title: Taste detection and recognition thresholds in Japanese patients with Alzheimer-type dementia.
abstract: OBJECTIVE
  Alzheimer-type dementia (AD) is pathologically characterized by massive neuronal loss in the brain, and the taste cortex is thought to be affected. However, there are only a few reports regarding the gustatory function of AD patients, and the conclusions of this research are inconsistent.
  
  
  METHODS
  This prospective study enrolled 22 consecutive patients with mild to moderately severe Alzheimer-type dementia (AD) with mean age of 84.0 years, and 49 elderly volunteers without dementia with mean age of 71.0 years as control subjects. The control subjects were divided into two groups according to age: a younger group (N=28, mean age: 68.5) and an older group (N=21, mean age: 83.0). The gustatory function was investigated using the filter paper disc method (FPD) and electrogustometry (EGM).
  
  
  RESULTS
  The gustatory function as measured by the FPD was significantly impaired in patients with AD as compared with age-matched control subjects; no such difference was found between the younger and the older control groups. On the other hand, as for the EGM thresholds, there were no differences between the AD patient group and the age-matched controls.
  
  
  CONCLUSIONS
  The FPD method demonstrated decreased gustatory function in AD patients beyond that of aging. On the other hand, EGM thresholds did not differ between the AD patient group and the age-matched controls. These results suggest that failure of taste processing in the brain, but not taste transmission in the peripheral taste system, occurs in patients with AD.
authors.affiliation: Department of Otorhinolaryngology, Shiga University of Medical Science, Otsu, Shiga, Japan. Electronic address: takao971@belle.shiga-med.ac.jp.
authors.forename: Takao
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: Department of Otorhinolaryngology, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Irikawa
authors.affiliation: Department of Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Daijiro
authors.initials: D
authors.lastname: Yanagisawa
authors.affiliation: Department of Biomedical MR Science Center, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Shiino
authors.affiliation: Department of Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Tooyama
authors.affiliation: Department of Otorhinolaryngology, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000544:Alzheimer Disease / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000503:physiopathology*; D011446:Prospective Studies; D013649:Taste; D013651:Taste Disorders / Q000503:physiopathology*; D055697:Taste Perception; D013652:Taste Threshold
keywords: Aging; Alzheimer; Dementia; Elderly; Gustatory function; Taste