( Migraines ( There ( ( are ( ( several kinds ) ( of ( migraine headaches ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Migraines)) (NP (EX There)) (VP (VBP are) (NP (NP (JJ several) (NNS kinds)) (PP (IN of) (NP (JJ migraine) (NNS headaches))))) (. .)))
Migraines There are several kinds of 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))) (. .)))