title: Incidence and severity of postoperative cerebellar mutism syndrome in children with medulloblastoma: a prospective study by the Children's Oncology Group.
abstract: OBJECTIVE
  Cerebellar mutism syndrome (CMS) is a unique postoperative syndrome typically arising 1 to 2 days after resection of a midline posterior fossa tumor; it consists of diminished speech progressing to mutism, emotional lability, hypotonia, and ataxia. Most descriptions have been limited to small institutional series using a retrospective chart review methodology.
  
  
  METHODS
  The authors incorporated a CMS questionnaire in two large clinical trials (Children's Cancer Group [CCG] 9931, treatment for high-risk medulloblastoma/primitive neuroectodermal tumor; and CCG/Pediatric Oncology Group [POG] A9961, treatment for average-risk medulloblastoma) to prospectively survey for incidence, severity, and possible causes of CMS in children with newly diagnosed medulloblastoma. Information pertaining to 450 of the 463 patients enrolled in the studies was available for review (82 patients in CCG 9931, and 368 patients in CCG/POG A9961). Cerebellar mutism syndrome occurred in 107 (24%) of 450 children. Symptom intensity was judged to have been severe in 43%, moderate in 49%, and mild in 8% of these 107 patients. Mutism and ataxia were the features most frequently judged as severe. In both cohorts, preoperative brainstem invasion was the only feature that correlated with risk of CMS. One year after diagnosis, nonmotor speech/language deficits, neurocognitive deficits, and/or ataxia persisted in a significant fraction of patients.
  
  
  CONCLUSIONS
  Nearly one quarter of patients who underwent resection of a medulloblastoma developed symptoms of CMS, of which 92% were judged to be of moderate or severe intensity. Brainstem invasion by tumor was the only risk factor that correlated positively with CMS occurrence; there was a negative correlation with cerebellar hemisphere tumor location. As more radical resections are attempted for medulloblastoma, the potential for increased morbidity must be carefully weighed against prognostic factors, especially in patients with brainstem invasion.
authors.affiliation: Department of Pediatrics, University of Michigan Health System, Ann Arbor, Michigan 48109-0203, USA. prob@umich.edu
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Robertson
authors.forename: Karin M
authors.initials: KM
authors.lastname: Muraszko
authors.forename: Emiko J
authors.initials: EJ
authors.lastname: Holmes
authors.forename: Richard
authors.initials: R
authors.lastname: Sposto
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Packer
authors.forename: Amar
authors.initials: A
authors.lastname: Gajjar
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dias
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Allen
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery*; D009155:Mutism / Q000453:epidemiology* / Q000209:etiology; D018242:Neuroectodermal Tumors, Primitive / Q000188:drug therapy / Q000453:epidemiology / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index