Scientists from Columbia University in the US have used advanced imaging techniques to identify brain activity and regions associated with cognitive motor dissociation (CMD) or ‘hidden consciousness’. CMD refers to a condition in which a person appears comatose and unresponsive, while inwardly showing signs of conscious brain activity. The findings of this study may aid doctors in easily identifying CMD in the future and developing tailored treatments for individuals who can understand but cannot respond to external stimuli.
CMD occurs in approximately 15-25% of individuals who have suffered brain injuries, such as head trauma, brain hemorrhage, or cardiac arrest. It is characterized by a breakdown in the communication between the brain’s instructions and the muscles required to carry out those instructions.
The scientists employed a technique called bi-clustering analysis to identify patterns of brain injury that are common among CMD patients but differ from those without CMD. To compare brain activity between CMD and non-CMD brains, the researchers utilized electroencephalograms (EEGs) to examine the brain activity of 107 participants who were asked to perform simple movements. Subsequently, magnetic resonance imaging (MRI) scans and machine learning techniques were employed to detect patterns that matched CMD with specific brain regions and activity.
The study revealed that all CMD patients had intact brain structures associated with arousal and command comprehension, suggesting that they were able to hear and understand verbal instructions. However, there were structural gaps in regions related to physical action, explaining their inability to respond physically.
Further research is necessary to refine these techniques and accurately identify CMD through brain scans. Nonetheless, this development holds promise for improving diagnostic accuracy and potentially identifying patients with the best chances of recovery.
The ultimate aim is to make these analysis and detection methods available in all healthcare facilities that treat brain injuries, utilizing EEG and MRI scans along with a deeper understanding of which types of brain damage affect consciousness.
The research also contributes to efforts in helping individuals trapped in coma-like states. Enhancing treatment methods relies on obtaining a better understanding of patients’ levels of consciousness.
Neurologist Jan Claassen from Columbia University expressed the significance of this study, stating, “Our study shows that it may be possible to screen for hidden consciousness using widely available structural brain imaging, moving the detection of CMD one step closer to general clinical use.”
The study has been published in the scientific journal Brain.