Epilepsy: SCORE, Source Imaging and Surface EMG signals during seizures
Several research projects on epilepsy have been conducted in collaboration with the Danish Epilepsy Hospital.
Standardised Computer-based Organised Reporting of EEG is a European initiative endorsed by the International Federation for Clinical Neurophysiology and the International League against epilepsy. The aim is to establish a standardised method for assessing and reporting EEG recordings using a software. The SCORE work-group led by Sándor Beniczky, has elaborated a consensus proposal that went through a pan-European review process. The software will promote the quality assurance in assessing and reading EEGs, help train young neurophysiologists, and will provide a powerful research tool by generating a multinational database.
Source imaging of EEG activity during seizures
The accurate identification of the brain region where the electric seizureactivity starts is of utmost importance for planning of the surgical treatment of patients with focal epilepsy who do not respond to the anti-epileptic drug treatment. Using specific mathematical algorithms (inverse solutions), the current source density in the brain can be calculated from the signals recorded by non-invasive EEG electrodes placed on the scalp. The blinded prospective study showed an accuracy of 73% and a positive predictive value (for seizurefreedom) of 75%.
Quantitative analysis of surface EMG signals during epileptic seizures
Muscles are at the end of the common final neural pathways involved in motor seizures. Thus, surface EMG signals provide valuable information on the CNS activity during such seizures. Quantitative analysis showed that muscle activation during epileptic seizures is different from the physiologic, maximal voluntary activation and the activation during psychogenic seizures. Furthermore, the pathophysiology of the tonic seizure is different from the tonic phase of the tonic-clonic seizure. Surface EMG proved to be an efficient tool for characterising the specific dynamic evolution of the tonic-clonic seizures, showing that the seizure initiation can predict its termination. Based on these data, an algorithm has been developed for seizure detection based on surface EMG data.
Seizure detection using accelerometers
Patients with generalised tonic-clonic seizures have an increased risk of injuries and of sudden death. As patients lose consciousness during the seizures, they cannot call for help. A seizure detection device has been developed using an accelerometer built into a wrist-watch. The algorithm triggers an alarm at the beginning of the clonic phase. The prospective blinded, controlled study showed a sensitivity of 90% and a false-alarm rate of 0.2/day.
Sándor Beniczky, MD, PhD, Professor, firstname.lastname@example.org
Peter Orm Hansen, MD, PhD, Head Consultant, email@example.com
Lene Duez, MD, firstname.lastname@example.org
Mustafa Aykut Kural, Research Assistant, email@example.com