When someone has suffered a severe brain injury and is in a coma in the intensive care unit, relatives and medical staff at some point are faced with the following question: Has the patient regained consciousness? Then they ask him, for example, to shake his hand. If the patient does not react at all, it is usually assumed that he is still in such a deep coma that he cannot understand anything.

Research shows, however, that this is not always the case – and that there are people who, although outwardly do not react in any way, their brains are nevertheless functioning. In contrast to previous studies in individual research centers, which identified brain function in approximately 15-20% of the relevant cases examined, a new research by the well-known scientific journal “New England Journal of Medicine” “raises” this percentage to 25 %.

Jelena Bodien, lead author of the research from Massachusetts General Hospital’s Center for Neurotechnology and Neurorehabilitation, explains that “some patients with severe brain damage appear not to process external stimuli. But when we examine them with advanced technological methods, such as functional magnetic neuroimaging (fMRI) and electroencephalography (EEG), we find brain functions that show us something different.”

The findings of the investigation

The research looked at patients with severe brain damage from the US and Europe. These patients had suffered – in several cases already a few months ago – craniocerebral injuries in a traffic accident, stroke or resuscitation after cardiac arrest. While the scientists scanned the patients’ brains, they were given instructions such as “imagine opening and closing your hand” or “imagine doing such and such a sport.”

241 of the examined patients showed no external reaction. 60 of them, however, were found to process the instructions in their minds, and indeed for several minutes. These people therefore, as the authors of the research write, can pay attention to an external stimulus, are able to understand language, and have short-term memory.

The great moral dilemma

This international research is very important, believes Julian Bezel, representative of the Neurological Intensive Care Committee of the German Society of Neurology (DGN). And that’s because it examined the largest group of patients to date, was conducted in six medical centers and dealt with the phenomenon in a more systematic way, as the neurologist, who was not involved in the study, points out. In addition, the research raises, among other things, an important ethical dilemma: whether the treatment of such patients should be continued or not.

Disturbances of consciousness can last for days, weeks, months, or even years. “Research like this can be a trigger, so that in some cases more patients are tested with methods like EEG and observed for a longer period of time,” Bezel says. In cases of doubt, patients should therefore be given more time.

However, it remains unclear whether special treatments help such people. Behavioral treatments, drugs or other methods have been tried for a long time, but without much or long-term success. A team from Massachusetts General Hospital is also using a new technological method, connecting patients’ brains to computers as a means of communication.

Another brain function, another consciousness

Frank Erbgut, president of the German Brain Foundation, considers on the other hand that this new study did not establish anything fundamentally new: “That this phenomenon actually exists is clear.” However, the indications, for example in an electroencephalogram, do not mean that these people really have a higher level of consciousness. Patients under anesthesia also show such signs.

However, both experts agree on the appropriate way to treat such patients. “People in intensive care and recovery wards should always be treated as if they perceive something from external stimuli. You talk to them and treat them with respect. And this is something that is already happening today,” says Erbgut.

It is unknown how many of these patients there are

So how many people are there who, although they don’t react outwardly, their brains seem to respond? Both the authors of the study and the German scientists explain that it is very difficult to give a clear answer to this question. Besides, in the recent study the tests were not standardized and the patients were selected. And beyond that, “the brain lesions had completely different causes,” adds Erbgut.

According to Bezel, however, the percentages found in studies like this show that “even more patients in a coma than we thought are able to perceive what is happening around them”. And as Bezel himself has found, in many cases those who visit comatose patients talk next to them as if they weren’t even there. “Nursing staff, on the other hand, usually act very correctly: they greet the patient, introduce themselves or tell them what they are doing at that moment.” And this is how everyone who is next to comatose patients should behave – both visitors and doctors.

Edited by: Giorgos Passas