Functional (psychogenic) seizures are associated with thyroid disorders

Objective: We investigated medical comorbidities in patients with functional seizures (FS) and those with epilepsy (idiopathic generalized epilepsies [IGEs] or temporal lobe epilepsy [TLE]). We hypothesized that the nature of medical comorbidities differs between these three groups. This might be helpful to postulate on the pathophysiology of FS. Materials and Methods: In a retrospective study, all adult patients with a diagnosis of IGE, TLE, or FS were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, Iran, from 2008 until 2020. The three groups of patients were matched with regard to their age. Age, sex, and medical comorbidities were registered routinely for all patients at the time of the first visit. Results: Nine hundred and sixty-six patients were studied (254 patients with IGE, 467 persons with TLE, and 245 individuals with FS). The groups differed significantly with regard to having medical comorbidities. The most striking difference was comorbid thyroid disorders; this was more common among patients with FS. The diagnosis of FS was independently significantly associated with thyroid disorder comorbidity (odds ratio: 2.77, 95% confidence interval: 1.06–7.23; P = 0.038). Conclusion: Thyroid disorders are significantly associated with FS. We can make the following suggestions to advance the field: a. It is necessary to reproduce this observation in larger multicenter studies; b. We recommend to evaluate thyroid function in all patients with FS; c. It might be helpful to design clinical trials to investigate whether correction of any clinical or subclinical thyroid disorders changes the treatment outcome in patients with FS.