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A systematic review of neuroimaging in delirium: predictors, correlates and consequences
Author(s) -
Nitchingham Anita,
Kumar Varun,
Shenkin Susan,
Ferguson Karen J.,
Caplan Gideon A.
Publication year - 2018
Publication title -
international journal of geriatric psychiatry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 129
eISSN - 1099-1166
pISSN - 0885-6230
DOI - 10.1002/gps.4724
Subject(s) - delirium , neuroimaging , hyperintensity , medicine , functional neuroimaging , psychology , magnetic resonance imaging , white matter , diffusion mri , intensive care medicine , psychiatry , radiology
Objective Neuroimaging advances our understanding of delirium pathophysiology and its consequences. A previous systematic review identified 12 studies (total participants N = 764, delirium cases N = 194; years 1989–2007) and found associations with white matter hyperintensities (WMH) and cerebral atrophy. Our objectives were to perform an updated systematic review of neuroimaging studies in delirium published since January 2006 and summarise the available literature on predictors, correlates or outcomes. Methods Studies were identified by keyword and MeSH‐based electronic searches of EMBASE, MEDLINE and PsycINFO combining terms for neuroimaging, brain structure and delirium. We included neuroimaging studies of delirium in adults using validated delirium assessment methods. Results Thirty‐two studies (total N = 3187, delirium N = 1086) met the inclusion criteria. Imaging included magnetic resonance imaging (MRI; N = 9), computed tomography ( N = 4), diffusion tensor imaging ( N = 3), transcranial Doppler ( N = 5), near infrared spectroscopy ( N = 5), functional‐MRI ( N = 2), single photon emission computed tomography ( N = 1), proton MRI spectroscopy ( N = 1), arterial spin‐labelling MRI ( N = 1) and 2‐ 13 fluoro‐2‐deoxyglucose positron emission tomography ( N = 1). Despite heterogeneity in study design, delirium was associated with WMH, lower brain volume, atrophy, dysconnectivity, impaired cerebral autoregulation, reduced blood flow and cerebral oxygenation and glucose hypometabolism. There was evidence of long‐term brain changes following intensive care unit delirium. Conclusions Neuroimaging is now used more widely in delirium research due to advances in technology. However, imaging delirious patients presents challenges leading to methodological limitations and restricted generalisability. The findings that atrophy and WMH burden predict delirium replicates findings from the original review, while advanced techniques have identified other substrates and mechanisms that warrant further investigation.