title: 2-18F-fluoro-2-deoxyglucose positron emission tomography in delirium.
abstract: Delirium is a common, serious, yet poorly understood syndrome. Growing evidence suggests cerebral metabolism is fundamentally disturbed; however, it has not been investigated using 2-18F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in delirium. This prospective study thus explored FDG PET patterns of cerebral glucose metabolism in older inpatients with delirium. A particular emphasis was on the posterior cingulate cortex (PCC), a key region for attention, which is a central feature of delirium. Delirium scans were compared with post-delirium scans using visual analysis and semi-quantitative analysis with NeuroQ; 13 participants (8 female, median 84 y) were scanned during delirium, and 6 scanned again after resolution. On visual analysis, cortical hypometabolism was evident in all participants during delirium (13/13), and improved with delirium resolution (6/6). Using NeuroQ, glucose metabolism was higher post-delirium in the whole brain and bilateral PCC compared to during delirium ( p < 0.05). Greater metabolism in both PCCs correlated with better performance on a neuropsychological test of attention, the WAIS-IV Digit Span Test forwards, and with shorter delirium duration. This research found widespread, reversible cortical hypometabolism during delirium and PCC hypometabolism was associated with inattention during delirium.
authors.affiliation: 1 Faculty of Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Haggstrom
authors.affiliation: 2 Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Nelson
authors.affiliation: 2 Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Eva A
authors.initials: EA
authors.lastname: Wegner
authors.affiliation: 1 Faculty of Medicine, University of New South Wales, Sydney, Australia.|2 Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Gideon A
authors.initials: GA
authors.lastname: Caplan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention; D003693:Delirium / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose
keywords: Fluorodeoxyglucose F18; cerebral metabolism; delirium; functional neuroimaging; positron emission tomography