title: Post-operative diffusion weighted imaging as a predictor of posterior fossa syndrome permanence in paediatric medulloblastoma.
abstract: OBJECTIVE
  Posterior fossa syndrome (PFS) is a serious complication faced by neurosurgeons and their patients, especially in paediatric medulloblastoma patients. The uncertain aetiology of PFS, myriad of cited risk factors and therapeutic challenges make this phenomenon an elusive entity. The primary objective of this study was to identify associative factors related to the development of PFS in medulloblastoma patient post-tumour resection.
  
  
  METHODS
  This is a retrospective study based at a single institution. Patient data and all related information were collected from the hospital records, in accordance to a list of possible risk factors associated with PFS. These included pre-operative tumour volume, hydrocephalus, age, gender, extent of resection, metastasis, ventriculoperitoneal shunt insertion, post-operative meningitis and radiological changes in MRI. Additional variables included molecular and histological subtypes of each patient's medulloblastoma tumour. Statistical analysis was employed to determine evidence of each variable's significance in PFS permanence.
  
  
  RESULTS
  A total of 19 patients with appropriately complete data was identified. Initial univariate analysis did not show any statistical significance. However, multivariate analysis for MRI-specific changes reported bilateral DWI restricted diffusion changes involving both right and left sides of the surgical cavity was of statistical significance for PFS permanence.
  
  
  CONCLUSIONS
  The authors performed a clinical study that evaluated possible risk factors for permanent PFS in paediatric medulloblastoma patients. Analysis of collated results found that post-operative DWI restriction in bilateral regions within the surgical cavity demonstrated statistical significance as a predictor of PFS permanence-a novel finding in the current literature.
authors.affiliation: Neurosurgical Service, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Felicia H Z
authors.initials: FHZ
authors.lastname: Chua
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
authors.forename: Ady
authors.initials: A
authors.lastname: Thien
authors.affiliation: Neurosurgical Service, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Lee Ping
authors.initials: LP
authors.lastname: Ng
authors.affiliation: Neurosurgical Service, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.|Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.|SingHealth Duke-NUS Neuroscience Academic Clinical Program, Singapore, Singapore.
authors.forename: Wan Tew
authors.initials: WT
authors.lastname: Seow
authors.affiliation: Neurosurgical Service, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.|Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.|SingHealth Duke-NUS Neuroscience Academic Clinical Program, Singapore, Singapore.
authors.forename: David C Y
authors.initials: DCY
authors.lastname: Low
authors.affiliation: Department of Pathology and Laboratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Kenneth T E
authors.initials: KTE
authors.lastname: Chang
authors.affiliation: Department of Pathology and Laboratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Derrick W Q
authors.initials: DWQ
authors.lastname: Lian
authors.affiliation: Department of Pathology and Laboratory Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Eva
authors.initials: E
authors.lastname: Loh
authors.affiliation: Neurosurgical Service, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore. sharon.low.y.y@singhealth.com.sg.|Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. sharon.low.y.y@singhealth.com.sg.|SingHealth Duke-NUS Neuroscience Academic Clinical Program, Singapore, Singapore. sharon.low.y.y@singhealth.com.sg.
authors.forename: Sharon Y Y
authors.initials: SYY
authors.lastname: Low
mesh_terms: D000293:Adolescent; D002528:Cerebellar Neoplasms / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging* / Q000473:pathology*; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D008527:Medulloblastoma / Q000601:surgery*; D015999:Multivariate Analysis; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011184:Postoperative Period; D012189:Retrospective Studies
keywords: Cerebellar mutism; Medulloblastoma; Posterior fossa syndrome