The Effect of Chinese Herbal Medicine on Traumatic Anosmia: A Prospective, Randomized Clinical Trial

Abstract

Objective: Chinese herbal medicine (CHM) has been implemented as a form of treatment for olfactory dysfunction. In this study, we aimed to use a tailored Guizhi decoction for the treatment of traumatic olfactory dysfunction.Methods: Patients who had lost olfactory function after experiencing head trauma and whose olfactory function was anosmic were selected. The eligible patients were randomly assigned to two groups. In the CHM group, a tailored Guizhi decoction was prescribed, with patients also undergoing olfactory training (OT). In the OT group, patients performed OT only. The olfactory function of each patient was evaluated by both the phenyl ethyl alcohol (PEA) odor detection threshold test and the traditional Chinese version of the University of Pennsylvania Smell Identification Test (TC-UPSIT), at both 3 and 6 months after the completion of treatment.Results: A total of 38 patients in the CHM group and 40 in the OT group completed the study. The TC-UPSIT scores of patients slightly rose after treatment in both the CHM and OT groups. Nevertheless, there were no significant differences in TC-UPSIT scores before and after treatment in both groups. However, the PEA thresholds improved significantly in both CHM and OT groups (p = 0.005 and 0.016, respectively). Of note, there were no significant differences in threshold or identification scores between the CHM and OT groups.Conclusion: Our results show that adding a tailored Guizhi decoction to OT conferred a limited benefit to the olfactory function of patients experiencing traumatic anosmia.