title: Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results.
abstract: BACKGROUND
  Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up.
  
  
  METHODS
  Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions.
  
  
  RESULTS
  A new, proposed definition of "post-operative pediatric CMS" was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed.
  
  
  CONCLUSIONS
  The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.
authors.affiliation: Department of Oncology and Palliation, North Zealand Hospital, Dyrehavevej 29, 3400, Hilleroed, Denmark. info@posteriorfossa.org.
authors.forename: Thora
authors.initials: T
authors.lastname: Gudrunardottir
authors.affiliation: Centre for Neuroscience of Speech, University of Melbourne, Melbourne, Australia.|Neuroscience of Speech, Murdoch Children's Research Institute, Melbourne, Australia.
authors.forename: Angela T
authors.initials: AT
authors.lastname: Morgan
authors.affiliation: Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Lux
authors.affiliation: Department of Oncology, Queen's Medical Centre, Nottingham, UK.|Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Walker
authors.affiliation: Division of Neuropsychology, Brain Tumor Institute, Neurofibromatosis Institute, Children's National Health System, Washington, DC, USA.
authors.forename: Karin S
authors.initials: KS
authors.lastname: Walsh
authors.affiliation: Division of Neurology, Brain Tumor Institute, Children's National Health System, Washington, DC, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Wells
authors.affiliation: Division of Pediatric Neurosurgery, New York University Langone Medical Center, New York, USA.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Wisoff
authors.affiliation: Department of Neurosurgery, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Marianne
authors.initials: M
authors.lastname: Juhler
authors.affiliation: Department of Neurology, Ataxia Unit, Cognitive Behavioral Neurology Unit, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Schmahmann
authors.affiliation: Department of Pediatric Neurosurgery, Children's National Health System, Washington, DC, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Keating
authors.affiliation: Department of Pediatric Neurology, Erasmus MC/Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Coriene
authors.initials: C
authors.lastname: Catsman-Berrevoets
mesh_terms: D002526:Cerebellar Diseases / Q000150:complications / Q000175:diagnosis* / Q000209:etiology*; D016208:Databases, Factual / Q000706:statistics & numerical data; D006801:Humans; D007055:Iceland; D009155:Mutism / Q000150:complications / Q000175:diagnosis* / Q000209:etiology*; D010372:Pediatrics; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: Cerebellar cognitive affective syndrome; Cerebellar mutism; Cerebellar tumor surgery; Children; Consensus; Posterior fossa syndrome