New Method Simplifies Brain Evaluations for Planning Epilepsy Surgery

'BESPoC' method allows children to engage in short, simple conversations instead of current hours-long testing process

CINCINNATI, Sept. 4, 2025 /PRNewswire/ -- Some children with poorly controlled epilepsy require significant surgery to remove the seizure-causing portions of their brains. 

To minimize the risks of lost brain function, neurologists and neurosurgeons make extensive efforts before surgery to precisely map the areas within a child's brain that support speech and language.

This process, called electrical stimulation mapping (ESM), passes small electric currents between electrodes in the brain to disrupt normal activity. Then, experts ask patients to complete a long series of tasks to identify which brain areas are critical to language and speech.

In a study published Aug. 16, 2025, in Annals of Neurology, experts at Cincinnati Children's describe a faster, simpler mapping method that produces accurate results and may serve to replace traditional ESM for epilepsy surgery planning and beyond. They call the new method Behavior-iEEG-Spectral-Power Correlation (BESPoC).

"The advantage of BESPoC is that it is very flexible. It does not require the patient to engage in any kind of structured task," says corresponding author Ravindra Arya, MD, DM, Division of Neurology. "We believe that this study can potentially revolutionize presurgical functional mapping for many patients who cannot participate in the current standard-of-care trial-based testing."

BESPoC compares well to established methods

The research team tested an emerging theory that naturalistic conversation does at least as well, if not better, at activating the brain's language and speech areas as two other methods ESM and high-gamma modulation (HGM). 

The study was based on data from 134 patients who were monitored while engaged in standard picture naming and auditory naming tasks compared to having conversations with a family member.

"The naturalistic conversation compared well with standard tasks for localization of HGM and ESM language sites, and determined neuropsychological outcomes better than conventional tasks," says the study's first author Brian Ervin, PhD, a post-doctoral fellow at Cincinnati Children's.

Importantly, these conversations between parents and children can be as short as five minutes.  Also, the new method appears better suited for young children and those with developmental disabilities who may not have enough vocabulary or may not be able to participate in long sessions of standard brain mapping.

For example, one patient with seizures related to tuberous sclerosis complex had significant cognitive and behavior symptoms that did not allow him to be evaluated in the epilepsy unit. However, in the intensive care unit, while receiving an infusion of a calming medication, the child's mother was able to communicate with him and the research team was able to collect critical language mapping data.

Next steps

This method can be adapted to study brain activity during other naturalistic behaviors, such as playing video games. Arya and his team plan to leverage this method to map brain regions involved in short-term visual memory.

Also, while this study was based on sensors placed surgically within the brain (for clinical purposes), Arya plans to evaluate brain mapping with BESPoC while running EEG tests that use scalp sensors. Success will require overcoming technical challenges, but if the results prove valid the potential applications of the method could expand.

Long term, this easier-to-perform method might provide deeper insight into how the brain areas and networks involved in speech and language function change in patients with epilepsy, and potentially other developmental disorders. And for adults, this could become a tool to study memory mapping, which would be important for better understanding of aging and dementia.  

"This method is easy to apply and potentially flexible across a range of neural signals and behaviors. We hope that it has an exciting future," the researchers say.

About the study

In addition to Ervin and Arya, Cincinnati Children's co-authors included Clayton Frink, BS, Jason Buroker, BS, Paul Horn, PhD, Anna Byars, PhD, Craig Scholle, BS, Hansel Greiner, MD, Francesco Mangano, DO, and Katherine Holland, MD, PhD. Co-authors also included experts from the Johns Hopkins University School of Medicine and the University of California, Irvine.

Funding sources for this study included the National Institutes of Health (R01 NS115929), an American Epilepsy Society Postdoctoral Fellowship, and a Cincinnati Children's Research Foundation Procter Scholar Award.

SOURCE Cincinnati Children's Hospital Medical Center