Li Hangdao, Sun Junfeng, Zhang Daqu, Omire-Mayor Daryl, Lewin Peter A, Tong Shanbao
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA19104, USA.
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Brain Stimul. 2017 May-Jun;10(3):695-702. doi: 10.1016/j.brs.2017.02.008. Epub 2017 Feb 27.
Preconditioning methods, which could increase tolerance of brain to subsequent ischemic injuries with a small dose of non-injury stimuli, have gained attention. Capitalizing on noninvasiveness and safety of ultrasound modality, the pulsed transcranial ultrasound stimulation (pTUS) approach may provide a novel treatment for patients with high risk of stroke.
This study's goal was to investigate whether the risk of stroke could be minimized or eliminated by prior exposure to low-intensity, pulsed transcranial ultrasound stimulation (pTUS).
Rats were randomly assigned to control (n = 12) and pTUS preconditioning (pTUS-PC) groups (n = 14). The animals in pTUS-PC group were exposed to transcranial ultrasound stimulation before the induction of photothrombotic stroke, whereas control animals were handled identically but without the ultrasound stimulation. Cerebral blood flow was monitored using laser speckle imaging in both groups during stroke induction, as well as 24 and 48 h after stroke, respectively. Also, infarct volumes and edema were measured at 48 h after stroke.
pTUS-PC rats had smaller ischemic areas during stroke induction, and 24 and 48 h after the stroke, and smaller infarct volume (1.770 ± 0.169%) than the controls (3.215 ± 0.401%) (p < 0.01). Moreover, the pTUS-PC group experienced lower volume of brain edema than the control group (pTUS-PC rats: 6.658 ± 1.183%; control rats: 12.48 ± 1.386%, p < 0.01).
These results support the hypothesis that transcranial ultrasound stimulation applied before photothrombosis could provide neuroprotection by increasing the brain's tolerance to subsequently induced focal ischemic injury.
预处理方法能够通过小剂量的非损伤性刺激来提高大脑对后续缺血性损伤的耐受性，已受到关注。利用超声模态的非侵入性和安全性，脉冲经颅超声刺激（pTUS）方法可能为中风高危患者提供一种新的治疗方法。
本研究的目的是调查预先暴露于低强度脉冲经颅超声刺激（pTUS）是否可以将中风风险降至最低或消除。
将大鼠随机分为对照组（n = 12）和pTUS预处理（pTUS - PC）组（n = 14）。pTUS - PC组的动物在光血栓性中风诱导前接受经颅超声刺激，而对照组动物的处理方式相同，但不进行超声刺激。在中风诱导期间以及中风后24小时和48小时，分别使用激光散斑成像监测两组的脑血流量。此外，在中风后48小时测量梗死体积和水肿情况。
与对照组相比，pTUS - PC组大鼠在中风诱导期间、中风后24小时和48小时的缺血面积更小，梗死体积也更小（pTUS - PC组为1.770±0.169%，对照组为3.215±0.401%，p < 0.01）。此外，pTUS - PC组的脑水肿体积低于对照组（pTUS - PC组大鼠为6.658±1.183%；对照组大鼠为12.48±1.386%，p < 0.01）。
这些结果支持以下假设，即光血栓形成前应用经颅超声刺激可通过提高大脑对随后诱导的局灶性缺血损伤的耐受性来提供神经保护。
