If at least 4 of the following "POUNDing" features, LR of<unk>  is 24
Pulsatile quality
Onset/duration of 4-72 hours
Unilateral
Nausea or vomiting
Disabling in quality
Basilar-type<unk>  may be associated with fully reversible dysarthria, vertigo, tinnitus, decreased hearing, double vision or ataxia
Migraine headache
Tension headache
Cluster headache
Postpartum headache
Meningitis/encephalitis
Post-lumbar puncture headache
Neoplastic meningitis
Benign paroxysmal positional vertigo