( ( ( Constriction , ) ( ( ( then ( ( dilation and ) inflammation ) ) ( of ( blood vessels ) ) ) ( that ( go ( to ( the person ) ) ) ) ) ) ( ( s ( ( ( scalp and ) brain ) ( might ( be ( ( the cause ) ( of ( the ( migraine headaches ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Constriction)) (, ,) (NP (NP (RB then) (NN dilation) (CC and) (NN inflammation)) (PP (IN of) (NP (NN blood) (NNS vessels))) (SBAR (WHNP (WDT that)) (S (VP (VBP go) (PP (TO to) (NP (DT the) (NN person)))))))) (VP (VBZ s) (NP (NP (NN scalp) (CC and) (NN brain)) (SBAR (S (VP (MD might) (VP (VB be) (NP (NP (DT the) (NN cause)) (PP (IN of) (NP (DT the) (JJ migraine) (NNS headaches)))))))))) (. .)))
Constriction, then dilation and inflammation of blood vessels that go to the person s scalp and brain might be the cause of the migraine headaches.
(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))) (. .)))