title: Quantitative and fiber-selective evaluation of pain and sensory dysfunction in patients with Parkinson's disease.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  CPT was higher at all three frequencies and PTT was lower at 2000 Hz and 250 Hz in PD patients with pain versus healthy controls (P < 0.05). CPT was higher at 2000 Hz and 250 Hz and PTT was lower at 2000 Hz and 250 Hz in PD patients without pain versus healthy controls (P < 0.05). PD patients with pain exhibited higher CPT at 5 Hz and 250 Hz than PD patients without pain (P < 0.05). Dopaminergic therapy did not affect CPT or PPT in PD patients (P > 0.05).
  
  
  CONCLUSIONS
  Abnormal Aδ fiber- and Aβ fiber-dependent sensory inputs may exist in PD. Abnormal sensory inputs via C fibers and Aδ fibers might be associated with the presence of pain in PD. Because dopaminergic therapy failed to mitigate these sensory and pain dysfunctions, mechanisms not involving the dopaminergic pathway are likely to be implicated.
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Yi
authors: Y
authors: Chen
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Cheng-Jie
authors: CJ
authors: Mao
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Si-Jiao
authors: SJ
authors: Li
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China; Institute of Neuroscience, Soochow University, Suzhou 215123, China.
authors: Fen
authors: F
authors: Wang
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Jing
authors: J
authors: Chen
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Hui-Jun
authors: HJ
authors: Zhang
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Ling
authors: L
authors: Li
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China.
authors: Sha-Sha
authors: SS
authors: Guo
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China; Institute of Neuroscience, Soochow University, Suzhou 215123, China; Beijing Key Laboratory for Parkinson's Disease, Beijing 100053, China.
authors: Ya-Ping
authors: YP
authors: Yang
authors: Department of Neurology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215004, China; Institute of Neuroscience, Soochow University, Suzhou 215123, China; Beijing Key Laboratory for Parkinson's Disease, Beijing 100053, China. Electronic address: liucf@suda.edu.cn.
authors: Chun-Feng
authors: CF
authors: Liu
mesh_terms: D000344:Afferent Pathways / Q000187:drug effects / Q000503:physiopathology; D000368:Aged; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D005385:Fingers / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000502:physiology*; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000502:physiology*; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D010525:Peripheral Nerves / Q000187:drug effects / Q000503:physiopathology*; D012684:Sensory Thresholds / Q000187:drug effects / Q000502:physiology*
keywords: Pain; Parkinson's disease; Thresholds