Pain in Parkinson's disease: bridging pathophysiology, clinical features, and personalized management.

Pain is a highly prevalent and disabling non-motor symptom of Parkinson's disease (PD), yet it remains underrecognized and frequently undertreated in clinical practice. Although long considered a secondary consequence of motor dysfunction, pain in PD is now increasingly understood as a manifestation of disease-related alterations in nociceptive processing. These changes extend beyond dopaminergic deficiency and involve broader neurotransmitter imbalances and impaired descending inhibitory control across different neuroanatomical regions, providing a framework for understanding pain as an intrinsic feature of PD rather than a purely peripheral or motor-related phenomenon. We also summarize the main categories of pain experienced in PD, each with distinct clinical features and underlying pathophysiological mechanisms, and link them with current management strategies. A multimodal, mechanism-informed approach that integrates optimization of dopaminergic therapy with non-dopaminergic pharmacological treatments, neuromodulation, rehabilitation, and complementary interventions is key to a personalized treatment plan for pain in patients with PD. Finally, we highlight emerging translational directions, including candidate biomarkers that may help objectify pain and its related dysfunction in the PD population. Focusing on the neurobiological basis of pain in PD, this review aims to support a shift toward mechanism-based assessment and management, with an ultimate goal of improving pain outcomes and quality of life for individuals living with the disease.