A pattern of molecules that appear in the blood before a seizure happens has been discovered by researchers at the Royal College of Surgeons in Ireland. The finding may lead to the development of an early warning system, which would enable people with temporal lobe epilepsy to know when they are at risk of having a seizure.

The molecules are fragments of transfer RNAs (tRNAs), a chemical closely related to DNA that performs an important role in building proteins within the cell. When cells are stressed, tRNAs are cut into fragments.

Elevated levels of the fragments in the blood could reflect that brain cells are under stress in the build up to a seizure event.

Epilepsy Biomarker

Using blood samples from people with epilepsy at the Epilepsy Monitoring Unit in Beaumont Hospital, Dublin and in a similar specialist centre in Marburg, Germany, the group at FutureNeuro, the SFI Research Centre for Chronic and Rare Neurological Diseases, hosted at RCSI, found that fragment levels of three tRNAs “spike” in the blood many hours before a seizure.

“People with epilepsy often report that one of the most difficult aspects of living with the disease is never knowing when a seizure will occur. The results of this study are very promising. We hope that our tRNA research will be a key first step toward developing an early warning system,"

said Dr Marion Hogg, FutureNeuro investigator, Honorary Lecturer at RCSI, and the study’s lead author.

New Technologies

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy in adults. Roughly 0.1% of the world’s population is affected.

“New technologies to remove the unpredictability of uncontrolled seizures for people with epilepsy are a very real possibility. Building on this research we in FutureNeuro hope to develop a test prototype, similar to a blood sugar monitor that can potentially predict when a seizure might occur,"

said Professor David Henshall, Director of FutureNeuro and Professor of Molecular Physiology and Neuroscience at RCSI who was a co-author on the paper.

The work supported in part by the Science Foundation Ireland (SFI), the European Regional Development Fund and by FutureNeuro industry partners. FutureNeuro, which is funded by Science Foundation Ireland, aims to deliver advances in understanding disease initiation and progress.

Marion C. Hogg, Rana Raoof, Hany El Naggar, Naser Monsefi, Norman Delanty, Donncha F. O’Brien, Sebastian Bauer, Felix Rosenow, David C. Henshall, Jochen H.M. Prehn Elevation of plasma tRNA fragments precedes seizures in human epilepsy J Clin Invest. 2019. https://doi.org/10.1172/JCI126346.

Image: Maxwell Photography

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