title: Endoscopic fenestration of cavum velum interpositum cysts: a case study of two symptomatic patients.
abstract: BACKGROUND
  Cavum velum interpositum (CVI) is commonly an incidental asymptomatic finding on imaging studies. Encystment can occur and, in most situations, is also asymptomatic. Clinical symptoms occurring in patients with CVI cysts have been reported infrequently with the result that the relationship of these symptoms and the cyst are usually unclear. This report contributes to the knowledge base of symptoms that can occur in patients with CVI and the response of symptoms to effective treatment.
  
  
  METHODS
  We report the clinical outcomes of a 3-year-old male patient and a 13-year-old female patient with symptoms and CVI cysts on imaging who were treated successfully with endoscopic fenestration.
  
  
  RESULTS
  The developmental delay and occasional headache present in the 3-year-old male patient resolved after endoscopic fenestration; however, the 13-year-old patient who had neuropsychiatric symptoms did not improve.
  
  
  CONCLUSIONS
  Our cases add to the literature describing the response to cyst treatment in symptomatic patients harboring CVI cysts. Symptoms due to CSF pathway obstruction may respond to cyst fenestration, while the response of symptoms in patents who do not have clear CSF circulation disorders is less predictable.
authors.affiliation: Division of Neurosurgery, Department of Surgery, University of British Columbia and BC Children's Hospital, Vancouver, British Columbia, Canada.
authors.forename: Calvin K W
authors.initials: CK
authors.lastname: Tong
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Singhal
authors.forename: D Douglas
authors.initials: DD
authors.lastname: Cochrane
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology* / Q000601:surgery*; D002675:Child, Preschool; D003560:Cysts / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D044583:Neuroendoscopy / Q000379:methods*