Chinese Herbal Medicine Added to Olfactory Training Confers Limited Functional Benefit to Patients with Traumatic Anosmia

What is the effect of the Chinese herbal medicine (CHM) Guizhi decoction on traumatic anosmia?

BOTTOM LINE

Adding a tailored Guizhi decoction treatment to olfactory training (OT) confers a limited benefit to the olfactory function of patients experiencing traumatic anosmia.

BACKGROUND: Traumatic anosmia has a poor prognosis, with approximately one-third of patients recovering spontaneously. The effects of medications including steroids, zinc, and minocycline on anosmia are unclear, and the effects of OT on anosmia are controversial. Chinese medicine modalities, including CHM and acupuncture, have also been used to treat olfactory dysfunction.

STUDY DESIGN: Prospective study.

SETTING: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.

SYNOPSIS: Researchers randomly divided a group of 78 patients who had lost olfactory function after experiencing head trauma into a CHM group (n = 38; 20 men, mean age 39.95 years), who received a tailored Guizhi decoction, and an OT group (n = 40; 21 men, mean age 44.60 years), who used OT only. Olfactory function was evaluated by 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 three and six months after treatment. TC-UPSIT scores of patients rose slightly and PEA thresholds improved significantly after treatment in both groups. There were no significant differences in threshold or identification scores between the groups. Authors note that because they enrolled only patients who had been unresponsive to steroid and zinc treatment, it was more difficult to evaluate the effect of Guizhi decoction on the further promotion of olfactory neuroregeneration. Therefore, whether the treatment can improve olfactory function in patients with a reserve of olfactory neurons requires further investigation.

CITATION: Jiang RS, Yan K, Chiang YF, et al. The effect of Chinese herbal medicine on traumatic anosmia: a prospective, randomized clinical trial. Laryngoscope. 2023;133:1473–1479.