Mechanisms and Characteristics of Chronic Pain in Alzheimer's Disease: A Narrative Review.

Alzheimer's disease is a neurodegenerative illness that significantly diminishes patients' quality of life. Chronic pain remains a major contributor to exacerbating patients' well-being. This comprehensive review aims to explore the mechanisms underlying pain perception in AD as well as identify potential targets and future considerations for pain relief. AD causes structural and functional alterations in the affected brain, including shrinkage of gray matter volume and disruptions in brain network connectivity. Besides memory loss, pain is a significant yet often neglected symptom. Effective pain management in AD is challenged by the adverse effects of pain-relief medications and communication difficulties, especially as the disease progresses. Both non- and pharmacological interventions are currently used to alleviate pain in AD. Pharmacological options include opioids, nonsteroidal anti-inflammatory drugs, paracetamol/acetaminophen, and adjuvant pain relievers like antidepressants and antiepileptic medications, though these are not officially approved for pain relief in AD. Non-pharmacological strategies, such as exercise therapy, music therapy, Reiki, reflexology, and behavioral therapy, are preferred to prevent the side effects of medication. However, the use of these methods is limited due to a lack of high-quality research. The review highlights a crucial link between neurological changes in AD and the perception of pain, underscoring the need for customized pain management approaches for this population. Emphasizing non-pharmacological interventions could potentially improve pain management in AD patients, provided that further research supports their effectiveness.