( ( These conditions ) ( ( ( cause ( ( ( `` ( ( vasodilation , ) '' ) ) or ) ( dilation ( of ( ( ( the ( blood vessels ) ) , ) ( the ( ( most immediate ) precursor ) ) ) ) ) ) ) ( to ( a ( migraine headache ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS conditions)) (VP (VBP cause) (NP (NP (`` ``) (NNS vasodilation) (, ,) ('' '')) (CC or) (NP (NP (NN dilation)) (PP (IN of) (NP (NP (DT the) (NN blood) (NNS vessels)) (, ,) (NP (DT the) (ADJP (RBS most) (JJ immediate)) (NN precursor)))))) (PP (TO to) (NP (DT a) (JJ migraine) (NN headache)))) (. .)))
These conditions cause &quot;vasodilation,&quot; or dilation of the blood vessels, the most immediate precursor to a migraine headache.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (NN blood) (NNS vessels)) (PP (IN in) (NP (DT the) (NN head)))) (VP (VBP dilate)))) (, ,) (NP (NP (DT a) (NN migraine)) (, ,) (NP (DT a) (JJ severe) (NN headache)) (, ,)) (VP (MD can) (VP (VB occur))) (. .)))