Use of TMS to understand in-vivo the functional pathophysiology of Dravet syndrome and predict treatment response

Simona Balestrini, MD, PhD – UCL Queen Square Institute of Neurology Sanjay Sisodiya, PhD, FRCP – UCL Queen Square Institute of Neurology 

$150,000 TWO YEAR CLINICAL RESEARCH AWARD Dravet syndrome (DS) is caused by a genetic change that leads to severe epilepsy with difficult-to-treat seizures, cognitive impairment, other neurological and physical symptoms, and heightened risk of premature mortality. Despite treatment with multiple antiepileptic drugs, people with DS often do not respond to them and there is no treatment to cure DS. Transcranial magnetic stimulation (TMS) is a non-invasive tool ideal for characterising brain activity in people with epilepsy, as it can probe directly the workings of brain circuits in life. We have already applied TMS in people with DS and found very specific changes when compared with people with other epilepsies and healthy controls. These changes suggest that the underlying genetic change causes alteration of neuronal excitability, leading to seizures and other neurological dysfunction. Our findings were in keeping with the changes in brain activity found in animal models of DS. Our work suggests that TMS can be used as a reliable tool to study disease mechanisms in the living brain in people. Our key questions are: what are the mechanisms leading from the genetic change to seizures, cognitive difficulties and other symptoms common in DS? What happens over time to neurons and their connections in the brain in people with DS? How can we use this information to better treat seizures and the other issues in DS? We will use TMS to understand better the alterations of brain activity in a given person with DS, providing the key link between the genetic change and epilepsy, responses to treatments and other outcomes in DS. We will analyse various measures of brain activity over time and in association with treatment and severity of the disease. TMS is a novel, non-invasive, and safe technique in epilepsy, able to tell us what genetic changes cause in the living brain.