Best Faith V, Hartings Jed A, Ngwenya Laura B
Department of Neurosurgery, University of Cincinnati, Cincinnati, OH 45267, USA; Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45267, USA.
Department of Neurosurgery, University of Cincinnati, Cincinnati, OH 45267, USA.
Exp Neurol. 2025 Mar;385:115120. doi: 10.1016/j.expneurol.2024.115120. Epub 2024 Dec 20.
Cortical spreading depolarizations (CSDs) are the most common electrophysiological dysfunction following a traumatic brain injury (TBI), and clustered CSDs (≥3 CSDs in 2 h) are associated with poor outcomes 6 months after TBI. While many experimental studies have investigated a single CSD after injury, no known studies have investigated how time after injury affects the characteristics and impact of a CSD cluster. This study sought to determine the characteristics of a cluster of repetitive CSDs when induced at three different time points after moderate experimental TBI. Adult male Sprague Dawley rats underwent a lateral fluid percussion or sham injury, and repetitive CSDs were induced 0-, 3-, or 7-days post injury (dpi). Properties were analyzed from 2-h-long electrocorticographic (ECoG) and laser Doppler flowmetry (LDF) recordings. We did not observe deterioration of CSDs (2-Way ANOVA, p = 0.3572), depressions of background electrical activity (p = 0.0991), or hemodynamic responses (p = 0.1298) over the course of the recording. Repetitive CSD direct current shift durations were the longest when induced at 0dpi (p = 0.0161), while the durations of CSDs induced at 3dpi and 7dpi were similar to CSD durations in uninjured tissue (p = 0.9857). No differences were seen in the depression of background activity duration (p = 0.1901), and normal hemodynamic responses were observed at each time point. These findings confirm that CSDs are prolonged in impaired tissue and suggest that the impaired tissue may be more at risk of further damage when repetitive CSDs occur early after injury.
皮质扩散性抑制（CSDs）是创伤性脑损伤（TBI）后最常见的电生理功能障碍，而簇状CSDs（2小时内≥3次CSDs）与TBI后6个月的不良预后相关。虽然许多实验研究调查了损伤后的单次CSD，但尚无已知研究调查损伤后的时间如何影响CSD簇的特征和影响。本研究旨在确定中度实验性TBI后三个不同时间点诱导的重复性CSD簇的特征。成年雄性Sprague Dawley大鼠接受侧方液压冲击或假手术损伤，并在损伤后0、3或7天（dpi）诱导重复性CSD。从长达2小时的脑电图（ECoG）和激光多普勒血流仪（LDF）记录中分析相关特性。在记录过程中，我们未观察到CSDs的恶化（双向方差分析，p = 0.3572）、背景电活动的抑制（p = 0.0991）或血流动力学反应（p = 0.1298）。重复性CSD的直流偏移持续时间在0dpi诱导时最长（p = 0.0161），而在3dpi和7dpi诱导的CSD持续时间与未损伤组织中的CSD持续时间相似（p = 0.9857）。背景活动抑制持续时间未见差异（p = 0.1901），且在每个时间点均观察到正常的血流动力学反应。这些发现证实了CSDs在受损组织中会延长，并表明当重复性CSDs在损伤后早期发生时，受损组织可能更易遭受进一步损伤。
