Peripheral and central nervous system correlates in fibromyalgia

Abstract

Background: Fibromyalgia (FM) is a syndrome characterized by altered pain processing at central and peripheral level, whose pathophysiologic mechanisms remain obscure. We aimed at exploring the structural changes of peripheral nociceptor measured by skin biopsy, the functional changes of central nociceptive pathway assessed by laser evoked potentials (LEP), and their correlation with clinical features and comorbidities.Methods: Eight-one patients diagnosed with FM underwent skin biopsies with quantification of intraepidermal nerve fiber density (IENFD) at the thigh and distal leg, and LEP recording by stimulating hand, thigh and foot. Nerve conduction study (NCS), clinical features, comorbidity with migraine and mood disorders, and previous, non-active immune-mediated disorders were recorded.Results: IENFD was reduced in 85% of patients at the thigh and in 12.3% of patients at the distal leg, whereas it was normal in 14.8% of patients. N2P2 habituation index from laser stimulation at the thigh was altered in 97.5% of patients and correlated with reduced IENFD at the thigh. LEP latencies and amplitudes did not differ among groups. No association was found between IENFD, LEP, clinical features, and comorbidities.Conclusions: FM patients most commonly showed a mild loss of peripheral nociceptors at the thigh rather than distal small fiber neuropathy. This finding was associated with an altered habituation index and strengthened the hypothesis that central sensitization plays a key role in the pathogenesis of the disease.Significance: Central impairment of pain processing likely underlies FM, which in most patients is associated with mild proximal small fiber pathology.

Pain matters for central sensitization: sensory and psychological parameters in patients with fibromyalgia syndrome

“…56,57,64 A recently published study by Vecchio et al showed an association between a reduction of intraepidermal nerve fiber density at the thigh and reduced laser-evoked habituation index in 81 patients with FMS. 63 The authors concluded that central sensitization may be the most relevant mechanism in FMS. We defined the following parameters as signs for central sensitization: decreased MPT and/or increased MPS and/or the presence of DMA.…”

High‐dose spironolactone lacks effectiveness in treatment of fibromyalgia (RCT)

“…Actual concepts of FMS suggest a multifactorial pathology including disruption of inhibitory pain modulation (Uygur‐Kucukseymen et al., 2020), altered BDNF expression (Polli et al., 2020), central sensitization (Vecchio et al., 2020), peripheral neuropathies (Leinder et al., 2016), post‐traumatic stress disorder and corresponding behavioural features (Conversona et al., 2019) as well a variety of psychological and social stress factors and chronic fatigue (Haeuser, 2016).…”

Therapeutic effect of duloxetine combined with ozone trigger point injection on fibromyalgia---A retrospective observational study

“…The results proved our hypothesis. Relevant researches data were reported that the pathogenesis of FM involves disciplines of central nervous system, automatic nervous system, neurotransmitter, hormone secretion, immune system, genetics and psychiatry [29][30][31][32][33][34]. Among them, neurotransmitter of 5-HT and cytokines such as IL-6 and IL-8 were closely related to the development of FM [35][36][37][38][39][40][41][42].…”