Rethinking Seizure Care Blog

Hidden Consciousness Detected by an EEG in Patients with a Brain Injury in Intensive Care

Posted by RSC Diagnostics on Nov 5, 2019


Researchers from Columbia University and New York-Presbyterian recently made a discovery regarding patients in the ICU with brain injuries. The EEGs the patients were given showed that there was evidence of a “hidden consciousness” that was showing up in the first few days after the injury. They found that patients who showed these signs had a greater chance of recovery. The analysis found that about one out of every seven patients showed evidence of the hidden consciousness.

How Was the Study Conducted?

The researchers made use of a machine learning technique to study a collection of data gathered from 104 patients who were unresponsive. The technique used would search the EEG information for “patient-specific brain activity that showed they were able to understand instructions to move their hands.” The findings from the study were recently published in the New England Journal of Medicine. The research that has been done thus far shows a lot of potential for use in the future. This is because there is currently not a 100% accurate method of predicting the recovery chance for all patients with brain injuries who are unconscious.

If the researchers are able to confirm their initial findings when they begin doing larger studies, it could mean that they will have a better way of truly determining which patients are more likely to become conscious again. The knowledge could change the way that people with these types of brain injuries are treated.

How Important Could the Research Be?

When someone has a brain injury and they are unconscious, it is devastating for the family members who do not know what is going to happen next. It is also problematic for the doctors, who are doing their best to treat the patient, but who simply do not have enough information to know whether the patient may recover or not. During those first few weeks after a brain injury, the doctors and family members begin talking about what should happen with the patient. They determine how much support is given and whether to remove the treatments that are sustaining the person’s life.

Currently, doctors are using imaging, electrophysiological studies, and neurological examinations conducted at the bedside to try to determine the likelihood of the patient to wake up and become responsive. These tools are not always accurate, though.

More and more studies are showing that even though some patients might be unresponsive, they still have hidden cognitive abilities, which means there could be a chance for delayed recovery. The hidden conscious was originally detected through the use of an MRI machine more than a decade ago. Over the years, studies have shown that there are signs of hidden consciousness in about “14% of chronically unresponsive patients.” Of course, using MRIs is not possible in many settings.

Therefore, the new techniques being created by the researchers on this latest study hold a lot of potential. In addition to undergoing the standard neurological tests, the patients are asked to open and close their hands or to stop opening and closing their hands multiple times. Information from the EEG is then analyzed to look for signs that patients were able to understand the difference between the commands.

They found that within four days of the injury, 15% of the patients that were still unresponsive had brain activity patterns. Out of those patients, about 50% of them showed improvement and were able to follow verbal commands before they were discharged. This is compared to 26% of patients who did not have that brain activity.

A year out of the study, they found that 44% of the patients that had brain activity patterns were functional on their own for up to eight hours a day. Only 14% of those who did not have the signals had this type of functionality.

While this study shows a substantial amount of promise, there are still many things to learn and other studies that will need to be done to corroborate this one.




Topics: Continuous EEG Monitoring