Non-motor symptoms of Parkinsonâs disease (PD) have received increasingly more recognition in recent years. Pain is among such non-motor sensory disorders and occurs frequently in patients with PD. Although chronic pain among patients with PD can be caused by motor symptoms, it has also been reported independently of these symptoms. Extensive co morbidity has been reported between chronic pain syndromes and mood and anxiety disorders. Dysfunction in endogenous pain inhibition caused by a dopaminergic deficiency in the basal ganglia, particularly in the striatum and mesolimbic areas, is the main pathophysiological mechanism involved in PD-associated nociceptive abnormalities. In addition to the anatomic overlap between the brain regions associated with pain processing and those that comprise the dopamine system, there is substantial overlap between the cognitive and affective functions inï¬uenced by dompaminergic (DA) neurotransmission. DA neurotransmission plays an important role in outcome prediction, attention, response inhibition, and motivation as well as in affective symptoms associated with anxiety and depression.
Last date updated on July, 2014