Langston, Michael E.

AbstractThe purpose of this case‐matched study was to determine how frequently fibromyalgia is associated with different paroxysmal neurological disorders and explore the utility of fibromyalgia as a predictor for the diagnosis of psychogenic non‐epileptic seizures. The billing diagnosis codes of 1,730 new, non‐selected patient encounters were reviewed over a three‐year period for an epileptologist in a neurology clinic to identify all patients with historical diagnoses of fibromyalgia. The frequency with which epileptic seizures, psychogenic non‐epileptic seizures, and physiological non‐epileptic events were comorbid with fibromyalgia was assessed. Age and gender case‐matched controls were used for a between‐group comparison. Wilcoxon tests were used to analyse interval data, and Chi‐square was used to analyse categorical data (p<0.05). Fibromyalgia was retrospectively identified in 95/1,730 (5.5%) patients in this cohort. Females represented 95% of the fibromyalgia sample (age: 53 years; 95% CI: 57, 51). Forty‐three percent of those with fibromyalgia had a non‐paroxysmal, neurological primary clinical diagnosis, most commonly chronic pain. Paroxysmal events were present in 57% of fibromyalgia patients and 54% of case‐matched controls. Among patients with fibromyalgia and paroxysmal disorders, 11% had epileptic seizures, 74% had psychogenic non‐epileptic seizures, and 15% had physiological non‐epileptic events, compared to case‐matched controls with 37% epileptic seizures, 51% psychogenic non‐epileptic events, and 12% physiological non‐epileptic events (p = 0.009). Fibromyalgia was shown to be a predictor for the diagnosis of psychogenic non‐epileptic seizures in patients with undifferentiated paroxysmal spells. However, our results suggest that the specificity and sensitivity of fibromyalgia as a marker for psychogenic non‐epileptic seizures in a mixed general neurological population of patients is less than previously described.