Department of Psychiatry and Psychotherapy, Heidelberg University, Germany.
J ECT. 2012 Dec;28(4):248-9. doi: 10.1097/YCT.0b013e318254f437.
The individual time-course of the seizure threshold (ST) in electroconvulsive therapy is mostly unknown. It is assumed that a typical seizure is followed by a short refractory period and that ST increases in the long run. We hypothesize ST to be lowered immediately after the refractory period, particularly after inadequate or abortive seizures where risk for prolonged seizures is generally higher. Ketamine anesthesia does not possess pronounced anticonvulsive properties like propofol, etomidate, thiopental, or methohexital. It is therefore ideal to test such a hypothesis. We report the case of a geriatric patient with a major depressive episode, who received 5 consecutive electroconvulsive therapies with S-ketamine, all with identical right unilateral high-energy stimulation and restimulation. Whereas all primary stimulations were inadequate, all restimulations showed significantly improved seizure parameters such as midictal amplitude, maximal postictal heart rate, and average seizure energy index. In this patient, the refractory period turned out to be longer than 1 minute, and ST was lower in all 5 instances of restimulation. This ST decrease could be clinically useful in one-session restimulations.
电抽搐治疗中个体发作阈值（ST）的时程变化大多未知。一般认为典型的发作之后会有一个短暂的不应期，而 ST 会随着时间的推移而增加。我们假设 ST 在不应期后会立即降低，特别是在发作不足或中止的情况下，因为这些情况下延长发作的风险通常更高。氯胺酮麻醉不像丙泊酚、依托咪酯、硫喷妥钠或甲己炔巴比妥那样具有明显的抗惊厥作用。因此，理想的情况下可以用它来检验这种假设。我们报告了一例老年患者，患有严重抑郁症，接受了 5 次连续的 S-氯胺酮电抽搐治疗，均采用相同的右侧单侧高能量刺激和再刺激。尽管所有的初次刺激都不足，但所有的再刺激都显示出明显改善的发作参数，如发作中期振幅、最大发作后心率和平均发作能量指数。在这名患者中，不应期超过 1 分钟，所有 5 次再刺激的 ST 均降低。这种 ST 降低在单次再刺激中可能具有临床意义。
