Resting-state Functional MRI as an Assessment Tool in Acute Disorders of Consciousness: A Systematic Review
Karnig Kazazian1, Danelle Czink1, Adrian Owen1, Loretta Norton2
1Western University, 2King's University College at Western University
Objective:
To synthesize current evidence on the prognostic utility of resting state functional fMRI in acute disorders of consciousness (DoC).
Background:
Rs-fMRI measures spontaneous, temporally correlated brain activity in the absence of external stimulation, providing objective insight into the integrity of large-scale neural networks. Emerging evidence suggests that rs-fMRI can improve prognostication in patients with acute DoC following severe brain injury in the intensive care unit (ICU) with greater precision than standard clinical or structural imaging tools.
Design/Methods:
A systematic search of Embase and MEDLINE was conducted in June 2025 for studies published from 2006 onward. Eligible articles included peer-reviewed empirical studies enrolling adult patients with an acute DoC (<28 days post-onset) in whom resting-state fMRI was acquired and outcome metrics were reported. Studies focusing exclusively on chronic DoC were excluded.
Results:
25 of 351 screen studies met eligibility in which a formal analysis was conducted between acute rs-fMRI measures and outcome metrics, in 601 patients. fMRI was acquired 11.15 +/- 11.28 days after ICU admission. Eight studies focused on traumatic brain injury patients, 8 on cardiac arrest, 1 on encephalopathy, and 8 included a mixture of etiologies. The most assessed resting-state networks were the default mode network (n=17), executive control (n=9), visual (n=5), auditory (n=5), salience (n=5), and sensorimotor (n=5). Despite significant variation existing across studies, 24 out of 25 demonstrated a statistically significant relationship between acute rs-fMRI measures and the extent of functional and neurological recovery. Outcomes focused on recovery of consciousness and functional or neurological status, commonly evaluated at discharge or within 3–12 months of injury.
Conclusions:
Rs-fMRI reliably differentiates outcome trajectories in acute DoC and holds promise as a sensitive adjunct to conventional prognostication. Standardized acquisition and analytic frameworks are needed to validate its clinical utility and facilitate translation into ICU practice due to substantial variation in outcome metrics across studies.
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