title: Medication overuse as a cause of chronic headache in shunted hydrocephalus patients.
abstract: OBJECTIVE
  To highlight the group of hydrocephalus patients known to have a long history of shunt revisions and refractory chronic headache. When a shunt in perfect working order has no effect on headache, other causes of headache should be investigated. In this paper, patients with medication overuse headache are identified and the positive effect of medication withdrawal are described.
  
  
  METHODS
  Patients with hydrocephalus and shunt referred from the neurosurgical department to the Danish Headache Centre were identified. In all cases, over- and underdrainage was ruled out prior to referral. Six patients with medication overuse headache were documented and their charts were reviewed retrospectively with specific attention to: shunt revisions, inpatient and outpatient contacts, headache data and medication use before and after withdrawal of analgesic medication overuse.
  
  
  RESULTS
  A marked reduction in shunt revisions and inpatient contacts in five out of six patients was found and a reduction in outpatient contacts in four out of six patients. Furthermore, an improvement in headache intensity was found in three out of six patients and a reduction in duration was found in two out of six patients.
  
  
  CONCLUSIONS
  This study indicates that it is important to identify shunt patients with persistent chronic headache from causes other than shunt malfunction. By reducing their analgesic intake, it is possible to reduce headaches, the number of surgical interventions and hospital contacts. Hopefully this will raise awareness and lead to further research on the subject.
authors.affiliation: Danish Headache Centre, Department of Neurology, Glostrup Hospital, University of Copenhagen, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Willer
authors.forename: R H
authors.initials: RH
authors.lastname: Jensen
authors.forename: M
authors.initials: M
authors.lastname: Juhler
mesh_terms: D000328:Adult; D000700:Analgesics / Q000009:adverse effects*; D002557:Cerebrospinal Fluid Shunts; D002908:Chronic Disease; D005260:Female; D051271:Headache Disorders, Secondary / Q000150:complications*; D006801:Humans; D006849:Hydrocephalus / Q000150:complications* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000150:complications / Q000188:drug therapy; D010865:Pilot Projects; D012086:Reoperation; D012189:Retrospective Studies; D018781:Tension-Type Headache / Q000150:complications / Q000188:drug therapy; D055815:Young Adult
chemical_list: D000700:Analgesics