A PRISMA-compliant systematic review and meta-analysis
Parkinson’s disease (PD) is the second-most-common chronic and progressive neurodegenerative disease. The long-term use of levodopa leads to a loss of efficacy and to complications. Therefore, many patients with PD have turned to complementary therapies to help relieve their symptoms. Acupuncture is most commonly used as a complementary therapy in patients with PD. This paper presents a systematic review and meta-analysis of the effects of acupuncture for patients with PD. This study was performed to summarize and evaluate evidence regarding the effectiveness of acupuncture in the relief of PD symptoms.
Seven databases, namely, MEDLINE, EMBASE, the Cochrane Library, the China National Knowledge Infrastructure [CNKI], and three Korean medical databases, were searched from their inception through August 2015 without language restrictions. Randomized controlled trials (RCTs) were included if they contained reports of acupuncture compared with no treatment and conventional treatment alone or acupuncture plus conventional treatment compared with conventional treatment alone for PD symptoms. Assessments were performed with the unified PD rating scales (UPDRS) I, II, III, and IV and the total score, the Webster scale, and effectiveness rating. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale and the Cochrane risk of bias (ROB).
In all, 982 potentially relevant articles were identified; 25 RCTs met our inclusion criterion, 19 of 25 RCTs were high-quality studies (i.e., a score of 6 or higher). The included RCTs showed favorable results for acupuncture plus conventional treatment compared with conventional treatment alone in the UPDRS II, III, and IV and the total score. Acupuncture was effective in relieving PD symptoms compared with no treatment and conventional treatment alone, and acupuncture plus conventional treatment had a more significant effect than conventional treatment alone.
Our systematic review and meta-analysis suggested evidence for the effectiveness of acupuncture in the treatment of PD. Acupuncture was more effective in relieving PD symptoms than no treatment or conventional treatment alone. In addition, acupuncture plus conventional treatment had a significant effect compared to conventional treatment alone according to the UPDRS, Webster scale, and effectiveness rates.
All of the studies included in the present study were conducted in 2 Asian countries, the Republic of Korea and China. One pilot RCT in our initial sample was conducted in the West, but it was excluded because it reported insufficient outcome data. Acupuncture is today used to relieve PD symptoms in many clinics in the West as well, but there has been little research on its effectiveness. Further studies on this topic should be carried out in both the East and the West in the future.
Previous reviews carried out quality assessment only with ROB, and the number and quality of trials are too low to draw any firm conclusions on the effectiveness of acupuncture of PD.[12,13] Our study carried out quality assessment using the ROB and the Physiotherapy Evidence Database (PEDro) scale rating. A study with a PEDro scale rating of 6 points or more is considered to be a high-quality study. Our study included 25 trials with an average score of 6 on the PEDro scale, thus we can draw firm conclusions regarding the effectiveness of acupuncture of PD.
Most of the included RCTs stated that the rationale for acupuncture point selection was drawn from Traditional Chinese Medicine (TCM) theory. None of the trials included in this research used a single acupuncture point; all used various points in combination. For the RCTs that reported the variances for the number of acupuncture points, meta-analysis of the data revealed no significant between-group differences for either UPDRS total score (P = 0.55) or total efficacy (P = 0.33). It is therefore likely that a study testing a combination of 2 acupuncture points would report the same efficacy as studies evaluating more points. Points LR3, GB34, and GV20, in particular, were found to be the main acupuncture points used to treat PD in clinical trials. Some preclinical randomized trials clarify the mechanism in the substantia nigra pars compacta (SNpc) for the efficacy of acupuncture points LR3, GB34, and GV20 in PD, such as preventing the cell death of SNpc.[41,42] According to this evidence, we recommend acupuncture points LR3, GB34, and GV20 of the WHO standard acupuncture points as the basic acupuncture points for clinical treatment settings. Their use may result in higher quality clinical trials and treatment.
The included trials showed favorable results for acupuncture plus conventional treatment compared with conventional treatment alone using only UPDRS II, UPDRS III, and the UPDRS total score. The present study has publication bias as an outcome measure of the UPDRS. UPDRS I, II, and IV were used in 2 trials, UPDRS III in 5 trials as the outcome measure of the effects of acupuncture on PD. Overall, the results of UPDRS III for the outcome measure have been mainly presented instead all of the results of UPDRS I through V. Future studies must present all data measured by UPDRS as supplementary data regardless of the results of the outcome measure for the reduction of publication bias. Future trials that assess the effectiveness of acupuncture for PD must overcome publication bias.
Levodopa is the primary treatment for PD, but its long-term use can increase the potential for complications. If a patient’s PD symptoms do not interfere with daily life or negatively affect his or her job during the early phase of PD, treatment with levodopa or other antiparkinsonism drugs does not need to start early. In our study, we studied alternative treatments that can be used in the early phase of PD or before the use of levodopa.
According to the meta-analysis of herbal medicine performed by Wang et al, combined herbal medicine and conventional treatments have significantly better effects than conventional treatments on UPDRS I to IV and the total score. The studies that used total efficacy to compare the effects of combined TCM and conventional treatment versus conventional treatment alone found that combined treatment had a significant effect on PD symptoms, and the studies that used total efficacy to compare the effects of TCM versus placebo found that TCM had a significant effect on PD symptoms. Two studies used total efficacy to compare the effects of acupuncture versus conventional treatment alone showed a significant effect of acupuncture on PD symptoms, but the studies are too small to allow any firm conclusions to be drawn.Furthermore, a study to compare the effects of herbal medicine plus acupuncture versus conventional treatment alone on PD symptoms would help in clinical treatment. In fact, clinicians have proposed treatment with acupuncture without prescribing conventional medicines for the treatment of PD. Therefore, patients in an early stage of PD before the use of levodopa may be better served by treatment with acupuncture and herbal medicine rather than with conventional medicine.
Although this meta-analysis has revealed many positive conclusions, it also has some limitations. Most importantly, some of the studies had methodological shortcomings such as an inadequate level of blinding. Although it is difficult to blind the acupuncture therapist to the patient, attempts should have been made to blind the patients and outcome assessors to minimize performance bias. There has been much discussion about the use of placebo in acupuncture research. Our study included 2 trials with placebo comparisons, but it is difficult to regard them as a real sham controls because the needle was inserted into the skin near the GB34 and LR3 acupuncture points.[16,17] Recently, phantom acupuncture has been reported as a sham control and was characterized by an acupuncture needling intervention induced solely by visual display. Phantom acupuncture can be a viable sham control for acupuncture because it completely excludes the somatosensory component of real needling while maintaining the credibility of the acupuncture context in many subjects. If carried out in this method, a clinical trial with sham control will be more appropriate. In the present study, there was 0% heterogeneity in the RCTs assessing acupuncture efficacy by UPDRS I to III (Fig. (Fig.2(1–3)),2(1–3)), UPDRS total score (Fig. (Fig.2(5)),2(5)), acupuncture versus no treatment (Fig. (Fig.3(1)),3(1)), and acupuncture versus conventional treatment alone by the Webster scale rating (Fig. (Fig.3(2)).3(2)). Those reporting outcomes in terms of acupuncture plus conventional treatment versus conventional treatment alone by the Webster scale rating (Fig. (Fig.3(3)),3(3)), in contrast, had 93% heterogeneity, and those doing so in terms of acupuncture plus conventional treatment versus conventional treatment by total effectiveness (Fig. (Fig.4(2))4(2)) had 73% heterogeneity. The source of this methodological heterogeneity may be a lack of blinding among the patients and outcome assessors involved.
Based on our findings, we recommend the use of acupuncture plus conventional treatment for patients with PD. It is also recommended that treatment efficacy be assessed with UPDRS III, which is the most effective scale in evaluating improvements in motor function. Furthermore, we recommend that future studies in this area use validated outcome measures in conjunction with subjective reports of symptom improvement and ensure the blinding of both patients and outcome assessors to obtain high-quality data.
We performed a systematic review and meta-analysis to evaluate the effects of acupuncture in the relief of PD symptoms. We found that acupuncture has significant positive effects in the relief of PD symptoms. Acupuncture can be used for patients with PD in combination with conventional treatment.
Medicine (Baltimore). 2017 Jan; 96(3): e5836.