“As Little as Possible, As Much as Required”: Epilepsy Surgery in Children and Adults

Extensive, multilobar or hemispheric epileptogenic zones are usually associated with early epilepsy onset, a catastrophic course and, eventually, with the urgent need for early surgical intervention. The prevalent underlying etiologies of drug-resistant epilepsy in infants and young children are focal cortical dysplasia and glioneuronal tumors. The completeness of resection is the best predictor of postoperative seizure freedom, due to the intrinsic epileptogenicity of these lesions. Presurgical workup in the first years of life is challenging, due to the limitations of MRI diagnostics at an age of yet immature myelination. Infants and young children with a focal brain lesion may be favorable candidates for epilepsy surgery despite the prevalence of generalized EEG seizures and a diffuse pattern of hypsarrhythmia with multifocal bilateral interictal epileptiform discharges. Seizure semiology in focal epilepsies manifesting in the first years of life is rarely lateralizing and hardly ever localizing. Focal epileptogenic lesions in infancy may present with infantile spasms in the context of West syndrome. Young children undergo mostly multilobar and hemispheric procedures, in stark contrast to adults undergoing temporal lobe resections. Younger children require more extensive procedures, but have the potential to compensate neurological deficits due to increased brain plasticity in early life. Postoperative seizure freedom and anticonvulsant tapering are expected to have a positive effect on cognitive development, considering the devastating effects of seizures and anticonvulsants on the developing brain. This very young pediatric population differs to a great extent from adult cohorts with later epilepsy onset, due to a more limited epileptogenic zone, and later epilepsy surgery.