Parkinson’s disease (PD) is a progressive neurodegenerative disorder that affects millions of people worldwide. It is characterized by motor symptoms such as tremor, rigidity, and bradykinesia, as well as non-motor symptoms such as constipation, sleep disorders, and cognitive impairment. The current treatment options for PD are mainly pharmacological, but they have limited efficacy and cause various side effects. Therefore, there is a need for alternative and complementary therapies that can improve the quality of life of PD patients.
The acupuncture community is conducting numerous research projects to evaluate the efficacy of electrical acupuncture for the treatment of Parkinson’s disease.
In this article, we will review some of the recent research on the efficacy of acupuncture for the treatment of PD, focusing on the following aspects:
- The effects of acupuncture on motor and non-motor symptoms of PD
- The possible mechanisms of acupuncture for PD
- The future directions and recommendations for acupuncture research in PD
Effects of acupuncture on motor and non-motor symptoms of PD
Several systematic reviews and meta-analyses have been conducted to evaluate the effects of acupuncture on PD outcomes, such as motor function, activities of daily living, quality of life, depression, and constipation. The results of these reviews are generally positive, but not consistent or conclusive.
For example, a recent overview of systematic reviews by Huang et al1 included 11 reviews that examined the use of acupuncture for the treatment of PD. The authors found that acupuncture appears to be a clinically effective and safe treatment for PD, especially when combined with anti-PD medication. Acupuncture may improve some motor and non-motor symptoms of PD, such as tremor, rigidity, bradykinesia, gait, balance, sleep, mood, and bowel function. However, the authors also noted that the methodological quality and evidence quality of the included reviews were very low, and that the results should be interpreted cautiously.
Another recent systematic review and meta-analysis by Li et al2 focused on the efficacy of acupuncture for the treatment of PD-related constipation (PDC), which is one of the most common and bothersome non-motor symptoms of PD. The authors included 10 randomized controlled trials (RCTs) that compared acupuncture with sham acupuncture, medication, or no treatment in PD patients with PDC. The results showed that acupuncture significantly increased the frequency of complete spontaneous bowel movements (CSBMs) and improved the constipation symptom and efficacy assessment scale (CSEAS) scores compared with the control groups. The authors concluded that acupuncture was effective and safe for PDC, and suggested that it could be used as an adjunctive therapy for PD patients.
Possible mechanisms of acupuncture for PD
The exact mechanisms of acupuncture for PD are still unclear, but several hypotheses have been proposed based on animal and human studies. Some of the possible mechanisms are:
- Acupuncture may modulate the levels of neurotransmitters, such as dopamine, serotonin, glutamate, and gamma-aminobutyric acid (GABA), in the brain regions affected by PD, such as the basal ganglia, the thalamus, and the cortex. Acupuncture may also enhance the expression of neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF), which can protect and regenerate the dopaminergic neurons in the substantia nigra, the main site of neuronal degeneration in PD.
- Delaying the dopamine neuron depletion: Acupuncture may protect the dopamine neurons from degeneration by modulating the expression of genes and proteins related to apoptosis, autophagy, and neuroinflammation.
- Improving the dopaminergic system: Acupuncture may enhance the synthesis, release, and uptake of dopamine in the brain by activating the dopamine receptors, increasing the activity of tyrosine hydroxylase, and inhibiting the activity of monoamine oxidase.
- Improving the motor control network: Acupuncture may improve the motor function of PD patients by modulating the activity and connectivity of the basal ganglia, the thalamus, the cortex, and the cerebellum, which are involved in the regulation of movement.
- Relieving oxidative stress: Acupuncture may reduce the oxidative damage to the brain cells by increasing the levels of antioxidants, such as glutathione, superoxide dismutase, and catalase, and decreasing the levels of reactive oxygen species, such as hydrogen peroxide, hydroxyl radical, and nitric oxide.
However, the exact mechanisms of acupuncture for PD are still unclear and need further investigation. The effectiveness and safety of acupuncture for PD also depend on various factors, such as the type, frequency, duration, and location of acupuncture, as well as the individual characteristics of the patients12.
The future directions and recommendations for acupuncture research in PD
Acupuncture research in PD is a promising and emerging field, but it also faces many challenges and limitations. Some of the future directions and recommendations for acupuncture research in PD are:
- Conducting more high-quality randomized controlled trials (RCTs) with rigorous design, adequate sample size, appropriate control groups, standardized intervention protocols, and relevant outcome measures.
- Developing and applying more valid and reliable tools to measure the effects of acupuncture on PD symptoms, such as motor function, non-motor function, quality of life, and neuroimaging.
- Exploring the optimal acupuncture parameters, such as acupoint selection, stimulation methods, frequency, duration, and course of treatment, for different PD stages and subtypes.
- Investigating the underlying mechanisms of acupuncture for PD from multiple perspectives, such as neurophysiology, neurochemistry, neuroimmunology, and neuroplasticity.
- Evaluating the cost-effectiveness and safety of acupuncture for PD compared with conventional treatments or other complementary therapies.
- Developing and implementing clinical practice guidelines and health policies based on the best available evidence and expert consensus to promote the integration of acupuncture into the standard care of PD.
