{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["009:25"], "contactPoint": {"@type": "vcard:Contact", "fn": "NIH", "hasEmail": "mailto:info@nih.gov"}, "description": "Background\n          Fibromyalgia syndrome displays sympathetically maintained pain features such as frequent post-traumatic onset and stimuli-independent pain accompanied by allodynia and paresthesias. Heart rate variability studies showed that fibromyalgia patients have changes consistent with ongoing sympathetic hyperactivity. Norepinephrine-evoked pain test is used to assess sympathetically maintained pain syndromes. Our objective was to define if fibromyalgia patients have norepinephrine-evoked pain.\n        \n        \n          Methods\n          Prospective double blind controlled study. Participants: Twenty FM patients, and two age/sex matched control groups; 20 rheumatoid arthritis patients and 20 healthy controls. Ten micrograms of norepinephrine diluted in 0.1 ml of saline solution were injected in a forearm. The contrasting substance, 0.1 ml of saline solution alone, was injected in the opposite forearm. Maximum local pain elicited during the 5 minutes post-injection was graded on a visual analog scale (VAS). Norepinephrine-evoked pain was diagnosed when norepinephrine injection induced greater pain than placebo injection. Intensity of norepinephrine-evoked pain was calculated as the difference between norepinephrine minus placebo-induced VAS scores.\n        \n        \n          Results\n          Norepinephrine-evoked pain was seen in 80 % of FM patients (95% confidence intervals 56.3 \u2013 94.3%), in 30 % of rheumatoid arthritis patients and in 30 % of healthy controls (95% confidence intervals 11.9 \u2013 54.3) (p < 0.05). Intensity of norepinephrine-evoked pain was greater in FM patients (mean \u00b1 SD 2.5 \u00b1 2.5) when compared to rheumatoid arthritis patients (0.3 \u00b1 0.7), and healthy controls (0.3 \u00b1 0.8) p < 0.0001.\n        \n        \n          Conclusions\n          Fibromyalgia patients have norepinephrine-evoked pain. This finding supports the hypothesis that fibromyalgia may be a sympathetically maintained pain syndrome.", "distribution": [{"@type": "dcat:Distribution", "description": "Visit the original government dataset for complete information, documentation, and data access.", "downloadURL": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC65524/", "mediaType": "text/html", "title": "Official Government Data Source"}], "identifier": "https://healthdata.gov/api/views/whxh-sg85", "issued": "2025-07-14", "keyword": ["fibromyalgia", "nih", "norepinephrine", "pain-study", "sympathetic-pain"], "landingPage": "https://healthdata.gov/d/whxh-sg85", "modified": "2025-09-06", "programCode": ["009:032"], "publisher": {"@type": "org:Organization", "name": "National Institutes of Health"}, "theme": ["NIH"], "title": "Norepinephrine-evoked pain in fibromyalgia. A randomized pilot study [ISRCTN70707830]"}