A clinical study of the diagnosis of olfactory disturbance by means of a standard olfactory acuity test (author's transl)

Abstract

A standard olfactory acuity test was performed on 296 patients with olfactory disturb. ances. These patients were classified into 4 groups, based on clinical examinations including anterior rhinoscopy, X-ray examination, intravenous olfaction test by alinamine and observation of the olfactory epithelium by selfox endoscopy. These groups were; Group A, with respiratory olfactory disturbance (9 cases), B, with epithelial olfactory disturbance (75 cases), C, with combined olfactory disturbance (184 cases), and D, with central olfactory disturbance (28 cases). In addition, 32 normal subjects with anterior nasal packings by small cotton filters were also examined as Group, E, having artificial respiratory olfactory disturbance.The results were as follows:1) The detection threshold and the recognition threshold were scaled out in more than 50% of B, C and D groups. In A and E groups, there was an elevation in both thresholds.2) There was no conceivable difference in the threshold for the 5 standard odors (β-phenyl ethyl alcohol, iso-valeric acid, methyl cyclopentenolone, γ-undecalactone and scatol) in each case.3) The difference between the detection and the recognition thresholds in Group E was under the level of 2, i. e., within the range of normal variation. A similar result was obtained in Group A. However, the difference was larger in B, C and D groups.4) The cause of respiratory olfactory disturbance in group A was considered to be due to the disturbance of air flow to reach the olfactory area, while in group E, it should be due to the disturbance to reach the entire nasal cavity. Thus, the difference in the threshold between A and E must originate from the condition whether the odors reaches only the olfactory area or the entire nasal cavity.5) The difference in the threshold between A, E groups and B, C, D, groups was considered to be due to whether the perception of odors at the olfactory area was normal.6) It was assumed that the detection threshold was related to the perception at other parts of the nasal cavity than the olfactory area.By using the standard olfactory acuiy test, topical diagnosis of olfactory disturbance can be easily conducted.