title: Posterior fossa decompression for life-threatening tonsillar herniation in patients with gliomatosis cerebri: report of three cases.
abstract: OBJECTIVE
  Gliomatosis cerebri (GC) is a rare type of primary brain tumor that diffusely infiltrates more than two lobes of the brain while the normal cerebral architecture is maintained. To the best of our knowledge, the association between an acquired tonsillar herniation and GC has never been reported. In this article, we describe three patients with progressive gliomatosis of the cerebellar hemispheres who subsequently showed signs and symptoms secondary to tonsillar herniation. Early recognition of this potentially life-threatening complication allowed us to recommend prompt surgical intervention.
  
  
  METHODS
  One patient with primary, or Type I, GC presented with suboccipital headaches, and two patients with secondary, or Type II, GC presented with the signs and symptoms of progressive myelopathy. Serial imaging studies demonstrated progressive involvement of the cerebellum, descent of the cerebellar tonsils through the foramen magnum, and cervicomedullary spinal cord compression.
  
  
  METHODS
  Once the tonsillar herniation was recognized, all three patients underwent posterior fossa decompression, a cervical laminectomy to the lowest level of the tonsillar herniation, and duraplasty. All three patients experienced immediate improvement in their conditions.
  
  
  CONCLUSIONS
  Early recognition of tonsillar herniation, a possibly overlooked cause of death in patients with GC, allows for early surgical intervention as a potentially lifesaving procedure and significant improvement in the patient's condition.
authors.affiliation: Department of Neurosurgery, Brain Tumor Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. jweinberg@mdanderson.org
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Weinberg
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.forename: Zvi R
authors.initials: ZR
authors.lastname: Cohen
authors.forename: Lauren
authors.initials: L
authors.lastname: Langford
authors.forename: Victor A
authors.initials: VA
authors.lastname: Levin
mesh_terms: D000328:Adult; D002526:Cerebellar Diseases / Q000175:diagnosis / Q000601:surgery*; D002528:Cerebellar Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000601:surgery*; D003399:Craniotomy / Q000379:methods*; D019299:Decompression, Surgical; D018450:Disease Progression; D004630:Emergencies; D004677:Encephalocele / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018302:Neoplasms, Neuroepithelial / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D009460:Neurologic Examination