Staged transarterial embolization for infants with hemimegalencephaly - Children's National

A multidisciplinary team at Children's National has published the largest reported cohort to date examining seizure burden and management in infants with hemimegalencephaly (HME) treated with staged transarterial embolization (TAE), a minimally invasive endovascular technique pioneered at Children's National for infants who are too young to safely undergo hemispherectomy.

This study, published in Pediatric Neurology, was a collaborative effort among Neurology, Radiology, the Zickler Family Prenatal Pediatrics Institute and the Center for Neuroscience Research, reflecting a multidisciplinary approach to advancing care for children with complex epilepsy.

HME is a rare developmental brain malformation associated with early-onset, drug-resistant epilepsy and significant neurodevelopmental impairment. While hemispherectomy is often considered the standard surgical treatment, very young infants face substantial operative risks, including blood loss, hemodynamic instability and coagulopathy. Staged TAE was developed to provide seizure control during this vulnerable period through a less invasive alternative.

The big picture

The study evaluated eight infants with HME and refractory epilepsy who underwent staged TAE between 2018 and 2023. Investigators analyzed seizure burden, electroclinical features and antiseizure medication management before, during and after treatment.

Prior to embolization, most patients experienced frequent seizures and epileptic spasms despite treatment with multiple antiseizure medications. Following staged TAE, seizure burden declined substantially, with several patients becoming seizure-free immediately after treatment. Many patients also required less aggressive antiseizure medication management following intervention.

"Our institution developed this protocol for infants who have disabling seizures despite appropriate trials of medical therapy but are considered too young for a surgical - hemispherectomy approach," said Ersida Buraniqi, MD, epileptologist and first author of the study. "These findings demonstrate that staged embolization can provide meaningful seizure reduction during a critical period of brain development."

Advancing the field

For infants with HME who have failed two antiseizure medications, staged TAE offers a novel treatment strategy that can achieve seizure reduction through progressive endovascular disconnection of the affected hemisphere.

Beyond clinical outcomes, the study provides one of the most detailed descriptions to date of electroclinical management during staged embolization, including continuous EEG monitoring and peri-procedural treatment strategies. The findings also highlight opportunities to further investigate EEG changes during embolization as potential real-time markers of regional ischemia and treatment response.

"Staged transarterial embolization has fundamentally changed how we can approach some of our youngest and most medically fragile patients with hemimegalencephaly," said Tayyba Anwar, MD, co-director of the Hemimegalencephaly Program and corresponding author of the study. "By offering meaningful seizure control through a minimally invasive approach, we have the opportunity to intervene earlier during a critical window of brain development while avoiding many of the risks associated with hemispherectomy in very young infants."

Why this matters

Early seizure control is closely linked to improved neurodevelopmental outcomes in infants with HME. These findings suggest that staged TAE may help reduce seizure burden during a critical period of brain development while potentially delaying or avoiding higher-risk surgical intervention in very young infants.

The study further demonstrates leadership by Children's National in developing innovative therapies for complex pediatric epilepsy and lays the groundwork for future research focused on long-term seizure control, neurodevelopmental outcomes and EEG biomarkers that may help optimize patient selection and procedural monitoring.

Additional Children's National authors include Rae Leonor F. Gumayan, MD, MPH, Shani Israel, BS, Courtney Reed Lowe, BA, Catherine Landry, BS, Lindsay Ruffini, CPNP-AC/PC, Panagiotis Kratimenos, MD, PhD, Monica S. Pearl, MD, Tammy Tsuchida, MD, PhD.

Read the full study "Seizure Burden and Management in Infants With Hemimegalencephaly Pre- and Post-Staged Transarterial Embolization" here.