Fibromyalgia patients exhibited significantly higher resting muscle sympathetic nerve activity compared to healthy controls (31.1 vs 24.3 bursts/min), which positively correlated with pain intensity.
Case-Control (n=21)
No
Does baroreflex stimulation via lower body negative pressure alter muscle sympathetic nerve activity and correlate with pain intensity in female fibromyalgia patients compared to healthy controls?
Fibromyalgia patients exhibit increased sympathetic outflow at rest which correlates with pain intensity, suggesting that autonomic dysfunction and altered baroreflex control play a role in pain chronification.
Absolute Event Rate: 31.1% vs 24.3%
p-value: p=0.028
The role of the sympathetic nervous system dysfunction in fibromyalgia (FM) is unclear. A large series of studies has shown that various abnormalities of the autonomic nervous system are present in fibromyalgia and contribute at least in part to the patients’ complaints and symptoms. In FM patients (n = 10) and healthy controls (HC; n = 11) pain intensity (numeric rating scale; NRS), cardiac baroreflex sensitivity (BRS) and muscle sympathetic nerve activity (MSNA) via microneurography at rest and during baroreflex stimulation (lower body negative pressure; LBNP) were assessed. Resting sympathetic activity was higher in FM at baseline (FM patients: 31.1 ± 2.3 bursts/min; HC: 24.3 ± 1.5 bursts/ min, F = 5.736; p = 0.028) and during baroreflex stimulation (F = 5.057; p = 0.044). Pain intensity correlated with MSNA activity (r = 0.760; p = 0.018) and showed a tendency to a negative correlation with BRS (r=-0.641; p = 0.063). Changes in the baroreflex circuit with increased sympathetic outflow are associated with increased pain perception in FM.
Best et al. (Fri,) conducted a case-control in Fibromyalgia (n=21). Lower body negative pressure (LBNP) vs. Healthy controls was evaluated on Baseline muscle sympathetic nerve activity (MSNA) burst frequency (p=0.028). Fibromyalgia patients exhibited significantly higher resting muscle sympathetic nerve activity compared to healthy controls (31.1 vs 24.3 bursts/min), which positively correlated with pain intensity.