An exploratory research report on brain mineralization in postoperative delirium and cognitive decline

• Published in: The European journal of neuroscience Vol. 59; no. 10; pp. 2646 - 2664
• Main Authors: Lammers‐Lietz, Florian, Borchers, Friedrich, Feinkohl, Insa, Hetzer, Stefan, Kanar, Cicek, Konietschke, Frank, Lachmann, Gunnar, Chien, Claudia, Spies, Claudia, Winterer, Georg, Zaborszky, Laszlo, Zacharias, Norman, Paul, Friedemann
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.05.2024
• Subjects: Aged; Aged, 80 and over; anaesthesia; Basal forebrain; Basal ganglia; basal nucleus of Meynert; Brain - diagnostic imaging; Brain - metabolism; cholinergic system; Cholinergic transmission; Cognition; Cognitive ability; Cognitive Dysfunction - etiology; Cognitive Dysfunction - physiopathology; Complications; Delirium; Delirium - etiology; Female; Forebrain; Humans; Magnetic Resonance Imaging; Male; Mineralization; Neurodegenerative diseases; Neuroimaging; Postoperative; Postoperative Cognitive Complications; postoperative cognitive dysfunction; Postoperative Complications; Surgery; susceptibility weighted imaging; magnetic resonance imaging; postoperative cognitive dysfunction; cholinergic system; basal nucleus of Meynert; susceptibility weighted imaging; delirium; anaesthesia; surgery
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.16282

Delirium is a severe postoperative complication associated with poor overall and especially neurocognitive prognosis. Altered brain mineralization is found in neurodegenerative disorders but has not been studied in postoperative delirium and postoperative cognitive decline. We hypothesized that mineralization‐related hypointensity in susceptibility‐weighted magnetic resonance imaging (SWI) is associated with postoperative delirium and cognitive decline. In an exploratory, hypothesis‐generating study, we analysed a subsample of cognitively healthy patients ≥65 years who underwent SWI before (N = 65) and 3 months after surgery (N = 33). We measured relative SWI intensities in the basal ganglia, hippocampus and posterior basal forebrain cholinergic system (pBFCS). A post hoc analysis of two pBFCS subregions (Ch4, Ch4p) was conducted. Patients were screened for delirium until the seventh postoperative day. Cognitive testing was performed before and 3 months after surgery. Fourteen patients developed delirium. After adjustment for age, sex, preoperative cognition and region volume, only pBFCS hypointensity was associated with delirium (regression coefficient [90% CI]: B = −15.3 [−31.6; −0.8]). After adjustments for surgery duration, age, sex and region volume, perioperative change in relative SWI intensities of the pBFCS was associated with cognitive decline 3 months after surgery at a trend level (B = 6.8 [−0.9; 14.1]), which was probably driven by a stronger association in subregion Ch4p (B = 9.3 [2.3; 16.2]). Brain mineralization, particularly in the cerebral cholinergic system, could be a pathomechanism in postoperative delirium and cognitive decline. Evidence from our studies is limited because of the small sample and a SWI dataset unfit for iron quantification, and the analyses presented here should be considered exploratory.