Electroencephalographic Measures of Delirium in the Perioperative Setting: A Systematic Review.

Postoperative delirium (POD) is frequent in older adults and is associated with adverse cognitive and functional outcomes. In the last several decades, there has been an increased interest in exploring tools that easily allow the early recognition of patients at risk of developing POD. The electroencephalogram (EEG) is a widely available tool used to understand delirium pathophysiology, and its use in the perioperative setting has grown exponentially, particularly to predict and detect POD. We performed a systematic review to investigate the use of EEG in the pre-, intra-, and postoperative settings. We identified 371 studies, and 56 met the inclusion criteria. A range of techniques was used to obtain EEG data, from limited 1-4 channel setups to complex 256-channel systems. Power spectra were often measured preoperatively, yet the outcomes were inconsistent. During surgery, the emphasis was primarily on burst suppression (BS) metrics and power spectra, with a link between the frequency and timing of BS, and POD. The EEG patterns observed in POD aligned with those noted in delirium in different contexts, suggesting a reduction in EEG activity. Further research is required to investigate preoperative EEG indicators that may predict susceptibility to delirium.

Plasma p-tau217 concordance with amyloid PET among ethnically diverse older adults.

INTRODUCTION: Commercially available plasma p-tau217 biomarker tests are not well studied in ethnically diverse samples. METHODS: We evaluated associations between ALZPath plasma p-tau217 and amyloid-beta positron emission tomography (Aß-PET) in Hispanic/Latino (88% of Cuban or South American ancestry) and non-Hispanic/Latino older adults. One- and two-cutoff ranges were derived and evaluated to assess agreement with Aß-PET. RESULTS: A total of 239 participants underwent blood draw and Aß-PET (age 70.8 ± 7.8, 55.2% female, education 15.6 ± 3.4 years, 48.9% Hispanic/Latino, 94.9% white). Plasma p-tau217 showed excellent discrimination of Aß-PET positive and negative participants (visual read: AUC = 0.91 [0.87-0.95], p < 0.001; Centiloids quantification: AUC = 0.90 [0.86-0.94]). There was a greater percent agreement between low p-tau217 and negative Aß-PET (95.8%) than high p-tau217 and positive Aß-PET (86.3%). Analyses within ethnicity-specific subgroups suggested similar p-tau217 performance. DISCUSSION: Plasma p-tau217 (ALZPath) relates to brain Aß in Hispanic/Latino and non-Hispanic/Latino older adults. Independent validation and replication are necessary to establish reference ranges and inform appropriate contexts of use across ethno-racially diverse populations. HIGHLIGHTS: Plasma p-tau217 (ALZPath) and Aß-PET were measured in Hispanic/Latino and non-Hispanic/Latino older adults.Plasma p-tau217 accurately discriminated Aß-PET positive and negative participants.Applying a two-cutoff "intermediate" plasma p-tau217 approach could reduce need for more invasive and costly testing.Plasma p-tau217 associations with Aß-PET were strong within both Hispanic/Latino and non-Hispanic/Latino groups.