Graduate School of Hebei Medical University, China.
Qinhuangdao Municipal No. 1 Hospital, China.
Brain Res Bull. 2020 Aug;161:127-135. doi: 10.1016/j.brainresbull.2020.05.006. Epub 2020 May 18.
Ischemic stroke is one of the leading causes of death and disability worldwide. Low-intensity transcranial ultrasound stimulation (LITUS) is a promising neuroprotective treatment for ischemic stroke. Diffusion-weighted imaging (DWI) can be highly sensitive in the detection of ischemic brain injury. Relative apparent diffusion coefficient (rADC) values can be used to evaluate the effect of LITUS on ischemic stroke.
The aim of this study was to determine the neuroprotective effect of LITUS at different time points using endothelin-1-induced middle cerebral artery occlusion in rats as a model of ischemic stroke.
Endothelin-1 (ET-1) was injected into the cerebral parenchyma near the middle cerebral artery, which induced focal, reversible, low-flow ischemia in rats. After occlusion of the middle cerebral artery for 30 min, 120 min, and 240 min, LITUS stimulation was used respectively. DWI was performed at 1, 3, 6, 12, 18, 24, 48, and 72 h after ischemia using a 3 T scanner. The rADC values were calculated, and functional outcomes assessed using neurobehavioral scores after ischemia. Nissl staining and estimation of Na-K-ATPase activity were used to assess the neuropathology after completing the last Magnetic Resonance Imaging (MRI) examination.
Endothelin-1-induced occlusion of the middle cerebral artery resulted in significant dysfunction and neuronal damage in rats. Rats that received LITUS exhibited reduced damage of the affected brain tissue after cerebral ischemia. The greatest protective effect was found when LITUS stimulation occurred 30 min after cerebral ischemia.
Imaging, behavioral, and histological results suggested that LITUS stimulation after an ischemic stroke produced significant neuroprotective effects.
缺血性中风是全球范围内导致死亡和残疾的主要原因之一。低强度经颅超声刺激（LITUS）是一种有前途的缺血性中风神经保护治疗方法。弥散加权成像（DWI）在检测缺血性脑损伤方面具有高度敏感性。相对表观扩散系数（rADC）值可用于评估 LITUS 对缺血性中风的影响。
本研究旨在使用内皮素-1 诱导的大脑中动脉闭塞作为缺血性中风模型，确定 LITUS 在不同时间点的神经保护作用。
将内皮素-1（ET-1）注入大脑中动脉附近的脑实质中，诱导大鼠局灶性、可逆性、低血流缺血。大脑中动脉闭塞 30 min、120 min 和 240 min 后，分别使用 LITUS 刺激。在缺血后 1、3、6、12、18、24、48 和 72 h 使用 3 T 扫描仪进行 DWI。计算 rADC 值，并在完成最后一次磁共振成像（MRI）检查后使用神经行为评分评估功能结果。尼氏染色和 Na-K-ATPase 活性估计用于评估神经病理学。
内皮素-1 诱导的大脑中动脉闭塞导致大鼠出现明显的功能障碍和神经元损伤。接受 LITUS 治疗的大鼠在脑缺血后表现出受影响脑组织损伤减少。在脑缺血后 30 min 进行 LITUS 刺激时，观察到最大的保护作用。
影像学、行为学和组织学结果表明，缺血性中风后 LITUS 刺激产生了显著的神经保护作用。
