(IPOD-PET2) Investigating Biomarkers in Postoperative Delirium using PET and MRI

This study focuses on the overlapping pathology of dementia and delirium. Both disorders are associated with increased morbidity, and mortality as well as significant impairments to quality of life. Both costs billions of dollars in healthcare expenses annually. Both lack adequate treatments, whether preventative or therapeutic, likely due to an inadequate understanding of disease pathogenesis. The inter-relationship between dementia and delirium is poorly understood with each condition predisposing to the other. Our working hypothesis is that delirium results as an inflammation “stress test” for the brain revealing an underlying neurodegeneration that may manifest as further cognitive decline after the insult. Several important biomarkers are shared by dementia and delirium, notably EEG slow wave activity (SWA). Our recent preliminary data show that similar to dementia, the peak of the increased SWA occurs in temporal regions in delirium. Further cerebrospinal fluid biomarkers of delirium including amyloid and total tau are altered in subjects who incur delirium, suggesting that delirium reveals an underlying tendency to dementia pathology. We hypothesize that these brain regions are predisposed to slowing by local dementia-like amyloid pathology, hence we predict that patients who incur delirium will have higher amyloid load in their brains on positron emission tomography (PET) scanning than in those that do not.
This cohort study will conduct preoperative and 1-year postoperative brain imaging on 120 participants recruited from IPOD-B3 [#2015-0374].