title: Dutch Normal-Pressure Hydrocephalus Study: randomized comparison of low- and medium-pressure shunts.
abstract: OBJECTIVE
  The goal of this prospective study was to compare outcome after placement of a low- or medium-pressure shunt in patients with normal-pressure hydrocephalus (NPH).
  
  
  METHODS
  Ninety-six patients with NPH were randomized to receive a low-pressure ventriculoperitoneal shunt (LPV; 40 +/- 10 mm H2O) or medium high-pressure ventriculoperitoneal shunt (MPV; 100 +/- 10 mm H2O). The patients' gait disturbance and dementia were quantified by applying an NPH scale, and their level of disability was evaluated by using the modified Rankin scale (mRS). Patients were examined prior to and 1, 3, 6, 9, and 12 months after surgery. Primary outcome measures were determined by differences between preoperative and last NPH scale scores and mRS grades. The LPV and MPV shunt groups were compared by calculating both the differences between mean improvements and the proportions of patients showing improvement. Intention-to-treat analysis of mRS grades yielded a mean improvement of 1.27 +/- 1.41 for patients with LPV shunts and 0.68 +/- 1.58 for patients with MPV shunts (p = 0.06). Improvement was found in 74% of patients with LPV shunts and in 53% of patients with MPV shunts (p = 0.06) and a marked-to-excellent improvement in 45% of patients with LPV shunts and 28% of patients with MPV shunts (p = 0.12). All outcome measures indicated trends in favor of the LPV shunt group, with only the dementia scale reaching significance. After exclusion of serious events and deaths unrelated to NPH, efficacy analysis showed the advantage of LPV shunts to be diminished. Reduction in ventricular size was also significantly greater for patients in the LPV shunt group (p = 0.009). Subdural effusions occurred in 71% of patients with an LPV shunt and in 34% with an MPV shunt; however, their influence on patient outcome was limited.
  
  
  CONCLUSIONS
  Outcome was better for patients who had an LPV shunt than for those with an MPV shunt, although most differences were not statistically significant. The authors advise that patients with NPH be treated with an LPV shunt.
authors.affiliation: Department of Neurology, Westeinde Hospital, The Hague, The Netherlands.
authors.forename: A J
authors.initials: AJ
authors.lastname: Boon
authors.forename: J T
authors.initials: JT
authors.lastname: Tans
authors.forename: E J
authors.initials: EJ
authors.lastname: Delwel
authors.forename: S M
authors.initials: SM
authors.lastname: Egeler-Peerdeman
authors.forename: P W
authors.initials: PW
authors.lastname: Hanlo
authors.forename: H A
authors.initials: HA
authors.lastname: Wurzer
authors.forename: C J
authors.initials: CJ
authors.lastname: Avezaat
authors.forename: D A
authors.initials: DA
authors.lastname: de Jong
authors.forename: R H
authors.initials: RH
authors.lastname: Gooskens
authors.forename: J
authors.initials: J
authors.lastname: Hermans
mesh_terms: D000368:Aged; D002423:Cause of Death; D002552:Cerebral Ventricles / Q000473:pathology; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D003704:Dementia / Q000503:physiopathology / Q000628:therapy; D004185:Disability Evaluation; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D009069:Movement Disorders / Q000503:physiopathology / Q000628:therapy; D009426:Netherlands; D009460:Neurologic Examination; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013353:Subdural Effusion / Q000209:etiology; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects / Q000145:classification*