Figure 1

Flow chart of the study population enrollment. The special diagnostics include primary brain injury (traumatic brain injury, ischemic stroke, hemorrhagic stroke, epilepsy, or intracranial infection), severe burn and trauma, chronic alcohol or drug abuse, severe electrolyte imbalances, hyponatremia, hyperglycemia, hypoglycemia, with pre-existing liver or kidney failure affecting consciousness, receiving cardiac resuscitation recently.