 5 and 25 sessions. Intensity of iTBS-P priming stimuli ranged from 75 to 120% of motor threshold (MT) and pulse number ranged from 600 to 1800. Associations among intensity, pulse number, and clinical outcome were analyzed using a mixed methods linear model with change in IDS-SR as the primary outcome variable, priming stimulation intensity (subthreshold or suprathreshold), pulse number (<1200 or >1200 pulses), and gender as fixed factors, and number of iTBS-P treatments and age as continuous covariates.

Results

Subjects who received subthreshold intensity iTBS-P experienced greater reduction in depressive symptoms than those who received suprathreshold iTBS-P (p = 0.011) with no effect of pulse number after controlling for stimulus intensity.

Conclusions

Subthreshold intensity iTBS-P was associated with greater clinical improvement than suprathreshold stimulation. This finding is consistent with iTBS-P acting through homeostatic plasticity mechanisms.

中文翻译：

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亚阈值刺激强度与间歇性 theta-burst 刺激启动对重度抑郁症的更大临床疗效相关

背景

间歇性 theta-burst 刺激启动 (iTBS-P) 可以改善重度抑郁症 (MDD) 患者的临床结果，这些患者没有从左背外侧前额叶皮层 (DLPFC) 的 10 Hz 刺激中显示出早期益处，也称为高频左侧（HFL）刺激。诱导临床获益所需的 iTBS-P 的强度和脉冲数尚未得到系统检查。

客观的

研究强度和脉搏数对iTBS-P临床疗效的影响。

方法

我们对 71 名参与者进行了回顾性审查，他们至少接受了 5 次 HFL 治疗，但临床获益有限，并接受了 5 到 25 次治疗的 iTBS-P 增强。iTBS-P 启动刺激的强度范围为运动阈值 (MT) 的 75% 至 120%，脉冲数范围为 600 至 1800。使用 IDS 变化的混合方法线性模型分析强度、脉冲数和临床结果之间的关联-SR 作为主要结果变量，启动刺激强度（阈下或阈上）、脉冲数（<1200 或 >1200 脉冲）和性别作为固定因素，iTBS-P 治疗次数和年龄作为连续协变量。

结果

接受亚阈值强度 iTBS-P 的受试者比接受超阈值 iTBS-P (p = 0.011) 的受试者抑郁症状减轻更多，控制刺激强度后脉冲数没有影响。

结论

与超阈值刺激相比，阈下强度 iTBS-P 与更大的临床改善相关。这一发现与通过稳态可塑性机制起作用的 iTBS-P 一致。