title: Pathogenesis of Delayed Tension Intraventricular Pneumocephalus in Shunted Patient: Possible Role of Nocturnal Positive Pressure Ventilation.
abstract: BACKGROUND
  Delayed intraventricular pneumocephalus is a very rare and potentially serious complication of ventriculoperitoneal shunt. It can occur several months or years after shunting. Its pathogenesis is unclear. We herein discuss the underlying mechanisms and particularly the possible role of positive pressure ventilation.
  
  
  METHODS
  A 60 year-old man presented with a lateral ventricle neurocytoma microsurgically resected complicated by a late-onset (15 months) postoperative hydrocephalus requiring an adjustable ventriculoperitoneal (VP) shunt. One month later, the patient was diagnosed with a sleep apnea and required a continuous positive airway pressure (CPAP) device. A few weeks afterward the patient presented with headaches and alteration of consciousness. CT-Scan revealed a massive intraventricular pneumocephalus associated with a millimetric left petrous bone defect. A transient breakout of the positive ventilation and a subtemporal surgical repair of the defect led to the rapid resolution of the pneumocephalus.
  
  
  CONCLUSIONS
  Delayed intraventricular pneumocephalus requires two conditions: a VP shunt and an osteodural defect. The CPAP may play an important trigger role in the pathogenesis of this complication through a ball valve mechanism. The management relies on transient suspension of the positive ventilation and the surgical repair of the identified defect with or without pressure adjustments of the valve.
  
  
  CONCLUSIONS
  Intraventricular pneumocephalus is a potentially serious complication of patients with a VP shunt and receiving positive pressure ventilation. The introduction of a CPAP device must be discussed with the neurosurgeon beforehand in shunted patients.
authors.affiliation: Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon, France.
authors.forename: Sidi
authors.initials: S
authors.lastname: Salem-Memou
authors.affiliation: Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon, France; Research and Education Unit of Medicine, Claude Bernard University Lyon, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Vallee
authors.affiliation: Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon, France; Research and Education Unit of Medicine, Claude Bernard University Lyon, France.
authors.forename: Timothée
authors.initials: T
authors.lastname: Jacquesson
authors.affiliation: Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon, France; Research and Education Unit of Medicine, Claude Bernard University Lyon, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jouanneau
authors.affiliation: Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon, France. Electronic address: berhouma.moncef@gmail.com.
authors.forename: Moncef
authors.initials: M
authors.lastname: Berhouma
mesh_terms: D002551:Cerebral Ventricle Neoplasms / Q000601:surgery; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects*; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000601:surgery*; D020547:Lateral Ventricles / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D018306:Neurocytoma / Q000601:surgery; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000379:methods; D010579:Petrous Bone / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D011007:Pneumocephalus / Q000000981:diagnostic imaging* / Q000209:etiology*; D012891:Sleep Apnea Syndromes / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects*
keywords: Hydrocephalus; Nocturnal positive pressure ventilation; Pneumocephalus; Pneumoventricle; Sleeping apnea; Ventriculoperitoneal shunt