Table.

Approaches to study consciousness in the acute brain injury setting

Brain at rest

Structural MR imaging (e.g., FLAIR, high resolution T1, diffusion tensor imaging) [7, 9], Head CT

Resting EEG, resting state functional MRI [8, 10]

Measures of the extent of brain injury in the serum, plasma, cerebrospinal fluid, and brain interstitial fluid (NSE, S110Beta, GFAP, Vimentin, Myelin Basic Protein, Inflammatory markers such as IgG electrophoresis)

Passive perturbation tasks

Long latency evoked potentials, event related potentials[11, 12]

Autonomic nervous system modulation[13]

Transcranial magnetic stimulation with EEG co-registration[14] (Figure 2)

Active perturbation tasks

Behavioral assessment: Coma Recovery Scale-revised [5], other less appropriate clinical scales (FOUR score, Glasgow Coma Score) (Figure 1)

Differential electromyographic response [6]

Functional MRI - motor imagery or activation paradigm [16, 17] (Figure 3)

Functional EEG - motor imagery or activation paradigm [15, 17] (Figure 4)

Interventional studies (measures of success may include any of the above)

Medication (i.e., amantadine) [20]

Mechanical: electrical thalamic stimulation, focused ultrasound [19, 21]

References are just a small sample of available studies. More comprehensive reviews of the literature are available.[1] Bolded citations were conducted in critical care setting.