Improving the presurgical evaluation of patients with refractory focal epilepsy using advanced neuroimaging techniques

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Epilepsy is a common neurological condition affecting around 1% of the population (600,000 people in the UK). Frequent seizures carry risk of injury and death and significant psychosocial consequences, affecting relationships, employment and the ability to drive. There are over 20 medications to treat epilepsy, but a third of people with epilepsy continue to have seizures despite medication.Surgical treatment of epilepsy in which the abnormal part of the brain is removed is an effective technique to cure or improve seizures suitable for some people with epilepsy. The National Hospital for Neurology and Neurosurgery, with the Epilepsy Society and UCL Institute of Neurology, is the largest centre in the UK undertaking epilepsy surgery (100 operations a year) and has an internationally known research programme to improve the identification of patients for surgery and understand and improve the outcomes.In order for a person to be suitable for surgery, it is necessary to confirm that seizures are arising from one part of the brain and that it is safe to remove this part. This requires many tests including MRI brain scans. Despite advances in technology, around 30% of people with seizures arising from one part of the brain have completely normal MRI scans. Further investigation with other types of scan is expensive, may involve radiation exposure and is not available in most places, unlike MRI. If imaging cannot identify the source of seizures, recording wires may be placed directly onto the brain surface. This is available in only a few places, is invasive, very expensive and carries some risk.In my previous research, presented and published internationally, I developed MRI techniques to improve the safety of surgery and understand its effects on the brain. I showed preliminary results in which new MRI techniques could identify the source of seizures in patients with normal MRI scans.In the first part of this project, I will assess several new MRI techniques to determine which are helpful in identifying the source of seizures in people with severe epilepsy and normal standard scans. I will use new ways of acquiring MRI scans and will work with colleagues in the UCL Centre for Medical Image Computing, with whom I have worked for the last 5 years, and the Montreal Neurological Institute to develop new ways to analyze the scans by computer to detect subtle abnormalities not seen by the human eye.These developments will enable a larger proportion of people with epilepsy to undergo surgery and be cured or significantly improved from epilepsy. MRI may replace some more expensive and less readily available scans. This will simplify and shorten the investigation pathway so surgery can take place more quickly. Since MRI is widely available at all epilepsy surgery centres, the new techniques can be introduced elsewhere to improve assessment and treatment for people with epilepsy. Understanding of these techniques can also be applied to other conditions such as dementia and stroke.In the second part, I will build on my prior work using MRI to make surgery safer. I used a special type of MRI scan to identify connections in the brain important for vision and displayed these connections to the surgeon when they were operating so they could treat epilepsy without damaging vision and thus allow people to return to driving. At present, there are many limitations with this and analysis takes a long time. I will improve the technique to give more detailed and accurate images of the brain more quickly. The results and software will be made freely available to allow other centres to adopt the technique.Overall more people will be identified as suitable for surgical treatment, more quickly and at lower cost using techniques that are applicable to all epilepsy surgery centres rather than just at highly specialised units. A greater understanding of these new MRI techniques will allow them to be used in many other conditions.