Paper on assessment of conscious states

How can we tell whether an immobiised patient is conscious or not? This was the starting point for the master thesis of three clinical psychology students that I supervised. The students reviewed and provided a synthesis of the recent scientific literature on the subject. After the thesis work was over and the students had left the university for clinical positions, I collaborated with them to rewrite the work into a article intended for Norwegian clinicians.

Table 1:

STATE OF  CONSCIOUSNESS	WAKEFULLNESS	AWARENESS	INTENTIONAL BEHAVIOUR
Normal awake state	Yes	Yes	Yes
unresponsive wakefulness syndrome	Yes	No	No
Minimally conscious state	Yes	Occasionally	Some
Locked-in-syndrome	Yes	Yes	Very limited motor capacity
Coma	No	No	No

The paper gives a definition of consciousness and outlines the clinical disorders of consciousness (see table 1 above). We then categorise four different types of assessment of consciousness: behaviour checklists, electrophysiology, imaging of activation and imaging of networks. We discuss each approach's standing, merits and disadvantages (table 2). Finally we discuss to which extent the assessment approaches reflect the theoretical definition.

Table 2:

APPROACH	TYPE	EXAMPLES	PRINCIPLE	ADVANTAGES	DISADVATAGES
Behaviour checklist	Active or passive	GCS-R, SMART, etc., see Seel et al. (2010) for review	Checklist for whether actions occur, spontaneously or on instruction	Has clinical standard	Unable to capture consciousness that does not appear in the behavior
Electro-physiology	Active or passive	EEG, ERP	Electrodes measure simultaneous fireing of groups of neurons	Equipment readily available can be used on all patients, also at bedside	Hard to say where the signal comes from, hard to say which processing the response involves
Imaging of brain activity	Active	fMRI, PET	Imaging of the metabolism from activity in different parts of the brain	Good localization of the signal, can determine whether a task activates the same areas as in healthy people	Expensive and scarce equipment, cannot be applied to all patients. Measures the capacity for consciousness, but this capacity is not necessarily in use
Imaging of networks	Passive	Default mode network, DTI	Measures which parts of the brain that are connected, or that are activated simultaneously	As above, but does not require active participation from the patient	As above, but in addition it is unclear how the networks should be interpreted

As we wanted to inform Norwegian clinicians working in adjacent fields and next-of-kin to patients with consciousness afflictions, we wanted the paper to be easily accessible. We published in a peer-reviewed Norwegian online open-access journal (abstract in English)

Link to the publication in psykologisk.no (Scandinavian Psychologist).