The results of a recent study suggest that brain scans performed on children with epilepsy can be carried out more effectively if the child is given a ‘movie’ to watch.
The research, led by University College London and the epilepsy unit at Great Ormond Street Hospital, sought ways to improve the results of tests in children that combine EEG and functional magnetic resonance imaging (fMRI), in order to encourage more specialists to use them.
These so called EEG-fMRI scans are used to analyse the brains of people with epilepsy and assess the different patterns of electrical activity that are occurring. Used appropriately they can help doctors to identify the regions that are responsible for specific functions, and pinpoint the area(s) in which seizures originate (the seizure focus (plural foci)).
This mapping of brain activity is a vital part of epilepsy surgery planning, and it requires the person to be very still. In adult patients,the scans are typically carried out while the individual lies motionless with their eyes closed. Children typically find this a lot more difficult and are often given mild sedation; however this is not a perfect solution as it requires more medical supervision and carries low risks, and sedation itself can impact upon the test results. Early surgical intervention has been linked to better outcomes in eligible children with epilepsy, hence the need to optimise pre-surgical assessments.
For this study, 46 children with focal epilepsy and 20 healthy controls aged between the ages six and 18 underwent EEG-fMRI imaging. For two ten-minute sessions, all subjects were simply told to lie at rest during scanning, and for a further two sessions they were given a cartoon to watch inside the scanner.
During scanning, the researchers monitored the interictal epileptiform discharges (IEDs – activity that resembles epilepsy in between seizures) in the brain of each child. Tracking IEDs effectively is important in locating seizure foci.
According to results published in the scientific journal PLoS One, viewing the cartoons did not alter the children’s brain activity, so (importantly) it didn’t affect the interpretation of scans; however having something to watch helped them to be less restless.
Although movement increased with scan duration, watching the cartoon reduced movement by around 40% when played within the first 20 minutes.
The research concludes: ‘A child-friendly natural stimulus improves the tolerability of EEG-fMRI and reduces in-scanner movement, without having an effect on IED occurrence and quality of EEG-fMRI maps. This allowed us to scan children as young as six and obtain localising information without sedation.’
The authors acknowledge several limitations to their study, but it is clear that it gives a good foundation for further research.