title: Awake surgery for hemispheric low-grade gliomas: oncological, functional and methodological differences between pediatric and adult populations.
abstract: BACKGROUND
  Brain mapping through a direct cortical and subcortical electrical stimulation during an awake craniotomy has gained an increasing popularity as a powerful tool to prevent neurological deficit while increasing extent of resection of hemispheric diffuse low-grade gliomas in adults. However, few case reports or very limited series of awake surgery in children are currently available in the literature.
  
  
  METHODS
  In this paper, we review the oncological and functional differences between pediatric and adult populations, and the methodological specificities that may limit the use of awake mapping in pediatric low-grade glioma surgery.
  
  
  RESULTS
  This could be explained by the fact that pediatric low-grade gliomas have a different epidemiology and biologic behavior in comparison to adults, with pilocytic astrocytomas (WHO grade I glioma) as the most frequent histotype, and with WHO grade II gliomas less prone to anaplastic transformation than their adult counterparts. In addition, aside from the issue of poor collaboration of younger children under 10 years of age, some anatomical and functional peculiarities of children developing brain (cortical and subcortical myelination, maturation of neural networks and of specialized cortical areas) can influence direct electrical stimulation methodology and sensitivity, limiting its use in children.
  
  
  CONCLUSIONS
  Therefore, even though awake procedure with cortical and axonal stimulation mapping can be adapted in a specific subgroup of children with a diffuse glioma from the age of 10 years, only few pediatric patients are nonetheless candidates for awake brain surgery.
authors.affiliation: Institute of Neurosurgery, Catholic University Medical School, Rome, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Trevisi
authors.affiliation: Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34295, Montpellier, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Roujeau
authors.affiliation: Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34295, Montpellier, France. h-duffau@chu-montpellier.fr.|Team "Plasticity of Central Nervous System, Stem Cells and Glial Tumors," National Institute for Health and Medical Research U1051, Institute for Neurosciences of Montpellier, Montpellier University Medical Center, Montpellier, France. h-duffau@chu-montpellier.fr.
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
mesh_terms: D000328:Adult; D000375:Aging; D001932:Brain Neoplasms; D002648:Child; D005910:Glioma / Q000601:surgery*; D006801:Humans; D016343:Monitoring, Intraoperative; D019635:Neurosurgical Procedures / Q000379:methods*; D014851:Wakefulness
keywords: Awake surgery; Brain mapping; Brain maturation; Children; Direct electrical stimulation; Low-grade gliomas