title: Alteration of brain activation patterns in nonallergic rhinitis patients using functional magnetic resonance imaging before and after treatment with intranasal azelastine.
abstract: BACKGROUND
  Although nonallergic rhinitis (NAR) patients tend to be more sensitive to chemical/olfactory stimuli, a suprathreshold olfactory response or the presence of specific olfactory receptor genes do not explain why their symptoms are triggered by such exposures.
  
  
  OBJECTIVE
  To investigate differential neurogenic responses to azelastine in NAR patients, using functional magnetic resonance imaging (fMRI) in response to specific olfactory triggers.
  
  
  METHODS
  A longitudinal study design on 12 subjects with a physician diagnosis of NAR previously demonstrated to be clinically responsive to intranasal azelastine (Astelin) was performed. Subjects underwent fMRI during exposure to unpleasant (hickory smoke) and pleasant (vanilla) odorants while off and then on azelastine for 2 weeks. The olfactory fMRI paradigm consisted of a visually triggered sniff every 21 seconds with synchronized delivery of a 4 second pulse of odorant. Each odorant was presented 18 times over 4-6-minute fMRI runs. Continuous fresh air was presented to wash out each odorant after presentation.
  
  
  RESULTS
  Nonallergic rhinitis patients exhibited increased blood flow to several regions of the brain in response to both pleasant and unpleasant odorants, specifically in odor-sensitive regions, while off intranasal azelastine. Treatment with intranasal azelastine significantly attenuated blood flow to regions of the brain relevant to either olfactory sensation or sensory processing in response to these odorants compared with fresh air.
  
  
  CONCLUSIONS
  The general reduction compared with increase in brain activation in NAR patients on versus off azelastine suggests that a possible effect of this medication may be reduction of brain responses to odorants.
authors.affiliation: Department of Internal Medicine, Division of Immunology/Allergy Section, University of Cincinnati College of Medicine, Ohio, USA. Jonathan.Bernstein@uc.edu
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Bernstein
authors.forename: Lloyd
authors.initials: L
authors.lastname: Hastings
authors.forename: Erin L
authors.initials: EL
authors.lastname: Boespflug
authors.forename: Jane B
authors.initials: JB
authors.lastname: Allendorfer
authors.forename: Martine
authors.initials: M
authors.lastname: Lamy
authors.forename: James C
authors.initials: JC
authors.lastname: Eliassen
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009812:Odorants; D055696:Olfactory Perception; D010793:Phthalazines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012220:Rhinitis / Q000188:drug therapy* / Q000503:physiopathology*; D012906:Smoke; D016896:Treatment Outcome; D031669:Vanilla; D055815:Young Adult
chemical_list: D010793:Phthalazines; D012906:Smoke; C020976:azelastine