The hippocampus and amygdala play an important role in the pathophysiology of posttraumatic stress disorder (PTSD). In fact, chronic PTSD has been consistently linked to reductions in hippocampal and amygdala volume. However, the acute impact posttraumatic stress has on the volume of these brain regions has received limited attention. Determining the acute impact posttraumatic stress has on brain volume may improve our understanding of the development of PTSD. Therefore, the present study recruited participants acutely (i.e., ∼1-month posttrauma) following trauma exposure and examined the relationship between brain volume (assessed at ∼1-month posttrauma) and posttraumatic stress symptoms (assessed at ∼1 and >3-months posttrauma) to determine whether brain volume was associated with acute posttraumatic stress symptom expression. Twenty-one trauma-exposed (TE) patients and 19 nontrauma-exposed (NTE) controls were recruited for the present study. Brain volume was assessed by structural magnetic resonance imaging completed during the ∼1-month assessment. Left hippocampal volumes were smaller in TE than NTE participants. Among TE participants, bilateral hippocampal volumes decreased as the number of days posttrauma increased. Further, bilateral hippocampal volumes varied negatively with the severity of posttraumatic stress symptoms at ∼1-month posttrauma. The present findings suggest that there is a progressive decrease in hippocampal volume acutely (e.g., within approximately 1 month) following trauma exposure, and demonstrates that acutely assessed hippocampal volumes vary with posttraumatic stress symptom expression. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

---

海马体积随医疗创伤后的急性创伤后应激症状而变化。

海马体和杏仁核在创伤后应激障碍 (PTSD) 的病理生理学中起重要作用。事实上，慢性创伤后应激障碍一直与海马和杏仁核体积的减少有关。然而，创伤后压力对这些大脑区域体积的严重影响受到的关注有限。确定创伤后压力对脑容量的急性影响可能会提高我们对 PTSD 发展的理解。因此，本研究在创伤暴露后立即招募参与者（即，创伤后大约 1 个月），并检查脑容量（在创伤后大约 1 个月时评估）与创伤后应激症状（在大约 1 个月和 > 3 个月时评估）之间的关系posttrauma) 以确定脑容量是否与急性创伤后应激症状表达相关。本研究招募了 21 名创伤暴露 (TE) 患者和 19 名非创伤暴露 (NTE) 对照。通过在约 1 个月的评估期间完成的结构磁共振成像评估脑容量。TE 的左侧海马体积小于 NTE 参与者。在 TE 参与者中，双侧海马体积随着创伤后天数的增加而减少。此外，双侧海马体积随着创伤后约 1 个月的创伤后应激症状的严重程度而呈负向变化。目前的研究结果表明，外伤暴露后海马体积急剧地（例如，在大约 1 个月内）逐渐减少，并表明急性评估的海马体积随创伤后应激症状的表现而变化。（PsycInfo 数据库记录 (c) 2021 APA，