Approximately one-third of children with epilepsy do not respond to medication, and a proportion of these children may be considered for surgery to remove the part of the brain where their seizures originate.
Before surgery, a neurosurgeon needs to obtain an accurate image of the child’s brain and the areas in which important functions (such as language) are located, to avoid removing or damaging them during the operation. This is achieved using imaging and neuropsychological testing. However, children’s seizures often originate in one of these critical brain regions, and this makes the decision of whether or not to operate even more difficult.
Using state of the art neuroimaging techniques, as well as language and neuropsychological tests, we studied children three to five years after they underwent surgery for epilepsy and recorded their cognitive and educational outcomes. Comparing these results with a control group we were able to demonstrate that children who had surgery had fewer seizures and better language and neuropsychological results than children who did not have surgery. We also found that the majority of children who were seizure-free after surgery showed significant increases in brain volume and improved cognitive scores.
Additionally, children who had surgery to the specific parts of the brain that support memory (i.e. the temporal lobes), did not suffer additional memory loss as result of surgery and some memory functions even improved significantly. This is due to the ability of the younger brain to compensate for injury (‘brain plasticity’) which we were able to show using functional and structural neuroimaging (see Figure, showing increases of grey matter in frontal and temporal brain regions associated with IQ gains after epilepsy surgery, from report by Skirrow et al. 2019, Epilepsia).
Based on the patient data generated through this research, doctors can now make better predictions of cognitive outcomes for children following surgery. These results have also helped make the case for earlier detection and surgical treatment in children for whom surgery is an option, as well as providing an important benchmark for the evaluation of non-invasive neuroimaging methods.
This research has been vital for the field of paediatric epilepsy surgery. We are immensely grateful for Epilepsy Research UK and its supporters who without, this research would not have been possible.
Building on the results of our Epilepsy Research UK project, we are currently conducting a 20-year review and follow up with over 1,000 children who underwent surgery for their epilepsy at Great Ormond Street Hospital since 2000. Next, we are planning an even larger study to chart patients health and educational trajectory (after they left hospital care) during adulthood. The aim is to better predict who will benefit from neurosurgery in terms of seizure freedom and to establish the longer-term impact of epilepsy surgery on educational development. A major international multi-centre effort is also directed at improving presurgical neuroimaging diagnostics, using the application of artificial intelligence (AI), to help doctors detect hidden brain abnormalities that give rise to seizures.
Earlier in the month, we shared a Research Blog from Rachel who is one of many young people who, thanks to this ground-breaking research, is now seizure-free and has achieved a life free from epilepsy. You can read her story here.
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