Addressing Epilepsy With Noninvasive Brain Mapping

CAMBRIDGE, MA – More than five million Americans have been diagnosed with epilepsy or another seizure disorder. Epilepsy costs the average person more than $317,000 in lifetime wages. For patients with severe seizures, the treatment often involves a surgery that removes a small part of the brain, requiring the neurosurgeon to know precisely where the seizure is originating, but there are limited tools available for localization. If the seizure activity originates deep within the brain, doctors may implant electrodes at a depth requiring an extremely invasive procedure that can cause damage including hemorrhages. Less invasive techniques, such as MRIs and PET scans, cannot precisely sense the rapid electrical activity associated with seizures.

Draper is exploring a method that is noninvasive, yet precisely maps activity deep within the brain through focusing electrical current. The work is part of President Barack Obama’s BRAIN Initiative through a grant from the National Institutes of Health’s National Institute of Mental Health.

Other researchers have used electrical impedance tomography (EIT) to detect changes with neural activity by injecting small currents through scalp electrodes. However, this approach yields poor spatial resolution because the current spreads out, explained Daniel Freeman, Draper’s principal investigator for the Magnetically-Focused Electrical Impedance Tomography (mf-EIT) project.

“We’re borrowing a technique used in particle accelerators in which magnetic fields are used to precisely control the movement of particles,” Freeman said. “In our case, we’re trying to move some sodium ions through the brain in a controlled path.” Draper’s technique could give clinicians a much clearer picture of neural activity, allowing the clinicians and surgeons to know precisely which part of the brain to address with interventions.

“This approach could potentially complement tools like CT scans and MRIs to provide more assurance for surgical planning, reduce risk for patients and lead to more precise treatment,” said Dr. Philip Parks, Draper’s neurotechnologies program manager. “By recording activity deep in the brain, this technology could also help with diagnosis and treatment for bipolar disorder, depression, and other conditions.”

Draper is also working with BRAIN initiative funding on Transform DBS, where the company is supporting Massachusetts General Hospital on a Defense Advanced Research Projects Agency (DARPA) effort to develop a deep brain stimulation device to treat conditions like post-traumatic stress disorder and depression. Outside of the BRAIN initiative, Draper’s neurotechnology portfolio includes working with DARPA on the Hand Proprioception and Touch Interfaces (HAPTIX) program to develop prosthetic technology that can give amputees a realistic sense of touch and limb awareness by using miniature implanted electrodes to record sensory and motor signals from individual nerve fibers of interest. The neurotechnology portfolio also includes work funded by GlaxoSmithKline to develop tiny implantable nerve stimulation devices that could ultimately be inserted through a catheter or an injection to treat chronic health conditions like heart disease, diabetes, chronic pain, and other conditions. Draper has also invested internal research and development funding to develop small biocompatible particles that could be implanted into the brain and body to enable non-invasive recordings of brain signals related to conditions like epilepsy, depression, and chronic pain.