Speer Andrew M, Willis Mark W, Herscovitch Peter, Daube-Witherspoon Margaret, Shelton Jennifer Repella, Benson Brenda E, Post Robert M, Wassermann Eric M
Biological Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Building 10 Room 5N234, Bethesda, MD 20892-1430, USA.
Biol Psychiatry. 2003 Oct 15;54(8):826-32. doi: 10.1016/s0006-3223(03)00324-x.
The changes in brain activity produced by repetitive transcranial magnetic stimulation (rTMS) of the prefrontal cortex (PFC) remain unclear. We examined intensity-related changes in brain activity with positron emission tomography (PET) in normal volunteers during rTMS delivered to the left PFC.
In 10 healthy volunteers, we delivered 1-Hz rTMS at randomized intensities over left PFC with a figure-eight coil. Intensities were 80, 90, 100, 110, and 120% of the right-hand muscle twitch threshold. Regional cerebral blood flow (rCBF) scans were acquired with H(2)(15)O PET during rTMS at each intensity.
Repetitive transcranial magnetic stimulation intensity was inversely correlated with rCBF in the stimulated and contralateral PFC, ipsilateral medial temporal lobe, both parahippocampi, and posterior middle temporal gyri. Positive correlations of rCBF with intensity occurred in ipsilateral anterior cingulate, cerebellum, contralateral insula, primary auditory cortex, and somatosensory face area.
The intensity-related inverse relationship between 1-Hz rTMS and prefrontal activity appears opposite to that seen with rTMS over the motor cortex in a companion study. Intensity-dependent increases in rCBF were seen in a number of distant cortical and subcortical areas with PFC rTMS, suggesting activation of left anterior cingulate, claustrum, and cerebellum. The regional differences in direction of rTMS effects and the greater activation of distant structures at higher intensities suggest the potential importance of higher-intensity prefrontal rTMS for therapeutic applications in neuropsychiatric patients.
经颅磁刺激（rTMS）对前额叶皮质（PFC）产生的大脑活动变化尚不清楚。我们在正常志愿者接受左侧PFC的rTMS过程中，使用正电子发射断层扫描（PET）检查了与强度相关的大脑活动变化。
在10名健康志愿者中，我们使用八字形线圈以随机强度对左侧PFC进行1赫兹的rTMS。强度为右手肌肉抽搐阈值的80%、90%、100%、110%和120%。在每个强度的rTMS期间，使用H₂¹⁵O PET进行局部脑血流（rCBF）扫描。
重复经颅磁刺激强度与受刺激侧和对侧PFC、同侧内侧颞叶、双侧海马旁回以及颞中回后部的rCBF呈负相关。rCBF与强度的正相关出现在同侧前扣带回、小脑、对侧岛叶、初级听觉皮层和躯体感觉面部区域。
在一项配套研究中，1赫兹rTMS与前额叶活动之间强度相关的反比关系似乎与运动皮层的rTMS情况相反。PFC的rTMS在许多远处的皮质和皮质下区域可见rCBF强度依赖性增加，提示左侧前扣带回、屏状核和小脑被激活。rTMS效应方向的区域差异以及高强度时远处结构的更大激活表明高强度前额叶rTMS在神经精神疾病患者治疗应用中的潜在重要性。
