Suprathreshold odor intensity perception in early-stage Parkinson's disease
Funding agencies: This study was supported by USAMRAA W81XWH-09-1-0467 (RL Doty, PI).
Relevant conflicts of interest/financial disclosures: Dr. Doty is President and major shareholder in Sensonics, Inc., the manufacturer of the commercial version of the University of Pennsylvania Smell Identification Test. All authors of this paper were supported by USAMRAA W81XWH-09-1-046. No other financial disclosures or potential conflicts of interest related to this article are reported.
Full financial disclosures and author roles may be found in the online version of this article.
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.
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.
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.
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. © 2014 International Parkinson and Movement Disorder Society