title: Cavum veli interpositi: just an anatomical variant or a potentially symptomatic CSF compartmentalization?
abstract: BACKGROUND
  The cavum veli interpositi (CVI) usually is a small CSF-containing abnormality of septum pellucidum, asymptomatic and rare after the age of 3 years. When symptomatic, it is large and can be related to psychiatric disorders, syndromic association of mental retardation and seizures or to hydrocephalus.
  
  
  METHODS
  This is the first reported case of an otherwise healthy pediatric patient with a large CVI experiencing episodes of hypertonic loss of consciousness unrelated to epileptic, cardiologic or psychiatric causes without signs of chronic increase in intracranial pressure (ICP).
  
  
  RESULTS
  Supposing a CSF compartmentalization in the CVI as the cause of acute poussés of ICP due to block of CSF pathways and considering the severity of the symptoms, an endoscopic fenestration was performed with a reduction of cyst dimensions.
  
  
  CONCLUSIONS
  We suggest considering the fenestration of large CVI even in otherwise asymptomatic patients to avoid the risk of CSF compartmentalization with ICP poussés.
authors.affiliation: Department of Neurosciences and Biomedical Technologies, University of Milano-Bicocca, Ospedale San Gerardo, Monza, Italy. carlo.giussani @ unimib.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Giussani
authors.forename: Leonardo
authors.initials: L
authors.lastname: Fiori
authors.forename: Andrea
authors.initials: A
authors.lastname: Trezza
authors.forename: Matteo
authors.initials: M
authors.lastname: Riva
authors.forename: Erik P
authors.initials: EP
authors.lastname: Sganzerla
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis* / Q000601:surgery; D002552:Cerebral Ventricles / Q000473:pathology* / Q000601:surgery; D014695:Cerebral Ventriculography; D002648:Child; D003560:Cysts / Q000175:diagnosis* / Q000601:surgery; D004724:Endoscopy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D014057:Tomography, X-Ray Computed; D014474:Unconsciousness / Q000209:etiology*