Ahmanson-Lovelace Brain Mapping Center, University of California Los Angeles, Los Angeles, California; Department of Radiology, Northwestern University, Chicago, Illinois.
Ahmanson-Lovelace Brain Mapping Center, University of California Los Angeles, Los Angeles, California.
Biol Psychiatry. 2019 Mar 15;85(6):466-476. doi: 10.1016/j.biopsych.2018.09.021. Epub 2018 Oct 5.
Converging evidence suggests that electroconvulsive therapy (ECT) induces neuroplasticity in patients with severe depression, though how this relates to antidepressant response is less clear. Arterial spin-labeled functional magnetic resonance imaging tracks absolute changes in cerebral blood flow (CBF) linked with brain function and offers a potentially powerful tool when observing neurofunctional plasticity with functional magnetic resonance imaging.
Using arterial spin-labeled functional magnetic resonance imaging, we measured global and regional CBF associated with clinically prescribed ECT and therapeutic response in patients (n = 57, 30 female) before ECT, after two treatments, after completing an ECT treatment "index" (∼4 weeks), and after long-term follow-up (6 months). Age- and sex-matched control subjects were also scanned twice (n = 36, 19 female), ∼4 weeks apart.
Patients with lower baseline global CBF were more likely to respond to ECT. Regional CBF increased in the right anterior hippocampus in all patients irrespective of clinical outcome, both after 2 treatments and after ECT index. However, hippocampal CBF increases postindex were more pronounced in nonresponders. ECT responders exhibited CBF increases in the dorsomedial thalamus and motor cortex near the vertex ECT electrode, as well as decreased CBF within lateral frontoparietal regions.
ECT induces functional neuroplasticity in the hippocampus, which could represent functional precursors of ECT-induced increases in hippocampal volume reported previously. However, excessive functional neuroplasticity within the hippocampus may not be conducive to positive clinical outcome. Instead, our results suggest that although hippocampal plasticity may contribute to antidepressant response in ECT, balanced plasticity in regions relevant to seizure physiology including thalamocortical networks may also play a critical role.
越来越多的证据表明，电抽搐治疗（ECT）可在重度抑郁症患者中诱导神经可塑性，尽管其与抗抑郁反应的关系尚不清楚。动脉自旋标记功能磁共振成像可追踪与脑功能相关的脑血流（CBF）的绝对变化，当使用功能磁共振成像观察神经功能可塑性时，它提供了一种潜在的强大工具。
我们使用动脉自旋标记功能磁共振成像，在 ECT 治疗前、两次治疗后、完成 ECT 治疗“指数”（约 4 周）后以及长期随访（6 个月）后，测量了与临床规定的 ECT 相关的患者（n=57，30 名女性）的全局和区域 CBF 以及治疗反应。还对年龄和性别匹配的对照组进行了两次扫描（n=36，19 名女性），间隔约 4 周。
基线时 CBF 较低的患者更有可能对 ECT 产生反应。所有患者的右侧前海马区 CBF 在两次治疗后和 ECT 指数后均增加，无论临床结局如何。然而，无反应者的指数后海马 CBF 增加更为明显。ECT 反应者表现出背内侧丘脑和顶点 ECT 电极附近运动皮层的 CBF 增加，以及外侧额顶叶区域的 CBF 减少。
ECT 可诱导海马的功能性神经可塑性，这可能代表先前报道的 ECT 诱导的海马体积增加的功能性前体。然而，海马内过度的功能性神经可塑性可能不利于积极的临床结局。相反，我们的结果表明，尽管海马可塑性可能有助于 ECT 的抗抑郁反应，但与癫痫生理学相关的区域（包括丘脑皮质网络）的平衡可塑性也可能发挥关键作用。
