Peterchev Angel V, Krystal Andrew D, Rosa Moacyr A, Lisanby Sarah H
1] Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA [2] Department of Biomedical Engineering, Duke University, Durham, NC, USA [3] Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA.
Neuropsychopharmacology. 2015 Aug;40(9):2076-84. doi: 10.1038/npp.2015.122. Epub 2015 Apr 28.
Electroconvulsive therapy (ECT) at conventional current amplitudes (800-900 mA) is highly effective but carries the risk of cognitive side effects. Lowering and individualizing the current amplitude may reduce side effects by virtue of a less intense and more focal electric field exposure in the brain, but this aspect of ECT dosing is largely unexplored. Magnetic seizure therapy (MST) induces a weaker and more focal electric field than ECT; however, the pulse amplitude is not individualized and the minimum amplitude required to induce a seizure is unknown. We titrated the amplitude of long stimulus trains (500 pulses) as a means of determining the minimum current amplitude required to induce a seizure with ECT (bilateral, right unilateral, bifrontal, and frontomedial electrode placements) and MST (round coil on vertex) in nonhuman primates. Furthermore, we investigated a novel method of predicting this amplitude-titrated seizure threshold (ST) by a non-convulsive measurement of motor threshold (MT) using single pulses delivered through the ECT electrodes or MST coil. Average STs were substantially lower than conventional pulse amplitudes (112-174 mA for ECT and 37.4% of maximum device amplitude for MST). ST was more variable in ECT than in MST. MT explained 63% of the ST variance and is hence the strongest known predictor of ST. These results indicate that seizures can be induced with less intense electric fields than conventional ECT that may be safer; efficacy and side effects should be evaluated in clinical studies. MT measurement could be a faster and safer alternative to empirical ST titration for ECT and MST.
传统电流幅度（800 - 900毫安）的电休克疗法（ECT）非常有效，但存在认知副作用的风险。降低电流幅度并使其个体化，可能由于在大脑中产生的电场强度较低且更具局限性，从而减少副作用，但ECT剂量的这一方面在很大程度上尚未得到充分探索。磁惊厥疗法（MST）诱导的电场比ECT更弱且更具局限性；然而，脉冲幅度未个体化，且诱导惊厥所需的最小幅度尚不清楚。我们对长刺激序列（500个脉冲）的幅度进行滴定，以确定在非人类灵长类动物中，使用ECT（双侧、右侧单侧、双额叶和额内侧电极放置）和MST（顶点圆形线圈）诱导惊厥所需的最小电流幅度。此外，我们研究了一种新方法，即通过使用经ECT电极或MST线圈传递的单个脉冲对运动阈值（MT）进行非惊厥性测量，来预测这种幅度滴定的惊厥阈值（ST）。平均ST显著低于传统脉冲幅度（ECT为112 - 174毫安，MST为最大设备幅度的37.4%）。ECT中的ST比MST更具变异性。MT解释了ST方差的63%，因此是已知最强的ST预测因子。这些结果表明，与传统ECT相比，使用强度较低的电场也可诱导惊厥，这可能更安全；疗效和副作用应在临床研究中进行评估。对于ECT和MST，MT测量可能是一种比经验性ST滴定更快、更安全的替代方法。
