Lengthened Cutaneous Silent Period in Fibromyalgia Suggesting Central Sensitization as a Pathogenesis

PLoS One. 2016 Feb 12;11(2):e0149248. doi: 10.1371/journal.pone.0149248. eCollection 2016.

Abstract

The pathogenesis of fibromyalgia (FM) has not been clearly elucidated, but central sensitization, which plays an important role in the development of neuropathic pain, is considered to be the main mechanism. The cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is useful for the evaluation of sensorimotor integration at the spinal and supraspinal levels. To understand the pathophysiology of FM, we compared CSP patterns between patients with FM and normal healthy subjects. Twenty-four patients with FM diagnosed in accordance with the 1990 American College of Rheumatology classification system and 24 age- and sex-matched healthy volunteers were recruited. The CSP was measured from the abductor pollicis brevis muscle. Demographic data, number of tender points, and visual analog scale and FM impact questionnaire scores were collected. The measured CSP and clinical parameters of the patient and control groups were compared. In addition, possible correlations between the CSP parameters and the other clinical characteristics were analyzed. Mean CSP latencies did not differ between patients (55.50 ± 10.97 ms) and healthy controls (60.23 ± 11.87 ms; p = 0.158), although the mean CSP duration was significantly longer in patients (73.75 ± 15.67 ms) than in controls (63.50 ± 14.05 ms; p = 0.021). CSP variables did not correlate with any clinical variables. The significantly longer CSP duration in FM patients suggests central dysregulation at the spinal and supraspinal levels, rather than peripheral small fiber dysfunction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Central Nervous System Sensitization*
  • Electromyography
  • Female
  • Fibromyalgia / diagnosis*
  • Fibromyalgia / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Neurons, Afferent / pathology*
  • Reaction Time
  • Reflex
  • Skin / physiopathology
  • Spinal Cord / physiopathology*
  • Young Adult

Grants and funding

This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIP; no. NRF-2015R1A5A7037674) and the Technology Innovation Program (or the Industrial Strategic Technology Development Program) (10049743, “Establishing a medical device development open platform, as a hub for accelerating close firm-hospital communication”) funded by the Ministry of Trade, Industry and Energy (MI, Korea). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.