Operator-administered olfactory and gustatory test
The Connecticut Chemosensorial Clinical Research Center (CCCRC) orthonasal olfaction test [12-16] was used to evaluate the olfactory function. As required by the test protocol, olfactory threshold was determined by means of 60 mL deionized waters solutions, with increasing concentration of N-butyl-alcohol. The most concentrated bottle (bottle 0) presented 4% dilution. The other 8 bottles (bottles 1-8) contained decreasing concentrations with consequent 1:3 dilutions. For each threshold step, two identical squeezable bottles were presented to the patient: one containing the N-butanol solution, from the major to the minor dilution, and the other filled with deionized water. The test was conducted as previously described for both nostrils, and the average value determined the overall score [17].
Ten well-known Italian odorants were used to assess the olfactory discriminative function: chocolate (Nutella, Ferrero, Italy), coffee, Baby powder (Manetti & Roberts, Florence, Italy), Vicks-VapoRub (Proctor & Gamble, Cincinnati, OH, USA), ammonia, fruit-flavored chewing gum (Perfetti Van Melle Italia S.r.l, Lainate, Italy), ketchup (Heinz, Pittsburgh, PA, USA), orange, soap (Ivory, Proctor & Gamble, Cincinnati, OH, USA) and black pepper. The odorants were presented one at a time, in identical and opaque 180 mL containers covered by gauze. Therefore, the patient had to identify the odorant on a 20 items list containing the 10 test samples and 10 distractors.
The threshold and discriminative test scores were finally converted into the CCCRC composite score. The scoring system is shown in Table 2 [Table 2].
As regards the gustatory function assessment, the primary taste solutions were identical to those used in the telephone test and already proposed by other authors [9,10]. As the only variation, at the hospital, deionized water was used as solvent and control instead of normal drinking water. One at a time, approximately 1 ml of each basic flavor was put on the patient’s tongue with a cotton swab, taking care to test the bitter last. Therefore, the patient had to indicate the perceived taste: salty, acid, sweet, bitter or neutral. Depending on the number of primary tastes perceived, the score could vary between 0 and 4. The scoring system is reported in table 3 [Table 3].