Revitalizing Pediatric Hemispherectomy: New Approaches to a Long-Established Pediatric Epilepsy Surgery
Harnessing decades of clinical experience and the latest surgical techniques and technologies, pediatric epilepsy surgeons and epileptologists at NewYork-Presbyterian/Columbia University Irving Medical Center and NewYork-Presbyterian/Weill Cornell Medical Center are bringing fresh perspectives and innovative approaches to the most severe forms of epilepsy. Through multidisciplinary collaboration and the rapid translation of bench-to-bedside discoveries, these surgeons are revitalizing pediatric hemispherectomy, a long-established surgery for children with catastrophic epilepsy, to improve outcomes and quality of life.
“Hemispheric epilepsy surgery encompasses a broad category of surgical resection and disconnection procedures that are performed to treat children with catastrophic epilepsy, which is characterized by medically refractory, severe, and disabling seizures that often arise from a single hemisphere of the brain,” explains Guy M. McKhann II, MD, Director of Epilepsy and Movement Disorder Surgery at NewYork-Presbyterian/Columbia. “These children can have hundreds of seizures a day, and with so much seizure activity, the side of the brain causing the seizures isn’t able to develop along with the other side. As a result, the functions controlled by the affected hemisphere aren’t developing the way they should, and the child is often left with significant developmental delays and impairments.”
“For pediatric epilepsy patients, timely and accurate diagnosis and treatment can be life-changing,” says Neil A. Feldstein, MD, Director of Pediatric Neurological Surgery at NewYork-Presbyterian/Columbia. “Our pediatric epilepsy surgery team has one of the largest hemispherectomy experience bases in the Northeast. Through multidisciplinary collaboration with epilepsy experts at both NewYork-Presbyterian/Columbia and NewYork-Presbyterian/Weill Cornell, we have achieved dramatic success with this procedure. Generally, 70-80% of patients undergoing this surgery have markedly improved seizure control and many are cured of their seizures.”
A Multidisciplinary Approach to Epilepsy
At the Pediatric Epilepsy Centers at both of our hospital centers, pediatric and adult epilepsy neurosurgeons partner with a multidisciplinary team of experts in epileptology, neurophysiology, neuroradiology, neuropsychology and social work to form a comprehensive plan of care that addresses the unique and changing needs of children with epilepsy at every stage of life, beginning in infancy and continuing through the transition to adulthood.
“Every patient is different, and this is especially true in epilepsy,” says Caitlin Hoffman, MD, Director of Pediatric Epilepsy Surgery at New York-Presbyterian/Weill Cornell. “Children with epilepsy have complex and multifaceted needs because their condition intersects with every aspect of their growth and development. Historically, the onus has been on the patients and their families to figure out how to put the pieces of the medical puzzle together, but we feel the responsibility should reside with the practitioners.”
“Our goal is to provide patients with an extraordinarily tailored plan of care that meets their individualized needs,” she continues. “The recent merger of our two pediatric neurosurgery teams at NewYork-Presbyterian/Columbia University Irving Medical Center and NewYork-Presbyterian/Weill Cornell Medical Center has opened new doors for multidisciplinary collaboration with specialists in the field that enables us to provide our patients with the highest level of coordinated and personalized care.”
Because effective epilepsy treatment is dependent on an accurate diagnosis, patients first undergo a comprehensive evaluation to determine the nature and exact source of the seizures. This diagnostic process involves the latest technologies to localize seizure onset, and includes advanced neuroimaging, including a high resolution brain MRI, inpatient EEG and video-EEG monitoring, and the epilepsy team’s comprehensive evaluation of the patient.
At NewYork-Presbyterian, pediatric epilepsy patients are medically managed by epileptologists. Children who are considered medically refractory to anti-seizure medications or who suffer unwanted side effects from these medications receive comprehensive evaluation to explore alternative treatment options, including epilepsy surgery. Surgical interventions to remediate seizures include resection of the seizure onset zone; disconnection surgery (detaching the problematic area from the rest of the brain); vagus nerve stimulation (the delivery of electrical pulses to the vagus nerve to decrease the incidence of seizures), or laser ablation called laser interstitial thermal therapy (LiTT).
“In the past, surgical treatment for children with epilepsy was considered only after a long period of seizures and multiple medication trials,” says Dr. Feldstein. “Today, children who will develop intractable epilepsy can be identified earlier. For instance, we know that certain conditions of infancy lend themselves to this procedure, such as perinatal stroke; Sturge-Weber Syndrome; hemimegalencephaly, a rare neurological condition in which one side of the brain is abnormally larger than the other, and Rasmussen’s Encephalitis.”
“Good candidates for this surgery are children in which the non-dominant hemisphere is the side that is generating the seizures or those in whom dominance has not yet been established,” continues Dr. Feldstein. “For these patients, the disconnection results in fewer side effects, such as loss of language or fine motor control. Depending on the root cause of the epilepsy, the hemisphere that is affected is likely not normal in function.”
Innovative Approaches to Hemispherectomy
Hemispherectomy is classified into two general types: functional hemispherotomy, which involves disconnecting the white matter fibers of the brain without removing all of the brain tissue, and anatomical hemispherectomy, which involves removing the majority of the hemisphere. In recent years, there has been a movement away from anatomical hemispherectomy due to associated morbidity including hydrocephalus, a build-up of fluid in the brain, and hemosiderosis, an extremely rare but fatal condition caused by chronic iron deposition on brain tissue.
“The concept of functional hemispheric disconnection surgery has seen a lot of evolution in the last decade,” says Dr. Hoffman. “It has evolved to what we now call hemispherotomy, in which we perform an elegant disconnection of all of the important highways leading from the affected hemisphere but leave the remaining brain intact. This approach improves functional outcomes and decreases the risk of hemosiderosis and hydrocephalus.
“At NewYork-Presbyterian, our goal is to be at the forefront of innovation with the latest minimally invasive approaches to the treatment of pediatric epilepsy,” continues Dr. Hoffman. “The use of LiTT to perform aspects of disconnection, while not yet mainstream practice, is a potentially useful modality in specific patients which may see further development over the coming years. We are also exploring the use of focused ultrasound (FUS) and the efficacy of this modality for certain forms of refractory epilepsy.”
Maximizing Positive Outcomes: The Timing of Pediatric Hemispherectomy
Hemispherectomies are performed in children as young as one or two years of age or even in infancy. The ideal age for this procedure depends on the child’s overall health and the severity of his or her epilepsy. “There is accumulating evidence that surgically curing epilepsy at an earlier age can provide a better quality of life,” says Dr. Feldstein. “Many of these children have catastrophic epilepsy of infancy and have no useful function of the opposite side of the body, and often haven’t developed dominance yet on either side. We can be surgically aggressive in these children with reasonable expectation of preservation of good quality of function.”
“When we recognize that medications are not helping a patient, we begin to think the patient is a candidate for surgical intervention,” says Cigdem Inan Akman, MD, Chief of the Division of Child Neurology and Director of the Pediatric Epilepsy Program at NewYork-Presbyterian/Columbia University Irving Medical Center. “The younger the child is at this juncture, the better the outcome will be because we are giving the child the earliest opportunity to use his or her innate potentials without the obstacle of seizures. The brain has a plasticity to it, so a young child is likely to have a quick and favorable recovery.”
New Opportunities for Continuing Success
When it comes to epilepsy surgery, studies consistently show that experienced neurosurgeons at neuroscience centers of excellence such as “NewYork-Presbyterian Hospital-Columbia and Weill Cornell” achieve the best possible patient outcomes.
“Our merged team of pediatric neurosurgeons comprise one of the most skilled and experienced epilepsy surgery teams in the world,” says Dr. Feldstein. “We are leaders in the use of state-of-the-art technology and techniques, including preoperative and intraoperative brain mapping. We draw on our deep experience to choose the safest, least invasive techniques likely to provide each patient with maximum benefit.”
“In the next 5-10 years, pediatric epilepsy surgeons are going to figure out better ways to perform hemispherectomies with less invasive methods to make it safer for children and more acceptable to parents,” adds Dr. McKhann. “These minimally invasive approaches to the diagnosis and treatment of epilepsy are changing the landscape of pediatric epilepsy.”
“Hemispherectomy is a long-established surgery for children diagnosed with drug resistant epilepsy secondary to unilateral hemispheric syndromes,” says Dr. Akman. “At NewYork-Presbyterian we continue to expand our growing understanding of the epilepsy disease process in children, and we look forward to seizing on new opportunities to make this procedure even more successful, relevant and important to improve the quality of life for children and their caregivers.”
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