BACKGROUND: 

Previous studies suggest a role of the thalamus in cognitive function, while others implicate it as a central effect site of anesthetics. Yet, its role in postoperative neurocognition in the aging brain remains uncertain. We used presurgical thalamic volume as a functional indicator and determined its association with postoperative delirium (POD).

METHODS: 

For this study, 301 older adults (aged ≥65) without dementia and scheduled for surgery were enrolled. Before surgery, participants underwent magnetic resonance imaging (MRI). Thalamus volume was segmented using Freesurfer (Version 5.3.). Participants were screened for POD twice a day until discharge or for a maximum of 7 days. POD was defined as a positive screening on ≥1 of 4 validated instruments: Richmond Agitation Sedation Scale (RASS), Nursing Delirium Screening Scale (Nu-DESC), Confusion Assessment Method (CAM), and Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) score. A logistic regression associated thalamus volume with POD with adjustment for age, global brain atrophy, and physical status according to the American Society of Anesthesiologists (ASA) classification.

RESULTS: 

In this cohort, 44 participants (14.6%) were diagnosed with POD. Independently of age, global brain atrophy, and physical status score, a higher preoperative thalamus volume was associated with a reduced odds of POD (odds ratio per 1-cm³ increment; 0.73 [95% confidence interval (CI), 0.58–0.92]; P = .008).

CONCLUSIONS: 

A larger thalamus volume was associated with reduced odds of POD. Thus, the thalamus marks a region of interest in POD in the aging brain. These findings may help to understand the neuronal basis of POD.

中文翻译：

---

术后谵妄的术前丘脑体积：老年患者的纵向观察队列研究

背景： 

先前的研究表明丘脑在认知功能中发挥着重要作用，而其他研究则表明它是麻醉剂的中枢作用部位。然而，它在老化大脑术后神经认知中的作用仍不确定。我们使用术前丘脑体积作为功能指标，并确定其与术后谵妄（POD）的关联。

方法： 

在这项研究中，招募了 301 名没有痴呆症且计划接受手术的老年人（年龄≥65 岁）。手术前，参与者接受了磁共振成像（MRI）。使用 Freesurfer（5.3 版）对丘脑体积进行分割。参与者每天接受两次 POD 筛查，直至出院或最多 7 天。POD 被定义为 4 种经过验证的仪器中≥1 种的阳性筛查：里士满激动镇静量表 (RASS)、护理谵妄筛查量表 (Nu-DESC)、意识模糊评估方法 (CAM) 和重症监护病房意识模糊评估方法 ( CAM-ICU）评分。根据美国麻醉医师协会 (ASA) 分类，根据年龄、全脑萎缩和身体状况进行调整后，将丘脑体积与 POD 相关联的逻辑回归。

结果： 

在该队列中，44 名参与者 (14.6%) 被诊断患有 POD。独立于年龄、全脑萎缩和身体状况评分，术前较高的丘脑体积与 POD 几率降低相关（每 1-cm ³增量的几率比；0.73 [95% 置信区间 (CI)，0.58–0.92] ；P = .008)。

结论： 

丘脑体积越大，POD 发生率越低。因此，丘脑标志着衰老大脑中 POD 的一个感兴趣区域。这些发现可能有助于理解 POD 的神经元基础。