title: Pain sensitivity and clinical progression in Parkinson's disease.
abstract: Pain sensitivity in Parkinson's disease is known to be altered in an L-dopa-dependent manner with increased spinal nociception and experimental pain perception in the medication-defined "off" state. As Parkinson's disease-related pain can be an early symptom in Parkinson's disease, the present study aimed to investigate experimental pain sensitivity and spinal nociception during clinical progression. The nociceptive flexion reflex as a marker of spinal nociception as well as electrical and heat pain thresholds were assessed during the medication-defined "off" state in 29 patients with Parkinson's disease divided into 3 severity groups (according to their Unified Parkinson's Disease Rating Scale motor score) and compared with 27 healthy elderly subjects. Parkinson's disease-related pain was also quantified. Data provided evidence that spinal nociception and pain sensitivity are preserved during the early phase of Parkinson's disease. Following increased spinal nociception (F(1,36) = 6.838, P = .013), experimental thermal and electrical pain sensitivity were augmented during the course of Parkinson's disease (F(1,34) = 5.397, P = .014; F(1,34) = 6.038, P = 0.053), whereas spinal nociception further increased (F(1,34) = 5.397, P < .001). Increased experimental pain sensitivity was observed in patients exhibiting Parkinson's disease-related pain. Spinal alterations either on the local level or induced by diminished dopaminergic descending inhibition probably led to increased pain sensitivity in later stages. Because Parkinson's disease-related pain is correlated with experimental pain sensitivity these 2 observations likely reflect a causal relation.
authors.affiliation: Department of Neurology, Philipps University, Marburg, Germany. mylius@med.uni-marburg.de
authors.forename: Veit
authors.initials: V
authors.lastname: Mylius
authors.forename: Juliane
authors.initials: J
authors.lastname: Brebbermann
authors.forename: Helena
authors.initials: H
authors.lastname: Dohmann
authors.forename: Isabel
authors.initials: I
authors.lastname: Engau
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Oertel
authors.forename: Jens C
authors.initials: JC
authors.lastname: Möller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D018450:Disease Progression; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D010300:Parkinson Disease / Q000150:complications*; D012018:Reflex / Q000502:physiology; D020886:Somatosensory Disorders / Q000209:etiology*; D013116:Spinal Cord / Q000503:physiopathology; D011795:Surveys and Questionnaires