Real-Time Imaging of Epileptic Seizures with stereo Electrical Impedance Tomography (sEIT)

Around 400,000 people suffer from epilepsy in the UK, and 30% of this population do not respond to any anti-epileptic drug. For a significant proportion of these, surgical removal of the brain tissue generating the seizures is the best treatment option for becoming seizure-free. However, with the existing methods (3T MRI and stereo-electroencephalography (sEEG)), it can remain a challenge to map the seizure pathways in the brain and localise the seizure onset zone (the "focus") with precision. Difficulties in the precise localisation of seizure foci have limited the number of patients eligible for surgery and lowered its effectiveness, evidenced by seizure recurrence in over half of these individuals. sEIT is a recently developed method that has great potential to localise the focus more accurately, without disrupting current pre-surgical practice at the hospital. The idea is that physiological changes that occur during seizures - such as swelling of the brain cells and synchronous neuronal activity - change the electrical resistance of the brain tissue. By injecting safe levels of current into the brain (using the 'depth' electrodes already implanted into the brain for presurgical evaluation), we can image these changes in resistance and map the initiation and propagation of seizures. This method has already been validated in animal models in which the seizure focus and subsequent propagation were identified with the accuracy of 5 mm. We propose to translate sEIT technology to human patients with the aims to first (a) increase surgery uptake and improve post-surgical outcomes, and eventually (b) replace the surgery with the sEIT controlled closed-loop deep brain stimulation. If successful, this method will directly benefit pre-surgical planning in the short-to-medium term and revolutionize epilepsy treatment in the long term.

The specific aims of the project are:
1) Improve localisation accuracy of seizure foci and study subsequent seizure progression by sEIT using the depth electrodes already routinely placed for presurgical evaluation.
2) Study the mechanisms of seizure progression and areas of the eloquent cortex, which should not be resected to minimise postsurgical functional deficits.
3) Design and test the optimal closed-loop stimulation paradigm to suppress the seizures without the need of surgical recession.

Novelty:
The sEIT method has been validated in animal models, however the technique is not yet implemented in human patients. Successful translation will allow to use sEIT to improve surgical outcomes and potentially create a close-loop DBS paradigm, which would replace a human brain resection surgery.

Alignment with EPSRC:
The research will be focused on the implementation of novel sEIT technique in human patients. The project has a potential to transform epileptic seizure focus localization procedure and following resection surgery. National Hospital for Neurology and Neurosurgery Telemetry ward patients will be recruited once the technology is optimised and tested for compliance with corresponding standards. The collaboration with a world-renown UK hospital will attract additional investment opportunities in the UK R&D sector and provide opportunities for other researchers and engineers to join in later stages of the technology implementation into a marketable product.

Any companies or collaborators involved:
Cyqiq LTD

The critical mass of scientists and engineers that i4health will produce will ensure the UK's continued standing as a world-leader in medical imaging and healthcare technology research. In addition to continued academic excellence, they will further support a future culture of industry and entrepreneurship in healthcare technologies driven by highly trained engineers with deep understanding of the key factors involved in delivering effective translatable and marketable technology. They will achieve this through high quality engineering and imaging science, a broad view of other relevant technological areas, the ability to pinpoint clinical gaps and needs, consideration of clinical user requirements, and patient considerations. Our graduates will provide the drive, determination and enthusiasm to build future UK industry in this vital area via start-ups and spin-outs adding to the burgeoning community of healthcare-related SMEs in London and the rest of the UK. The training in entrepreneurship, coupled with the vibrant environment we are developing for this topic via unique linkage of Engineering and Medicine at UCL, is specifically designed to foster such outcomes. These same innovative leaders will bolster the UK's presence in medical multinationals - pharmaceutical companies, scanner manufacturers, etc. - and ensure the UK's competitiveness as a location for future R&D and medical engineering. They will also provide an invaluable source of expertise for the future NHS and other healthcare-delivery services enabling rapid translation and uptake of the latest imaging and healthcare technologies at the clinical front line. The ultimate impact will be on people and patients, both in the UK and internationally, who will benefit from the increased knowledge of health and disease, as well as better treatment and healthcare management provided by the future technologies our trainees will produce.

In addition to impact in healthcare research, development, and capability, the CDT will have major impact on the students we will attract and train. We will provide our talented cohorts of students with the skills required to lead academic research in this area, to lead industrial development and to make a significant impact as advocates of the science and engineering of their discipline. The i4health CDT's combination of the highest academic standards of research with excellent in-depth training in core skills will mean that our cohorts of students will be in great demand placing them in a powerful position to sculpt their own careers, have major impact within our discipline, while influencing the international mindset and direction. Strong evidence demonstrates this in our existing cohorts of students through high levels of conference podium talks in the most prestigious venues in our field, conference prizes, high impact publications in both engineering, clinical, and general science journals, as well as post-PhD fellowships and career progression. The content and training innovations we propose in i4health will ensure this continues and expands over the next decade.