A double-blind, placebo-controlled study on the effectiveness of Chinese medicine decoction in treating phonotraumatic lesions

Abstract

Phonotrauma is one of the common causes leading to voice disorders and contributes to the formation of benign vocal fold lesions. There is sufficient evidence which showed contemporary treatment (e.g. anti-inflammatory medications and surgery) and voice rest are effective in the management of phonotraumatic lesions. Traditional Chinese medicine (TCM) has also been used as a therapeutic measure in treating dysphonia. A number of herbal medicine decoctions or formulae have been reported to be effective in treating dysphonia. Fluid nourishment decoction is a popular ancestral formula used to treat chronic pharyngeal and laryngeal inflammatory diseases. It consists of eight individual herbs, Rehmannia glutinosa (Shou di huang), Ophiopogon japonicus (Mai men dong), Scrophularia ningpoensis (Xuan shen), Paeonia suffruticosa (Mu dan pi), Fritillariae Cirrhosae (Bei Mu), Glycyrrhiza uralensis (fresh) (Gan cao), Mentha haplocalyx (Bo he) and Paeonia lactiflora (Bai Shao). There is however relatively little specific information on how the decoction brings about the improvement. Indeed, there exists virtually no study that employed a randomized control design with objective outcome measures to investigate efficacy of this decoction in treating phonotraumatic lesions. This study employed a randomized-control style to investigate the effectiveness of the fluid nourishment decoction in treating dysphonia with phonotraumatic lesions. Those eligible subjects were randomly allocated into one of the two groups: (a) experimental group (herbal medicine); and (b) placebo group. The outcome measures used included (a) voice range profile (phonetogram), (b) voice activity and participation profile (VAPP, Ma & Yiu, 2001) (c) sentence recording for perceptual voice evaluation, (d) stroboscopy, and (e) voice symptom scale (VoiSS). Preliminary results showed that the group that received the herbal medicine decoction improved better in their vocal function than the placebo group of subjects.