Minimally Invasive Surgery is Changing the Diagnosis and Treatment of Pediatric Epilepsy

In a field of rapidly advancing techniques and technologies, NewYork-Presbyterian is at the forefront of innovation in the diagnosis and treatment of pediatric epilepsy, offering the latest cutting-edge, minimally invasive approaches including stereoelectroencephalography (SEEG), laser interstitial thermal therapy (LITT) and deep brain stimulation (DBS); improving the quality of life of children diagnosed with this debilitating disease.

Epilepsy, a large group of neurological disorders that cause seizures, affects approximately 1.2% of the total US population and 0.6% of children aged 0-17 years have active epilepsy (defined as being diagnosed by a doctor or taking a seizure medication or having at least one seizure in the past year).1 Among these children, approximately 25% continue to experience poor seizure control even with antiepileptic medications.2

Finding the safest, most effective, and innovative approaches to the diagnosis and treatment of epilepsy is the mission of NewYork-Presbyterian, where pediatric epilepsy neurosurgeons Neil A. Feldstein, MD and Caitlin Hoffman, MD along with their adult epilepsy surgical colleagues, Guy M. McKhann II, MD and Theodore H. Schwartz, MD, partner with a dedicated team of experts in epileptology, neurophysiology, neuroradiology, and neuropsychology to form a comprehensive team that addresses patients’ individualized needs.

For pediatric epilepsy patients, timely and accurate diagnosis and treatment can be life-changing. “Epilepsy can significantly impair children’s physical, cognitive, and psychosocial development,” says Neil A. Feldstein, MD, Director of Pediatric Neurological Surgery at NewYork-Presbyterian/Columbia University Medical Center. “Diagnosing and treating epilepsy in children is an opportunity to solve a problem early and change the course of the rest of their lives.”

“Epilepsy can impede the successful development of a growing and organizing mind,” says Dr. Hoffman, Director of Pediatric Neurological Surgery at New York-Presbyterian/Weill Cornell Medicine. “Our multidisciplinary team intersects with the patient at that critical developmental period, which is one of the most important factors in patient outcome.”

For patients who are refractory to antiseizure medications, epilepsy surgery may be the best and only chance of seizure control or cure. In these cases, it is necessary for the team to first locate the source of the seizures to determine the type of surgery that will offer the best chance for a cure. “There’s a huge amount of work involved in finding the exact source of the seizure activity, a process that includes high resolution MRI brain imaging, EEG tests, video-EEG monitoring, and the epilepsy team’s comprehensive evaluation of the patient,” says Guy M. McKhann II, MD, Director of Epilepsy Surgery and Brain Mapping for Tumors and Epilepsy at NewYork-Presbyterian/Columbia University Medical Center. “However, there are some patients for which, despite everything we do non-invasively, we’re still not sure where the seizures are coming from.”

“At that point, we recommend the patient undergo intracranial monitoring to determine the exact source of the seizure activity,” continues Dr. McKhann. “Traditionally, we would perform a large operation to insert a subdural electrode array, a grid of small electrodes, into the brain to answer this question. However, this involves a large craniotomy, despite it being just a diagnostic surgery. It is a fairly large hurdle to cross, particularly in situations in which you’re not certain if the surgery is even going to definitively answer the question.”

Stereoelectroencephalography (SEEG)

“More recently, over the past 5 years, we are offering patients with medically refractory epilepsy a more refined and less invasive intracranial monitoring called stereoelectroencephalography (SEEG), a robot-assisted procedure that involves the insertion of thin electrode leads through small 2.5 mm. skull holes to detect seizure activity in the brain,” says Dr. McKhann. “SEEG is diagnostic surgery that helps us better understand our chances of curing epilepsy and the risks involved in attempting that cure. Because it is minimally invasive, SEEG allows us to take a safer approach to answer the question of the seizures’ origin without having to perform a large craniotomy.”

SEEG was first brought from Italy and France to North America earlier this decade. In 2014-2015, Dr. McKhann, Dr. Feldstein, and epilepsy neurologist Alison Pack, MD from the CCEC travelled to learn SEEG from colleagues from the Cleveland Clinic and France. A team from NYP/Weill Cornell Medicine followed in 2017-2018—Dr. Hoffman, Srishti Nangia, MD, pediatric neurologist, and Belinda Oyinkan Marquis, MD, child neurologist. The epilepsy team at New York-Presbyterian then became one of the early epilepsy centers to prominently adopt SEEG, and have since performed over 100 cases. SEEG is appropriate for patients with medically refractory focal epilepsy, epilepsy that originates from a limited area of the brain.

In 2018, Drs. Feldstein and McKhann and their team demonstrated how SEEG has successfully replaced more invasive approaches for pediatric focal epilepsy. “Our results of 25 pediatric patients who underwent SEEG implantations demonstrate that SEEG is a safe and effective technique for invasive seizure onset zone (SOZ) localization in medically refractory localization-related epilepsy (LRE) in the pediatric population,” says Dr. Feldstein. “Patients who are not found to have focally localizable seizures are spared craniotomies.”3

“With SEEG, we are successfully treating patients whose families would never have allowed us to put subdural arrays in their children,” says Dr. McKhann. “Some of these children now no longer seize because we performed SEEG, which gave us the information we needed to move ahead with treatment that solved the patients’ seizures.”

“Our multidisciplinary team remains on the frontlines to bring all of the modern surgical tools to improve the lives of children with epilepsy,” said Zachary Grinspan, MD, MS, Director of the Pediatric Epilepsy Program at NewYork-Presbyterian/Weill Cornell Medicine.

Laser interstitial thermal therapy (LITT)

At NewYork-Presbyterian, most 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 may be recommended for surgery, including resection of the seizure onset zone; disconnection surgery (detaching the problematic area from the rest of the brain); vagus nerve stimulation (VNS - the delivery of mild electrical pulses to the vagus nerve to decrease the incidence of seizures); or a type of laser ablation called laser interstitial thermal therapy (LITT).

“LITT is a minimally invasive technique in which the surgeon uses a small laser fiber and MRI navigation to precisely target and ablate the seizure focus without making a large opening in the skull,” says Dr. McKhann, “The power of real-time MRI feedback generates a detailed temperature map of the patient’s brain, which ensures the laser is focused on the seizure origin.”

“Applications of LITT for epilepsy are growing rapidly, and, while more evidence of safety and efficacy are needed, there are clear potential advantages for some patients,” continues Dr. McKhann. “If the patient’s anatomy is conducive, LITT can be used to eradicate lesions such as hypothalamic hamartoma, a rare and benign malformation of the hypothalamus, or other non-cancer tumors that can cause epilepsy such as ganglioglioma and dysembryoplastic neuroepithelial tumors (DNET).

“LITT is most appropriate for patients with medial temporal lobe or hypothalamic seizures,” explains Dr. Schwartz, Director of the Center for Epilepsy and Pituitary Surgery and Co-Director of Surgical Neuro-oncology at Weill Cornell Medicine. “In addition, when coupled with SEEG, LITT can be used to block seizure propagation or choke-points to reduce the frequency and severity of a patient’s epilepsy.”

Deep Brain Stimulation (DBS)

Another innovative minimally invasive approach toward refractory epilepsy is deep brain stimulation (DBS). Long recognized for its efficacy in movement disorders, DBS has been gaining acceptance in the treatment of epilepsy based on the results of the Stimulation of Anterior Nucleus of Thalamus for Epilepsy (SANTE) trial. The institution’s participation in the trial was led by Michael Kaplitt, MD, PhD, a pioneering functional neurosurgeon at the Weill Cornell Brain and Spine Center.4 “The SANTE trial demonstrated that DBS offers hope for seizure reduction to patients who have failed other forms of therapy and who have no other treatment options,” says Dr. Hoffman. Since the conclusion of the trial, Dr. Hoffman and Dr. Kaplitt are working to extend the use of this procedure to pediatric epilepsy.

Focused Ultrasound (FUS)

In an effort to provide more non-invasive modalities for refractory epilepsy patients, Dr. Hoffman is opening a clinical trial to explore the efficacy of focused ultrasound (FUS) in treating temporal lobe epilepsy. “This is the first application of FUS for epilepsy at our institution,” explains Dr. Hoffman. “We have identified and are proposing a novel target in the brain to treat mesial temporal sclerosis. Building from a prior feasibility study that we conducted last year, this approach would represent a non-invasive, conformal treatment option without exposure to radiation for poor surgical candidates.”

“If proven effective in this clinical trial, FUS can offer hope to patients with refractory seizures who have no other treatment options,” she added. “Left untreated, these patients steadily lose cognitive function as refractory seizures result in a progressive, degenerative process.”5

Expanding Global Scope and Reach: The Neurosurgical Mission in Tanzania

The scope and reach of the NewYork-Presbyterian pediatric neurosurgery team extends well beyond the Western hemisphere. For the past eleven years, the team has been integrally involved in the Neurosurgical Mission in Tanzania. The goal of the mission is to deliver basic neurosurgical care using locally available equipment and resources, and to empower doctors and nurses in Tanzania with a high level of expertise in the management of neurosurgical disorders and neurosurgical procedures.

Tanzania is one of several developing nations with a high incidence of epilepsy due to the prevalence of conditions (parasitic, bacterial, or viral infections; perinatal brain damage; head injuries;) that can cause seizures. The burden on children is high, but the multidisciplinary tools to evaluate and treat the condition are still in development in these countries. Since early evaluation and intervention can prevent cognitive and functional decline, teaching local providers to assess and treat these patients can greatly serve communities and children.

This past year, Dr. Hoffman traveled to Tanzania to offer a full educational session on epilepsy. Dr. Hoffman helped local neurosurgeons perform the first open surgery for the treatment of refractory epilepsy, and hopes to build on this experience to support a sustainable program to treat children with epilepsy in Tanzania and surrounding countries.

“The Mission in Tanzania is also an opportunity to educate residents and fellows at NewYork-Presbyterian,” says Dr. Hoffman. “We offer annual fellowship positions to graduates interested in spending extended time in Dar Es Salaam, and include residents in our annual visits, courses, and surgeries.”

International Teaching Conference on Pediatric Epilepsy

Dr. Hoffman and Cigdem Akman, MD, Chief, Division of Pediatric Neurology and Pediatric Epilepsy at NewYork-Presbyterian/Columbia University Medical Center, traveled to Doha, Qatar earlier this year to participate in an international teaching conference on pediatric epilepsy.

The pediatric neurosurgery team is thrilled to provide these innovative surgical techniques, minimally invasive modalities, and global initiatives to improve the quality of life of children with epilepsy. “These minimally invasive approaches to the diagnosis and treatment of epilepsy are changing the landscape of pediatric epilepsy,” says Dr. Feldstein. “As a result of our experience with these modalities, we have expanded our reach to patients who previously were either not candidates for surgery or were not interested in undergoing invasive surgery to diagnose and treat their seizures.”

References

  1. CDC: Epilepsy Fast Facts. https://www.cdc.gov/epilepsy/about/fast-facts.htm
  2. Epilepsy Foundation: Epilepsy: Impact on the Life of the Child. https://www.epilepsy.com/article/2014/3/epilepsy-impact-life-child
  3. Safety and efficacy of stereoelectroencephalography in pediatric focal epilepsy: a single-center experience. Published online July 20, 2018; DOI: 10.3171/2018.5.PEDS1856.
  4. Electrical stimulation of the anterior nucleus of thalamus for treatment of refractory epilepsy. Epilepsia. 2010 May;51(5):899-908. doi: 10.1111/j.1528-1167.2010.02536.x. Epub 2010 Mar 17.
  5. Magnetic resonance-guided focused ultrasound for ablation of mesial temporal epilepsy circuits: modeling and theoretical feasibility of a novel noninvasive approach. Parker WE, Weidman EK, Chazen JL, Niogi SN, Uribe-Cardenas R, Kaplitt MG, Hoffman CE.J Neurosurg. 2019 Jun 14:1-8. doi: 10.3171/2019.4.JNS182694. [Epub ahead of print]