Reply: Neural substrates of vulnerability to post-surgical delirium with prospective diagnosis.
Reply: Neural substrates of vulnerability to post-surgical delirium with prospective diagnosis.
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答复:具有前瞻性诊断的术后谵妄易感性的神经基础。
DOI:
10.1093/brain/aww150
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发表时间:
2016
期刊:
影响因子:
--
通讯作者:
SAGESStudyGroup
中科院分区:
文献类型:
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作者:
Cavallari,Michele;Guttmann,CharlesRG;Jones,RichardN;Inouye,SharonK;Alsop,DavidC;SAGESStudyGroup
Sir, In investigating the association between microstructural brain abnormalities and postoperative delirium we had no a priori hypotheses regarding specific brain networks. Our findings, obtained through such an unbiased approach, supported the hypothesis that impaired connectivity across neural networks involved in cognitive and behavioural tasks predisposes to delirium under the stress of surgery (Cavallari et al., 2016). Specifically, we found that presurgical diffusion abnormalities in connections and nodes of brain networks involved in attention (eg frontoparietal control network, cerebellum), memory (eg hippocampus), arousal (eg basal forebrain), and coordinated activities (eg thalamus, corpus callosum) predisposed to postsurgical delirium. A potential pathogenic role of damage to those networks had been previously hypothesized (Ross, 1991; Sanders, 2011) based on case reports of cerebrovascular or multiple sclerosis lesions in strategic locations (for a review see Alsop et al., 2006), as well as on more recent functional MRI and diffusion tensor imaging (DTI) studies of delirium (Choi et al., 2012; Morandi et al., 2012; Shioiri et al., 2010). Our findings support the dysconnectivity hypothesis of delirium in a larger, prospective cohort of dementia-free older individuals.The choice of delirium measures to investigate its neural correlates can significantly impact the ability to detect associations that may help elucidate its intricate pathophysiology. Although useful in clinical practice, dichotomous measures, such as delirium occurrence, may not be ideal due to the intrinsic loss of information on variability associated with categorization (Altman, 2006; Rothman et al., 2008) and potential misclassification of subsyndromal or partial forms. As continuous measures better reflects the intrinsic nature of delirium as a spectrum disorder, characterized by a continuum between no symptoms, subsyndromal, and the full delirium syndrome, we decided to use delirium severity as the main outcome measure in our primary analysis. Peak CAM-Severity (CAM-S) score, defined as the highest CAMS score of all daily hospital assessments regardless of whether or not the patient was delirious, was used to indicate delirium severity in our analyses. Therefore, our main finding of diffusion abnormalities associated with delirium severity has the advantage of being independent from the diagnostic criteria applied to classify delirium status. The use of delirium severity as the main outcome allowed us to utilize the entire sample since all the study participants had daily CAM ratings; thus, the chart review approach for diagnosis did not pertain to this analysis.