title: High Plasma Levels of Neuropeptide Y Correlate With Good Clinical Outcome But are not Correlated to Cerebral Blood Flow or Vasospasm After Subarachnoid Hemorrhage.
abstract: OBJECTIVE
  Delayed cerebral ischemia (DCI) is a serious and frequent complication following subarachnoid hemorrhage. Treatments with convincing effect are lacking and the pathophysiology behind DCI remains poorly understood. Neuropeptide Y (NPY) is a potent endogenous vasoconstrictor and a role of NPY in the development of DCI has been proposed. This study investigated the relationship between plasma-NPY and cerebral blood flow (CBF), cerebral vasospasm, DCI, and clinical outcome.
  
  
  METHODS
  In 90 patients with subarachnoid hemorrhage, NPY was measured in peripheral blood days 2 to 11. Any occurrence of DCI was recorded and CBF was quantified day 3 and day 8 using computed tomography (CT) perfusion. CT angiography was performed day 8. Clinical outcome was assessed after 3 months.
  
  
  RESULTS
  No correlation was found between plasma-NPY and CBF or angiographic vasospasm. The correlation between reduced plasma-NPY and DCI reached borderline statistical significance (P=0.05). Increased levels of NPY measured on days 2 to 4 were correlated to good outcome (P=0.006).
  
  
  CONCLUSIONS
  Our findings in peripheral blood were not supportive of a causal relationship between NPY secretion and DCI. Although high levels of plasma-NPY were correlated with good clinical outcome, NPY did not show promise as a clinically useful biomarker.
authors.affiliation: *Department of Neurosurgery, The Neuroscience Centre†Department of Radiology, The Diagnostic Centre‡Department of Neuroscience and Pharmacology, The Neuroscience Centre§Section for Transfusion Medicine, Capital Region Blood Bank, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark.
authors.forename: Rune
authors.initials: R
authors.lastname: Rasmussen
authors.forename: Trine
authors.initials: T
authors.lastname: Stavngaard
authors.forename: Iben R
authors.initials: IR
authors.lastname: Jessing
authors.forename: Jane
authors.initials: J
authors.lastname: Skjøth-Rasmussen
authors.forename: Niels V
authors.initials: NV
authors.lastname: Olsen
authors.forename: Sisse R
authors.initials: SR
authors.lastname: Ostrowski
authors.forename: Pär I
authors.initials: PI
authors.lastname: Johansson
authors.forename: Marianne
authors.initials: M
authors.lastname: Juhler
mesh_terms: D000328:Adult; D000368:Aged; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009478:Neuropeptide Y / Q000097:blood*; D013345:Subarachnoid Hemorrhage / Q000097:blood* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D020301:Vasospasm, Intracranial / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D009478:Neuropeptide Y