Hyperexcitable C nociceptors in fibromyalgia. Issue 2 (12th February 2014)

• Record Type: Journal Article
• Authors: Serra, Jordi; Collado, Antonio; Solà, Romà; Antonelli, Francesca; Torres, Xavier; Salgueiro, Monika; Quiles, Cristina; Bostock, Hugh
• Is Part Of: Annals of neurology. Volume 75:Issue 2(2014:Feb.)
• Page Start: 196
• Page End: 208
• Publication Date: 2014-02-12
• Subjects: Neurology -- Periodicals; Pediatric neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; 616.8
• DOI: 10.1002/ana.24065
• Languages: English
• ISSNs: 0364-5134

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="ana24065-sec-0001" sec-type="section"> <title>Objective</title> <p>To test the hypothesis that peripheral C nociceptor function may be abnormal in fibromyalgia and that C nociceptor dysfunction may contribute to the symptoms reported by these patients.</p> </sec> <sec id="ana24065-sec-0002" sec-type="section"> <title>Methods</title> <p>Microneurography was used to record C nociceptors of 30 female patients meeting criteria for fibromyalgia and compared with recordings from 17 female patients with small‐fiber neuropathy and 9 female controls.</p> </sec> <sec id="ana24065-sec-0003" sec-type="section"> <title>Results</title> <p>We obtained stable recordings of 186 C nociceptors in the fibromyalgia group, 114 from small‐fiber neuropathy patients, and 66 from controls. The mechanosensitive nociceptors in the fibromyalgia patients behaved normally, but the silent nociceptors in 76.6% of fibromyalgia patients exhibited abnormalities. Spontaneous activity was detected in 31% of silent nociceptors in fibromyalgia, 34% in small‐fiber neuropathy, and 2.2% in controls. Sensitization to mechanical stimulation was found in 24.2% of silent nociceptors in fibromyalgia, 22.7% in small‐fiber neuropathy, and 3.7% in controls. Abnormally high slowing of conduction velocity when first stimulated at 0.25Hz was more common in fibromyalgia.</p> </sec> <sec id="ana24065-sec-0004" sec-type="section"> <title>Interpretation</title> <p>We show for the first time that the majority of fibromyalgia patients have abnormal C nociceptors. Many silent nociceptors exhibit hyperexcitability resembling that in small‐fiber neuropathy, but high activity‐dependent slowing of conduction velocity is more common in fibromyalgia patients, and may constitute a distinguishing feature. We infer that abnormal peripheral C nociceptor ongoing activity and increased mechanical sensitivity could contribute to the pain and tenderness suffered by patients with fibromyalgia. ANN NEUROL 2014;75:196–208</p> </sec> </abstract>