Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA.
J Alzheimers Dis. 2018;62(1):319-333. doi: 10.3233/JAD-170496.
Using resting state functional magnetic resonance imaging (RS-fMRI), we explored: 1) pre- to post-operative changes in functional connectivity in default mode, salience, and central executive networks after total knee arthroplasty (TKA) with general anesthesia, and 2) the contribution of cognitive/brain reserve metrics these resting state functional declines. Individuals age 60 and older electing unilateral total knee arthroplasty (TKA; n = 48) and non-surgery peers with osteoarthritis (n = 45) completed baseline cognitive testing and baseline and post-surgery (post-baseline, 48-h post-surgery) brain MRI. We acquired cognitive and brain estimates for premorbid (vocabulary, reading, education, intracranial volume) and current (working memory, processing speed, declarative memory, ventricular volume) reserve. Functional network analyses corrected for pain severity and pain medication. The surgery group declined in every functional network of interest (p < 0.001). Relative to non-surgery peers, 23% of surgery participants declined in at least one network and 15% of the total TKA sample declined across all networks. Larger preoperative ventricular volume and lower scores on preoperative metrics of processing speed and working memory predicted default mode network connectivity decline. Premorbid cognitive and premorbid brain reserve did not predict decline. Within 48 hours after surgery, at least one fourth of the older adult sample showed significant functional network decline. Metrics of current brain status (ventricular volume), working memory, and processing speed predicted the severity of default mode network connectivity decline. These findings demonstrate the relevance of preoperative cognition and brain integrity on acute postoperative functional network change.
使用静息态功能磁共振成像 (RS-fMRI)，我们探索了：1）全麻下全膝关节置换术（TKA）后默认模式、突显和中央执行网络的功能连接的术前到术后变化，以及 2）认知/大脑储备指标对这些静息态功能下降的贡献。选择单侧全膝关节置换术（TKA；n=48）的 60 岁及以上个体和患有骨关节炎的非手术同龄人（n=45）完成基线认知测试以及基线和术后（术后基线、术后 48 小时）脑 MRI。我们获得了用于术前（词汇、阅读、教育、颅内体积）和当前（工作记忆、处理速度、陈述性记忆、脑室体积）储备的认知和大脑估计。功能网络分析针对疼痛严重程度和疼痛药物进行了校正。手术组在所有感兴趣的功能网络中均下降（p<0.001）。与非手术同龄人相比，23%的手术参与者在至少一个网络中下降，15%的总 TKA 样本在所有网络中下降。术前脑室体积较大以及术前处理速度和工作记忆指标得分较低预测默认模式网络连接下降。术前认知和术前大脑储备不能预测下降。术后 48 小时内，四分之一以上的老年样本显示出明显的功能网络下降。当前大脑状态（脑室体积）、工作记忆和处理速度的指标预测了默认模式网络连接下降的严重程度。这些发现表明术前认知和大脑完整性对急性术后功能网络变化具有重要意义。
