Scientists have discovered a specific pattern of brain waves that accurately reflects the moment of loss of consciousness during general anesthesia. The study, published in the journal Cell Reports Medicine, will enable doctors to prevent patients from undergoing sedation that is either too deep or, conversely, insufficient.
Researchers from Shanghai Jiao Tong University studied 31 patients who were administered propofol, a widely used anesthetic, prior to surgery. The researchers measured electrical activity at various points across the cranium.
Using mathematical methods, the scientists isolated signals responsible for consciousness from nine key brain regions. Particular attention was paid to the parietal cortex located at the top of the head, the occipital cortex localized at the back, and the thalamus situated deep within the brain.
The findings revealed that in a conscious state, the brain’s “alpha waves” are highly synchronized between the parietal area and the thalamus. This indicates that these regions are in constant and close communication. A similar connection was also observed between the parietal and occipital areas.
As soon as the anesthesia takes effect, this synchronization is disrupted, and communication between the different regions is severed. This specific change could serve as a quantitative biological measure for anesthesiologists to determine the depth of a patient’s sleep.
Although the study focuses solely on the effects of propofol, the scientists believe this is a significant step toward safer and more precise anesthesia management, minimizing complications caused by overdosing.
