Summary: Researchers at Lund University have found that certain immune proteins in the blood rise both before and after epileptic seizures. These inflammation-related proteins, including IL-6, could serve as detectable biomarkers using a routine blood test.
Source: Lund University
A research team at Lund University in Sweden has identified higher levels of specific immune proteins in the blood of people with epileptic seizures. These proteins, which reflect inflammatory responses, were elevated both between seizures and immediately after some seizures, suggesting a potential blood-based test to aid diagnosis.
Current diagnostic pathways for epilepsy are time- and resource-intensive. Distinguishing epileptic seizures from conditions that mimic them, such as psychogenic non-epileptic seizures (PNES), often requires prolonged hospital monitoring with continuous video and EEG, making faster, reliable diagnostic tools a clinical priority.
Epilepsy refers to abnormal brain activity that temporarily disrupts behavior, awareness or movement. Causes vary and include genetic predisposition, tumors, stroke, infections, or other brain injuries. Because inflammatory processes in the body can trigger seizures and because seizures themselves can provoke immune reactions, the research team examined immune-system proteins in blood as candidates for seizure biomarkers.
Lead investigator Christine Ekdahl Clementson, group leader and associate professor at Lund University and Consultant in Clinical Neurophysiology at Skåne University Hospital, emphasizes the careful design of the study. The team enrolled a well-characterized group of participants and controlled for confounding factors affecting immune function, such as other neurological or immunological disorders, infections, and psychiatric conditions.
The study also compared patients with verified epileptic seizures to those diagnosed with psychogenic non-epileptic seizures, a psychiatric condition that can present with seizure-like symptoms but does not have the electrographic findings typical of epilepsy. PNES is often underdiagnosed and can be mistakenly treated with antiepileptic medication, so a blood-based tool that helps differentiate the conditions could reduce diagnostic delay and inappropriate treatment.
Marie Taylor, a physician and doctoral student involved in the research, notes the burden of current diagnostic procedures: long hospital stays with 24/7 monitoring are stressful for patients and consume substantial clinical resources. A rapid blood test performed when a patient presents to an emergency department could offer immediate, actionable information about whether an immune response is associated with the event.
The researchers measured a panel of inflammation-related proteins and found five markers that were elevated in the acute phase in patients who had experienced epileptic seizures. One marker in particular, interleukin-6 (IL-6), was higher in blood samples taken between seizures (interictal) from people with temporal and frontal lobe epilepsy compared with controls. In patients with temporal lobe epilepsy, IL-6 rose further within hours after a seizure (postictal), whereas patients with psychogenic non-epileptic seizures showed no similar change.
The investigators describe these elevated proteins as a kind of inflammatory “fingerprint” because several proteins show distinct patterns over time. The presence of this fingerprint in peripheral blood suggests that simple serum sampling could help distinguish epileptic seizures from psychogenic events when patients first arrive for care.
The team stresses that further research is needed before any blood test can be implemented clinically. Their next steps include repeating the study in larger and more diverse patient groups and evaluating whether the same biomarkers and temporal patterns are present in children, where genetic causes of epilepsy are more common. Ongoing collaborations in Lund involve pediatric neurology and child and adolescent psychiatry to extend the findings to younger patients.
About this epilepsy research news
Author: Press Office
Source: Lund University
Contact: Press Office – Lund University
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Original Research: Open access. “Immune response in blood before and after epileptic and psychogenic non-epileptic seizures” by Matilda Ahl et al., Heliyon.
Abstract
Immune response in blood before and after epileptic and psychogenic non-epileptic seizures
Highlights
- Elevated IL-6 levels in serum of patients with temporal and frontal lobe epilepsy
- Altered postictal-to-interictal ratios for several immune factors after temporal lobe seizures but not after frontal lobe seizures
- No measurable change in IL-6 levels in patients with psychogenic non-epileptic seizures
Abstract
Inflammatory processes can both provoke epileptic seizures and be triggered by them, making systemic immune responses attractive candidates for diagnostic and prognostic biomarkers in epilepsy.
This study evaluated immune responses in serum before and after epileptic seizures and in psychogenic non-epileptic seizures (PNES). Serum samples from patients with video-EEG-verified temporal or frontal lobe epilepsy showed increased interleukin-6 (IL-6) levels interictally compared with controls. Patients with PNES did not show this IL-6 increase. In temporal lobe epilepsy, IL-6 levels rose further transiently within hours after a seizure, and postictal-to-interictal ratios for five additional immune factors were elevated in temporal lobe epilepsy but not in frontal lobe epilepsy.
These findings indicate that peripheral immune factors have potential as future biomarkers for epileptic seizures and that distinct inflammatory profiles may help distinguish among different seizure types independent of common comorbidities.