Copeptin as a predictor of seizure diagnosis and seizure type in emergency department patients

To evaluate the diagnostic utility of serum copeptin (CPT) levels in distinguishing epileptic seizures from Pseudo or functional/dissociative seizures (FDS) in adult patients presenting to the emergency department, and to investigate possible differences in CPT levels among various seizure types. This prospective, observational study was conducted at a tertiary research hospital between September 2023 and September 2024. Adult patients presenting to the emergency department with seizure complaints were screened and, after applying exclusion criteria, 59 patients were included. Patients were classified based on clinical, laboratory, and EEG findings into epileptic seizure or FDS groups. Serum CPT and interleukin-6 (IL-6) levels were measured using ELISA. Of the 59 patients, 24 were diagnosed with epileptic seizures and 35 with FDS. No statistially significant difference was found in serum CPT levels between the epileptic seizure and FDS groups (p = 0.755). Glucose, base deficit, CRP (C-reactive protein), and IL-6 levels were significantly elevated in the epileptic seizure group relative to FDS. Serum CPT values were not predictive of clinical outcomes or the need for intensive care admission. Serum CPT levels are not useful for differentiating between epileptic seizures and FDS in adult emergency patients. Further multicenter studies with larger cohorts and standardized sampling times are warranted to clarify the diagnostic and prognostic value of CPT in seizure disorders.