Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan, Taiwan.
Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
J Neural Eng. 2020 Nov 4;17(5):056030. doi: 10.1088/1741-2552/abb14d.
Greater occipital nerve (GON) block may provide substantial relief for headache in the occipital location. This study tested the feasibility of focused ultrasound (FUS) to induce the conduction block of GONs in rats.
For in vitro experiments, the nerve was dissected and cut from C2 to the site near the ear of the rats and preserved in Ringer's solution. Pulsed FUS was used for the block, and sensory action potentials were recorded in the GON. For in vivo experiments, the GONs of the rats were surgically exposed for precise ultrasonic treatment. All data are expressed as the mean ± the standard deviation.
A single ultrasonic treatment temporarily suppressed the amplitude of action potentials of the in vitro nerves to 42 ± 14% of the baseline values, and the time to recovery was 55 min. The in vivo results showed that FUS acutely inhibited the amplitude of action potentials to 41 ± 8% of the baseline value in rat GONs, and the time to recovery was 67 min. Histological examination revealed no appreciable changes in the nerve morphology caused by FUS. Therefore, FUS reversibly blocked the conduction of the rat GON when the sonication parameters were appropriate.
Noninvasive FUS may be a novel treatment paradigm for occipital headache by blocking the occipital nerve, and the procedure is repeatable if indicated.
枕大神经（GON）阻滞可能为枕部头痛提供显著缓解。本研究旨在测试聚焦超声（FUS）诱导大鼠 GON 传导阻滞的可行性。
在体外实验中，将神经从 C2 解剖并切断至大鼠耳部附近，并保存在 Ringer 溶液中。采用脉冲 FUS 进行阻滞，并记录 GON 中的感觉动作电位。在体内实验中，对大鼠的 GON 进行手术暴露以进行精确的超声治疗。所有数据均表示为平均值±标准差。
单次超声治疗可使体外神经的动作电位幅度暂时抑制至基线值的 42±14%，恢复时间为 55 分钟。体内结果显示，FUS 可使大鼠 GON 中的动作电位幅度急剧抑制至基线值的 41±8%，恢复时间为 67 分钟。组织学检查显示 FUS 对神经形态没有明显的影响。因此，在适当的超声参数下，FUS 可可逆地阻断大鼠 GON 的传导。
非侵入性 FUS 可能通过阻断枕大神经成为治疗枕部头痛的一种新方法，如果需要，可以重复该过程。
