title: Extended long-term (> 5 years) outcome of cerebrospinal fluid shunting in idiopathic normal pressure hydrocephalus.
abstract: BACKGROUND
  Shunt surgery has been established as the only durable and effective treatment for idiopathic normal pressure hydrocephalus.
  
  
  OBJECTIVE
  We evaluated the "extended" long-term follow-up (> 5 years) in a prospective study cohort who underwent shunting between 1990 and 1995. A secondary objective was to determine the cause of death in these patients.
  
  
  METHODS
  Fifty-one patients were included after confirmation of the diagnosis by extensive clinical and diagnostic investigations. Surgery included ventriculoatrial or ventriculoperitoneal shunting with differential pressure valves in the majority of patients. For each of the cardinal symptoms, postoperative outcome was assessed separately with the Krauss Improvement Index, yielding a value between 0 (no benefit) and 1 (optimal benefit) for the overall outcome.
  
  
  RESULTS
  Mean age at surgery was 70.2 years (range, 50-87 years). Thirty patients were women, and 21 were men. Short-term (18.8 +/- 16.6 months) follow-up was available for 50 patients. The Krauss Improvement Index was 0.66 +/- 0.28. Long-term (80.9 +/- 51.6 months) follow-up was available for 34 patients. The Krauss Improvement Index was 0.64 +/-0.33. Twenty-nine patients died during the long-term follow-up at a mean age of 75.8 years (range, 55-95 years). The major causes of death were cardiovascular disorders: cardiac failure (n = 7) and cerebral ischemia (n = 12). Other causes were pneumonia (n = 2), acute respiratory distress syndrome (n = 1), pulmonary embolism (n = 1), cancer (n = 2), renal failure (n = 1), and unknown (n = 3). There was no shunt-related mortality.
  
  
  CONCLUSIONS
  Idiopathic normal pressure hydrocephalus patients may benefit from shunting over the long term when rigorous selection criteria are applied. Shunt-related mortality is negligible. The main cause of death is vascular comorbidity.
authors.affiliation: Department of Neurosurgery, Medical School Hannover, Hannover, Germany.
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Mirzayan
authors.forename: Goetz
authors.initials: G
authors.lastname: Luetjens
authors.forename: Jan Juliaan
authors.initials: JJ
authors.lastname: Borremans
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Regel
authors.forename: Joachim Kurt
authors.initials: JK
authors.lastname: Krauss
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002557:Cerebrospinal Fluid Shunts; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011446:Prospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome