Functional Neuroimaging as an Assessment Tool in Critically Ill Patients.

Area of Science:

• Neuroscience
• Medical Imaging
• Critical Care Medicine

Background:

• Residual cognitive function in early stages of serious brain injury remains poorly understood.
• Functional neuroimaging, particularly fMRI, has proven useful in diagnosing and predicting outcomes in chronic disorders of consciousness.
• Acute disorders of consciousness, such as coma, present challenges for assessing cognitive function and making life-sustaining therapy decisions.

Purpose of the Study:

• To evaluate the efficacy of functional neuroimaging in assessing cognitive function in patients with acute disorders of consciousness.
• To explore the potential of fMRI to provide diagnostic and prognostic information in the early post-injury period.

Main Methods:

• A hierarchical functional magnetic resonance imaging (fMRI) approach was employed.
• Seventeen critically ill patients in the intensive care unit (ICU) were assessed.
• Evaluated auditory perception, speech perception, language comprehension, and covert command following.

Main Results:

• Preserved auditory function was identified in 88% of patients.
• Higher-order language comprehension was preserved in 29% of patients.
• One patient demonstrated covert conscious awareness through willful brain activity modulation, contradicting their clinical diagnosis.
• fMRI responsivity correlated positively with functional recovery, with better-recovered patients showing neural responses similar to controls.

Conclusions:

• fMRI shows promise in providing critical diagnostic and prognostic information in acutely unresponsive patients.
• Findings may assist in discussions regarding the continuation or withdrawal of life-sustaining therapies.
• This approach offers insights beyond standard clinical assessments in the early phase of brain injury.