Calming the electrical storm
by Mark Hansberry
Each year in the United States, more than 50,000 children under 18 are diagnosed with epilepsy, joining the estimated 700,000 children and young adults nationwide already living with the condition. Although some cases of epilepsy can be attributed to a genetic problem or head injury, about half have no obvious cause. By carefully evaluating and monitoring a patient's neurological function, experts in childhood epilepsy can zero in on the problem and effectively treat or manage a child's epilepsy.
When Abigail Ranger was just 5 years old, her mother Denise noticed that although Abigail's overall health was fine, she was sometimes unable to walk or grasp cups, scissors or crayons. She was also frequently fatigued and was increasingly frustrated by not being able to understand or be understood by others. Her physical problems, combined with her language and attention delays, made it very difficult for her to attend school and kept her homebound much of the time.
Concerned that Abigail might have cerebral palsy or significant developmental delays, Abigail's pediatrician referred her to Mid-Maine Medical Center for a complete evaluation. A thorough exam, follow-up visit to a neurologist and electroencephalogram (EEG), which monitors brain activity, confirmed that Abigail had epilepsy.
Epilepsy is a common disorder defined by unprovoked, recurrent seizures, which are temporary disturbances within the electrical system of the brain. When a seizure occurs, part of the brain generates a burst of abnormal electrical signals that temporarily interrupt function, causing obvious problems such as convulsions and decreased mental awareness, or subtle ones, like diminished sensory perception.
As Abigail grew, her seizures began to manifest not only as developmental delays, but also as violent convulsions marked by chaotic movements in her limbs, and long, disabling post-convulsion (or postictal) periods. She was besieged by two to three 30-minute seizures each day, with the postictal period lasting one to two hours, making not only education, but socialization difficult for Abigail. Neurologists in Portland, Maine, struggled to control her seizures using various medications, and although a few of them temporarily reduced the number and severity of the seizures, none provided a long-term solution. Also troubling, it appeared that the more successful a drug was in controlling Abigail's seizures, the more pronounced the side effects, such as irritability, hyperactivity and problems with her speech.
After almost four years of intensive anti-convulsive medication with minimal success, Denise began to search for alternative therapies for Abigail. Although she gave brief consideration to the ketogenic diet, which is very strict and controls seizures in some patients, her answer came from an article about the vagal nerve stimulator (VNS).
The VNS is a small device, similar to a pacemaker, that delivers a burst of electrical energy to the vagal nerve to reduce seizures. Specialists at Children's Hospital Boston have pioneered its use in children as young as 3 years old, and for children like Abigail, the VNS has brought the seizures under enough control that she is able to live a relatively normal life.
The vagus nerve serves as one of the many highways of information carrying messages from the body's organs to the brain, and has connections to areas in the brain instrumental in producing seizures. By stimulating the vagus nerve, the brain's potential to generate seizure activity can be significantly reduced.
The VNS is surgically inserted under the skin below the collarbone, and leads are painstakingly attached to the vagus nerve on the left side of the patient's neck. The device is then programmed to regularly stimulate the vagus nerve with a small amount of electrical current.
Denise knew that Children's, as one of the few centers in the country performing VNS implantation, was the right place to seek care for Abigail.
Children's is home to the nation's first program dedicated to the treatment and management of pediatric epilepsy. Each year, more than 3,000 children are cared for by the world-renowned specialists in Children's Epilepsy Program, making the hospital one of the most experienced programs in the country. Experts in neurology (specializing in epileptology), neurosurgery, radiology and nuclear medicine use the most advanced and sophisticated diagnostic methods to reduce or eliminate a patient's seizures and improve quality of life. It is this collaboration that sets Children's apart from other programs, says Blaise Bourgeois, MD, director of the Epilepsy Program. "By working closely with one another, our specialists can effectively diagnose each patient and prescribe the most appropriate treatment to achieve optimal results." The program has been so successful, in fact, that some of the diagnostic and therapeutic methods used throughout the world were first applied to the pediatric population at Children's.
When Abigail arrived at Children's, she was evaluated by James Riviello, MD, associate in neurology and an epileptologist in the Epilepsy Program. To pinpoint the origin of Abigail's seizures, Riviello recommended Long Term Monitoring (LTM), an interdisciplinary evaluation where experts in neurology, neuropsychology, nuclear medicine, radiology and neurosurgery continuously monitor a patient's neurological functioning during a seven-day hospitalization. After the evaluation, Riviello's team diagnosed Abigail with asymmetric perfusion in the temporal parietal regions, a condition in which the seizure activity is not confined to one area of the brain. "Since there wasn't a surgically resectable lesion and Abigail didn't respond to multiple medications, the VNS was a reasonable option for treatment," says Joseph Madsen, MD, the neurosurgeon on the Epilepsy Team.
So, two days after her ninth birthday, Abigail was wheeled into the operating room at Children's, where Madsen surgically implanted the VNS and Riviello programmed it to counteract Abigail's seizure activity. Once the VNS was implanted, Riviello reduced Abigail's medications from three to one.
The results were almost instantaneous and extremely positive. "The seizures decreased from two to three per day to maybe one every few days," says Denise. "They were less severe, and Abigail's post-convulsion period was much shorter." In addition, with every passing month, Abigail's vocabulary, awareness, school performance and social behavior dramatically improved. She was able to enjoy reading, playing and watching TV without interruption from repeated seizures. Abigail was also able to start going to the library and participating in various activities, including taking part in the Special Olympics. "Each month, I've seen an improvement," says Denise, "and she isn't experiencing the terrible side effects of the medications."
The VNS has not only improved Abigail's life, but Denise's as well. "I've been able to join many community groups like the Developmental Disability Council of Maine and can attend our council meetings knowing that Abigail will be alright at home," she says.
Abigail turns 13 this July, and despite needing to replace the VNS a few years ago because the batteries were fading, the device, along with only one anticonvulsant, has continued to effectively control Abigail's seizures and has freed her from the disruptive side effects of heavy medication. It has become such a regular part of her life, in fact, that she is able to activate the VNS on her own when she feels the symptoms of a seizure starting. "The vagal nerve stimulator has made such a difference in Abigail's life," says Denise. "It is truly a miracle."