David S. Silver, Sarah R. Markoff, Leah Naghi, Michael Silver and Lawrence May
Background: Fibromyalgia patients suffer from a constellation of symptoms, including widespread pain, fatigue and lack of restorative sleep. Previous studies have demonstrated relative sympathetic hyper reactivity in patients with the fibromyalgia syndrome. Methods: We studied 329 fibromyalgia patients and 58 controls, identified by the 1990 ACR criteria for fibromyalgia. Holter monitoring analyzed heart rate variability using time frequency domain quantified sympathetic and parasympathetic function. The data were used to determine if specific patterns exist in fibromyalgia patients that may help objectively define the syndrome. Findings: Patients with fibromyalgia demonstrated a statistically significant reduction of parasympathetic nervous system activation at night along with decreased total power of the autonomic nervous system. These findings indicate that parasympathetic nervous system function in fibromyalgia patients is severely suppressed, particularly at night, which may help to explain the sleep disturbance seen with fibromyalgia. Heart rate variability assessed by 24-hour holter monitoring may serve as a reproducible objective test for diagnosing and assessing therapy in fibromyalgia patients