Scientists Discover the Mystery of “Hidden Consciousness” in Brain-Injured Patients

Researchers have made a breakthrough in understanding the phenomenon of “hidden consciousness” in patients with traumatic brain injury. Despite being in a coma-like state, these patients show signs of awareness.

Identifying Brain Damage Associated with “Hidden Consciousness”

Columbia University researchers have identified the brain damage that may be responsible for “hidden consciousness” in brain-injured patients. This condition refers to patients who are unable to respond to simple commands, giving the appearance of being unconscious despite having some level of consciousness. However, with rehabilitation, these patients can recover.

Using EEG Scans to Predict Awareness and Recovery

Building on previous research, the study shows that subtle brain waves detected on electroencephalogram (EEG) scans can predict the presence of awareness and the likelihood of recovery in non-responsive brain injury patients. However, the specific pathways in the brain that are disrupted in states of “hidden consciousness” are still unknown.

The Prevalence of “Hidden Awareness”

Approximately 15-25% of cases of brain damage from head trauma, cardiac arrest, or cerebral hemorrhage result in “hidden awareness” or cognitive-motor dissociation (CMD). This study, led by Professor Jan Klassen and colleagues at Columbia University, sheds light on the condition and its underlying mechanisms.

Understanding the Inability to Follow Commands

Through EEG analysis of 107 patients with traumatic brain injury, the researchers found that 21 patients exhibited “hidden consciousness.” By comparing the structural MRI scans of these patients with those without the condition, the team identified specific patterns of brain damage associated with cognitive-motor dissociation.

The Role of Brain Structures in “Hidden Consciousness”

The study revealed that brain structures related to arousal and command comprehension were intact in all patients with “hidden consciousness.” This suggests that these patients can hear and understand commands but are unable to respond due to damage in the brain circuits responsible for relaying instructions to the muscles.

Impairments in Movement Production

On the other hand, the researchers found that patients with cognitive-motor dissociation had impairments in the brain areas responsible for integrating perceived motor commands into movement production. This explains why these patients are unable to act on verbal commands.

Implications for Clinical Trials and Diagnosis

The findings of this study can help identify brain injury patients with cognitive-motor dissociation, enabling further evaluation and diagnosis. Professor Klassen suggests that structural brain imaging, such as MRI, can be a more accessible method compared to using electroencephalogram for detecting hidden consciousness. This advancement could support the use of clinical trials for consciousness recovery.

Source: Express