title: Olfactory dysfunction in cerebellar ataxia and multiple system atrophy.
abstract: BACKGROUND
  Olfactory dysfunction has been reported in Parkinson's (PD) and Alzheimer's disease (AD).
  
  
  OBJECTIVE
  We studied olfactory function in eight patients with multiple system atrophy of cerebellar type (MSA-C), eleven patients with sporadic cerebellar ataxia of unknown etiology and thirteen controls matched for age and gender. Subjects received tests for n-butanol odor thresholds, odor identification, and odor discrimination.
  
  
  RESULTS
  Olfactory thresholds were abnormally high in 16% of the patients. Odor discrimination and odor identification were impaired in 44 % and 74% of the patients, respectively. There was no significant difference in olfactory function between patients with sporadic ataxia of unknown etiology and MSA-C patients.
  
  
  CONCLUSIONS
  The present data suggest that olfactory dysfunction is common to various neurodegenerative disorders and not specifically restricted to PD or AD. Cerebellar dysfunction affected suprathreshold olfactory function more severely than odor thresholds. Thus cerebellar lesions may affect the processing of odor-related information to a higher degree than the transport of odorants to the receptor through sniffing.
authors.affiliation: Dept. of Neurology, University Bonn, Germany. michael.abele@uni-bonn.de
authors.forename: Michael
authors.initials: M
authors.lastname: Abele
authors.forename: Alexander
authors.initials: A
authors.lastname: Riet
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
authors.forename: Thomas
authors.initials: T
authors.lastname: Klockgether
authors.forename: Ullrich
authors.initials: U
authors.lastname: Wüllner
mesh_terms: D002524:Cerebellar Ataxia / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications*; D000857:Olfaction Disorders / Q000209:etiology*