It could be said that your book is a necessity considering the percentage of diagnostic errors among severely brain-damaged patients?

It is estimated that approximately 40% of the diagnoses made in hospitals are wrong; people are declared to be in a coma or in a vegetative state whereas they are actually in a minimally conscious state or prisoners of locked-in syndrome (read Locked-in: conscious within a body that cannot move). Such a high error rate can be attributed to the fact that many centres don’t use sensitive tools. A lack of awareness regarding the existence of these tools is often observed, but also with regard to the criteria allowing you to distinguish a conscious state from an unconscious state. These shortcomings relate as much to the behavioural scales as they do to the paramedical techniques giving access to the brain’s metabolism, i.e. to the brain's responses.

Intensive care medicine has progressed so much over the past few years that it has saved the lives of many people for whom there would have been no hope in the past; however, the result has been an increase in the number of severely brain-damaged patients. And now, more than ever, it is vital that care for these patients is provided using the best available means. In fact, in Belgium, a federal network has recently been developed, which includes more than 30 centres. We managed to get them to use all the sensitive and standardised consciousness assessment scales, such as the Coma Recovery Scale-Revised, in order to ensure greater reliability in diagnoses and optimal care for patients in a vegetative state and a minimally conscious state. Within this context, one of our book’s objectives is to raise awareness among the medical corps of the interest of the various tools available.

The minimally conscious state was described in 2002 by Joseph Giacino, currently at Harvard University, with whom you have been working for several years. A fluctuating residual consciousness remains among these patients. Furthermore, you have demonstrated that their chances of recovery are better than for patients in a vegetative state and, contrary to the latter, that they experience physical pain. Does untangling this web currently constitute a fundamental medical and ethical stake?

Certainly. The accuracy of the diagnosis means that human tragedies can be avoided. The line between a vegetative state and a minimally conscious state is sometimes very vague, since disorders of consciousness are situated on a continuum. The entire set of tools must be used to decide on borderline cases. Of course, not all the centres are equipped with fMRI, for instance. But more often than not, the means available to them, especially behavioural scales and electrophysiology, should be sufficient to establish a detailed diagnosis; the most important thing is to use these means according to the correct procedures. If necessary, the patient can be taken to a centre equipped with a PET scan for an examination of their brain metabolism. Within this context, the Coma Science Group regularly sees patients from other European hospitals and nursing homes for a one-week assessment in the Liège University Hospital to establish a better documented diagnosis, prognosis and possible treatment.

One thing is for sure, it is essential to assess the patient several times on a behavioural level as well as with electrophysiology tools, fMRI, PET, etc., because we know that the capacities of a person in a minimally conscious state fluctuate, that there are "days with" and "days without". Furthermore, in people with paralysis or language comprehension problems, it is extremely difficult to detect signs of consciousness using behavioural scales. We must therefore make the most of all the existing ancillary tools. Through the information they provide, our book raises awareness among healthcare professionals about the range of possibilities available to them in terms of diagnosis and care. In general, it is possible to establish the correct diagnosis if the range of tools currently available is properly deployed.

You said that altered levels of consciousness are part of a continuum. Is each of these levels subject to subcategorization?

Our knowledge is continuously evolving and it is clear that we are moving towards an increasingly more elaborate division of the various categories that have been defined up until now. This progression tends to favour better care for patients.

A sign of the evolution taking place: the interest of subdividing the minimally conscious state into two sub-categories has recently been revealed. What we qualify as a “minimally conscious state +” relates to patients who respond to an instruction, i.e. they move their hand, open their mouth or close their eyes, etc., when they are asked to. The “minimally conscious state –“refers to low-level signs of consciousness, non-reflex movements such as visual pursuit (following a moving mirror with the eyes), locating painful stimulations or smiling at someone they know.