George I. Jallo

Pediatric Epilepsy Surgery: Preoperative Assessment and Surgical Treatment

(1) A detailed explanation of the catastrophic nature of medically refractory epilepsy, particularly in young infants and children. The authors understand that the cumulative harmful effects of frequent seizures on the developing brain can be catastrophic, resulting in aberrant synaptogenesis and abnormalities in neural networks, with permanent aberrant circuitry, continued seizures, and cognitive/psychosocial impairments. (2) Criteria for the selection of pediatric epilepsy surgery candidates, using data from the International League Against Epilepsy. Specifically, with the failure of 2-3 antiepileptic drugs, disabling seizure side effects, or disabling side effects of antiepileptic drugs, epilepsy surgery should be considered. In young infants and children with lesional magnetic resonance imaging scans, epilepsy surgery should be considered early. The Epilepsy Surgery Consortium of the International League Against Epilepsy reported that in medically refractory epilepsy, patients with identifiable lesions on cranial magnetic resonance imaging scans stand an 80% chance of seizure-free outcomes after epilepsy surgery. More recent studies, however, suggest that it takes over 20 years for a patient with medically refractory epilepsy to be referred to a tertiary care epilepsy center for consideration of epilepsy surgery. Clearly, and as this book emphasizes, we, as pediatric epileptologists and neurosurgeons, have our work cut out for us! A considerable amount of education is needed among our professional colleagues, as well as our families of children with epilepsy, about the risks vs benefits of epilepsy surgery. Increasing clinical and experimental evidence documents the progressive nature of medically refractory epilepsy, including cognitive decline and psychosocial maladjustment. Moreover, uncontrolled seizures carry risks of morbidity and mortality, including status epilepticus and sudden unexpected death with epilepsy. In addition, the young, developing brain possesses maximum developmental plasticity, which allows epilepsy surgery to be performed more easily, without significant risks of new neurologic deficits. (3) A full discussion of modalities used to identify the epileptogenic focus, including cranial magnetic resonance imaging, diffusion tensor imaging, fluid attenuated inversion recovery sequencing, and other modalities, such as interictal positron emission tomography scans, subtraction single proton emission computerized tomography, and functional magnetic resonance imaging. The authors clearly detail presurgical evaluations for epilepsy surgery, including video electroencephalogram monitoring, structural and functional neuroimaging, and neuropsychometric testing. They understand that the congruence of data is critical. They further understand that ‘‘generalized’’ epileptiform discharges, particularly in combination with a lesional magnetic resonance imaging brain scan, does not exclude epilepsy surgery. In fact, these ‘‘generalized’’ discharges simply speak to the ‘‘maladaptive plasticity’’ of the developing brain in the context of early-onset lesional epilepsy. The pictures of different types of neuroimaging are very detailed and beautifully configured in the text. The co-registration of these data on a three-dimensional, volumetric magnetic resonance imaging scan provides a level of detail that enhances the accuracy of the presurgical plan.