Enhancing prefrontal oscillatory activity and working memory performance with noninvasive brain stimulation in early-course schizophrenia

项目摘要。精神分裂症是一种严重的精神疾病， 仅在美国每年就有1600亿美元。为了减轻这一负担，一种有希望的方法涉及发现 针对特定神经元回路功能障碍的新型治疗干预，特别是在疾病早期， 改善疾病的进程。在最近的工作中，我们发现背外侧核的振荡活动， 经颅磁刺激（TMS）和脑电图（EEG）评估的前额叶皮层（DLPFC）明显 在慢性精神分裂症（Ch-SCZ）患者中减少。DLPFC振荡缺陷也存在于早期过程中 （EC-SCZ）患者，并与他们的工作记忆（WM）表现降低有关。但迄今为止的发现 受相关性/横断面设计的限制，留下DLPFC振荡缺陷的潜在因果作用 认知功能障碍还不清楚本提案的总体目标是确定， 增强DLPFC振荡活性，我们看到EC-SCZ患者的WM功能相应改善。 除了用于评估皮质功能外，如与EEG组合，TMS还可以在 重复高频模式（rTMS），以调节大脑活动，包括前额叶皮层振荡。 Theta Burst Stimulation（TBS）是一种rTMS，它对神经活动的影响比 常规rTMS;连续TBS（cTBS）和间歇TBS（iTBS）可降低和增强皮质 兴奋性，分别。最近的研究表明，DLPFC的iTBS可以急性增强前额叶 健康个体的兴奋性。然而，TBS对DLPFC振荡活动的直接影响， SCZ仍然未知。该提案的第一个广泛目标是使用iTBS来急剧改善DLPFC的赤字 EC-SCZ患者的振荡活动。 WM依赖于一个神经网络，其中DLPFC作为一个中心枢纽。脑电图研究报告说，SCZ 患者在WM任务中有DLPFC振荡异常，我们最近发现DLPFC减少 振荡活动预示EC-SCZ患者的WM表现较差。因此， 用TBS增强DLPFC振荡活动可能有益于认知功能。第二大目标 建议使用iTBS来急性改善EC-SCZ患者的WM损伤。 为了实现这些目标，我们将对DLPFC振荡参数进行TMS/EEG评估，并评估 75例EC-SCZ患者在两次TBS治疗（DLPFC的iTBS和假TBS）前后的WM能力。 这项拟议的研究旨在提供初步证据，证明TBS可以急性增强DLPFC振荡活动， 这反过来又预测了EC-SCZ患者更好的WM表现。基于这些发现，未来 应用慢性剂量TBS的基于神经调节的治疗干预可能更持久， 改善/恢复SCZ患者的DLPFC振荡参数和相关WM损伤， 这将大大改善他们的认知功能和整体生活质量。

Project Summary. Schizophrenia is a severe mental illness with an estimated economic burden of more than $160 billion per year in the US alone. To mitigate this burden, a promising approach involves the discovery of novel treatment interventions targeting specific neuronal circuit dysfunction, especially early in the illness, thus ameliorating the course of the disorder. In recent work, we found that the oscillatory activity of the dorsolateral prefrontal cortex (DLPFC), assessed with Transcranial Magnetic Stimulation (TMS) and EEG, was markedly reduced in chronic schizophrenia (Ch-SCZ) patients. DLPFC oscillatory deficits are also present in early course (EC-SCZ) patients and are associated to their reduced working memory (WM) performance. But findings to date are limited by a correlational/cross-sectional design, leaving the potential causal role of DLPFC oscillatory deficits in SCZ cognitive dysfunction unclear. The overarching goal of this proposal is to establish whether, by acutely enhancing DLPFC oscillatory activity, we see a corresponding improvement in WM function in EC-SCZ patients. In addition to being used to assess cortical function, as in combination with EEG, TMS can be delivered in repetitive, high-frequency patterns (rTMS), to modulate brain activity, including prefrontal cortical oscillations. Theta Burst Stimulation (TBS) is a type of rTMS that induces more rapid effects on neural activity than conventional rTMS; continuous TBS (cTBS) and intermittent TBS (iTBS) can decrease and enhance cortical excitability, respectively. Recent studies have shown that iTBS of DLPFC can acutely enhance prefrontal excitability in healthy individuals. Yet, the immediate impact of TBS on DLPFC oscillatory activity in patients with SCZ remains unknown. The first broad Aim of this proposal is to use iTBS to acutely ameliorate deficits in DLPFC oscillatory activity in EC-SCZ patients. WM relies on a neural network in which DLPFC serves as a central hub. EEG studies have reported that SCZ patients have DLPFC oscillatory abnormalities during WM tasks, and we recently found that reduced DLPFC oscillatory activity predicts poorer WM performance in EC-SCZ patients. It therefore stands to reason that enhancing DLPFC oscillatory activity with TBS may benefit cognitive functioning. The second broad Aim of this proposal is to use iTBS to acutely ameliorate WM impairments in EC-SCZ patients. To achieve these goals, we will perform TMS/EEG assessments of DLPFC oscillatory parameters and evaluate WM ability before and after two TBS sessions (iTBS and sham TBS of DLPFC) in seventy-five EC-SCZ patients. The proposed study aims to provide initial evidence that TBS can acutely enhance DLPFC oscillatory activity, which in turn predicts better WM performance, in EC-SCZ patients. Building on these findings, future neuromodulation-based treatment interventions applying chronic doses of TBS may more persistently ameliorate/restore DLPFC oscillatory parameters and related WM impairments in SCZ patients early during the illness, thus significantly improving their cognitive functioning and overall quality of life.