Understanding and Treating Pain Syndromes in Parkinson's Disease.

Pain affects many people with Parkinson's disease (PD) and diminishes their quality of life. Different types of pain have been described, but their related pathophysiological mechanisms remain unclear. The aim of this chapter is to provide movement disorders specialists an update about the pathophysiology of pain and a practical guide for the management of pain syndromes in clinical practice. This chapter reviews current knowledge on the pathophysiological mechanisms of sensory changes and pain in PD, as well as assessment and treatment procedures to manage these symptoms. In summary, changes in peripheral and central pain processing have been demonstrated in PD patients. A decrease in pain threshold and tolerance to several stimuli, a reduced nociceptive withdrawal reflex, a reduced pain threshold, and abnormal pain-induced activation in cortical pain-related areas have been reported. There is no direct association between improvement of motor symptoms and sensory/pain changes, suggesting that motor and nonmotor symptoms do not inevitably share the same mechanisms. Special care in pain assessment in PD is warranted by the specific pathophysiological aspects and the complexity of motor and nonmotor symptoms associated with pain symptoms. Rehabilitation may represent a valid option to manage pain syndromes in PD. However, further research in this field is needed. An integrated approach to pain involving a multidisciplinary team of medical specialists and rehabilitation experts should allow a comprehensive approach to pain in PD.