title: The truth and coherence behind the concept of overdrainage of cerebrospinal fluid in hydrocephalic patients.
abstract: BACKGROUND
  Overdrainage, siphoning, and slit-ventricle syndrome are well-documented complications of shunting in hydrocephalic patients. Despite the prevalence of these conditions, their mechanisms are still not fully understood. In this paper, the authors trace the concept of overdrainage and the related phenomena of siphoning and slit-ventricle syndrome.
  
  
  OBJECTIVE
  To provide a historical overview of overdrainage and to reignite discussion of a topic that has been settled.
  
  
  RESULTS
  A medical literature search and review were performed via Google Scholar. Of 565 publications, 3 primary papers were identified and a timeline was developed demonstrating the convergence of the aforementioned concepts. From the primary papers, 25 relevant publications were selected and further analyzed searching for hypothesis, evidence, and conclusions.
  
  
  CONCLUSIONS
  Overdrainage, siphoning, and slit-ventricle syndrome are associated concepts that have converged into a pathophysiological theory where siphoning of CSF leads to overdrainage, which is then hypothesized to cause slit-ventricle syndrome in a small subset of patients. Our data suggests that while there have been numerous reports regarding overdrainage and its consequences, the evidence is not as robust as currently presumed and this subject requires prospective exploration.
authors.affiliation: Department of Neurosurgery, UCLA David Geffen School of Medicine, 10833 Le Conte Avenue, 13-154 CHS, Los Angeles, CA, 90095, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Cheok
authors.forename: Jason
authors.initials: J
authors.lastname: Chen
authors.forename: Jorge
authors.initials: J
authors.lastname: Lazareff
mesh_terms: D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects / Q000266:history*; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000266:history*