Determining the utility of OPM-MEG in a clinical context
Research type
Research Study
Full title
Determining the utility of OPM-MEG in a clinical context: next-stage neuroimaging of paediatric epilepsy
IRAS ID
332894
Contact name
Lara F Carr
Contact email
Sponsor organisation
Young Epilepsy
Duration of Study in the UK
3 years, 0 months, 0 days
Research summary
Magnetoencephalography (MEG) has been around since the 1970’s and is a method of recording the brain’s magnetic fields produced by electrical current flow in neurons. It is a direct measure of brain activity, providing clinicians with powerful information concerning brain function in health and disease. It is currently used in a relatively small population, commonly adults being considered for epilepsy surgery as current equipment are ill-fitted to children’s head size and shape.
EEG (electroencephalography) is the current clinical gold standard and records the electrical activity of neurons. It conforms to the head surface but is impeded by intervening tissues. MEG is far superior than EEG in providing accurate information about where a seizure may start. MEG can also be used to locate important brain areas such as movement or language that may be nearby seizure origins, maximising the likelihood of seizure freedom whilst helping to preserve important brain function/s.
However, until recently, conventional MEG scanners use sensors which require to very low temperatures or cryogenics (-260C) – using liquid helium to work, making the system expensive to maintain and environmentally unsustainable. Due to the need for this ‘cooling’, sensors are fixed within a large ‘thermos-like’ container in order to keep the patient safe, making the system bulky and static. The sensors are mounted in a large one-size-fits-all helmet and participants cannot move their heads freely throughout a recording - they must stay still, moving <5mm throughout, much like in an MRI scanner. These large helmets also do not suit the smaller head sizes, particularly of children, as they are based on an average adult head size. A combination of these system limitations have led to limited uptake of MEG into mainstream healthcare settings, many based only in academia, despite their obvious advantages over the clinical standard, electroencephalography (EEG).
Excited to be on the cutting edge of this research field, Young Epilepsy have installed a research OPM-MEG system alongside it’s longstanding clinical EEG service. This new generation of MEG uses a different type of sensor (optically-pumped magnetometer; OPM), which operates at room temperature and so it does not require any cooling material. These sensors are small, lightweight (about the size of a Lego brick), can be arranged in any orientation or configuration. They can be worn directly on the head within a helmet (not too dissimilar to a bike helmet), which is sized appropriately for each individual. With the sensors being closer to the head, the ability to localise the origin of the brain’s magnetic signal is significantly increased, providing particular benefit to paediatric populations. In addition to the improvement in signal quality and precision, participants are able to move more freely during the scan providing a more child-friendly environment.
The ultimate goals of this study are to demonstrate the OPM-MEG system’s ability to localise abnormal brain activity in agreement with current clinical standard of care. We will be comparing OPM-MEG to scalp electroencephalography (EEG) in participants being investigated for possible brain dysfunction, including those with suspected or diagnosed epilepsy to understand how MEG can be utilised in a broader population within and outside of epilepsy surgery pathways. In those who undergo epilepsy surgery, the accuracy of OPM-MEG data findings relative to surgical resections will be assessed post-hoc using follow-up clinical information from the referring clinician.
Participants will also provide valuable insight through a post-scan interview to help us better understand tolerability and to further refine this new, emerging tool.REC name
South Central - Berkshire B Research Ethics Committee
REC reference
24/SC/0016
Date of REC Opinion
25 Apr 2024
REC opinion
Further Information Favourable Opinion