Figure 1: Filter disc test for assessment of taste disorder. Each taste solution (sweet, salty, sour, and bitter) was administered to the subjects at five concentrations. For this test, the lowest concentration of each solution that a patient can detect and recognize is determined. A score of 3 or less indicates normal taste sensitivity, a score of 4 indicates a slight taste disorder, and a score of 5 indicates an intermediate taste disorder. The subject who cannot perceive level-5 of a taste solution is assessed as having a severe taste disorder.