Department of Neurology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan.
Department of Neurology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan.
Clin Neurophysiol. 2024 Nov;167:92-105. doi: 10.1016/j.clinph.2024.09.001. Epub 2024 Sep 11.
Transcranial focused ultrasound (TUS) can suppress human motor cortical excitability. However, it is unclear whether the TUS may interact with transcranial magnetic stimulation (TMS) when they co-delivered in multiple trials.
Nineteen subjects received three different TUS-TMS co-stimulation protocols to the motor cortex including concurrent stimulation (TUS-TMS-C), separated stimulation (TUS-TMS-S), and TMS only. In each condition, two runs of 30 stimulation trials were conducted with a five-minute rest between runs. Motor-evoked potentials (MEP) were recorded during stimulation and at 0, 10, 20, and 30 min after stimulation. The MEP amplitudes after intervention were normalized to the mean pre-intervention MEP amplitude and expressed as MEP ratios. An additional test with TUS alone was applied to all participants to assess whether TUS itself can elicit after-effects.
There were no significant after-effects of all three interventions on MEP ratios. However, 11 subjects who showed online inhibition (OI + ) during the TUS-TMS-C protocol, defined as having MEP ratio less than 1 during TUS-TMS-C, showed significant MEP suppression at 10, 20 and 30 min after TUS-TMS-C. In 8 subjects did not show online inhibition (OI-), defined as having MEP ratios greater than 1 during TUS-TMS-C, showed no significant inhibitory after-effects. OI + and OI- status did not change in a follow-up repeat TUS-TMS-C test. TUS alone did not generate inhibitory after-effects in either OI + or OI- participants.
Our results showed that co-delivery of TUS and TMS can elicit inhibitory after-effect in subjects who showed online inhibition, suggesting that TUS and TMS may interact with each other to produce plasticity effects.
TUS and TMS may interact with each other to modulate cortical excitability.
经颅聚焦超声（TUS）可抑制人类运动皮质兴奋性。然而，当它们在多次试验中共同传递时，TUS 是否可能与经颅磁刺激（TMS）相互作用尚不清楚。
19 名受试者接受了三种不同的 TUS-TMS 联合刺激方案，包括同时刺激（TUS-TMS-C）、分开刺激（TUS-TMS-S）和仅 TMS。在每种情况下，在两次共 30 次刺激试验中进行，两次试验之间休息 5 分钟。在刺激期间以及刺激后 0、10、20 和 30 分钟记录运动诱发电位（MEP）。干预后的 MEP 幅度与干预前平均 MEP 幅度归一化，并表示为 MEP 比。所有参与者均进行了单独的 TUS 测试，以评估 TUS 本身是否可以引起后效。
三种干预措施均未对 MEP 比产生明显的后效。然而，在 TUS-TMS-C 方案中显示在线抑制（OI+）的 11 名受试者，定义为在 TUS-TMS-C 期间 MEP 比小于 1，在 TUS-TMS-C 后 10、20 和 30 分钟显示出明显的 MEP 抑制。在 8 名未显示在线抑制（OI-）的受试者中，定义为在 TUS-TMS-C 期间 MEP 比大于 1，未显示出明显的抑制后效。OI+和 OI-状态在后续重复 TUS-TMS-C 测试中没有改变。无论是 OI+还是 OI-受试者，TUS 单独使用均未产生抑制后效。
我们的结果表明，在显示在线抑制的受试者中，TUS 和 TMS 的共同传递可引起抑制性后效，这表明 TUS 和 TMS 可能相互作用以产生可塑性效应。
TUS 和 TMS 可能相互作用以调节皮质兴奋性。
