Image Credit: CC BY 2.0 Allan Ajifo
Scientists have been trying to find a way to definitively determine if a brain injured patient is conscious.
In a recent study, an international team of researchers used fMRI brain scans to try and identify the parts of the brain that are typically active when an otherwise unresponsive individual is conscious.
For the research, scientists recorded the brain activity of 159 people, including 47 healthy volunteers who were under sedation and 112 who had suffered brain injuries with around half of these being totally unresponsive and the other half showing some slight flicker of awareness.
After analyzing the scans, the researchers identified four distinct patterns of brain activity, with the most complex being the most likely to show up in a healthy, fully conscious individual and the least likely to show up in a fully sedated individual or in a patient who is in a vegetative state.
Interestingly, some of the vegetative state patients did show that same pattern on occasion, suggesting that they were still exhibiting at least some semblance of awareness.
“Importantly, this complex pattern disappeared when patients were under deep anesthesia, confirming that our methods were indeed sensitive to the patients’ level of consciousness and not their general brain damage or external responsiveness,” said study author Davinia Fernandez-Espejo.
“In the future it might be possible to develop ways to externally modulate these conscious signatures and restore some degree of awareness or responsiveness in patients who have lost them, for example by using non-invasive brain stimulation techniques such as transcranial electrical stimulation.”