title: Impact of endoscopic sinus surgery on olfaction and use of alternative components in odor threshold measurement.
abstract: BACKGROUND
  One of the major causes of olfactory disturbances is chronic rhinosinusitis (CRS), and the main surgical modality to treat CRS is functional endoscopic sinus surgery (FESS). It, therefore, is essential to assess the effect of this surgery on olfaction. Also, it is necessary to find new ways of measuring olfaction so as to reduce dependability on standard tests available.
  
  
  OBJECTIVE
  To study the prevalence of olfactory impairment in patients with CRS and to evaluate the impact of FESS on olfaction. The study also aims at investigating the use of other odorants in place of butanol-1 in the Connecticut Chemosensory Clinical Research Center test.
  
  
  METHODS
  Forty patients of CRS without nasal polyposis were included in the study to analyze the prevalence of olfactory dysfunction and examine the influence of FESS at 1 and 3 months after surgery. Computed tomography scores (Lund Mackay scores) were calculated preoperatively, whereas other tests, viz., visual analog scale scoring, nasal endoscopy (Lund Kennedy scoring), and composite olfactory testing with odor thresholds of butanol-1, peppermint, lemon, clove, and ethyl acetate were carried out before surgery and after surgery at 1 and 3 months.
  
  
  RESULTS
  Of 40 patients, 70% had symptoms of hyposmia or of anosmia before surgery, which dropped to 22.5% at 1 month after surgery and to 10% at 3 months after surgery. Nasal endoscopy and visual analog scale scores improved significantly. Odor threshold and odor identification scores also improved compared with the preoperative levels. A significant positive correlation was found between the threshold scores of butanol-1 and other odorants, both before and after surgery.
  
  
  CONCLUSIONS
  Significant improvement was observed in olfaction after FESS, both in patient responses and in objective testing. The olfactory results with peppermint, lemon, clove, and ethyl acetate were close to those with butanol-1, and, hence, these other odorants can be used in place of butanol-1 in measuring the odor threshold.
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery, Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Gupta
authors.forename: Achal
authors.initials: A
authors.lastname: Gulati
authors.forename: Ishwar
authors.initials: I
authors.lastname: Singh
authors.forename: Uma
authors.initials: U
authors.lastname: Tekur
mesh_terms: D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D059747:Nasal Surgical Procedures / Q000009:adverse effects; D057605:Natural Orifice Endoscopic Surgery / Q000009:adverse effects; D000857:Olfaction Disorders / Q000453:epidemiology* / Q000209:etiology*; D010256:Paranasal Sinuses / Q000601:surgery*; D011184:Postoperative Period; D057234:Preoperative Period; D015995:Prevalence; D011446:Prospective Studies; D012220:Rhinitis / Q000601:surgery*; D012852:Sinusitis / Q000601:surgery*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome