Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.
Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA.
Epilepsia. 2022 Jul;63(7):1799-1811. doi: 10.1111/epi.17244. Epub 2022 May 19.
Increased understanding of the role of cortical structures in respiratory control may help the understanding of seizure-induced respiratory dysfunction that leads to sudden unexpected death in epilepsy (SUDEP). The aim of this study was to characterize respiratory responses to electrical stimulation (ES), including inhibition and enhancement of respiration.
We prospectively recruited 19 consecutive patients with intractable epilepsy undergoing stereotactic electroencephalography (EEG) evaluation from June 2015 to June 2018. Inclusion criteria were patients ≥18 years in whom ES was indicated for clinical mapping of ictal onset or eloquent cortex as part of the presurgical evaluation. ES was carried out at 50 Hz, 0.2 msec, and 1-10 mA current intensity. Common brain regions sampled across all patients were amygdala (AMY), hippocampus (HG), anterior cingulate gyrus (CING), orbitofrontal cortex (OrbF), temporal neocortex (TNC), temporal pole (TP), and entorhinal cortex (ERC). Seven hundred fifty-five stimulations were conducted. Quantitative analysis of breathing signal, that is, changes in breathing rate (BR), depth (TV), and minute ventilation (MV), was carried out during ES using the BreathMetrics breathing waveform analysis toolbox. Electrocardiography, arterial oxygen saturation, end-tidal and transcutaneous carbon dioxide, nasal airflow, and abdominal and thoracic plethysmography were monitored continuously during stimulations.
Electrical stimulation of TP and CING (at lower current strengths <3 mA) increased TV and MV. At >7-10 mA, CING decreased TV and MV. On the other hand, decreased TV and MV occurred with stimulation of mesial temporal structures such as AMY and HG. Breathing changes were dependent on stimulation intensity. Lateral temporal, entorhinal, and orbitofrontal cortices did not affect breathing either way.
These findings suggest that breathing responses other than apnea can be induced by ES. Identification of two regions-the temporal pole and anterior cingulate gyrus-for enhancement of breathing may be important in paving the way to future development of strategies for prevention of SUDEP.
深入了解皮质结构在呼吸控制中的作用，可能有助于理解癫痫（SUDEP）导致的与发作相关的呼吸功能障碍。本研究旨在描述电刺激（ES）引起的呼吸反应，包括呼吸抑制和增强。
我们前瞻性地招募了 19 名连续的难治性癫痫患者，他们在 2015 年 6 月至 2018 年 6 月期间接受立体定向脑电图（EEG）评估。纳入标准为年龄≥ 18 岁的患者，其 ES 指征是作为术前评估的一部分，对发作起始或语言皮质进行临床映射。ES 以 50Hz、0.2ms 和 1-10mA 电流强度进行。所有患者共采集杏仁核（AMY）、海马（HG）、前扣带回皮质（CING）、眶额皮质（OrbF）、颞叶新皮质（TNC）、颞极（TP）和内嗅皮质（ERC）等常见脑区。共进行了 755 次刺激。使用 BreathMetrics 呼吸波分析工具箱对 ES 期间的呼吸信号（即呼吸频率（BR）、深度（TV）和分钟通气量（MV）的变化）进行定量分析。在刺激过程中连续监测心电图、动脉血氧饱和度、潮气末和经皮二氧化碳、鼻气流以及腹部和胸部体描仪。
TP 和 CING（电流强度较低的<3mA）的 ES 增加了 TV 和 MV。而在>7-10mA 时，CING 降低了 TV 和 MV。另一方面，AMY 和 HG 等内侧颞叶结构的刺激会引起 TV 和 MV 的降低。呼吸变化取决于刺激强度。外侧颞叶、内嗅皮质和眶额皮质对呼吸没有任何影响。
这些发现表明，ES 除了引起呼吸暂停外，还可以引起其他呼吸反应。确定两个区域（颞极和前扣带回皮质）可以增强呼吸，这对于未来开发预防 SUDEP 的策略可能很重要。
