title: Suprathreshold odor intensity perception in early-stage Parkinson's disease.
abstract: BACKGROUND
  Whether Parkinson's disease (PD) influences suprathreshold changes in perceived odor intensity is unknown. In patients with Alzheimer's disease, patients with schizophrenia, and the elderly, such perception is reportedly normal. If generally true, this could reflect a core element of the olfactory system insulated to some degree from age- and disease-related pathological conditions.
  
  
  METHODS
  Odor intensity ratings for pentyl acetate were obtained from 29 early-stage PD patients when on and off dopamine-related medications (DRMs) and from 29 matched controls.
  
  
  RESULTS
  The ratings were significantly attenuated at the higher odorant concentrations, with the degree of attenuation associated with overall olfactory dysfunction. Ratings were higher on the right than on the left side of the nose of both patients and controls. No associations with DRMs, Unified Parkinson's Disease Rating Scale (UPDRS) scores, or striatal dopamine transporter imaging were found.
  
  
  CONCLUSIONS
  Parkinson's disease (PD) influences suprathreshold estimates of perceived odor intensity, negating the notion that such perception might be spared in this disease. No association with dopaminergic processes was apparent.
authors: Smell and Taste Center, Department of Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors: Richard L
authors: RL
authors: Doty
authors: Evan
authors: E
authors: Beals
authors: Allen
authors: A
authors: Osman
authors: Jacob
authors: J
authors: Dubroff
authors: Inna
authors: I
authors: Chung
authors: Fidias E
authors: FE
authors: Leon-Sarmiento
authors: Howard
authors: H
authors: Hurtig
authors: Gui-Shuang
authors: GS
authors: Ying
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants; D000857:Olfaction Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D055696:Olfactory Perception / Q000502:physiology*; D015609:Organotechnetium Compounds; D010300:Parkinson Disease / Q000150:complications* / Q000000981:diagnostic imaging; D012903:Smell / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
chemical_list: D015609:Organotechnetium Compounds; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1
keywords: Parkinson's disease; l-DOPA; olfaction; perception; psychophysics