Acute alteration in brain function
May include alteration of arousal or awareness, thought content, memory, or attention
Both cerebral cortices or brainstem must be affected
Delirium vs dementia vs other organic pathology vs functional (psychiatric)
Must quickly determine if coma is from diffuse or focal impairment
May include alteration of arousal or awareness, thought content, memory, or attention
Altered mental status
Hypoxic encephalopathy
Sedation 
Acute toxic-metabolic encephalopathy 
Extrapyramidal reaction
Hypoglycemia
Tremor
Hyperosmolar state 