Brain injury markers in new-onset seizures in adults: A pilot study

Abstract

Background: Biochemical markers of brain pathology could potentially contribute to diagnosis and prediction in epilepsy. We describe levels of five brain injury markers in adults with new-onset seizures, and assess group differences in patients with a single seizure, epilepsy, and poststroke epilepsy. Methods: In this prospective observational study, adults with new-onset seizures were recruited at Sahlgrenska University Hospital, Sweden, and concentrations of glial fibrillary acidic protein (GFAP), neurofilament light (NfL), microtubule-associated protein tau (tau), S100 calcium-binding protein (S100B), and neuron-specific enolase (NSE) were measured. Participants were categorized as epilepsy, poststroke epilepsy (PSE), or single seizure (no additional seizures). Patients were followed until a diagnosis of epilepsy or PSE, or for at least two years in single seizure cases. Results: The cohort included 23 (37%) individuals with a single seizure, 24 (39%) with epilepsy, and 15 (24%) with PSE. The concentrations of S100B were higher in patients with epilepsy and PSE than in single seizures (p = 0.0023 and p = 0.0162, respectively). The concentrations of NfL were higher in patients with PSE than in single seizures (p=0.0027). After age-normalization, levels of S100B were higher in patients with epilepsy and levels of NfL were higher in patients with PSE (p = 0.0021 and p = 0.0180). Conclusion: Levels of S100B and NfL were higher in patients with epilepsy or PSE than patients with single seizures. Further studies are needed to investigate the biomarker potential of brain injury markers as predictors of epilepsy course or indicators of epileptogenesis.

Blood biomarkers in epilepsy

“…Higher‐than‐control levels of GFAP in the blood has been reported in both children and adults with epilepsy 22–24 . We also detected higher GFAP levels in patients with poststroke epilepsy compared to patients with single seizures that did not develop epilepsy 5 . In addition, we observed that serum GFAP remained at elevated levels long after a patient experienced a stroke, which could indicate severe brain injury or prolonged response 5 .…”

“…20 A comparison study between epilepsy and PNES did not find significant differences in either patient group in relation to controls. 28 We did not find a difference in NSE levels between patients that developed epilepsy and those who only had a first seizure, 5 and Chang et al…”

“…A study on patients with Down syndrome also reported near‐significantly higher levels in those with epilepsy 31 . Elevated serum concentrations were detected in adults with poststroke epilepsy (PSE) when compared to single seizure patients, but not in patients with non‐stroke related epilepsy 5 …”

“…Patients with a first seizure represent an enriched high‐risk population that usually come in contact with health services—which allows blood sample collection that can be analyzed with high‐throughput screening methods. Pilot studies have demonstrated feasiblitiy 5–7 . Another approach is to study patients with an acute brain disease that entails a high risk of symptomatic epilepsy.…”

“…The expression of S100B is stimulated by CNS damage and the inflammatory response caused by a stroke, and the protein has been investigated as a biomarker of subsequent poststroke epilepsy. Levels of S100B are higher in patients with epilepsy after stroke than age‐matched patients with single seizures 5 . However, in the acute phase of stroke low levels of S100B have been associated with an increased risk of later poststroke epilepsy 8 .…”