Keywords

Functional brain imaging, Critical illness, Delirium

Abstract

Purpose

We undertook this pilot prospective cohort investigation to examine the feasibility of functional magnetic resonance imaging (fMRI) assessments in survivors of critical illness and to analyze potential associations between delirium and brain activation patterns observed during a working memory task (N-back) at hospital discharge and 3-month follow-up.

Materials and methods

At hospital discharge and 3 months later, fMRI assessed subjects' functional activity during an N-back task. Multiple linear regression was used to examine associations between duration of delirium and brain activity, and elastic net regression was used to assess the relationship between brain activation patterns at 3 months and cognitive outcomes at 12 months.

Results

Of 47 patients who underwent fMRI at discharge, 38 (80%) completed the protocol; of 37 who underwent fMRI at 3 months, 34 (91%) completed the protocol. At discharge, the mean (SD) percentage of correct responses on the most challenging version (the N2 version) of the N-back task was 70.4 (23.2; range of 20-100) compared with 76 (23.4; range of 33-100) at 3 months. No association was observed between delirium duration in the hospital and brain region activity in any brain region at discharge or 3 months after adjusting for relevant covariates (P values across all 11 brain regions of interest were >.25).

Conclusions

Our data support the feasibility of using fMRI in survivors of critical illness at 3-month follow-up but not at discharge. In this small study, delirium was not associated with distinct or abnormal brain activation patterns, although overall performance on a cognitive task of working memory was poorer than observed in other cohorts of individuals with medically related executive dysfunction, mild cognitive impairment, and mild traumatic brain injury.

Original Publication Citation

Jackson JC, Morandi A, Girard TD, Graves AJ, Thompson JL, Shintani AK, Gunther ML, Cannistraci CJ, Rogers BP, Gore JC, Ely EW, Hopkins RO for the VISIONS (VISualizing Icu SurvivOrs Neuroradiological Sequelae) Investigation. (2015). Functional brain imaging in survivors of critical illness: A prospective feasibility study and exploration of the association between delirium and brain activation patterns. Journal of Critical Care, 30(3), 653, e1-7.

Document Type

Peer-Reviewed Article

Publication Date

2016-06-01

Publisher

J Crit. Care

Language

English

College

Family, Home, and Social Sciences

Department

Psychology

University Standing at Time of Publication

Full Professor

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Psychology Commons

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