Prevalence of smell loss in Parkinson's disease--a multicenter study

Parkinsonism Relat Disord. 2009 Aug;15(7):490-4. doi: 10.1016/j.parkreldis.2008.12.005. Epub 2009 Jan 11.


Previous data on the prevalence of olfactory dysfunction in Parkinson's disease (PD) range from 45% to 90%. The present multicenter study aimed to provide data on the prevalence of smell loss in a large sample of PD patients from three independent populations. Olfactory sensitivity was tested in 400 patients from Australia, Germany, and The Netherlands by means of a psychophysical olfactory test, the "Sniffin' Sticks", which is comprised of 3 subtests of olfactory function. Out of the total number of patients 45.0% presented as functionally anosmic, 51.7% were hyposmic, whereas only 3.3% were normosmic. This indicates that 96.7% of PD patients present with significant olfactory loss when compared to young normosmic subjects. This figure falls to 74.5%, however, when adjusted to age-related norms. Thus, olfactory dysfunction should be considered as a reliable marker of the disease.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Female
  • Humans
  • Male
  • Middle Aged
  • Odorants*
  • Olfaction Disorders / diagnosis
  • Olfaction Disorders / epidemiology*
  • Olfaction Disorders / etiology*
  • Parkinson Disease / classification
  • Parkinson Disease / complications*
  • Parkinson Disease / epidemiology*
  • Prevalence
  • Psychophysics
  • Sex Factors
  • Statistics as Topic