Hyperexcitable C nociceptors in fibromyalgia.
Ann Neurol
; 75(2): 196-208, 2014 Feb.
Article
em En
| MEDLINE
| ID: mdl-24243538
ABSTRACT
OBJECTIVE:
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.METHODS:
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.RESULTS:
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.INTERPRETATION:
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.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Nociceptores
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Fibromialgia
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Fibras Nervosas Amielínicas
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Middle aged
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article