Researchers have found that levels of immune proteins in the blood are higher before and after an epileptic seizure, a discovery which may facilitate improved epilepsy diagnosis.
According to researchers from Lund University in Sweden, a simple blood test can be used to identify essential biomarkers for an epilepsy diagnosis. Current methods for diagnosing epilepsy are resource-intensive, and the disease can be difficult to tell apart from other conditions.
Epilepsy can describe any abnormal activity in the brain that leads to losing control over behaviour and movement. Epilepsy can be congenital, but it can also be caused by strokes, tumours, and infections in the brain. Symptoms of the condition can vary significantly depending on the area of the brain where the episode begins.
The study, ‘Immune response in blood before and after epileptic and psychogenic non-epileptic seizures‘, has been published in Heliyon.
Identifying biomarkers in the immune system
Inflammatory processes caused by an immune response can also cause seizures. This led researchers to search for possible biomarkers for epilepsy diagnosis in the body’s immune system. Previous research has examined this hypothesis, but results have been varied and inconclusive.
“In our study, we have a carefully selected group of participants, and we have a lot of background information on each person. We have also taken into account a number of confounding factors that may affect the immune system, such as other neurological and immunological illnesses, infections, and various psychiatric conditions,” said Christine Ekdahl Clementson, an associate professor at Lund University.
The researchers compared epileptic seizures to psychogenic non-epileptic seizures. Psychogenic non-epileptic seizures are caused by a psychiatric diagnosis that presents itself through clinical symptoms similar to those in epilepsy; therefore, the conditions are frequently mistaken for each other. Psychogenic non-epileptic seizures are underdiagnosed and often mistreated with epilepsy medication. Identifying blood biomarkers for epilepsy diagnosis would help resolve this issue.
“The investigation to establish whether someone is suffering from epilepsy or is affected by psychogenic seizures is resource intensive. It may require the patient to be admitted to the hospital for several days with constant video and EEG surveillance, with medical staff on hand around the clock. It is hard on the patient that it takes time to reach a diagnosis,” explained Marie Taylor, a physician and doctoral student on the research team.
The discovery can improve the accuracy of epilepsy diagnoses
The researchers found that five protein-based inflammation markers were acutely elevated in people who had suffered an epileptic seizure.
“We call these markers ‘fingerprints’ since they involve several inflammation-related proteins with different reaction patterns. The patients who had epilepsy showed raised levels of one of the five proteins – IL-6 – even before their seizures, a value that transiently raised even further directly after the seizure,” said Taylor.
The researchers found no biometric changes in patients who had suffered psychogenic seizures. They suggested a simple blood test on a patient’s arrival at A&E could show whether the immunological response is elevated, allowing doctors to distinguish between the two conditions.
“The next stage is to repeat our studies on a broader and less homogenous patient group, where we investigate the fingerprint in adults with epilepsy. We also want to see whether the biomarkers respond in the same way in children, where the causes of epilepsy are more often genetic. We are doing this through an ongoing study in Lund, in collaboration with child and adolescent psychiatry as well as paediatric neurology,” concluded Clementson.