Study Shows Ontario Researchers Detect Consciousness in Unresponsive Brain-Injured Patient

September 4, 2024 TruthUSA

Despite showing no signs of awareness at the bedside, unresponsive patients with severe brain injury may still be conscious, as suggested by a recent study.

Reported in an Aug. 25 study published in the Proceedings of the National Academy of Sciences journal, researchers from London, Ont., found that a brain-injured patient, who was acutely unresponsive, could control mental activity by imagining playing tennis when instructed to do so. The authors noted that these findings could impact decisions on patient care, which are typically based on subjective behavioural responses.

“These findings have important practical and ethical implications for the patient’s standard of care and quality of life,” concluded the study led by Canadians Karnig Kazazian and Androu Abdalmalak from Western University in London.

Using a device to detect conscious processing in the brain, researchers tested three severely brain-injured ICU patients—one in a coma, another in a minimally conscious state (MCS–), and another in a vegetative state—on their ability to process language and imagine themselves performing a movement.

Neural Responses

The MCS– patient, tested on Day 15 of ICU stay, could passively perceive speech but showed no language expression or ability to imagine movements. On the other hand, the vegetative state patient, tested on Day 7 of ICU stay, demonstrated the most robust responses and could “willfully” control brain activity when instructed to do so.

“A successful motor imagery response reflects intention and does not occur in the absence of conscious awareness, suggesting that this patient’s true condition was cognitive motor dissociation,” the authors wrote. Cognitive motor dissociation occurs when patients are aware but unable to react to commands.

Additionally, researchers noted that the patient in a coma, tested on Day 2 of ICU stay, did not respond to the tests.

Brain Imaging Method

Functional near-infrared spectroscopy (fNIRS), an optical imaging method used by the researchers to measure neuronal activity, was less limited compared to other brain imaging methods like functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG). The authors highlighted that fNIRS could potentially improve diagnosis and prognosis in patients with acute brain injuries in the ICU. They suggested that further studies with larger sample sizes are necessary to fully comprehend the prognostic potential of fNIRS.

According to the authors, their findings offer the possibility of communicating with unresponsive patients in the future.

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