Acupuncture Effect and Mechanism for Treating Pain in Patients With Parkinson's Disease

# Acupuncture in Pain Relief for Patients With Parkinson's Disease: A Study on Efficacy and Brain Mechanisms

Parkinson's disease is known mainly for its motor symptoms, such as tremors and muscle rigidity. However, recent research has paid increasing attention to non-motor symptoms, which significantly affect patients' quality of life. Among these symptoms, pain stands out as especially relevant, affecting between 40 and 90% of those with the disease. Often, patients do not report pain to their physicians because they do not perceive its connection to Parkinson's, resulting in inadequate treatment that can even lead to hospitalization.

Pain in Parkinson's disease can arise from different causes, including motor fluctuations, dystonic muscle contractions, deep visceral pain, and musculoskeletal pain. As the disease progresses, patients may have lower pain tolerance compared to healthy individuals, being especially vulnerable to musculoskeletal pain.

Conventional treatment of pain in Parkinson's patients includes dopaminergic therapy, anti-inflammatory medications, physical therapy, and, in extreme cases, surgery. Although levodopa is frequently used, it does not always provide adequate relief, resulting in additional costs and treatment burden. Acupuncture, in turn, has been widely recognized worldwide as an effective therapy for various types of pain, including migraine, low back pain, chronic pain, and cancer pain. This ancient practice stimulates specific points on the body, known as acupoints, to correct energetic imbalances.

However, specific studies on the relief of Parkinson's-related pain were still scarce, as was the understanding of the brain mechanisms involved in this process.

This study was conducted to investigate both the efficacy and brain mechanisms of acupuncture in treating pain in Parkinson's patients. The researchers used an innovative approach, combining standardized clinical assessments with advanced neuroimaging techniques. Sixteen Parkinson's patients with pain participated in the study and were divided into two groups according to their personal preference: nine received acupuncture treatment and seven made up the control group. All participants continued their usual Parkinson's medications and were able to use analgesics as needed during the study period.

The group that received acupuncture underwent 16 sessions over eight weeks, with one to three sessions per week. Treatment focused on three specific acupuncture points: Bai-Hui, Shen Guan, and Yanglingquan, chosen based on traditional Chinese theory for neuropsychiatric and sensory problems. To understand the brain mechanisms involved, the researchers used resting-state functional MRI, a non-invasive technique that allows observation of brain activity and connections between different brain regions.

The results clearly demonstrated the efficacy of acupuncture in relieving Parkinson's-related pain. The group that received acupuncture showed a significant 46.2% reduction in scores on the King's Parkinson's Disease Pain Scale, while the control group showed no significant improvement. In addition to pain relief, patients who received acupuncture also showed a 21.6% improvement in overall scores on the Unified Parkinson's Disease Rating Scale, suggesting that the benefits of acupuncture may extend beyond simple pain control. Importantly, these positive effects were maintained for at least three months after treatment ended, indicating a lasting benefit.

Neuroimaging analyses revealed specific changes in brain connectivity, showing increased connections between regions important for pain processing, including areas related to both sensory and emotional aspects of the painful experience. In particular, strengthening of connections was observed between the primary somatosensory cortex, middle temporal gyrus, insular cortex, and prefrontal regions, all areas known for their role in pain processing and modulation.

From a clinical standpoint, these results bring valuable information for both patients and health professionals. For Parkinson's patients suffering from pain, acupuncture represents a safe and effective therapeutic alternative that can be used as a complement to conventional medical treatment. The non-pharmacological nature of acupuncture is especially attractive, considering that many Parkinson's patients already use multiple medications and may benefit from approaches that do not introduce new risks of drug interactions or side effects. For neurologists and other health professionals, the study provides robust scientific evidence for the inclusion of acupuncture in the available therapeutic arsenal.

The fact that benefits extend beyond pain control, also improving overall motor scores, suggests that acupuncture may have broader neuroprotective or neuromodulatory effects. The identification of specific brain mechanisms also contributes to a more grounded and personalized prescription of treatment.

It is important to recognize the limitations of this study for proper interpretation of the results. The relatively small number of participants (sixteen patients) limits the generalizability of the findings, although the observed effects were clinically significant. The absence of a sham acupuncture (placebo) control group represents another methodological limitation, although prior studies have already demonstrated the superiority of true acupuncture over sham acupuncture in chronic pain treatment. The division of participants based on personal preference, although ethically appropriate, may have introduced selection bias.

Additionally, the study did not evaluate different acupuncture protocols or alternative points, limiting our understanding of treatment optimization. Despite these limitations, the findings are promising and pave the way for larger and randomized future studies. The research represents a significant advance in understanding how integrative therapies can benefit patients with Parkinson's disease, offering a new perspective for the holistic management of this complex neurodegenerative condition.