A provider with a child patient
By Aaron L. Cardon, MD, MSc

RNS Clinical Study Explores Seizure-Reduction Benefits for Children with Intractable Epilepsy

Responsive neurostimulation (RNS) is proven safe and effective for adults with intractable focal epilepsy—seizures that don’t respond to medication and originate in one area of the brain. Now, a new clinical study at UNM Health Sciences Center is exploring the benefits of this advanced treatment for kids 12 and older.

Epilepsy is a neurological disorder in which the brain’s electrical pulses become disorderly, resulting in unprovoked seizures. Intractable or “refractory” epilepsy is when seizures are not controlled or reduced by at least three singular medications or drug combinations. Left untreated, epilepsy can contribute or lead to accidents, brain damage, developmental disabilities and nervous system disruption.

Seizures vary by individual and can be short and silent or lengthy and animated. Generalized seizures originate from multiple areas of the brain, while focal seizures start in just one.

For adults with focal intractable epilepsy, advanced brain surgery—responsive neurostimulation (RNS)—has proven lifechanging for thousands of patients over age 18 since 2003. The RNS device, developed by NeuroPace, Inc., acts like a “pacemaker” for the brain.

The adjustable, removable device sits on the skull and monitors brain waves at the site(s) from which seizures originate. The device responds within milliseconds to deliver a small electrical stimulation to restore appropriate brain electrical patterns—without pain or noticeable sensation.

Research shows that adults who get RNS have 67% fewer seizures in the first year after surgery, 75% fewer after two years, and 82% fewer in year three. RNS also can improve patients’ quality of life, including physical and emotional health and brain function.

While academic medical centers such as UNM Health Sciences Center have selectively placed RNS devices in patients younger than 18, pediatric use is not currently approved by the U.S. Food and Drug Administration (FDA).

Our adult and pediatric multidisciplinary team led by Hae Won Shin, M.D. is participating in a to demonstrate the safety and effectiveness of RNS in carefully selected children ages 12 and older with intractable focal epilepsy.

RNS Implantation Trial for Pediatrics

Most patients who hope to be candidates for this trial must first undergo invasive brain surgery to find the source of their seizures and determine whether the RNS device might be a safe and effective option. This is good news for patients—our highly selective enrollment criteria means we can use the patient’s individual brain imaging and seizure patterns to determine which treatment is most likely to be successful.

Each patient’s epilepsy is unique, so every treatment must be tailored based on their:

  • Age
  • Frequency of seizures
  • Type of seizures
  • Seizure origin point or points in the brain
  • Response to medication
  • Cultural preferences

When determining a course of treatment for epilepsy, patients have several tests to understand their optimal treatment options. Evaluation can take a few weeks or months to complete and begins in the outpatient setting. Typical evaluation assessments cover:

  • Baseline cognitive and neurologic status
  • Daily quality of life
  • Brain imaging to assess structural abnormalities
  • Baseline mental health
  • Review of past treatments, including medication resistance
  • Seizure type, frequency, origin and impact
  • How thoroughly the patient understands their epilepsy

When outpatient testing is complete, most patients begin a two-phase evaluation to further understand their epilepsy and prepare for surgery.

Phase 1 requires monitoring in the hospital for three to 10 days. We will perform a video EEG, in which the patient’s seizures are recorded and observed by the epilepsy team. Doctors may also record images of the brain and conduct neuropsychological testing to understand the patient’s cognition, memory, and language skills.

When the cause or focus remain unclear after these non-invasive tests, phase 2 evaluation may require more advanced testing, typically with surgery to place electrodes on the surface or deep in the brain to precisely locate where seizures begin and more carefully monitor and map the brain’s activity and functions. These tests allow epileptologists to safely monitor seizures for up to several weeks and identify opportunities to manage and prevent seizures.

Our diverse team of neurologists and epilepsy experts works together to achieve the most precise understanding and determine the best course of treatment to help provide seizure relief. This approach creates a robust environment for trainees while providing the best outcomes for patients of all ages.

Training the Next Generation of Pediatric Epileptologists

UNM Health Sciences Center neurology fellows and residents are involved in every aspect of patient care. They collaborate with our expert faculty—when you get care from our trainees, you’re getting expertise from our internationally recognized expert faculty who are guiding their recommendations.

In 2023, we will welcome our first epilepsy fellow, and in 2022 our clinical neurosciences fellowship covers the subfields of neurology and includes EEG and EMG experiences. The epilepsy fellowship was designed to empower residents to continue expanding their EEG and clinical diagnostic skills in a fellowship setting, opening more clinical experience time, specifically with epilepsy patients, and deeper, wider experience.

Our epilepsy fellowship is also an opportunity for passionate individuals to deepen their knowledge of epilepsy medication combinations. There are more than 30 FDA-approved medications for epilepsy that work differently alone and in combination for individual patients. Our trainees learn to recommend optimal medication combinations and/or alternative treatments including diet changes such as the ketogenic or modified Atkins’ diets, precise neurosurgical resection or ablation of the seizure focus, RNS or vagus nerve stimulation (VNS), which can reduce seizures with regular electrical stimulation via the vagus nerve in the neck.

Patients and families challenged with intractable focal epilepsy may feel frustrated while working toward optimal treatment. Current treatments are imperfect, and epilepsy can be debilitating. But there is hope.

With thousands of combinations of medicines, devices like RNS therapy and alternative solutions, we’re confident we can help even our youngest patients and their families enjoy more seizure-free days.


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Categories: Neurology