title: Nocturnal blood pressure decrease is associated with increased regional cerebral blood flow in patients with a history of ischemic stroke.
abstract: BACKGROUND
  It remains controversial whether there is a J-shaped relationship between blood pressure and recurrent stroke among patients with a recent history of ischemic stroke.
  
  
  OBJECTIVE
  To investigate the relationship between regional cerebral blood flow (rCBF) and the dipping of nocturnal blood pressure in patients receiving antihypertensive treatment after ischemic stroke.
  
  
  RESULTS
  Forty-seven patients with a previous history of ischemic stroke and 37 patients with a history of non-ischemic stroke underwent 24-h ambulatory blood pressure monitoring and rCBF measurement with single photon emission computed tomography. Of the 47 patients with ischemic stroke, 30 were diagnosed as having suffered atheromatous or embolic stroke, and 37 had an ischemic lesion in the territory of the carotid artery. Systolic and diastolic blood pressures during daytime and night-time were controlled at less than 140/90 mmHg by a low-salt diet or long-acting antihypertensive agents, or both. In patients with ischemic stroke, there were significant negative correlations between the percentage change in nocturnal blood pressure and rCBFs in the thalamus (r = -0.33, P = 0.02), putamen (r = -0.34, P = 0.02) and cerebral cortex (r = -0.31, P = 0.03). Multivariate analysis revealed that only the percentage change in nocturnal blood pressure was related to rCBF. There was a significant positive correlation between rCBFs in the thalamus and the cerebral cortex (r = 0.74, P < 0.05). In patients with non-ischemic stroke, there was no significant correlation between the percentage change in nocturnal blood pressure and rCBFs.
  
  
  CONCLUSIONS
  These findings indicate that the decrease in nocturnal blood pressure is associated with the increase in rCBF in patients with a history of ischemic stroke in the territory of the carotid artery.
authors.affiliation: Department of Internal Medicine, Reimeikyo Rehabilitation Hospital, Ikarigaseki, Hirosaki, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Osanai
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Baba
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okuguchi
authors.forename: Norifumi
authors.initials: N
authors.lastname: Metoki
authors.forename: Naotaka
authors.initials: N
authors.lastname: Maeda
authors.forename: Yosiyuki
authors.initials: Y
authors.lastname: Konta
authors.forename: Ken
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002545:Brain Ischemia / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012008:Recurrence; D020521:Stroke / Q000503:physiopathology*
chemical_list: D000959:Antihypertensive Agents