Quantitative and fiber-selective evaluation of pain and sensory dysfunction in patients with Parkinson's disease.

Introduction: Pain and sensory disturbances affect many patients with Parkinson's disease (PD). The present study aimed to evaluate the pain and sensory sensitivity of each class of afferent fibers in PD patients and determine the effects of dopaminergic therapy on pain and sensory sensitivity.

Methods: Current perception threshold (CPT) and pain tolerance thresholds (PTT) at three frequencies, 2000 Hz, 250 Hz, and 5 Hz, to stimulate Aβ fibers, Aδ fibers, and small C-polymodal fibers, respectively, were measured in 72 PD patients and 35 healthy controls.

Parkinson's disease patients with pain suffer from more severe non-motor symptoms.

Non-motor symptoms, including pain, depression, sleep disorder, and olfactory dysfunction, occur frequently in patients with Parkinson's disease (PD), even before the onset of motor symptoms. Although studies have examined the correlation between pain and depression or sleep disorder in PD, few studies have investigated the correlation between pain and a range of other non-motor symptoms of PD. PD patients (n = 142) with or without pain were included in the study.