Hydrocephalus:
if you see hydrocephalus in a patient with consistent severe headaches, this could be a sign of impending herniation. Patient will need emergent relief of intracranial pressure.
Botulism:
Rapidly progressive paralysis with blurry vision, sluggish pupils and diplopia. This condition is caused by an irreversible toxin and the antitoxin should be given as soon as possible, so needs high clinical suspicion. The diagnosis is by injecting patient’s serum in mice to see if it causes paralysis (takes a few days).
The antitoxin is at LaGuardia Airport !!!