Consciousness Arousal

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.

Confusion and Delirium

Dementia:

- progressive cognitive impairment developing over mos to yrs; often affects memory, language, visuospatial, and executive function; attention often spared