title: Symptomatic Subdural Hygroma and Hydrocephalus following Chiari I Decompression.
abstract: BACKGROUND
  The aim of the present case report is to describe an unusual complication of foramen magnum decompression (FMD) for the Chiari 1 hindbrain malformation and its successful management with non-operative measures.
  
  
  METHODS
  A 2-year-old girl with the Chiari 1 malformation underwent FMD, including suboccipital craniotomy, C1 laminectomy and durotomy without opening the arachnoid.
  
  
  RESULTS
  After initial postoperative improvement, the patient deteriorated, developing subdural hygromas and hydrocephalus. These were treated successfully with observation and acetazolamide.
  
  
  CONCLUSIONS
  Subdural hygromas may complicate FMD. A slit valve opening in the arachnoid might be part of the pathophysiology. While surgical intervention may be necessary in some circumstances, non-operative measures may be effective as well.
authors.affiliation: Division of Pediatric Neurosurgery, Rainbow Babies and Children's Hospital, The Neurological Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Filis
authors.forename: Karam
authors.initials: K
authors.lastname: Moon
authors.forename: Alan R
authors.initials: AR
authors.lastname: Cohen
mesh_terms: D000086:Acetazolamide / Q000627:therapeutic use; D001139:Arnold-Chiari Malformation / Q000175:diagnosis / Q000601:surgery*; D002675:Child, Preschool; D019299:Decompression, Surgical / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D005539:Foramen Magnum / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008991:Monitoring, Physiologic / Q000379:methods; D019370:Observation / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000628:therapy; D018570:Risk Assessment; D012720:Severity of Illness Index; D013353:Subdural Effusion / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D000086:Acetazolamide