EEG, or electroencephalogram, enables real-time and non-invasive monitoring of cortical brain activity even outside the hospital. This study shows that the BrainStatus device developed by Bittium Biosignals from Oulu is usable in an ambulance even on long transport distances. In addition to detecting epileptic seizures, this method could help identify and direct patients with severe cerebral artery occlusion directly to ae university hospital for mechanical clot removal.
A joint study by the Imaging centre and Neurocenter of Kuopio University Hospital, the emergency medical services of the Wellbeing Services County of North Savo, and the University of Eastern Finland evaluated the usability of a compact EEG device (BrainStatus®) developed by Bittium Biosignals from Oulu during ambulance transports. The study has been published in the open online publication PLOS One.
Stroke can be seen in the electroencephalogram
EEG has traditionally been used to assess level of consciousness, alertness and epileptic activity. In recent years, interest in the use of EEG outside the hospital has been growing. Certain computational parameters have been found to be sensitive to detecting occlusions of the large arteries of the frontal circulation of the brain from EEG recordings. So far, this has only been studied with relatively short recordings, the technical quality of which has significantly limited the usability of the method.
In this study, 10 patients receiving treatment for acute stroke in the inpatient ward of the Neurocenter of Kuopio University Hospital were selected and their EEG waa recorded during their ambulance transport to another care facility in the North Savo Hospital District. In addition to the technical quality and clinical usability of the recordings, disturbances in the real-time transfer of the recorded EEG data to the remote server were assessed during the transports. The transport times varied from just over 40 minutes to almost 3.5 hours.
"This study showed that the technical quality of an EEG recording can remain stable even over longer transport distances, and that there are only a few blind spots in the real-time transfer of data within the hospital district, says Sampsa Lohi, the first author of the research article", a doctoral researcher at the University of Eastern Finland and a specialist in neurology and clinical neurophysiology.
"The transfer distance to the treatment facility for a patient with an acute stroke or a prolonged epileptic seizure (status epilepticus) can be long, and this method could be used to direct patients to the appropriate treatment facility or, in some cases, even start treatment during the transport."
There is still a long way to a clinical tool
Clinical evaluation of the wirelessly transferred EEG by a specialized doctor is technically possible, but there is no established method for identifying stroke from EEG.
"Large-scale use would require developing reliable and evidence-based computational methods and their incorporation into existing clinical tools", continues Sampsa Lohi.
"The development of such tools is still in the early stages."
Potential for international collaboration
The clinical utility of EEG recordings performed outside the hospital is currently a topic of international interest. Using the results for example in the development of machine learning-based algorithms requires large datasets of recordings. Sharing and utilizing the recorded data in national and multinational multi-centre studies is an important topic of the larger doctoral thesis behind this study.
Further information:
Sampsa Lohi, doctoral researcher, specialist in neurology and clinical neurophysiology, University of Eastern Finland
sampsal(a)student.uef.fi
Professor Reetta Kälviäinen, University of Eastern Finland, neurology
reetta.kalviainen(a)uef.fi
Professor emeritus Esa Mervaala, University of Eastern Finland, clinical neurophysiology
esa.mervaala(a)uef.fi
Research article:
Lohi, S., Jäkälä, P., Kurola, J., Tuunanen, P., Westeren-Punnonen, S., Muraja-Murro, A., Kälviäinen, R., Mervaala, E. (2025). Feasibility of recording EEG in the ambulance using a portable, wireless EEG recording system. PLOS One. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0327415.