Intraoperative neurophysiological monitoring for the resection of brain tumors in pediatric patients

Intraoperative neurophysiology (ION) is the gold standard to map and monitor brain functions during supratentorial surgery in critical areas. This is of great value for the surgery of brain gliomas in adults but the same ION techniques can be used in the pediatric population with respect to both epilepsy and brain tumor surgery. While the principles of most ION techniques are the same for adults and children, the developing nervous system has peculiar characteristics in terms of anatomical and physiological maturation of afferent and efferent pathways within the brain and the spinal cord. Accordingly, some adjustments, particularly with regards to stimulation parameters, are needed in younger children. This paper will review current ION techniques to assist during the resection of brain tumors in children, focusing on the aspects peculiar to mapping and monitoring of sensori-motor functions in the pediatric population. On the other hand, awake surgery, of common use in adult patients when aiming to identify cortical and subcortical cognitive functions, is of very limited use in children and will not be discussed here.