A team of researchers at Belgium’s University of Liège have undertaken some hopeful research into brain wave activity of patients in comas as a result of serious brain injury. They looked to separate patients in such situations into more distinct groupings, be it the permanently vegetative state (where life support is generally terminated as there is no hope of recovery) or an alternative minimally conscious state (from which there is a greater chance of a better outcome).
The team used electroencephalography (EEG) to record the electrical activity of the brain in six minimally conscious and five vegetative people while they slept. These individuals had been diagnosed using traditional tests for reflex movements and responses to sounds and other stimuli.
Five of the six minimally conscious people exhibited brain-wave patterns that are typical of normal sleep, alternating between rapid eye movement (REM) and non-REM, or “slow-wave”, sleep during the night.
This research follows work from earlier this year by the same team, detailing brain activity responses corresponding to sounds, showing some level of brain function is retained in minimally conscious patients.
The use of detection of REM sleep in minimally conscious patients may be a long way off in terms of being diagnostically useful in determining patient outcomes, as Adrian Owen of University of Western Ontario in London, Canada, points out “It is certainly possible, but just because they show the same patterns of brain activity that are seen when healthy people dream does not necessarily mean they are dreaming.”.