title: Hydrocephalus and arachnoid cysts.
abstract: OBJECTIVE
  The management of arachnoid cysts (AC) remains controversial. An additional problem derives from the management of hydrocephalus associated with an AC. In this work, we discuss existing procedures proposed in the current literature for their treatment.
  
  
  METHODS
  We reviewed selected reports on intracranial ACs placing special interest in those about the association of hydrocephalus and ACs. We also briefly surveyed data of our patients with this association.
  
  
  CONCLUSIONS
  Hydrocephalus is often found in midline and posterior fossa ACs. Interhemispheric lesions may also evolve with ventriculomegaly, while middle fossa lesions rarely produce hydrocephalus. Patients' age, cyst location and size, and macrocephaly have all been related to the development of hydrocephalus. Some authors remark on the role played by hydrocephalus and hypothesize that some ACs would result from disturbed cerebrospinal fluid (CSF) dynamics. They also propose that ACs might represent a localized form of hydrocephalus. We also comment on hydrocephalus in relation to the diverse locations of ACs. Neuroendoscopic techniques have transformed previous ways of management as cystoperitoneal shunting and open fenestration.
  
  
  CONCLUSIONS
  ACs may be pathogenetically related with hydrocephalus, and conversely, ACs may cause hydrocephalus. In some patients, aberrant CSF dynamics seems to play a major role in the development of both cyst and hydrocephalus. Hydrocephalus and ACs may be treated exclusively with neuroendoscopic procedures, although some patients will still require CSF shunting. The ideal option seems to consist of choosing the method that offers the highest success with a single procedure for treating the hydrocephalus and the AC simultaneously.
authors.affiliation: Regional Service of Neurosurgery, Virgen de la Arrixaca University Hospital, 30120 El Palmar, Murcia, Spain. juanf.martinezlage@cablemurcia.com
authors.forename: Juan F
authors.initials: JF
authors.lastname: Martínez-Lage
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Pérez-Espejo
authors.forename: María-José
authors.initials: MJ
authors.lastname: Almagro
authors.forename: Antonio López
authors.initials: AL
authors.lastname: López-Guerrero
mesh_terms: D016080:Arachnoid Cysts / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D005315:Fetal Diseases; D006801:Humans; D006849:Hydrocephalus / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed