The Power of Precision

Alexandria was delivered via a routine C-section delivery. Within 24 hours of her birth, though, her mother, Kacy, noticed the newborn’s eye twitching. A neonatologist determined the twitch was a seizure, and Alexandria was immediately transferred to the hospital’s neonatal intensive care unit (NICU). There, an MRI showed that Alexandria had suffered a stroke, either in the womb or during delivery. 

After 10 days in the NICU, the newborn was discharged home on anti-seizure medication and remained seizure-free for the next three years. In 2020, however, Alexandria experienced a grand mal seizure — the first of eight she would suffer that year, each of which lasted nearly an hour. 

“They were awful,” recalls Kacy. “You never knew when the next seizure would hit. It was like waiting for a bomb to go off.” 

Though experts at Children’s Hospital of Philadelphia’s Neuroscience Center attempted to manage Alexandria’s seizures with multiple medications, nothing provided lasting seizure control. The team began to consider more aggressive options, including a highly technical surgical procedure that would disconnect the injured half of Alexandria’s brain – essentially, “shutting down” one side to save the other.

A life-changing solution

A functional hemispherotomy is a surgical procedure to disconnect the outer portion (the cortex) of one half of the brain (hemisphere) from the other half and from the brainstem. This procedure can cure serious seizure disorders (epilepsy) if all seizures begin in one side of the brain. When that side of the brain is disconnected, it stops sending seizures, and the other side of the brain takes over. 

A 14-day continuous electroencephalogram (EEG) confirmed that all of Alexandria’s seizures originated in one hemisphere of her brain, which meant she was an ideal candidate for a hemispherotomy. 

The procedure would not be without sacrifice. Alexandria’s seizures originated in the left hemisphere of her brain, which controls movement on the right side of the body. Disconnecting it would impact Alexandria’s motor skills on that side. But for children like Alexandria with severe, drug-resistant epilepsy, the toll of seizures can be greater than the loss of one hemisphere. 

“There are three things every parent wants for their child,” says Benjamin Kennedy, MD, Director of Epilepsy and Functional Neurosurgery in CHOP’s Division of Neurosurgery. “They are the same three things we want for our patients: to optimize neurologic development, to ensure safety and to improve quality of life. Sometimes being aggressive about seizure control is the best way to achieve those goals, even if it means sacrificing some of the brain.”

Most children who undergo a hemispherotomy need rehabilitation after surgery. Initially, they may be weak on one side, have facial droop or need a temporary feeding tube. But over time, they regain mobility. Dr. Kennedy expected that with diligent physical and occupational therapy, function on the right side of Alexandria’s body would gradually improve.

In addition, performing a hemispherotomy early on in a child’s life helps maintain optimal development. There is a window of opportunity for brain development, and the older a child gets, the less adaptable the brain becomes. As a result, earlier epilepsy surgery results in not only better seizure outcomes, but better cognitive and developmental outcomes as well. Says Dr. Kennedy, “As counterintuitive as it sounds, you can actually improve cognition while sacrificing brain tissue.”

Advanced technique, better outcomes

In decades past, surgeons would remove the entire hemisphere, causing frequent complications and high mortality rates. Modern techniques focus on disconnection, rather than removal, but still carry the risk of hydrocephalus, a dangerous buildup of cerebrospinal fluid in the brain, which occurs because the surgery can disrupt the fluid’s normal flow and absorption.

According to Dr. Kennedy, the fluid buildup isn’t caused by the disconnection itself, but by bigger, more invasive surgeries that leave behind blood and debris that clog the brain’s drainage system. To reduce this risk, neurosurgeons at CHOP do this extensive procedure through a remarkably tiny opening, taking special care not to disturb the parts of the brain that help absorb spinal fluid. “We’ve shown that with meticulous surgical technique, we can almost completely eliminate the risk of hydrocephalus,” says Dr. Kennedy.

For patients like Alexandria who have experienced a stroke or trauma that already damaged their brain tissue, surgeons can make an even smaller opening, called a “burr hole.” 

“In these cases, I use a microscope through the burr hole to complete the entire disconnection,” says Dr. Kennedy. “These patients typically experience less pain and recover more quickly.” 

At CHOP, precision techniques like these are resulting in better patient outcomes. Dr. Kennedy’s seizure-freedom rates remain among the best reported in the United States, with only 1% of patients developing hydrocephalus.

Dancing toward a bright future

At 4 years old, Alexandria underwent a hemispherotomy through a burr hole the size of a quarter. The small incision aided in a rapid recovery, and after a month of inpatient rehabilitation, as well as continued occupational and physical therapy, Alexandria’s right-side function greatly improved. She has been weaned off all anti-seizure medication and has not experienced another seizure since surgery. 

“We’ve seen kids swim, hit softballs and even go rock climbing,” says Dr. Kennedy. “Some go on to live independently, attend college and hold jobs.” 

Alexandria is now a thriving 6-year-old, who loves dance class and playing on the playground. “In 2020, we never would have guessed that she’d one day be off her meds and living a normal life,” says Kacy. “It really is amazing.”

To find out how you can support this life-changing work, contact Liz Barone at baroneeb@chop.edu.