“An estimated 65 million people worldwide have epilepsy, and one in 26 Americans will develop epilepsy in their lifetime. Most of these people are able to control their seizures with medications, but approximately 30% to 40% have what’s called drug-resistant or medically refractory epilepsy, in which they don’t respond to standard anti-seizure medications.  There are a few options available for people with drug-resistant epilepsy who need alternative RXs. The most common alternative one is epilepsy surgery, which has been performed since the 1940s.  For a patient with focal epilepsy, where the seizures are being caused by one part of the brain, you try to remove the seizure focus.  Somewhere between 60% and 70% of patients with drug-resistant epilepsy who have this surgery become seizure-free, which is the standard of care if the medications were not to work.  Open brain surgery is effective but also carries higher risk for complications, pain and psychological impacts. Recently, minimally invasive epilepsy brain surgery has advanced quite significantly, particularly a procedure called laser ablation for patients with epilepsy. In that surgery, inserted is a small laser fiber and burn away the seizure focus in the brain but an opening up of the skull is not needed.”

UChicago Medicine (https://www.uchicagomedicine.org/forefront/neurosciences-articles/new-treatment-options-for-people-with-drug-resistant-epilepsy)