title: Discordance between olfactory psychophysical measurements and olfactory event related potentials in five patients with olfactory dysfunction following upper respiratory infection.
abstract: BACKGROUND
  Subjective olfactory tests are easy to perform and popularly applied in the clinic, but using only these, it is difficult to diagnose all disorders of the olfactory system. The olfactory event related potentials technique offers further insight into the olfactory system and is an ideal objective test. This analysis was of subjective and objective data on the olfactory function of twelve patients with loss of smell associated with an upper respiratory infection (URI).
  
  
  METHODS
  We tested the twelve patients with URI induced olfactory loss by medical history, physical examination of the head and neck, olfactory tests and medical imaging. Olfactory function was assessed by Toyota and Takagi olfactometry including olfactory detection and recognition thresholds and olfactory event-related potentials (OERPs) recorded with OEP-98C Olfactometer.
  
  
  RESULTS
  An unusual phenomenon was observed in five patients in whom the subjective detection and recognition thresholds were normal, while the expected OERPs were not detectable.
  
  
  CONCLUSIONS
  We suggest that the discordance between olfactory psychophysical measurements and OERPs might be the results of abnormal electrophysiology related with olfactory neuropathy caused by viral URI. In addition, the measurement of OERPs might play a significant role in evaluating olfactory dysfunction.
authors.affiliation: Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Guan
authors.forename: Dao-feng
authors.initials: DF
authors.lastname: Ni
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Zhi-qiang
authors.initials: ZQ
authors.lastname: Gao
mesh_terms: D000328:Adult; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000857:Olfaction Disorders / Q000175:diagnosis*; D012141:Respiratory Tract Infections / Q000150:complications*; D012684:Sensory Thresholds; D012903:Smell / Q000502:physiology*