Consciousness/Arousal (description of patient & timing is most helpful)
Arousal: spectrum from awake/alert → drowsy → stupor → coma. Terms vague & subjective, so most useful to describe response to increasing stimulation (eg, voice → noxious).
Coma: lack of response to external stimuli. Degree formalized in Glasgow Coma Scale. Caused by focal lesions in brainstem (reticular activating system), thalamus, or diffuse dysfxn of both cerebral hemispheres.
Mimics: locked-in synd., akinetic mutism, catatonia.
Delirium/acute confusional state: altered attention & awareness, develops over hrs to days, often fluctuating, accompanied by cognitive Δs (eg,
al Δs); sometimes
w/ sleep–wake dysregulation, autonomic Δs, emotionality