Evaluating and managing patients with pediatric epilepsy
More than 300,000 U.S. children younger than 15 years have epilepsy. More than 90,000 of them have intractable seizures. For children with epilepsy, seizures are often only one of the concerns. One in 4 children with epilepsy has some degree of intellectual disability. For children with intractable seizures, the frequency rises to 1 in 2 and the impairments tend to be more severe.
Pediatric neurologists specializing in epilepsy at Mayo Clinic note that children with epilepsy are also at increased risk of mood disorders, depression and anxiety. The best way to manage the risk of associated comorbidities is to treat the seizures themselves, but it is important to address seizures within the context of potential emotional and intellectual deficits.
While their goal is always to treat the epilepsy, Mayo's surgical service is also very attentive to quality of life. When the seizure focus is in eloquent cortex, Mayo neurosurgeons and pediatric neurology epilepsy specialists try to help parents weigh the benefit of seizure reduction against surgically induced deficits.
Managing comorbidities associated with epilepsy
Children with controlled seizures may appear normal, but they still have cognitive issues and anxiety that can interfere with attention, and social problems that can impact both the child and the family. Impairments in social, emotional or intellectual processing and development have been found to vary with age of seizure onset, intractability and anatomical locus of seizure focus. The earlier the age of onset, the greater the risk to the developing brain.
Mayo Clinic speech pathologists note that seizures may affect areas of the brain important to language development and that language dysfunction can impede learning and inhibit social interaction during development. Neuropsychological assessment provides a snapshot of where on a scale of normal behavior a child is functioning relative to cognitive, behavioral and emotional processing within the context of a complex neurological condition.
Mayo neuropsychologists help integrate the medical, cognitive and psychosocial data for the family. Their goal is to help families, teachers, students, school administrators and paraprofessionals understand how the child's epilepsy is impacting performance and provide systematic recommendations on how to address weaknesses and maximize strengths.
Armed with the results of cognitive testing, families feel not only informed but also empowered. When a child's seizures are controlled by medication, families can mistakenly blame continued disabilities on anti-epileptic medications. Although seizure frequency and severity play a role in the duration of behavioral and intellectual deficits, it is the underlying neuropathology, not the seizures themselves, that affects development. Among the biological factors that can impact emotional and cognitive function are structural brain abnormalities, irregularities in neurotransmitter pathways, and general or localized brain atrophy.
Surgical interventions for intractable seizures
At Mayo Clinic, the surgical work-up can be done in one to two weeks. It includes state-of- the-art functional brain mapping and studies to determine the locus, frequency, severity and duration of seizures and whether other medical conditions coexist with the seizures.
At Mayo Clinic Hospital — Rochester, in Minnesota, pediatric surgical candidates undergo EEG monitoring in one of the five pediatric rooms or in the pediatric intensive care unit, all of which are hardwired with ceiling cameras for behavioral observation and continuous EEG monitoring via external or intracranial EEG leads. Inpatient EEG video monitoring helps minimize risks associated with medication withdrawal, a process that is often required to record seizures. Monitoring may take from 24 hours to several days.
Mayo Clinic is one of the few centers that records the EEG and has technicians monitoring the patient every second of the day or night. This allows them to record seizure activity when the patient or family member is sleeping or the seizure is subtle. This continuous, 24/7 monitoring by trained, on-site technicians increases safety and can reduce the length of stay on the unit.
The EEG video monitoring unit is designed so that an adult family member can stay with the child at all times. Although children are restricted to their rooms, they are free to move about within their rooms. The unit's rooms are equipped with the latest technology, including interactive computer games. Child-life specialists visit several times a day with crafts, toys, games and videos and also work with children and families to help them through procedures that may be uncomfortable or are unfamiliar.
Localizing seizure focus through SISCOM
SISCOM stands for subtraction ictal single-photon emission computerized tomography (SPECT) coregistered to MRI. Pioneered by Mayo, it fuses the MRI image with the SPECT image, an innovation particularly useful in seizure localization. Mayo researchers are using SISCOM to study children with multifocal or indeterminate focal MRI or EEG findings.
A SISCOM study involves a radioactive tracer that is injected by technologists as soon as possible during a seizure. Unlike adults, children are often unable to verbalize when they are having a seizure, so continuous EEG monitoring and observation are critical.
The ketogenic diet — a high-fat, low-carbohydrate diet that mimics the fasting state and stimulates the ketogenic metabolism pathway — was first used in the 1920s at Mayo Clinic. It has since been discovered to improve seizure control in children with intractable epilepsy, and more than 100 Mayo Clinic pediatric epilepsy patients are currently on the diet.
Children who are candidates for the diet begin it during a three- or four-day stay in Mayo's pediatric hospital so that their parents can learn to manage the diet, and a child's response can be monitored before the child is discharged. Although the diet is rigorous, families seem to adapt quickly. Mayo dieticians have designed more than 100 menus for families to download and are willing to create specific recipes on request.
Epilepsy is a group of disorders, and differential diagnosis requires, first and foremost, a lengthy, detailed history and clinical assessment. At Mayo, the evaluation may extend to include metabolic tests and evaluations by autoimmune neurology, genetics and other subspecialty services. Because the clinical evaluation is comprehensive and families can feel overwhelmed, Mayo providers take plenty of time to explain, interpret and guide patients through the process. An epilepsy team conference allows all team members to carefully review data from all subspecialties so that the team can arrive at an agreed-upon treatment strategy.
At Mayo, treatment of pediatric epilepsy means finding the best method of seizure control, as well as addressing related cognitive and psychosocial impairments.