Dr. Stacy Fritz and five-year-old Megan Howell use a treadmill to improve Megan's gait and motor control. Those functions were impaired when doctors removed half of Megan's brain to stop recurring seizures.

                                     Photo by Erin Rivers

                                                                                                   Posted 08/30/2006

Researchers study how brain functions when half is removed

By Michelle P. Jordan
USC Department of Communication Sciences and Disorders

Megan Howell, 5, is more than ready for kindergarten this fall. She can write her name, count to 50, and recite her ABCs – pretty impressive for a child who only has half of her brain.

At 15 months of age, Megan underwent a hemispherectomy, a surgery in which the left half of her brain was removed in an effort to stop severe recurring seizures. Aside from a noticeable weakness on the right side of her body that hints at a problem, Megan functions nearly as well as her peers. The question is how?

How has the remaining hemisphere of her brain been able to compensate for the loss of skills, such as language, normally controlled by the missing part? How can a better understanding of this process lead to more effective therapy options for future patients?

Researchers at the University of South Carolina’s Arnold School of Public Health are striving to find out the answers to these questions by providing federally-funded, cutting-edge rehabilitation services not offered anywhere else in the nation.

A stroke during birth left Megan suffering from as many as 80 to 100 seizures daily, said her mother, Shelly Howell, of Topeka, Kan. Even though Megan was taking every anti-seizure medication safe for use in children, her condition continued to worsen. By 15 months old, Megan still could neither walk nor talk. Her body and her brain were too occupied with seizures or drugged with medication for there to be room for learning.

“She could only sit up. She was like a zombie on the medications,” her mother said.
When Megan began to have grand mal seizures that lasted nearly seven minutes, the point at which the brain begins to be deprived of oxygen, Howell and her husband, Jeff, had reached the end of traditional treatment options. Their choice: put Megan on an anti-seizure drug that can be fatal to children, or have half her brain removed.

The Howells opted for neurosurgery and in 2002, Megan underwent a hemispherectomy at the University of California Los Angeles. While the seizures stopped immediately, and have not returned since, the difficult road of recovery and rehabilitation was just beginning for the Howells.

The two primary hospitals that perform this surgery, UCLA and Johns Hopkins University, are unable to offer extended rehabilitation for patients recovering from a hemispherectomy. USC is beginning to find ways to enhance the long-term rehabilitation of these patients.

Dr. Stella de Bode, an assistant professor in USC’s Department of Communication Sciences and Disorders, knew Megan when her brain was whole and her body was wracked with seizures. De Bode, a former faculty member at UCLA, is the link that brought Megan and her mother to Columbia for two weeks this summer to participate in de Bode’s study, which is funded through a grant from the National Institute of Health.

De Bode and Dr. Stacy Fritz, a clinical assistant professor in USC’s physical therapy program, are working together to study the brain’s plasticity, its ability to reorganize and reassign neural pathways, after a hemispherectomy.

The study is utilizing two promising rehabilitation therapies – Locomotor Training and Constraint-Induced Movement Therapy – to improve participants’ gait and motor control. The goal is to determine which circuits in the brain help perform certain motor tasks.

This Quicktime video, without sound, shows how technicians work with Megan on the treadmill to correct her gait. Click HERE to start the action Click HERE to download the free Quicktime video plug-in.

Researchers have to understand the broader structural implications of a hemispherectomy before they can focus on the details to determine the most effective therapy strategies to help children like Megan, de Bode said. “All we know (about brain structure after a hemispherectomy), we know from studies of rats and cats,” she said. “After the removal of one hemisphere (from the animals), the remaining hemisphere atrophies. We wanted to know, does this happen in humans? If so, can we reverse it with therapy?” What their research has shown is that, in fact, the opposite occurs in humans. In people, the hemisphere that remains actually increases in volume overall, even

“We have to understand why,” de Bode said. “No one has ever looked at that before. It’s very technically challenging to study the structural and functional aspects of such a situation because the brain is deformed.”

It is due to this degree of difficulty that USC’s state-of-the-art brain imaging equipment, like that found at the McCausland Center, has proven to be invaluable. But it’s not just high-tech equipment and a challenging topic that sets this research and rehabilitation study apart from others.

Unlike in many studies, participants here receive a $2,000 stipend to help defray travel and hotel costs, but they also take home something even more precious – functional improvements.

It’s a situation in which researchers and participants both benefit, de Bode said.
“With one hand, I do research; with the other, I help families now, not just 10 or 15 years down the road,” she said. “The families see benefits now,” and research is advanced.
For Megan’s mom, that’s enough.

“If (USC’s research study) helps Megan just the tiniest bit, then it’s worth it,” Howell said. “And if we can help the university better understand hemispherectomies so we can help other families, it’s worth it. Knowledge is power.”

For more information:

  • Physician says procedure is relatively safe, offers patients a high chance of becoming seizure-free

 • Hemispherectomy guide, Encyclopedia of Surgery

 • Study confirms benefits of hemispherectomy surgery