A 65yrs of Lady c/o heaviness of head followed by vertigo since 4 years. During attack the head becomes so heat that she have to pour cold water over head even in cold season and feels throbbing pulsation over vertex and  thirsty also frequency of micturation. Patient is known for Hypertension since 10 yrs on Amlodipin 5mg.

Patient taking Vertin 8mg tds and symptoms somehow decrease but the symptoms still going on on one's in a week. Please suggest pathophysiology and treatment.